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[Code of Federal Regulations]
[Title 49, Volume 4]
[Revised as of October 1, 2003]
[CITE: 49CFR236]

[Page 499-534]
 

TITLE 49--TRANSPORTATION
CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION
PART 236--RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES



Sec.
236.0 Applicability, minimum requirements, and civil penalties.

             Subpart A--Rules and Instructions: All Systems

                                 General

236.1 Plans, where kept.
236.2 Grounds.
236.3 Locking of signal apparatus housings.
236.4 Interference with normal functioning of device.
236.5 Design of control circuits on closed circuit principle.
236.6 Hand-operated switch equipped with switch circuit controller.
236.7 Circuit controller operated by switch-and-lock movement.
236.8 Operating characteristics of electromagnetic, electronic, or 
          electrical apparatus.
236.9 Selection of circuits through indicating or annunciating 
          instruments.
236.10 Electric locks, force drop type; where required.
236.11 Adjustment, repair, or replacement of component.
236.12 Spring switch signal protection; where required.
236.13 Spring switch; selection of signal control circuits through 
          circuit controller.
236.14 Spring switch signal protection; requirements.
236.15 Timetable instructions.
236.16 Electric lock, main track releasing circuit.
236.17 Pipe for operating connections, requirements.

                     Roadway Signals and Cab Signals

236.21 Location of roadway signals.
236.22 Semaphore signal arm; clearance to other objects.
236.23 Aspects and indications.
236.24 Spacing of roadway signals.
236.25 [Reserved]
236.26 Buffing device, maintenance.

[[Page 500]]

                             Track Circuits

236.51 Track circuit requirements.
236.52 Relayed cut-section.
236.53 Track circuit feed at grade crossing.
236.54 Minimum length of track circuit.
236.55 Dead section; maximum length.
236.56 Shunting sensitivity.
236.57 Shunt and fouling wires.
236.58 Turnout, fouling section.
236.59 Insulated rail joints.
236.60 Switch shunting circuit; use restricted.

                            Wires and Cables

236.71 Signal wires on pole line and aerial cable.
236.72 [Reserved]
236.73 Open-wire transmission line; clearance to other circuits.
236.74 Protection of insulated wire; splice in underground wire.
236.75 [Reserved]
236.76 Tagging of wires and interference of wires or tags with signal 
          apparatus.

                   Inspections and Tests; All Systems

236.101 Purpose of inspection and tests; removal from service of relay 
          or device failing to meet test requirements.
236.102 Semaphore or searchlight signal mechanism.
236.103 Switch circuit controller or point detector.
236.104 Shunt fouling circuit.
236.105 Electric lock.
236.106 Relays.
236.107 Ground tests.
236.108 Insulation resistance tests, wires in trunking and cables.
236.109 Time releases, timing relays and timing devices.
236.110 Results of tests.

                Subpart B--Automatic Block Signal Systems

                                Standards

236.201 Track-circuit control of signals.
236.202 Signal governing movements over hand-operated switch.
236.203 Hand operated crossover between main tracks; protection.
236.204 Track signaled for movements in both directions, requirements.
236.205 Signal control circuits; requirements.
236.206 Battery or power supply with respect to relay; location.
236.207 Electric lock on hand-operated switch; control.

                         Subpart C--Interlocking

                                Standards

236.301 Where signals shall be provided.
236.302 Track circuits and route locking.
236.303 Control circuits for signals, selection through circuit 
          controller operated by switch points or by switch locking 
          mechanism.
236.304 Mechanical locking or same protection effected by circuits.
236.305 Approach or time locking.
236.306 Facing point lock or switch-and-lock movement.
236.307 Indication locking.
236.308 Mechanical or electric locking or electric circuits; requisites.
236.309 Loss of shunt protection; where required.
236.310 Signal governing approach to home signal.
236.311 Signal control circuits, selection through track relays or 
          devices functioning as track relays and through signal 
          mechanism contacts and time releases at automatic 
          interlocking.
236.312 Movable bridge, interlocking of signal appliances with bridge 
          devices.
236.313 [Reserved]
236.314 Electric lock for hand-operated switch or derail.

                         Rules and Instructions

236.326 Mechanical locking removed or disarranged; requirement for 
          permitting train movements through interlocking.
236.327 Switch, movable-point frog or split-point derail.
236.328 Plunger of facing-point lock.
236.329 Bolt lock.
236.330 Locking dog of switch-and-lock movement.
236.331-236.333 [Reserved]
236.334 Point detector.
236.335 Dogs, stops and trunnions of mechanical locking.
236.336 Locking bed.
236.337 Locking faces of mechanical locking; fit.
236.338 Mechanical locking required in accordance with locking sheet and 
          dog chart.
236.339 Mechanical locking; maintenance requirements.
236.340 Electromechanical interlocking machine; locking between 
          electrical and mechanical levers.
236.341 Latch shoes, rocker links, and quandrants.
236.342 Switch circuit controller.

                          Inspection and Tests

236.376 Mechanical locking.
236.377 Approach locking.
236.378 Time locking.
236.379 Route locking.
236.380 Indication locking.
236.381 Traffic locking.
236.382 Switch obstruction test.
236.383 Valve locks, valves, and valve magnets.

[[Page 501]]

236.384 Cross protection.
236.385 [Reserved]
236.386 Restoring feature on power switches.
236.387 Movable bridge locking.

                   Subpart D--Traffic Control Systems

                                Standards

236.401 Automatic block signal system and interlocking standards 
          applicable to traffic control systems.
236.402 Signals controlled by track circuits and control operator.
236.403 Signals at controlled point.
236.404 Signals at adjacent control points.
236.405 Track signaled for movements in both directions, change of 
          direction of traffic.
236.406 [Reserved]
236.407 Approach or time locking; where required.
236.408 Route locking.
236.409 [Reserved]
236.410 Locking, hand-operated switch; requirements.

                         Rules and Instructions

236.426 Interlocking rules and instructions applicable to traffic 
          control systems.

                          Inspection and Tests

236.476 Interlocking inspections and tests applicable to traffic control 
          systems.

  Subpart E--Automatic Train Stop, Train Control and Cab Signal Systems

                                Standards

236.501 Forestalling device and speed control.
236.502 Automatic brake application, initiation by restrictive block 
          conditions stopping distance in advance.
236.503 Automatic brake application; initiation when predetermined rate 
          of speed exceeded.
236.504 Operation interconnected with automatic block-signal system.
236.505 Proper operative relation between parts along roadway and parts 
          on locomotive.
236.506 Release of brakes after automatic application.
236.507 Brake application; full service.
236.508 Interference with application of brakes by means of brake valve.
236.509 Two or more locomotives coupled.
236.510 [Reserved]
236.511 Cab signals controlled in accordance with block conditions 
          stopping distance in advance.
236.512 Cab signal indication when locomotive enters block where 
          restrictive conditions obtain.
236.513 Audible indicator.
236.514 Interconnection of cab signal system with roadway signal system.
236.515 Visibility of cab signals.
236.516 Power supply.

                     Rules and Instructions; Roadway

236.526 Roadway element not functioning properly.
236.527 Roadway element insulation resistance.
236.528 Restrictive condition resulting from open hand-operated switch; 
          requirement.
236.529 Roadway element inductor; height and distance from rail.
236.530 [Reserved]
236.531 Trip arm; height and distance from rail.
236.532 Strap iron inductor; use restricted.
236.533 [Reserved]
236.534 Entrance to equipped territory; requirements.

                   Rules and Instructions; Locomotives

236.551 Power supply voltage; requirement.
236.552 Insulation resistance; requirement.
236.553 Seal, where required.
236.554 Rate of pressure reduction; equalizing reservoir or brake pipe.
236.555 Repaired or rewound receiver coil.
236.556 Adjustment of relay.
236.557 Receiver; location with respect to rail.
236.558-236.559 [Reserved]
236.560 Contact element, mechanical trip type; location with respect to 
          rail.
236.561 [Reserved]
236.562 Minimum rail current required.
236.563 Delay time.
236.564 Acknowledging time.
236.565 Provision made for preventing operation of pneumatic break-
          applying apparatus by double-heading cock; requirement.
236.566 Locomotive of each train operating in train stop, train control 
          or cab signal territory; equipped.
236.567 Restrictions imposed when device fails and/or is cut out en 
          route.
236.568 Difference between speeds authorized by roadway signal and cab 
          signal; action required.

                      Inspection and Tests; Roadway

236.576 Roadway element.
236.577 Test, acknowledgement, and cut-in circuits.

                    Inspection and Tests; Locomotive

236.586 Daily or after trip test.
236.587 Departure test.
236.588 Periodic test.
236.589 Relays.

[[Page 502]]

236.590 Pneumatic apparatus.

  Subpart F--Dragging Equipment and Slide Detectors and Other Similar 
                           Protective Devices

                                Standards

236.601 Signals controlled by devices; location.

                         Subpart G--Definitions

236.700 Definitions.
236.701 Application, brake; full service.
236.702 Arm, semaphore.
236.703 Aspect.
236.704 [Reserved]
236.705 Bar, locking.
236.706 Bed, locking.
236.707 Blade, semaphore.
236.708 Block.
236.709 Block, absolute.
236.710 Block, latch.
236.711 Bond, rail joint.
236.712 Brake pipe.
236.713 Bridge, movable.
236.714 Cab.
236.715-236.716 [Reserved]
236.717 Characteristics, operating.
236.718 Chart, dog.
236.719 Circuit, acknowledgment.
236.720 Circuit, common return.
236.721 Circuit, control.
236.722 Circuit, cut-in.
236.723 Circuit, double wire; line.
236.724 Circuit, shunt fouling.
236.725 Circuit, switch shunting.
236.726 Circuit, track.
236.727 Circuit, track; coded.
236.728 Circuit, trap.
236.729 Cock, double heading.
236.730 Coil, receiver.
236.731 Controller, circuit.
236.732 Controller, circuit; switch.
236.733 Current, foreign.
236.734 Current of traffic.
236.735 Current, leakage.
236.736 Cut-section.
236.737 Cut-section, relayed.
236.738 Detector, point.
236.739 Device, acknowledging.
236.740 Device, reset.
236.741 Distance, stopping.
236.742 Dog, locking.
236.743 Dog, swing.
236.744 Element, roadway.
236.745 Face, locking.
236.746 Feature, restoring.
236.747 Forestall.
236.748 [Reserved]
236.749 Indication.
236.750 Interlocking, automatic.
236.751 Interlocking, manual.
236.752 Joint, rail, insulated.
236.753 Limits, interlocking.
236.754 Line, open wire.
236.755 Link, rocker.
236.756 Lock, bolt.
236.757 Lock, electric.
236.758 Lock, electric, forced drop.
236.759 Lock, facing point.
236.760 Locking, approach.
236.761 Locking, electric.
236.762 Locking, indication.
236.763 Locking, latch operated.
236.764 Locking, lever operated.
236.765 Locking, mechanical.
236.766 Locking, movable bridge.
236.767 Locking, route.
236.768 Locking, time.
236.769 Locking, traffic.
236.770 Locomotive.
236.771 Machine, control.
236.772 Machine, interlocking.
236.773 Movements, conflicting.
236.774 Movement, facing.
236.775 Movement, switch-and-lock.
236.776 Movement, trailing.
236.777 Operator, control.
236.778 Piece, driving.
236.779 Plate, top.
236.780 Plunger, facing point lock.
236.781 [Reserved]
236.782 Point, controlled.
236.783 Point, stop-indication.
236.784 Position, deenergized.
236.785 Position, false restrictive.
236.786 Principle, closed circuit.
236.787 Protection, cross.
236.788 Receiver.
236.789 Relay, timing.
236.790 Release, time.
236.791 Release, value.
236.792 Reservoir, equalizing.
236.793 Rod, lock.
236.794 Rod, up-and-down.
236.795 Route.
236.796 Routes, conflicting.
236.797 Route, interlocked.
236.798 Section, dead.
236.799 Section, fouling.
236.800 Sheet, locking.
236.801 Shoe, latch.
236.802 Shunt.
236.802a Siding.
236.803 Signal, approach.
236.804 Signal, block.
236.805 Signal, cab.
236.806 Signal, home.
236.807 Signal, interlocking.
236.808 Signals, opposing.
236.809 Signal, slotted mechanical.
236.810 Spectacle, semaphore arm.
236.811 Speed, medium.
236.812 Speed, restricted.
236.813 Speed, slow.
236.813a State, most restrictive.
236.814 Station, control.
236.815 Stop.
236.816 Superiority of trains.
236.817 Switch, electro-pneumatic.
236.818 Switch, facing point.
236.819 Switch, hand operated.
236.820 Switch, interlocked.

[[Page 503]]

236.820a Switch, power-operated.
236.821 Switch, sectionalizing.
236.822 Switch, spring.
236.823 Switch, trailing point.
236.824 System, automatic block signal.
236.825 System, automatic train control.
236.826 System, automatic train stop.
236.827 System, block signal.
236.828 System, traffic control.
236.829 Terminal, initial.
236.830 Time, acknowledging.
236.831 Time, delay.
236.831a Track, main.
236.832 Train.
236.833 Train, opposing.
236.834 Trip.
236.835 Trunking.
236.836 Trunnion.
236.837 Valve, electro-pneumatic.
236.838 Wire, shunt.

Appendix A to Part 236--Civil Penalties

    Authority: 49 U.S.C. 20103, 20107 and 49 CFR 1.49.

    Source: 33 FR 19684, Dec. 25, 1968, unless otherwise noted.

Sec. 236.0  Applicability, minimum requirements, and civil penalties.

    (a) Except as provided in paragraph (b) of this section, this part 
applies to railroads that operate on standard gage track which is part 
of the general railroad system of transportation.
    (b) This part does not apply to rail rapid transit operations 
conducted over track that is used exclusively for that purpose and that 
is not part of the general system of railroad transportation.
    (c) Where a passenger train is operated at a speed of 60 or more 
miles per hour, or a freight train is operated at a speed of 50 or more 
miles per hour, a block signal system complying with the provisions of 
this part shall be installed or a manual block system shall be placed 
permanently in effect which shall conform to the following conditions:
    (1) A passenger train shall not be admitted to a block occupied by 
another train except under flag protection;
    (2) No train shall be admitted to a block occupied by a passenger 
train except under flag protection;
    (3) No train shall be admitted to a block occupied by an opposing 
train except under flag protection; and
    (4) A freight train, including a work train, may be authorized to 
follow a freight train, including a work train, into a block but the 
following train must proceed prepared to stop within one-half the range 
of vision but not exceeding 20 miles per hour.
    (d) Where any train is operated at a speed of 80 or more miles per 
hour, an automatic cab signal, automatic train stop or automatic train 
control system complying with the provisions of this part shall be 
installed.
    (e) Nothing in this section authorizes the discontinuance of a block 
signal system, interlocking, traffic control system, automatic train 
stop, train control, or cab signal system without approval of the 
Federal Railroad Administration.
    (f) Any person (an entity of any type covered under 1 U.S.C. 1, 
including but not limited to the following: a railroad; a manager, 
supervisor, official, or other employee or agent of a railroad; any 
owner, manufacturer, lessor, or lessee of railroad equipment, track, or 
facilities; any independent contractor providing goods or services to a 
railroad; and any employee of such owner, manufacturer, lessor, lessee, 
or independent contractor) who violates any requirement of this part or 
causes the violation of any such requirement is subject to a civil 
penalty of at least $500 and not more than $11,000 per violation, except 
that: Penalties may be assessed against individuals only for willful 
violations, and, where a grossly negligent violation or a pattern of 
repeated violations has created an imminent hazard of death or injury to 
persons, or has caused death or injury, a penalty not to exceed $22,000 
per violation may be assessed. Each day a violation continues shall 
constitute a separate offense. See appendix A to this part for a 
statement of agency civil penalty policy.

[49 FR 3382, Jan. 26, 1984, as amended at 53 FR 52936, Dec. 29, 1988; 63 
FR 11624, Mar. 10, 1998]

[[Page 504]]

             Subpart A--Rules and Instructions: All Systems

                                 General

Sec. 236.1  Plans, where kept.

    As required for maintenance, plans shall be kept at all 
interlockings, automatic signals and controlled points. Plans shall be 
legible and correct.

[49 FR 3382, Jan. 26, 1984]

Sec. 236.2  Grounds.

    Each circuit, the functioning of which affects the safety of train 
operations, shall be kept free of any ground or combination of grounds 
which will permit a flow of current equal to or in excess of 75 percent 
of the release value of any relay or other electromagnetic device in the 
circuit, except circuits which include any track rail and except the 
common return wires of single-wire, single-break, signal control 
circuits using a grounded common, and alternating current power 
distribution circuits which are grounded in the interest of safety.

Sec. 236.3  Locking of signal apparatus housings.

    Signal apparatus housings shall be secured against unauthorized 
entry.

[49 FR 3382, Jan. 26, 1984]

Sec. 236.4  Interference with normal functioning of device.

    The normal functioning of any device shall not be interfered with in 
testing or otherwise without first taking measures to provide for safety 
of train operation which depends on normal functioning of such device.

[49 FR 3382, Jan. 26, 1984]

Sec. 236.5  Design of control circuits on closed circuit principle.

    All control circuits the functioning of which affects safety of 
train operation shall be designed on the closed circuit principle, 
except circuits for roadway equipment of intermittent automatic train 
stop system.

Sec. 236.6  Hand-operated switch equipped with switch circuit 
          controller.

    Hand-operated switch equipped with switch circuit controller 
connected to the point, or with facing-point lock and circuit 
controller, shall be so maintained that when point is open one-fourth 
inch or more on facing-point switch and three-eights inch or more on 
trailing-point switch, track or control circuits will be opened or 
shunted or both, and if equipped with facing-point lock with circuit 
controller, switch cannot be locked. On such hand-operated switch, 
switch circuit controllers, facing-point locks, switch-and-lock 
movements, and their connections shall be securely fastened in place, 
and contacts maintained with an opening of not less than one-sixteenth 
inch when open.

Sec. 236.7  Circuit controller operated by switch-and-lock movement.

    Circuit controller operated by switch-and-lock movement shall be 
maintained so that normally open contacts will remain closed and 
normally closed contacts will remain open until the switch is locked.

Sec. 236.8  Operating characteristics of electromagnetic, electronic, or 
          electrical apparatus.

    Signal apparatus, the functioning of which affects the safety of 
train operation, shall be maintained in accordance with the limits 
within which the device is designed to operate.

[49 FR 3382, Jan. 26, 1984]

Sec. 236.9  Selection of circuits through indicating or annunciating 
          instruments.

    Signal control and electric locking circuits shall not be selected 
through the contacts of instruments designed primarily for indicating or 
annunciating purposes in which an indicating element attached to the 
armature is arranged so that it can in itself cause improper operation 
of the armature.

[[Page 505]]

Sec. 236.10  Electric locks, force drop type; where required.

    Electric locks on new installations and new electric locks applied 
to existing installations shall be of the forced drop type.

Sec. 236.11  Adjustment, repair, or replacement of component.

    When any component of a signal system, the proper functioning of 
which is essential to the safety of train operation, fails to perform 
its intended signaling function or is not in correspondence with known 
operating conditions, the cause shall be determined and the faulty 
component adjusted, repaired or replaced without undue delay.

[49 FR 3382, Jan. 26, 1984]

Sec. 236.12  Spring switch signal protection; where required.

    Signal protection shall be provided for facing and trailing 
movements through spring switch within interlocking limits and through 
spring switch installed in automatic block signal, train stop, train 
control or cab signal territory where train movements over the switch 
are made at a speed exceeding 20 miles per hour, except that signal 
protection shall be required only with the current of traffic on track 
signaled for movement in only one direction.

    Note: Does not apply to spring switch installed prior to October 1, 
1950 in automatic block signal, automatic train stop, or automatic train 
control territory.

[49 FR 3383, Jan. 26, 1984]

Sec. 236.13  Spring switch; selection of signal control circuits through 
          circuit controller.

    The control circuits of signals governing facing movements over a 
main track spring switch shall be selected through the contacts of a 
switch circuit controller, or through the contacts of relay repeating 
the position of such circuit controller, which, when normally closed 
switch point is open one-fourth inch or more, will cause such signals to 
display their most restrictive aspects, except that where a separate 
aspect is displayed for facing movements over the switch in the reverse 
position the signal shall display its most restrictive aspect when the 
switch points are open one-fourth inch or more from either the normal or 
reverse position.

Sec. 236.14  Spring switch signal protection; requirements.

    (a) The indication of signal governing movements from siding to main 
track with the current of traffic on track signaled for movements in 
only one direction through a spring switch in automatic block signal 
territory shall be not less restrictive than ``Proceed at Restricted 
Speed' when the block, into which movements are governed by the signal, 
is occupied, and shall be ``Stop'' when the main track is occupied by a 
train approaching the switch within at least 1,500 feet in approach of 
the approach signal located stopping distance from the main track signal 
governing trailing movements over switch, except that the indication may 
be caused to be less restrictive if approach or time locking is used.
    (b) The indication of signal governing movements against the current 
of traffic from the reverse main of main tracks to a single track, or 
signal governing movements from a siding to a main track signaled for 
movements in either direction, through a spring switch, in automatic 
block signal territory, shall be not less restrictive than ``Proceed at 
Restricted Speed'' when the block, into which movements are governed by 
the signal, is occupied by a preceding train, and shall be ``Stop'' when 
the block on the single track into which the signal governs is occupied 
by an opposing train.
    (c) The indication of signal governing movements against the current 
of traffic from the reverse main of main tracks to a single track or 
signal governing movements from a siding to a main track signaled for 
movements in either direction through a spring switch in automatic block 
signal territory shall be ``Stop'' when the normal direction main track 
of the double track or the single track signaled for movements in both 
directions is occupied by a train approaching the switch within at least 
1,500 feet in approach of the approach signal located stopping distance 
from the main track signal governing trailing movements over

[[Page 506]]

switch, except that indication may be caused to be less restrictive if 
approach or time locking is used.

Sec. 236.15  Timetable instructions.

    Automatic block, traffic control, train stop, train control and cab 
signal territory shall be designated in timetable instructions.

Sec. 236.16  Electric lock, main track releasing circuit.

    When an electric lock releasing circuit is provided on the main 
track to permit a train or an engine to diverge from the main track 
without time delay, the circuit shall be of such length to permit 
occupancy of the circuit to be seen by a crew member stationed at the 
switch. When the releasing circuit extends into the fouling circuit, a 
train or engine on the siding shall be prevented from occupying the 
releasing circuit by a derail either pipe-connected to switch point or 
equipped with an independently operated electric lock.

[49 FR 3383, Jan. 26, 1984]

Sec. 236.17  Pipe for operating connections, requirements.

    (a) Steel or wrought-iron pipe one inch or larger, or members of 
equal strength, shall be used for operating connections for switches, 
derails, movable-point frogs, facing-point locks, rail-locking devices 
of movable bridge protected by interlocking, and mechanically operated 
signals, except up-and-down rod which may be three-fourths inch pipe or 
solid rod. Pipe shall be fully screwed into coupling and both ends of 
each pipe shall be riveted to pipe plug with 2 rivets.
    (b) Pipeline shall not be out of alignment sufficiently to interfere 
with proper operation, shall be properly compensated for temperature 
changes, and supported on carriers spaced not more than 8 feet apart on 
tangent and curve of less than 2[deg] and not more than 7 feet apart on 
curve of 2[deg] or more. With lever in any position, couplings in pipe 
line shall not foul carriers.

[49 FR 3383, Jan. 26, 1984]

                     Roadway Signals and Cab Signals

Sec. 236.21  Location of roadway signals.

    Each roadway signal shall be positioned and aligned so that its 
aspects can be clearly associated with the track it governs.

[49 FR 3383, Jan. 26, 1984]

Sec. 236.22  Semaphore signal arm; clearance to other objects.

    At least one-half inch clearance shall be provided between semaphore 
signal arm, and any object that may interfere with its operation.

Sec. 236.23  Aspects and indications.

    (a) Aspects shall be shown by the position of semaphore blades, 
color of lights, position of lights, flashing of lights, or any 
combination thereof. They may be qualified by marker plate, number 
plate, letter plate, marker light, shape and color of semaphore blades 
or any combination thereof, subject to the following conditions:
    (1) Night aspects of roadway signals, except qualifying 
appurtenances, shall be shown by lights; day aspects by lights or 
semaphore arms. A single white light shall not be used.
    (2) Reflector lenses or buttons or other devices which depend for 
visibility upon reflected light from an external source shall not be 
used hereafter in night aspects, except qualifying appurtenances.
    (b) The aspects of cab signals shall be shown by lights or by 
illuminated letters or numbers.
    (c) Each aspect displayed by a signal shall be identified by a name 
and shall indicate action to be taken. Only one name and indication 
shall apply to those aspects indicating the same action to be taken; the 
same aspect shall not be used with any other name and indication.
    (d) The fundamental indications of signal aspects shall conform to 
the following:
    (1) A red light, a series of horizontal lights or a semaphore blade 
in a horizontal position shall be used to indicate stop.
    (2) A yellow light, a lunar light, or a series of lights or a 
semaphore blade in the upper or lower quadrant at an angle of 
approximately 45 degrees to

[[Page 507]]

the vertical, shall be used to indicate that speed is to be restricted 
and stop may be required.
    (3) A green light, a series of vertical lights, or a semaphore blade 
in a vertical position in the upper quadrant or 60[deg] or 90[deg] in 
the lower quadrant shall be used to indicate proceed at authorized 
speed.
    (e) The names, indications, and aspects of roadway and cab signals 
shall be defined in the carrier's Operating Rule Book or Special 
Instructions. Modifications shall be filed with the FRA within thirty 
days after such modifications become effective.
    (f) The absence of a qualifying appurtenance, the failure of a lamp 
in a light signal, or a false restrictive position of an arm of a 
semaphore signal shall not cause the display of a less restrictive 
aspect than intended.

[33 FR 19684, Dec. 25, 1968, as amended at 49 FR 3383, Jan. 26, 1984]

Sec. 236.24  Spacing of roadway signals.

    Each roadway signal shall be located with respect to the next signal 
or signals in advance which govern train movements in the same direction 
so that the indication of a signal displaying a restrictive aspect can 
be complied with by means of a brake application, other than an 
emergency application, initiated at such signal, either by stopping at 
the signal where a stop is required, or by a reduction in speed to the 
rate prescribed by the next signal in advance where reduced speed is 
required.

Sec. 236.25  [Reserved]

Sec. 236.26  Buffing device, maintenance.

    Buffing device shall be maintained so as not to cause the signal to 
display a less restrictive aspect than intended.

                             Track Circuits

Sec. 236.51  Track circuit requirements.

    Track relay controlling home signals shall be in deenergized 
position, or device that functions as a track relay controlling home 
signals shall be in its most restrictive state, and the track circuit of 
an automatic train stop, train control, or cab signal system shall be 
deenergized in the rear of the point where any of the following 
conditions exist:
    (a) When a rail is broken or a rail or switch-frog is removed except 
when a rail is broken or removed in the shunt fouling circuit of a 
turnout or crossover, provided, however, that shunt fouling circuit may 
not be used in a turnout through which permissible speed is greater than 
45 miles per hour. It shall not be a violation of this requirement if a 
track circuit is energized:
    (1) When a break occurs between the end of rail and track circuit 
connector; within the limits of rail-joint bond, appliance or other 
protective device, which provides a bypath for the electric current, or
    (2) As result of leakage current or foreign current in the rear of a 
point where a break occurs.
    (b) When a train, locomotive, or car occupies any part of a track 
circuit, including fouling section of turnout except turnouts of hand-
operated main track crossover. It shall not be a violation of this 
requirement where the presence of sand, rust, dirt, grease, or other 
foreign matter prevents effective shunting, except that where such 
conditions are known to exist adequate measures to safeguard train 
operation must be taken.
    (c) Where switch shunting circuit is used:
    (1) Switch point is not closed in normal position.
    (2) A switch is not locked where facing-point lock with circuit 
controller is used.
    (3) An independently operated fouling-point derail equipped with 
switch circuit controller is not in derailing position.

[33 FR 19684, Dec. 25, 1968, as amended at 49 FR 3383, Jan. 26, 1984]

Sec. 236.52  Relayed cut-section.

    Where relayed cut-section is used in territory where noncoded 
direct-current track circuits are in use the energy circuit to the 
adjoining track shall be open and the track circuit shunted when the 
track relay at such cut-section is in deenergized position.

[[Page 508]]

Sec. 236.53  Track circuit feed at grade crossing.

    At grade crossing with an electric railroad where foreign current is 
present, the electric energy for noncoded direct current track circuit 
shall feed away from the crossing.

Sec. 236.54  Minimum length of track circuit.

    When a track circuit shorter than maximum inner wheelbase of any 
locomotive or car operated over such track circuit is used for control 
of signaling facilities, other means shall be used to provide the 
equivalent of track circuit protection.

[49 FR 3383, Jan. 26, 1984]

Sec. 236.55  Dead section; maximum length.

    Where dead section exceeds 35 feet, a special circuit shall be 
installed. Where shortest outer wheelbase of a locomotive operating over 
such dead section is less than 35 feet, the maximum length of the dead 
section shall not exceed the length of the outer wheelbase of such 
locomotive unless special circuit is used.

[49 FR 3383, Jan. 26, 1984]

Sec. 236.56  Shunting sensitivity.

    Each track circuit controlling home signal or approach locking shall 
be so maintained that track relay is in deenergized position, or device 
that functions as a track relay shall be in its most restrictive state 
if, when track circuit is dry, a shunt of 0.06 ohm resistance is 
connected across the track rails of the circuit, including fouling 
sections of turnouts.

[49 FR 3383, Jan. 26, 1984]

Sec. 236.57  Shunt and fouling wires.

    (a) Except as provided in paragraph (b) of this section, shunt wires 
and fouling wires hereafter installed or replaced shall consist of at 
least two discrete conductors, and each shall be of sufficient 
conductivity and maintained in such condition that the track relay will 
be in deenergized position, or device that functions as a track relay 
will be in its most restrictive state, when the circuit is shunted.
    (b) This rule does not apply to shunt wires where track or control 
circuit is opened by the switch circuit controller.

[49 FR 3383, Jan. 26, 1984]

Sec. 236.58  Turnout, fouling section.

    Rail joints within the fouling section shall be bonded, and fouling 
section shall extend at least to a point where sufficient tract centers 
and allowance for maximum car overhang and width will prevent 
interference with train, locomotive, or car movement on the adjacent 
track.

[49 FR 3383, Jan. 26, 1984]

Sec. 236.59  Insulated rail joints.

    Insulated rail joints shall be maintained in condition to prevent 
sufficient track circuit current from flowing between the rails 
separated by the insulation to cause a failure of any track circuit 
involved.

Sec. 236.60  Switch shunting circuit; use restricted.

    Switch shunting circuit shall not be hereafter installed, except 
where tract or control circuit is opened by the circuit controller.

[49 FR 3384, Jan. 26, 1984]

                            Wires and Cables

Sec. 236.71  Signal wires on pole line and aerial cable.

    Signal wire on pole line shall be securely tied in on insulator 
properly fastened to crossarm or bracket supported by pole or other 
support. Signal wire shall not interfere with, or be interfered by, 
other wires on the pole line. Aerial cable shall be supported by 
messenger.

[49 FR 3384, Jan. 26, 1984]

Sec. 236.72  [Reserved]

Sec. 236.73  Open-wire transmission line; clearance to other circuits.

    Open-wire transmission line operating at voltage of 750 volts or 
more shall be placed not less than 4 feet above the nearest crossarm 
carrying signal or communication circuits.

[[Page 509]]

Sec. 236.74  Protection of insulated wire; splice in underground wire.

    Insulated wire shall be protected from mechanical injury. The 
insulation shall not be punctured for test purposes. Splice in 
underground wire shall have insulation resistance at least equal to the 
wire spliced.

Sec. 236.75  [Reserved]

Sec. 236.76  Tagging of wires and interference of wires or tags with 
          signal apparatus.

    Each wire shall be tagged or otherwise so marked that it can be 
identified at each terminal. Tags and other marks of identification 
shall be made of insulating material and so arranged that tags and wires 
do not interfere with moving parts of apparatus.

[49 FR 3384, Jan. 26, 1984]

                   Inspections and Tests; All Systems

Sec. 236.101  Purpose of inspection and tests; removal from service of 
          relay or device failing to meet test requirements.

    The following inspections and tests shall be made in accordance with 
specifications of the carrier, subject to approval of the FRA, to 
determine if the apparatus and/or equipment is maintained in condition 
to perform its intended function. Electronic device, relay, or other 
electromagnetic device which fails to meet the requirements of specified 
tests shall be removed from service, and shall not be restored to 
service until its operating characteristics are in accordance with the 
limits within which such device or relay is designed to operate.

[49 FR 3384, Jan. 26, 1984]

Sec. 236.102  Semaphore or searchlight signal mechanism.

    (a) Semaphore signal mechanism shall be inspected at least once 
every six months, and tests of the operating characteristics of all 
parts shall be made at least once every two years.
    (b) Searchlight signal mechanism shall be inspected, and the 
mechanical movement shall be observed while operating the mechanism to 
all positions, at least once every six months. Tests of the operating 
characteristics shall be made at least once every two years.

[49 FR 3384, Jan. 26, 1984]

Sec. 236.103  Switch circuit controller or point detector.

    Switch circuit controller, circuit controller, or point detector 
operated by hand-operated switch or by power-operated or mechanically-
operated switch-and-lock movement shall be inspected and tested at least 
once every three months.

[49 FR 3384, Jan. 26, 1984]

Sec. 236.104  Shunt fouling circuit.

    Shunt fouling circuit shall be inspected and tested at least once 
every three months.

Sec. 236.105  Electric lock.

    Electric lock, except forced-drop type, shall be tested at least 
once every two years.

Sec. 236.106  Relays.

    Each relay, the functioning of which affects the safety of train 
operations, shall be tested at least once every four years except:
    (a) Alternating current centrifugal type relay shall be tested at 
least once every 12 months;
    (b) Alternating current vane type relay and direct current polar 
type relay shall be tested at least once every 2 years; and
    (c) Relay with soft iron magnetic structure shall be tested at least 
once every 2 years.

[49 FR 3384, Jan. 26, 1984]

Sec. 236.107  Ground tests.

    (a) Except as provided in paragraph (b) of this section, a test for 
grounds on each energy bus furnishing power to circuits, the functioning 
of which affects the safety of train operation, shall be made when such 
energy bus is placed in service, and shall be made at least once every 
three months thereafter.
    (b) The provisions of this rule shall not apply to track circuit 
wires, common return wires of grounded common single-break circuits, or 
alternating

[[Page 510]]

current power distribution circuits grounded in the interest of safety.

[49 FR 3384, Jan. 26, 1984]

Sec. 236.108  Insulation resistance tests, wires in trunking and cables.

    (a) Insulation resistance of wires and cables, except wires 
connected directly to track rails, shall be tested when wires, cables, 
and insulation are dry. Insulation resistance tests shall be made 
between all conductors and ground, and between conductors in each 
multiple conductor cable, and between conductors in trunking, when wires 
or cables are installed and at least once every ten years thereafter.
    (b) Then insulation resistance of wire or cable is found to be less 
than 500,000 ohms, prompt action shall be taken to repair or replace the 
defective wire or cable and until such defective wire or cable is 
replaced, insulation resistance test shall be made annually.
    (c) In no case shall a circuit be permitted to function on a 
conductor having an insulation resistance to ground or between 
conductors of less than 200,000 ohms during the period required for 
repair or replacement.

[49 FR 3384, Jan. 26, 1984]

Sec. 236.109  Time releases, timing relays and timing devices.

    Time releases, timing relays and timing devices shall be tested at 
least once every twelve months. The timing shall be maintained at not 
less than 90 percent of the predetermined time interval, which shall be 
shown on the plans or marked on the time release, timing relay, or 
timing device.

[49 FR 3384, Jan. 26, 1984]

Sec. 236.110  Results of tests.

    Results of tests made in compliance with Secs. 236.109 to 236.102, 
inclusive; 236.376 to 236.387, inclusive; 236.576; 236.577; and 236.586 
to 236.589, inclusive, shall be recorded on preprinted or computerized 
forms provided by the railroad. Such forms shall show the name of the 
railroad, place and date, equipment tested, results of tests, repairs, 
replacements, adjustments made, and condition in which the apparatus was 
left. Each record shall be signed by the employee making the test and 
shall be filed in the office of a supervisory official having 
jurisdiction. Results of tests made in compliance with Sec. 236.587 
shall be retained for 92 days. Results of all other tests listed in this 
section shall be retained until the next record is filed but in no case 
less than one year.

[53 FR 37313, Sept. 26, 1988]

                Subpart B--Automatic Block Signal Systems

                                Standards

Sec. 236.201  Track-circuit control of signals.

    The control circuits for home signal aspects with indications more 
favorable than ``proceed at restricted speed'' shall be controlled 
automatically by track circuits extending through the entire block.

Sec. 236.202  Signal governing movements over hand-operated switch.

    Signal governing movements over hand-operated switch in the facing 
direction shall display its most restrictive aspect when the points are 
open one-fourth inch or more and, in the trailing direction, three-
eighths inch or more, except that where a separate aspect is displayed 
for facing movements over the switch in the normal and in the reverse 
position, the signal shall display its most restrictive aspect when the 
switch points are open one-fourth inch or more from either the normal or 
reverse position.

Sec. 236.203  Hand operated crossover between main tracks; protection.

    At hand-operated crossover between main tracks, protection shall be 
provided by one of the following:
    (a) An arrangement of one or more track circuits and switch circuit 
controllers,
    (b) Facing point locks on both switches of the crossover, with both 
locks operated by a single lever, or
    (c) Electric locking of the switches of the crossover. Signals 
governing movements over either switch shall display their most 
restrictive aspect when any of the following conditions exist:
    (1) Where protection is provided by one or more track circuits and 
switch

[[Page 511]]

circuit controllers, and either switch is open or the crossover is 
occupied by a train, locomotive or car in such a manner as to foul the 
main track. It shall not be a violation of this requirement where the 
presence of sand, rust, dirt, grease or other foreign matter on the rail 
prevents effective shunting;
    (2) Where facing point locks with a single lever are provided, and 
either switch is unlocked;
    (3) Where the switches are electrically locked, before the electric 
locking releases.

Sec. 236.204  Track signaled for movements in both directions, 
          requirements.

    On track signaled for movements in both directions, a train shall 
cause one or more opposing signals immediately ahead of it to display 
the most restrictive aspect, the indication of which shall be not more 
favorable than ``proceed at restricted speed.'' Signals shall be so 
arranged and controlled that if opposing trains can simultaneously pass 
signals displaying proceed aspects and the next signal in advance of 
each such signal then displays an aspect requiring a stop, or its most 
restrictive aspect, the distance between opposing signals displaying 
such aspects shall be not less than the aggregate of the stopping 
distances for movements in each direction. Where such opposing signals 
are spaced stopping distance apart for movements in one direction only, 
signals arranged to display restrictive aspects shall be provided in 
approach to at least one of the signals. Where such opposing signals are 
spaced less than stopping distance apart for movements in one direction, 
signals arranged to display restrictive aspects shall be provided in 
approach to both such signals. In absolute permissive block signaling, 
when a train passes a head block signal, it shall cause the opposing 
head block signal to display an aspect with an indication not more 
favorable than ``stop.''

[33 FR 19684, Dec. 25, 1968, as amended at 49 FR 3384, Jan. 26, 1984]

Sec. 236.205  Signal control circuits; requirements.

    The circuits shall be so installed that each signal governing train 
movements into a block will display its most restrictive aspect when any 
of the following conditions obtain within the block:
    (a) Occupancy by a train, locomotive, or car,
    (b) When points of a switch are not closed in proper position,
    (c) When an independently operated fouling point derail equipped 
with switch circuit controller is not in derailing position,
    (d) When a track relay is in de-energized position or a device which 
functions as a track relay is in its most restrictive state; or when 
signal control circuit is deenergized.

[33 FR 19684, Dec. 25, 1968, as amended at 49 FR 3385, Jan. 26, 1984]

Sec. 236.206  Battery or power supply with respect to relay; location.

    The battery or power supply for each signal control relay circuit, 
where an open-wire circuit or a common return circuit is used, shall be 
located at the end of the circuit farthest from the relay.

Sec. 236.207  Electric lock on hand-operated switch; control.

    Electric lock on hand-operated switch shall be controlled so that it 
cannot be unlocked until control circuits of signals governing movements 
over such switch have been opened. Approach or time locking shall be 
provided.

[49 FR 3385, Jan. 26, 1984]

                         Subpart C--Interlocking

                                Standards

Sec. 236.301  Where signals shall be provided.

    Signals shall be provided to govern train movements into and through 
interlocking limits, except that a signal shall not be required to 
govern movements over a hand-operated switch into interlocking limits if 
the switch is provided with an electric lock and a derail at the 
clearance point, either pipe-connected to the switch or independently 
locked, electrically. Electric locks installed under this rule

[[Page 512]]

must conform to the time and approach locking requirements of Rule 314 
(without reference to the 20-mile exceptions), and those of either Rule 
760 or Rule 768, as may be appropriate.

Sec. 236.302  Track circuits and route locking.

    Track circuits and route locking shall be provided and shall be 
effective when the first pair of wheels of a locomotive or a car passes 
a point not more than 13 feet in advance of the signal governing its 
movement, measured from the center of the mast, or if there is no mast, 
from the center of the signal.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.303  Control circuits for signals, selection through circuit 
          controller operated by switch points or by switch locking 
          mechanism.

    The control circuit for each aspect with indication more favorable 
than ``proceed at restricted speed'' of power operated signal governing 
movements over switches, movable-point frogs and derails shall be 
selected through circuit controller operated directly by switch points 
or by switch locking mechanism, or through relay controlled by such 
circuit controller, for each switch, movable-point frog, and derail in 
the routes governed by such signal. Circuits shall be arranged so that 
such signal can display an aspect more favorable than ``proceed at 
restricted speed,'' only when each switch, movable-point frog, and 
derail in the route is in proper position.

Sec. 236.304  Mechanical locking or same protection effected by 
          circuits.

    Mechanical locking, or the same protection effected by means of 
circuits, shall be provided.

Sec. 236.305  Approach or time locking.

    Approach or time locking shall be provided in connection with 
signals displaying aspects with indications more favorable than 
``proceed at restricted speed.''

Sec. 236.306  Facing point lock or switch-and-lock movement.

    Facing point lock or switch-and-lock movement shall be provided for 
mechanically operated switch, movable-point frog, or split-point derail.

Sec. 236.307  Indication locking.

    Indication locking shall be provided for operative approach signals 
of the semaphore type, power-operated home signals, power-operated 
switches, movable-point frogs and derails, and for all approach signals 
except light signals, all aspects of which are controlled by polar or 
coded track circuits or line circuits so arranged that a single fault 
will not permit a more favorable aspect than intented to be displayed.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.308  Mechanical or electric locking or electric circuits; 
          requisites.

    Mechanical or electric locking or electric circuits shall be 
installed to prevent signals from displaying aspects which permit 
conflicting movements except that opposing signals may display an aspect 
indicating proceed at restricted speed at the same time on a track used 
for switching movements only, by one train at a time. Manual 
interlocking in service as of the date of this part at which opposing 
signals on the same track are permitted simultaneously to display 
aspects authorizing conflicting movements when interlocking is 
unattended, may be continued, provided that simultaneous train movements 
in opposite directions on the same track between stations on either side 
of the interlocking are not permitted.

    Note: Relief from the requirement of this section will be granted 
upon an adequate showing by an individual carrier to allow opposing 
signals on the same track simultaneously to display aspects to proceed 
through an interlocking which is unattended, provided that train 
movements in opposite directions on the same track between stations on 
either site of the interlocking are not permitted at the same time.

Sec. 236.309  Loss of shunt protection; where required.

    (a) A loss of shunt of 5 seconds or less shall not permit an 
established route to be changed at an automatic interlocking.
    (b) A loss of shunt of 5 seconds or less shall not permit the 
release of the

[[Page 513]]

route locking circuit of each power-operated switch hereafter installed.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.310  Signal governing approach to home signal.

    A signal shall be provided on main track to govern the approach with 
the current of traffic to any home signal except where the home signal 
is the first signal encountered when leaving yards or stations and 
authorized speed approaching such signal is not higher than slow speed. 
When authorized speed between home signals on route governed is 20 miles 
per hour or less, an inoperative signal displaying an aspect indicating 
``approach next signal prepared to stop'' may be used to govern the 
approach to the home signal.

Sec. 236.311  Signal control circuits, selection through track relays or 
          devices functioning as track relays and through signal 
          mechanism contacts and time releases at automatic 
          interlocking.

    (a) The control circuits for aspects with indications more favorable 
than ``proceed at restricted speed'' shall be selected through track 
relays, or through devices that function as track relays, for all track 
circuits in the route governed.
    (b) At automatic interlocking, signal control circuits shall be 
selected (1) through track relays, or devices that function as track 
relays, for all track circuits in the route governed and in all 
conflicting routes within the interlocking; (2) through signal mechanism 
contacts or relay contacts closed when signals for such conflicting 
routes display ``stop'' aspects; and (3) through normal contacts of time 
releases, time element relays, or timing devices for such conflicting 
routes, or contacts of relays repeating the normal position or normal 
state of such time releases, time element relays, or timing devices.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.312  Movable bridge, interlocking of signal appliances with 
          bridge devices.

    When movable bridge is protected by interlocking the signal 
appliances shall be so interlocked with bridge devices that before a 
signal governing movements over the bridge can display an aspect to 
proceed the bridge must be locked and the track alined, with the bridge 
locking members within one inch of their proper positions and with the 
track rail on the movable span within three-eighths inch of correct 
surface and alinement with rail seating device on bridge abutment or 
fixed span. Emergency bypass switches and devices shall be locked or 
sealed.

[33 FR 19684, Dec. 25, 1968, as amended at 49 FR 3385, Jan. 26, 1984]

Sec. 236.313  [Reserved]

Sec. 236.314  Electric lock for hand-operated switch or derail.

    Electric lock shall be provided for each hand-operated switch or 
derail within interlocking limits, except where train movements are made 
at not exceeding 20 miles per hour. At manually operated interlocking it 
shall be controlled by operator of the machine and shall be unlocked 
only after signals governing movements over such switch or derail 
display aspects indicating stop. Approach or time locking shall be 
provided.

                         Rules and Instructions

Sec. 236.326  Mechanical locking removed or disarranged; requirement for 
          permitting train movements through interlocking.

    When mechanical locking of interlocking machine is being changed or 
is removed from the machine, or locking becomes disarranged or broken, 
unless protection equivalent to mechanical locking is provided by 
electric locking or electric circuits, train movements through the 
interlocking shall not be permitted until each switch, movable-point 
frog or derail in the route is spiked, clamped or blocked in proper 
position so that it cannot be moved by its controlling lever, and then 
train movements shall not exceed restricted speed until the interlocking 
is restored to normal operation. It will not be necessary to comply with 
this requirement at interlockings where protection is in service in 
accordance with section 303, provided that the signal controls are 
arranged so that the signals cannot display an aspect the indication of

[[Page 514]]

which is less restrictive than ``proceed at restricted speed.''

Sec. 236.327  Switch, movable-point frog or split-point derail.

    Switch, movable-point frog, or split-point derail equipped with lock 
rod shall be maintained so that it can not be locked when the point is 
open three-eighths inch or more.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.328  Plunger of facing-point lock.

    Plunger of lever operated facing-point lock shall have at least 8-
inch stroke. When lock lever is in unlocked position the end of the 
plunger shall clear the lock rod not more than one inch.

Sec. 236.329  Bolt lock.

    Bolt lock shall be so maintained that signal governing movements 
over switch or derail and displaying an aspect indicating stop cannot be 
operated to display a less restrictive aspect while derail is in 
derailing position, or when switch point is open one-half inch or more.

Sec. 236.330  Locking dog of switch-and-lock movement.

    Locking dog of switch-and-lock movement shall extend through lock 
rod one-half inch or more in either normal or reverse position.

Secs. 236.331-236.333  [Reserved]

Sec. 236.334  Point detector.

    Point detector shall be maintained so that when switch mechanism is 
locked in normal or reverse position, contacts cannot be opened by 
manually applying force at the closed switch point. Point detector 
circuit controller shall be maintained so that the contacts will not 
assume the position corresponding to switch point closure if the switch 
point is prevented by an obstruction, from closing to within one-fourth 
inch where latch-out device is not used, and to within three-eighths 
inch where latch-out device is used.

Sec. 236.335  Dogs, stops and trunnions of mechanical locking.

    Driving pieces, dogs, stops and trunnions shall be rigidly secured 
to locking bars. Swing dogs shall have full and free movement. Top 
plates shall be maintained securely in place.

Sec. 236.336  Locking bed.

    The various parts of the locking bed, locking bed supports, and 
tappet stop rail shall be rigidly secured in place and alined to permit 
free operation of locking.

Sec. 236.337  Locking faces of mechanical locking; fit.

    Locking faces shall fit squarely against each other with a minimum 
engagement when locked of at least one-half the designed locking face.

Sec. 236.338  Mechanical locking required in accordance with locking 
          sheet and dog chart.

    Mechanical locking shall be in accordance with locking sheet and dog 
chart currently in effect.

Sec. 236.339  Mechanical locking, maintenance requirements.

    Locking and connections shall be maintained so that, when a lever or 
latch is mechanically locked the following will be prevented:
    (a) Mechanical machine. (1) Latch-operated locking. Raising lever 
latch block so that bottom thereof is within three-eighths inch of top 
of quadrant.
    (2) Lever-operated locking. Moving lever latch block more than 
three-eighths inch on top of quadrant.
    (b) Electromechanical machine. (1) Lever moving in horizontal plant. 
Moving lever more than five-sixteenths inch when in normal position or 
more than nine-sixteenths inch when in reverse position.
    (2) Lever moving in arc. Moving lever more than 5 degrees.
    (c) Power machine. (1) Latch-operated locking. Raising lever latch 
block to that bottom thereof is within seven thirty-seconds inch of top 
of quadrant.
    (2) Lever moving in horizontal plane. Moving lever more than five-
sixteenths inch when in normal position or more than nine-sixteenths 
inch when in reverse position.
    (3) Lever moving in arc. Moving lever more than 5 degrees.

[[Page 515]]

Sec. 236.340  Electromechanical interlocking machine; locking between 
          electrical and mechanical levers.

    In electro-mechanical interlocking machine, locking between electric 
and mechanical levers shall be maintained so that mechanical lever 
cannot be operated except when released by electric lever.

Sec. 236.341  Latch shoes, rocker links, and quadrants.

    Latch shoes, rocker links, and quadrants of Saxby and farmer 
machines shall be maintained so that locking will not release if a 
downward force not exceeding a man's weight is exerted on the rocker 
while the lever is in the mid-stroke position.

Sec. 236.342  Switch circuit controller.

    Switch circuit controller connected at the point to switch, derail, 
or movable-point frog, shall be maintained so that its contacts will not 
be in position corresponding to switch point closure when switch point 
is open one-fourth inch or more.

                          Inspection and Tests

Sec. 236.376  Mechanical locking.

    Mechanical locking in interlocking machine shall be tested when new 
locking is installed; and thereafter when change in locking is made, or 
locking becomes disarranged, or tested at least once every two years, 
whichever shall occur first.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.377  Approach locking.

    Approach locking shall be tested when placed in service and 
thereafter when modified, disarranged, or at least once every two years, 
whichever shall occur first.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.378  Time locking.

    Time locking shall be tested when placed in service and thereafter 
when modified, disarranged, or at least once every two years, whichever 
shall occur first.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.379  Route locking.

    Route locking or other type of switch locking shall be tested when 
placed in service and thereafter when modified, disarranged, or at least 
once every two years, whichever shall occur first.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.380  Indication locking.

    Indication locking shall be tested when placed in service and 
thereafter when modified, disarranged, or at least once every two years, 
whichever shall occur first.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.381  Traffic locking.

    Traffic locking shall be tested when placed in service and 
thereafter when modified, disarranged, or at least once every two years, 
whichever shall occur first.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.382  Switch obstruction test.

    Switch obstruction test of lock rod of each power-operated switch 
and lock rod of each hand-operated switch equipped with switch-and-lock-
movement shall be made when lock rod is placed in service or changed 
out, but not less than once each month.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.383  Valve locks, valves, and valve magnets.

    Valve locks on valves of the non-cut-off type shall be tested at 
least once every three months, and valves and valve magnets shall be 
tested at least once every year.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.384  Cross protection.

    Cross protection shall be tested at least once every six months.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.385  [Reserved]

Sec. 236.386  Restoring feature on power switches.

    Restoring feature on power switches shall be tested at least once 
every three months.

[[Page 516]]

Sec. 236.387  Movable bridge locking.

    Movable bridge locking shall be tested at least once a year.

                   Subpart D--Traffic Control Systems

                                Standards

Sec. 236.401  Automatic block signal system and interlocking standards 
          applicable to traffic control systems.

    The standards prescribed in Secs. 236.201, to 236.203, inclusive, 
Secs. 236.205, 236.206, 236.303, 236.307 and 236.309 to 236.311, 
inclusive, shall apply to traffic control systems.

[49 FR 3385, Jan. 26, 1984]

Sec. 236.402  Signals controlled by track circuits and control operator.

    The control circuits for home signal aspects with indications more 
favorable than ``proceed at restricted speed'' shall be controlled by 
track circuits extending through entire block. Also in addition, at 
controlled point they may be controlled by control operator, and, at 
manually operated interlocking, they shall be controlled manually in 
cooperation with control operator.

Sec. 236.403  Signals at controlled point.

    Signals at controlled point shall be so interconnected that aspects 
to proceed cannot be displayed simultaneously for conflicting movements, 
except that opposing signals may display an aspect indicating ``proceed 
at restricted speed'' at the same time on a track used for switching 
movements only, by one train at a time.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.404  Signals at adjacent control points.

    Signals at adjacent controlled points shall be so interconnected 
that aspects to proceed on tracks signaled for movements at greater than 
restricted speed cannot be displayed simultaneously for conflicting 
movements.

Sec. 236.405  Track signaled for movements in both directions, change of 
          direction of traffic.

    On track signaled for movements in both directions, occupancy of the 
track between opposing signals at adjacent controlled points shall 
prevent changing the direction of traffic from that which obtained at 
the time the track became occupied, except that when a train having left 
one controlled point reaches a section of track immediately adjacent to 
the next controlled point at which switching is to be performed, an 
aspect permitting movement at not exceeding restricted speed may be 
displayed into the occupied block.

Sec. 236.406  [Reserved]

Sec. 236.407  Approach or time locking; where required.

    Approach or time locking shall be provided for all controlled 
signals where route or direction of traffic can be changed.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.408  Route locking.

    Route locking shall be provided where switches are power-operated. 
Route locking shall be effective when the first pair of wheels of a 
locomotive or car passes a point not more than 13 feet in advance of the 
signal governing its movement, measured from the center of the signal 
mast or, if there is no mast, from the center of the signal.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.409  [Reserved]

Sec. 236.410  Locking, hand-operated switch; requirements.

    (a) Each hand-operated switch in main track shall be locked either 
electrically or mechanically in normal position, except:
    (1) Where train speeds over the switch do not exceed 20 miles per 
hour;
    (2) Where trains are not permitted to clear the main track;
    (3) Where a signal is provided to govern train movements from the 
auxiliary track to the signaled track; or
    (4) On a signaled siding without intermediate signals where the 
maximum authorized speed on the siding does not exceed 30 miles per 
hour.
    (b) Approach or time locking shall be provided and locking may be 
released either automatically, or by the control operator, but only 
after the control circuits of signals governing movement in either 
direction over the switch and

[[Page 517]]

which display aspects with indications more favorable than ``proceed at 
restricted speed'' have been opened directly or by shunting of track 
circuit.

    Note: Each carrier subject to this rule is hereby authorized to 
remove electrical or mechanical locks now installed within the purview 
of Sec. 236.410 when either exception (1) or (2) of the present rule is 
satisfied, subject to the condition that the following procedures and 
actions be accomplished:
    1. Each carrier intending to remove a lock under the findings made 
herein and based on the existence of one or more of the circumstances as 
set forth in exception (1) or (2) as contained in the revised section, 
shall:
    (a) Notify the FRA by letter setting forth the location of the lock 
involved and the specific exception on which removal is based.
    (b) Include in the letter to the FRA an assurance that the excepting 
circumstance relied upon will not be changed without either 
reinstallation of the electric or mechanical lock, or approval by the 
FRA of the changed circumstances.
    (c) Publish in its Time Table the not-to-exceed 20 miles per hour 
speed limit covering the area of the switch, when that is the exception 
relied upon; or, where exception (2) is relied upon, publish either in 
the Special Instructions part of its Time Table or in separate printed 
Special Instructions the location of each hand-operated switch where 
electric or mechanical lock is removed and, where train movements are 
made in excess of twenty (20) miles per hour, concurrently issuing 
specific instructions, by stating therein, that trains are not to be 
permitted to clear the main track at such switch.
    2. Following the foregoing, and upon acknowledgment of the letter to 
the FRA, such acknowledgment to be made promptly as an administrative 
action by the FRA's Bureau of Railroad Safety, and such acknowledging 
letter to be retained by the carrier as authority for the removal and as 
a record of the exception on which relied, the lock may then be removed.

    (c) Where a signal is used in lieu of electric or mechanical lock to 
govern movements from auxiliary track to signaled track, the signal 
shall not display an aspect to proceed until after the control circuits 
of signals governing movement on main track in either direction over the 
switch have been opened, and either the approach locking circuits to the 
switch are unoccupied or a predetermined time interval has expired.

    Note: Railroads shall bring all hand-operated switches that are not 
electrically or mechanically locked and that do not conform to the 
requirements of this section on the effective date of this part into 
conformity with this section in accordance with the following schedule:
    Not less than 33% during calendar year 1984.
    Not less than 66% during calendar year 1985.
    The remainder during calendar year 1986.

[33 FR 19684, Dec. 25, 1968, as amended at 49 FR 3386, Jan. 26, 1984]

                         Rules and Instructions

Sec. 236.426  Interlocking rules and instructions applicable to traffic 
          control systems.

    The rules and instructions prescribed in Secs. 236.327 and 236.328, 
Sec. 236.330 to Sec. 236.334, inclusive, and Sec. 236.342 shall apply to 
traffic control systems.

                          Inspection and Tests

Sec. 236.476  Interlocking inspections and tests applicable to traffic 
          control systems.

    The inspections and tests prescribed in Secs. 236.377 to 236.380, 
inclusive, and Secs. 236.382, 236.383, and 236.386 shall apply to 
traffic control systems.

[49 FR 3386, Jan. 26, 1984]

  Subpart E--Automatic Train Stop, Train Control and Cab Signal Systems

                                Standards

Sec. 236.501  Forestalling device and speed control.

    (a) An automatic train stop system may include a device by means of 
which the automatic application of the brakes can be forestalled.
    (b) Automatic train control system shall include one or more of the 
following features:
    (1) Low-speed restriction, requiring the train to proceed under slow 
speed after it has either been stopped by an automatic application of 
the brakes, or under control of the engineman, its speed has been 
reduced to slow speed, until the apparatus is automatically restored to 
normal because the condition which caused the restriction no longer 
affects the movement of the train.

[[Page 518]]

    (2) Medium-speed restriction, requiring the train to proceed under 
medium speed after passing a signal displaying an approach aspect or 
when approaching a signal requiring a stop, or a stop indication point, 
in order to prevent an automatic application of the brakes.

    Note: Relief from the requirements of paragraphs (b) (1) and (2) of 
this section will be granted, insofar as speed limits fixed by 
definitions of Slow and Medium speeds are concerned, upon an adequate 
showing by an individual carrier where automatic train control systems 
now in service enforce speed restrictions higher than those required by 
definitions in Secs. 236.700 to 236.838 inclusive.

    (3) Maximum-speed restriction, effecting an automatic brake 
application whenever the predetermined maximum speed limit is exceeded.

Sec. 236.502  Automatic brake application, initiation by restrictive 
          block conditions stopping distance in advance.

    An automatic train-stop or train-control system shall operate to 
initiate an automatic brake application at least stopping distance from 
the entrance to a block, wherein any condition described in Sec. 236.205 
obtains, and at each main track signal requiring a reduction in speed.

Sec. 236.503  Automatic brake application; initiation when predetermined 
          rate of speed exceeded.

    An automatic train control system shall operate to initiate an 
automatic brake application when the speed of the train exceeds the 
predetermined rate as required by the setting of the speed control 
mechanism.

Sec. 236.504  Operation interconnected with automatic block-signal 
          system.

    (a) A continuous inductive automatic train stop or train control 
system shall operate in connection with an automatic block signal system 
and shall be so interconnected with the signal system as to perform its 
intended function in event of failure of the engineer to acknowledge or 
obey a restrictive wayside signal or a more restrictive cab signal.
    (b) An intermittent inductive automatic train stop system shall 
operate in connection with an automatic block signal system and shall be 
so interconnected with the signal system that the failure of the 
engineer to acknowledge a restrictive wayside signal will cause the 
intermittent inductive automatic train stop system to perform its 
intended function.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.505  Proper operative relation between parts along roadway and 
          parts on locomotive.

    Proper operative relation between the parts along the roadway and 
the parts on the locomotive shall obtain under all conditions of speed, 
weather, wear, oscillation, and shock.

Sec. 236.506  Release of brakes after automatic application.

    The automatic train stop or train control apparatus shall prevent 
release of the brakes after automatic application until a reset device 
has been operated, or the speed of the train has been reduced to a 
predetermined rate, or the condition that caused the brake application 
no longer affects the movement of the train. If reset device is used it 
shall be arranged so that the brakes cannot be released until the train 
has been stopped, or it shall be located so that it cannot be operated 
by engineman without leaving his accustomed position in the cab.

Sec. 236.507  Brake application; full service.

    The automatic train stop or train control apparatus shall, when 
operated, cause a full service application of the brakes.

Sec. 236.508  Interference with application of brakes by means of brake 
          valve.

    The automatic train stop, train control, or cab signal apparatus 
shall be so arranged as not to interfere with the application of the 
brakes by means of the brake valve and not to impair the efficiency of 
the brake system.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.509  Two or more locomotives coupled.

    The automatic train stop, train control or cab signal apparatus 
shall be arranged so that when two or more locomotives are coupled, or a 
pushing or

[[Page 519]]

helping locomotive is used, it can be made operative only on the 
locomotive from which the brakes are controlled.

Sec. 236.510  [Reserved]

Sec. 236.511  Cab signals controlled in accordance with block conditions 
          stopping distance in advance.

    The automatic cab signal system shall be arranged so that cab 
signals will be continuously controlled in accordance with conditions 
described in Sec. 236.205 that obtain at least stopping distance in 
advance.

Sec. 236.512  Cab signal indication when locomotive enters block where 
          restrictive conditions obtain.

    The automatic cab signal system shall be arranged so that when a 
locomotive enters or is within a block, wherein any condition described 
in Sec. 236.205 obtains, the cab signals shall indicate ``Proceed at 
Restricted Speed.''

Sec. 236.513  Audible indicator.

    (a) The automatic cab signal system shall be so arranged that when 
the cab signal changes to display a more restrictive aspect, an audible 
indicator will sound continuously until silenced by manual operation of 
an acknowledging device.
    (b) The audible cab indicator of automatic cab signal, automatic 
train stop, or automatic train control system shall have a distinctive 
sound and be clearly audible throughout the cab under all operating 
conditions.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.514  Interconnection of cab signal system with roadway signal 
          system.

    The automatic cab signal system shall be interconnected with the 
roadway-signal system so that the cab signal indication will not 
authorize operation of the train at a speed higher than that authorized 
by the indication of the roadway signal that governed the movement of a 
train into a block except when conditions affecting movement of trains 
in the block change after the train passes the signal.

Sec. 236.515  Visibility of cab signals.

    The cab signals shall be plainly visible to member or members of the 
locomotive crew from their stations in the cab.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.516  Power supply.

    Automatic cab signal, train stop, or train control device hereafter 
installed shall operate from a separate or isolated power supply.

[49 FR 3386, Jan. 26, 1984]

                     Rules and Instructions; Roadway

Sec. 236.526  Roadway element not functioning properly.

    When a roadway element except track circuit of automatic train stop, 
train control or cab signal system is not functioning as intended, the 
signal associated with such roadway element shall be caused manually to 
display its most restrictive aspect until such element has been restored 
to normal operative condition.

Sec. 236.527  Roadway element insulation resistance.

    Insulation resistance between roadway inductor and ground shall be 
maintained at not less than 10,000 ohms.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.528  Restrictive condition resulting from open hand-operated 
          switch; requirement.

    When a facing point hand-operated switch is open one-fourth inch or 
more, a trailing point hand-operated switch three-eighths inch or more, 
or hand-operated switch is not locked where facing point lock with 
circuit controller is used, the resultant restrictive condition of an 
automatic train stop or train control device of the continuous type or 
the resultant restrictive cab signal indication of an automatic cab 
signal device on an approaching locomotive shall be maintained to within 
300 feet of the points of the switch.

Sec. 236.529  Roadway element inductor; height and distance from rail.

    Inductor of the inert roadway element type shall be maintained with 
the

[[Page 520]]

inductor pole faces at a height above the plane of the tops of the 
rails, and with its inner edge at a hmrizontal distance from the gage 
side of the nearest running rail, in accordance with specifications of 
the carrier.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.530  [Reserved]

Sec. 236.531  Trip arm; height and distance from rail.

    Trip arm of automatic train stop device when in the stop position 
shall be maintained at a height above the plane of the tops of the 
rails, and at a horizontal distance from its center line to gage side of 
the nearest running rail, in accordance with specifications of the 
carrier.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.532  Strap iron inductor; use restricted.

    No railroad shall use strap iron inductor or other roadway element 
with characteristics differing from its standard type on track where 
speed higher than restricted speed is permitted.

[49 FR 3386, Jan. 26, 1984]

Sec. 236.533  [Reserved]

Sec. 236.534  Entrance to equipped territory; requirements.

    Where trains are not required to stop at the entrance to equipped 
territory, except when leaving yards and stations and speed until 
entering equipped territory does not exceed restricted speed, the 
automatic train stop, train control, or cab signal device shall be 
operative at least stopping distance from the entrance to such territory 
except where the approach thereto is governed by automatic approach 
signal.

                   Rules and Instructions; Locomotives

Sec. 236.551  Power supply voltage; requirement.

    The voltage of power supply shall be maintained within 10 percent of 
rated voltage.

Sec. 236.552  Insulation resistance; requirement.

    When periodic test prescribed in Sec. 236.588 is performed, 
insulation resistance between wiring and ground of continuous inductive 
automatic cab signal system, automatic train control system, or 
automatic train stop system shall be not less than one megohm, and that 
of an intermittent inductive automatic train stop system, not less than 
250,000 ohms. Insulation resistance values between periodic tests shall 
be not less than 250,000 ohms for a continuous inductive automatic cab 
signal system, automatic train control system, or automatic train stop 
system, and 20,000 ohms for an intermittent inductive automatic train 
stop system.

[49 FR 3387, Jan. 26, 1984]

Sec. 236.553  Seal, where required.

    Seal shall be maintained on any device other than brake-pipe cut-out 
cock (double-heading cock), by means of which the operation of the 
pneumatic portion of automatic train-stop or train-control apparatus can 
be cut out.

Sec. 236.554  Rate of pressure reduction; equalizing reservoir or brake 
          pipe.

    The equalizing-reservoir pressure or brake-pipe pressure reduction 
during an automatic brake application shall be at a rate not less than 
that which results from a manual service application.

Sec. 236.555  Repaired or rewound receiver coil.

    Receiver coil which has been repaired or rewound shall have the same 
operating characteristics which it possessed originally or as currently 
specified for new equipment.

Sec. 236.556  Adjustment of relay.

    Change in adjustment of relay shall be made only in a shop equipped 
for that purpose except when receiver coils, electro-pneumatic valve, or 
other essential part of the equipment is replaced. Irregularities in 
power-supply voltage or other variable factors in the circuit shall not 
be compensated for by adjustment of the relay.

[[Page 521]]

Sec. 236.557  Receiver; location with respect to rail.

    (a) Receiver of intermittent inductive automatic train stop device 
of the inert roadway element type shall be maintained with bottom of the 
receiver at a height above the plane of the tops of the rails, and with 
its outer edge at a horizontal distance from the gage side of the 
nearest rail, in accordance with specifications of the carrier.
    (b) Receiver of continuous inductive automatic cab signal, train 
stop, or train control device of locomotive equipped with onboard test 
equipment, shall be maintained with the bottom of the receiver at a 
height above the plane of the tops of the rails, and with its outer edge 
at a horizontal distance from the gage side of the nearest rail, in 
accordance with specifications of the carrier.

[49 FR 3387, Jan. 26, 1984]

Secs. 236.558-236.559  [Reserved]

Sec. 236.560  Contact element, mechanical trip type; location with 
          respect to rail.

    Contact element of automatic train stop device of the mechanical 
trip type shall be maintained at a height above the plane of the tops of 
the rails, and at a horizontal distance from the gage side of the rail, 
in accordance with specifications of the carrier.

[49 FR 3387, Jan. 26, 1984]

Sec. 236.561  [Reserved]

Sec. 236.562  Minimum rail current required.

    The minimum rail current required to restore the locomotive 
equipment of continuous inductive automatic train stop or train control 
device to normal condition or to obtain a proceed indication of 
automatic cab signal device (pick-up) shall be in accordance with 
specifications of the carrier.

[49 FR 3387, Jan. 26, 1984]

Sec. 236.563  Delay time.

    Delay time of automatic train stop or train control system shall not 
exceed 8 seconds and the spacing of signals to meet the requirements of 
Sec. 236.24 shall take into consideration the delay time.

Sec. 236.564  Acknowledging time.

    Acknowledging time of intermittent automatic train-stop device shall 
be not more than 30 seconds.

Sec. 236.565  Provision made for preventing operation of pneumatic 
          brake-applying apparatus by double-heading cock; requirement.

    Where provision is made for preventing the operation of the 
pneumatic brake-applying appartus of an automatic train stop or train 
control device when the double-heading cock is placed in double-heading 
position, the automatic train stop or train control device shall not be 
cut out before communication is closed between the engineman's automatic 
brake valve and the brake pipe, when operating double-heading cock 
toward double-heading position.

Sec. 236.566  Locomotive of each train operating in train stop, train 
          control or cab signal territory; equipped.

    The locomotive from which brakes are controlled, of each train 
operating in automatic train stop, train control, or cab signal 
territory shall be equipped with apparatus responsive to the roadway 
equipment installed on all or any part of the route traversed, and such 
apparatus shall be in operative condition.

Sec. 236.567  Restrictions imposed when device fails and/or is cut out 
          en route.

    Where an automatic train stop, train control, or cab signal device 
fails and/or is cut out enroute, train may proceed at restricted speed 
or if an automatic block signal system is in operation according to 
signal indication but not to exceed medium speed, to the next available 
point of communication where report must be made to a designated 
officer. Where no automatic block signal system is in use train shall be 
permitted to proceed at restricted speed or where automatic block signal 
system is in operation according to signal indication but not to exceed 
medium speed to a point where absolute block can be established. Where 
an absolute block is established in advance of the train on which the

[[Page 522]]

device is inoperative train may proceed at not to exceed 79 miles per 
hour.

Sec. 236.568  Difference between speeds authorized by roadway signal and 
          cab signal; action required.

    If for any reason a cab signal authorizes a speed different from 
that authorized by a roadway signal, when a train enters the block 
governed by such roadway signal, the lower speed shall not be exceeded.

                      Inspection and Tests; Roadway

Sec. 236.576  Roadway element.

    Roadway elements, except track circuits, including those for test 
purposes, shall be gaged monthly for height and alinement, and shall be 
tested at least every 6 months.

Sec. 236.577  Test, acknowledgement, and cut-in circuits.

    Test, acknowledgement, and cut-in circuits shall be tested at least 
once every twelve months.

[49 FR 3387, Jan. 26, 1984]

                    Inspection and Tests; Locomotive

Sec. 236.586  Daily or after trip test.

    (a) Except where tests prescribed by Sec. 236.588 are performed at 
intervals of not more than 2 months, each locomotive equipped with an 
automatic cab signal or train stop or train control device operating in 
equipped territory shall be inspected for damage to the equipment and 
tested at least once each calendar day or within 24 hours before 
departure upon each trip.
    (b) Each equipped locomotive shall be tested to determine the 
locomotive equipment is responsive to the wayside equipment and shall be 
cycled to determine the device functions as intended.
    (c) Each locomotive equipped with intermittent inductive automatic 
train stop or non-coded continuous inductive automatic train stop or 
non-coded continuous inductive automatic train control device shall be 
tested to determine that the pickup of the device is within specified 
limits.

[49 FR 3387, Jan. 26, 1984]

Sec. 236.587  Departure test.

    (a) The automatic train stop, train control, or cab signal apparatus 
on each locomotive, except a locomotive or a multiple-unit car equipped 
with mechanical trip stop, shall be tested using one of the following 
methods:
    (1) Operation over track elements;
    (2) Operation over test circuit;
    (3) Use of portable test equipment; or
    (4) Use of onboard test device.
    (b) The test shall be made on departure of the locomotive from its 
initial terminal unless that apparatus will be cut out between the 
initial terminal and the equipped territory. If the apparatus is cut out 
between the initial terminal and the equipped territory the test shall 
be made prior to entering equipped territory.
    (c) If a locomotive makes more than one trip in any 24-hour period, 
only one departure test is required in such 24-hour period.
    (d)(1) Whoever performs the test shall certify in writing that such 
test was properly performed. The certification and the test results 
shall be posted in the cab of the locomotive and a copy of the 
certification and test results left at the test location for filing in 
the office of the supervisory official having jurisdiction.
    (2) If it is impractical to leave a copy of the certification and 
test results at the location f the test, the test results shall be 
transmitted to either (i) the dispatcher or (ii) one other designated 
individual at each location, who shall keep a written record of the test 
results and the name of the person performing the test. These records 
shall be retained for at least 92 days.

[49 FR 3387, Jan. 26, 1984, as amended at 53 FR 37313, Sept. 26, 1988]

    Effective Date Note: At 49 FR 3387, Jan. 26, 1984, Sec. 236.587 was 
revised. This section contains information collection and recordkeeping 
requirements and will not become effective until approval has been given 
by the Office of Management and Budget.

Sec. 236.588  Periodic test.

    Except as provided in Sec. 236.586, periodic test of the automatic 
train stop, train control, or cab signal apparatus shall be made at 
least once every 92

[[Page 523]]

days, and on multiple-unit cars as specified by the carrier, subject to 
approval by the FRA.

[49 FR 3387, Jan. 26, 1984]

Sec. 236.589  Relays.

    (a) Each relay shall be removed from service, subjected to thorough 
test, necessary repairs and adjustments made, and shall not be replaced 
in service unless its operating characteristics are in accordance with 
the limits within which such relay is designed to operate, as follows:
    (1) Master or primary relays of torque type depending on spring 
tension to return contacts to deenergized position in noncoded 
continuous inductive automatic train stop or train control system, at 
least once every two years; and
    (2) All other relays, at least once every six years.
    (b) [Reserved]

[49 FR 3387, Jan. 26, 1984]

Sec. 236.590  Pneumatic apparatus.

    Automatic train stop, train control, or cab signal pneumatic 
apparatus shall be inspected, cleaned, and the results of such 
inspection recorded as provided by Sec. 229.29(a). When a locomotive 
with automatic train stop, train control, or cab signal pneumatic 
apparatus receives out-of-use credit pursuant to Sec. 229.33, the 
automatic train stop, train control, or cab signal apparatus shall be 
tested in accordance with Sec. 236.588 prior to the locomotive being 
placed in service.

[61 FR 33873, July 1, 1996]

  Subpart F--Dragging Equipment and Slide Detectors and Other Similar 
                           Protective Devices

                                Standards

Sec. 236.601  Signals controlled by devices; location.

    Signals controlled by devices used to provide protection against 
unusual contingencies, such as landslides, dragging equipment, burned 
bridges or trestles and washouts shall be located so that stopping 
distance will be provided between the signal and the point where it is 
necessary to stop the train.

                         Subpart G--Definitions

Sec. 236.700  Definitions.

    For the purpose of these rules, standards, and instructions, the 
following definitions will apply.

Sec. 236.701  Application, brake; full service.

    An application of the brakes resulting from a continuous or a split 
reduction in brake pipe pressure at a service rate until maximum brake 
cylinder pressure is developed. As applied to an automatic or electro-
pneumatic brake with speed governor control, an application other than 
emergency which develops the maximum brake cylinder pressure, as 
determined by the design of the brake equipment for the speed at which 
the train is operating.

Sec. 236.702  Arm, semaphore.

    The part of a semaphore signal displaying an aspect. It consists of 
a blade fastened to a spectacle.

Sec. 236.703  Aspect.

    The appearance of a roadway signal conveying an indication as viewed 
from the direction of an approaching train; the appearance of a cab 
signal conveying an indication as viewed by an observer in the cab.

Sec. 236.704  [Reserved]

Sec. 236.705  Bar, locking.

    A bar in an interlocking machine to which the locking dogs are 
attached.

Sec. 236.706  Bed, locking.

    That part of an interlocking machine that contains or holds the 
tappets, locking bars, crosslocking, dogs and other apparatus used to 
interlock the levers.

Sec. 236.707  Blade, semaphore.

    The extended part of a semaphore arm which shows the position of the 
arm.

[[Page 524]]

Sec. 236.708  Block.

    A length of track of defined limits, the use of which by trains is 
governed by block signals, cab signals, or both.

Sec. 236.709  Block, absolute.

    A block in which no train is permitted to enter while it is occupied 
by another train.

Sec. 236.710  Block, latch.

    The lower extremity of a latch rod which engages with a square 
shoulder of the segment or quadrant to hold the lever in position.

Sec. 236.711  Bond, rail joint.

    A metallic connection attached to adjoining rails to insure 
electrical conductivity.

Sec. 236.712  Brake pipe.

    A pipe running from the engineman's brake valve through the train, 
used for the transmission of air under pressure to charge and actuate 
the automatic brake equipment and charge the reservoirs of the electro-
pneumatic brake equipment on each vehicle of the train.

Sec. 236.713  Bridge, movable.

    That section of a structure bridging a navigable waterway so 
designed that it may be displaced to permit passage of traffic on the 
waterway.

Sec. 236.714  Cab.

    The compartment of a locomotive from which the propelling power and 
power brakes of the train are manually controlled.

Secs. 236.715-236.716  [Reserved]

Sec. 236.717  Characteristics, operating.

    The measure of electrical values at which electrical or electronic 
apparatus operate (e.g., drop-away, pick-up, maximum and minimum 
current, and working value).

[49 FR 3387, Jan. 26, 1984]

Sec. 236.718  Chart, dog.

    A diagrammatic representation of the mechanical locking of an 
interlocking machine, used as a working plan in making up, assembling 
and fitting the locking.

Sec. 236.719  Circuit, acknowledgment.

    A circuit consisting of wire or other conducting material installed 
between the track rails at each signal in territory where an automatic 
train stop system or cab signal system of the continuous inductive type 
with 2-indication cab signals is in service, to enforce acknowledgement 
by the engineman at each signal displaying an aspect requiring a stop.

Sec. 236.720  Circuit, common return.

    A term applied where one wire is used for the return of more than 
one electric circuit.

Sec. 236.721  Circuit, control.

    An electrical circuit between a source of electric energy and a 
device which it operates.

Sec. 236.722  Circuit, cut-in.

    A roadway circuit at the entrance to automatic train stop, train 
control or cab signal territory by means of which locomotive equipment 
of the continuous inductive type is actuated so as to be in operative 
condition.

Sec. 236.723  Circuit, double wire; line.

    An electric circuit not employing a common return wire; a circuit 
formed by individual wires throughout.

Sec. 236.724  Circuit, shunt fouling.

    The track circuit in the fouling section of a turnout, connected in 
multiple with the track circuit in the main track.

Sec. 236.725  Circuit, switch shunting.

    A shunting circuit which is closed through contacts of a switch 
circuit controller.

Sec. 236.726  Circuit, track.

    An electrical circuit of which the rails of the track form a part.

Sec. 236.727  Circuit, track; coded.

    A track circuit in which the energy is varied or interrupted 
periodically.

Sec. 236.728  Circuit, trap.

    A term applied to a circuit used where it is desirable to provide a 
track

[[Page 525]]

circuit but where it is impracticable to maintain a track circuit.

Sec. 236.729  Cock, double heading.

    A manually operated valve by means of which the control of brake 
operation is transferred to the leading locomotive.

Sec. 236.730  Coil, receiver.

    Concentric layers of insulated wire wound around the core of a 
receiver of an automatic train stop, train control or cab signal device 
on a locomotive.

Sec. 236.731  Controller, circuit.

    A device for opening and closing electric circuits.

Sec. 236.732  Controller, circuit; switch.

    A device for opening and closing electric circuits, operated by a 
rod connected to a switch, derail or movable-point frog.

Sec. 236.733  Current, foreign.

    A term applied to stray electric currents which may affect a 
signaling system, but which are not a part of the system.

Sec. 236.734  Current of traffic.

    The movement of trains on a specified track in a designated 
direction.

Sec. 236.735  Current, leakage.

    A stray electric current of relatively small value which flows 
through or across the surface of insulation when a voltage is impressed 
across the insulation.

Sec. 236.736  Cut-section.

    A location other than a signal location where two adjoining track 
circuits end within a block.

Sec. 236.737  Cut-section, relayed.

    A cut-section where the energy for one track circuit is supplied 
through front contacts or through front and polar contacts of the track 
relay for the adjoining track circuit.

Sec. 236.738  Detector, point.

    A circuit controller which is part of the switch operating mechanism 
and operated by a rod connected to a switch, derail or movable point 
frog to indicate that the point is within a specified distance of the 
stock rail.

Sec. 236.739  Device, acknowledging.

    A manually operated electric switch or pneumatic valve by means of 
which, on a locomotive equipped with an automatic train stop or train 
control device, an automatic brake application can be forestalled, or by 
means of which, on a locomotive equipped with an automatic cab signal 
device, the sounding of the cab indicator can be silenced.

Sec. 236.740  Device, reset.

    A device whereby the brakes may be released after an automatic train 
control brake application.

Sec. 236.741  Distance, stopping.

    The maximum distance on any portion of any railroad which any train 
operating on such portion of railroad at its maximum authorized speed, 
will travel during a full service application of the brakes, between the 
point where such application is initiated and the point where the train 
comes to a stop.

Sec. 236.742  Dog, locking.

    A steel block attached to a locking bar or tappet of an interlocking 
machine, by means of which locking between levers is accomplished.

Sec. 236.743  Dog, swing.

    A locking dog mounted in such a manner that it is free to rotate on 
a trunnion which is riveted to a locking bar.

    Cross Reference: Element, contact. See receiver, Sec. 236.788.

Sec. 236.744  Element, roadway.

    That portion of the roadway apparatus of automatic train stop, train 
control, or cab signal system, such as electric circuit, inductor, or 
trip arm to which the locomotive apparatus of such system is directly 
responsive.

[49 FR 3387, Jan. 26, 1984]

Sec. 236.745  Face, locking.

    The locking surface of a locking dog, tappet or cross locking of an 
interlocking machine.

[[Page 526]]

Sec. 236.746  Feature, restoring.

    An arrangement on an electro-pneumatic switch by means of which 
power is applied to restore the switch movement to full normal or to 
full reverse position, before the driving bar creeps sufficiently to 
unlock the switch, with control level in normal or reverse position.

[49 FR 3388, Jan. 26, 1984]

Sec. 236.747  Forestall.

    As applied to an automatic train stop or train control device, to 
prevent an automatic brake application by operation of an acknowledging 
device or by manual control of the speed of the train.

Sec. 236.748  [Reserved]

Sec. 236.749  Indication.

    The information conveyed by the aspect of a signal.

    Cross Reference: Inductor, see Sec. 236.744.

Sec. 236.750  Interlocking, automatic.

    An arrangement of signals, with or without other signal appliances, 
which functions through the exercise of inherent powers as distinguished 
from those whose functions are controlled manually, and which are so 
interconnected by means of electric circuits that their movements must 
succeed each other in proper sequence, train movements over all routes 
being governed by signal indication.

Sec. 236.751  Interlocking, manual.

    An arrangement of signals and signal appliances operated from an 
interlocking machine and so interconnected by means of mechanical and/or 
electric locking that their movements must succeed each other in proper 
sequence, train movements over all routes being governed by signal 
indication.

Sec. 236.752  Joint, rail, insulated.

    A joint in which electrical insulation is provided between adjoining 
rails.

Sec. 236.753  Limits, interlocking.

    The tracks between the opposing home signals of an interlocking.

Sec. 236.754  Line, open wire.

    An overhead wire line consisting of single conductors as opposed to 
multiple-conductor cables.

Sec. 236.755  Link, rocker.

    That portion of an interlocking machine which transmits motion 
between the latch and the universal link.

Sec. 236.756  Lock, bolt.

    A mechanical lock so arranged that if a switch, derail or movable-
point frog is not in the proper position for a train movement, the 
signal governing that movement cannot display an aspect to proceed; and 
that will prevent a movement of the switch, derail or movable-point frog 
unless the signal displays its most restrictive aspect.

Sec. 236.757  Lock, electric.

    A device to prevent or restrict the movement of a lever, a switch or 
a movable bridge, unless the locking member is withdrawn by an 
electrical device, such as an electromagnet, solenoid or motor.

Sec. 236.758  Lock, electric, forced drop.

    An electric lock in which the locking member is mechanically forced 
down to the locked position.

Sec. 236.759  Lock, facing point.

    A mechanical lock for a switch, derail, or movable-point frog, 
comprising a plunger stand and a plunger which engages a lock rod 
attached to the switch point to lock the operated unit.

Sec. 236.760  Locking, approach.

    Electric locking effective while a train is approaching, within a 
specified distance, a signal displaying an aspect to proceed, and which 
prevents, until after the expiration of a predetermined time interval 
after such signal has been caused to display its most restrictive 
aspect, the movement of any interlocked or electrically locked switch, 
movable-point frog, or derail in the route governed by the signal, and 
which prevents an aspect to proceed from being displayed for any 
conflicting route.

[[Page 527]]

Sec. 236.761  Locking, electric.

    The combination of one or more electric locks and controlling 
circuits by means of which levers of an interlocking machine, or 
switches or other units operated in connection with signaling and 
interlocking, are secured against operation under certain conditions.

Sec. 236.762  Locking, indication.

    Electric locking which prevents manipulation of levers that would 
result in an unsafe condition for a train movement if a signal, switch, 
or other operative unit fails to make a movement corresponding to that 
of its controlling lever, or which directly prevents the operation of a 
signal, switch, or other operative unit, in case another unit which 
should operate first fails to make the required movement.

Sec. 236.763  Locking, latch operated.

    The mechanical locking of an interlocking machine which is actuated 
by means of the lever latch.

Sec. 236.764  Locking, lever operated.

    The mechanical locking of an interlocking machine which is actuated 
by means of the lever.

Sec. 236.765  Locking, mechanical.

    An arrangement of locking bars, dogs, tappets, cross locking and 
other apparatus by means of which interlocking is effected between the 
levers of an interlocking machine and so interconnected that their 
movements must succeed each other in a predetermined order.

Sec. 236.766  Locking, movable bridge.

    The rail locks, bridge locks, bolt locks, circuit controllers, and 
electric locks used in providing interlocking protection at a movable 
bridge.

Sec. 236.767  Locking, route.

    Electric locking, effective when a train passes a signal displaying 
an aspect for it to proceed, which prevents the movement of any switch, 
movable-point frog, or derail in advance of the train within the route 
entered. It may be so arranged that as a train clears a track section of 
the route, the locking affecting that section is released.

Sec. 236.768  Locking, time.

    A method of locking, either mechanical or electrical, which, after a 
signal has been caused to display an aspect to proceed, prevents, until 
after the expiration of a predetermined time interval after such signal 
has been caused to display its most restrictive aspect, the operation of 
any interlocked or electrically locked switch, movable-point frog, or 
derail in the route governed by that signal, and which prevents an 
aspect to proceed from being displayed for any conflicting route.

Sec. 236.769  Locking, traffic.

    Electric locking which prevents the manipulation of levers or other 
devices for changing the direction of traffic on a section of track 
while that section is occupied or while a signal displays an aspect for 
a movement to proceed into that section.

Sec. 236.770  Locomotive.

    A self-propelled unit of equipment which can be used in train 
service.

Sec. 236.771  Machine, control.

    An assemblage of manually operated devices for controlling the 
functions of a traffic control system; it may include a track diagram 
with indication lights.

Sec. 236.772  Machine, interlocking.

    An assemblage of manually operated levers or other devices for the 
control of signals, switches or other units.

    Cross Reference: Magnet, track, see Sec. 236.744.

Sec. 236.773  Movements, conflicting.

    Movements over conflicting routes.

Sec. 236.774  Movement, facing.

    The movement of a train over the points of a switch which face in a 
direction opposite to that in which the train is moving.

Sec. 236.775  Movement, switch-and-lock.

    A device, the complete operation of which performs the three 
functions of unlocking, operating and locking a switch, movable-point 
frog or derail.

[[Page 528]]

Sec. 236.776  Movement, trailing.

    The movement of a train over the points of a switch which face in 
the direction in which the train is moving.

Sec. 236.777  Operator, control.

    An employee assigned to operate the control machine of a traffic 
control system.

Sec. 236.778  Piece, driving.

    A crank secured to a locking shaft by means of which horizontal 
movement is imparted to a longitudinal locking bar.

Sec. 236.779  Plate, top.

    A metal plate secured to a locking bracket to prevent the cross 
locking from being forced out of the bracket.

Sec. 236.780  Plunger, facing point lock.

    That part of a facing point lock which secures the lock rod to the 
plunger stand when the switch is locked.

Sec. 236.781  [Reserved]

Sec. 236.782  Point, controlled.

    A location where signals and/or other functions of a traffic control 
system are controlled from the control machine.

Sec. 236.783  Point, stop-indication.

    As applied to an automatic train stop or train control system 
without the use of roadway signals, a point where a signal displaying an 
aspect requiring a stop would be located.

Sec. 236.784  Position, deenergized.

    The position assumed by the moving member of an electromagnetic 
device when the device is deprived of its operating current.

Sec. 236.785  Position, false restrictive.

    A position of a semaphore arm that is more restrictive than it 
should be.

Sec. 236.786  Principle, closed circuit.

    The principle of circuit design where a normally energized electric 
circuit which, on being interrupted or deenergized, will cause the 
controlled function to assume its most restrictive condition.

Sec. 236.787  Protection, cross.

    An arrangement to prevent the improper operation of a signal, 
switch, movable-point frog, or derail as the result of a cross in 
electrical circuits.

    Cross Reference: Ramp, see Sec. 236.744.

Sec. 236.788  Receiver.

    A device on a locomotive, so placed that it is in position to be 
influenced inductively or actuated by an automatic train stop, train 
control or cab signal roadway element.

Sec. 236.789  Relay, timing.

    A relay which will not close its front contacts or open its back 
contacts, or both, until the expiration of a definite time intervals 
after the relay has been energized.

Sec. 236.790  Release, time.

    A device used to prevent the operation of an operative unit until 
after the expiration of a predetermined time interval after the device 
has been actuated.

Sec. 236.791  Release, value.

    The electrical value at which the movable member of an 
electromagnetic device will move to its deenergized portion.

Sec. 236.792  Reservoir, equalizing.

    An air reservoir connected with and adding volume to the top portion 
of the equalizing piston chamber of the automatic brake valve, to 
provide uniform service reductions in brake pipe pressure regardless of 
the length of the train.

    Cross Reference: Rocker, see Sec. 236.755.

Sec. 236.793  Rod, lock.

    A rod, attached to the front rod or lug of a switch, movable-point 
frog or derail, through which a locking plunger may extend when the 
switch points or derail are in the normal or reverse position.

[[Page 529]]

Sec. 236.794  Rod, up-and-down.

    A rod used for connecting the semaphore arm to the operating 
mechanism of a signal.

Sec. 236.795  Route.

    The course or way which is, or is to be, traveled.

Sec. 236.796  Routes, conflicting.

    Two or more routes, opposing, converging or intersecting, over which 
movements cannot be made simultaneously without possibility of 
collision.

Sec. 236.797  Route, interlocked.

    A route within interlocking limits.

Sec. 236.798  Section, dead.

    A section of track, either within a track circuit or between two 
track circuits, the rails of which are not part of a track circuit.

Sec. 236.799  Section, fouling.

    The section of track between the switch points and the clearance 
point in a turnout.

Sec. 236.800  Sheet, locking.

    A description in tabular form of the locking operations in an 
interlocking machine.

Sec. 236.801  Shoe, latch.

    The casting by means of which the latch rod and the latch block are 
held to a lever of a mechanical interlocking machine.

Sec. 236.802  Shunt.

    A by-path in an electrical circuit.

Sec. 236.802a  Siding.

    An auxiliary track for meeting or passing trains.

Sec. 236.803  Signal, approach.

    A roadway signal used to govern the approach to another signal and 
if operative so controlled that its indication furnishes advance 
information of the indication of the next signal.

Sec. 236.804  Signal, block.

    A roadway signal operated either automatically or manually at the 
entrance to a block.

Sec. 236.805  Signal, cab.

    A signal located in engineman's compartment or cab, indicating a 
condition affecting the movement of a train and used in conjunction with 
interlocking signals and in conjunction with or in lieu of block 
signals.

Sec. 236.806  Signal, home.

    A roadway signal at the entrance to a route or block to govern 
trains in entering and using that route or block.

Sec. 236.807  Signal, interlocking.

    A roadway signal which governs movements into or within interlocking 
limits.

Sec. 236.808  Signals, opposing.

    Roadway signals which govern movements in opposite directions on the 
same track.

Sec. 236.809  Signal, slotted mechanical.

    A mechanically operated signal with an electromagnetic device 
inserted in its operating connection to provide a means of controlling 
the signal electrically, as well as mechanically.

Sec. 236.810  Spectacle, semaphore arm.

    That part of a semaphore arm which holds the roundels and to which 
the blade is fastened.

Sec. 236.811  Speed, medium.

    A speed not exceeding 40 miles per hour.

Sec. 236.812  Speed, restricted.

    A speed that will permit stopping within one-half the range of 
vision, but not exceeding 20 miles per hour.

[49 FR 3388, Jan. 26, 1984]

Sec. 236.813  Speed, slow.

    A speed not exceeding 20 miles per hour.

[[Page 530]]

Sec. 236.813a  State, most restrictive.

    The mode of an electric or electronic device that is equivalent to a 
track relay in its deenergized position.

[49 FR 3388, Jan. 26, 1984]

Sec. 236.814  Station, control.

    The place where the control machine of a traffic control system is 
located.

Sec. 236.815  Stop.

    As applied to mechanical locking, a device secured to a locking bar 
to limit its movement.

Sec. 236.816  Superiority of trains.

    The precedence conferred upon one train over other trains by train 
order or by reason of its class or the direction of its movement.

Sec. 236.817  Switch, electro-pneumatic.

    A switch operated by an electro-pneumatic switch-and-lock movement.

Sec. 236.818  Switch, facing point.

    A switch, the points of which face traffic approaching in the 
direction for which the track is signaled.

Sec. 236.819  Switch, hand operated.

    A non-interlocked switch which can only be operated manually.

Sec. 236.820  Switch, interlocked.

    A switch within the interlocking limits the control of which is 
interlocked with other functions of the interlocking.

Sec. 236.820a  Switch, power-operated.

    A switch operated by an electrically, hydraulically, or 
pneumatically driven switch-and-lock movement.

[49 FR 3388, Jan. 26, 1984]

Sec. 236.821  Switch, sectionalizing.

    A switch for disconnecting a section of a power line from the source 
of energy.

Sec. 236.822  Switch, spring.

    A switch equipped with a spring device which forces the points to 
their original position after being trailed through and holds them under 
spring compression.

Sec. 236.823  Switch, trailing point.

    A switch, the points of which face away from traffic approaching in 
the direction for which the track is signaled.

Sec. 236.824  System, automatic block signal.

    A block signal system wherein the use of each block is governed by 
an automatic block signal, cab signal, or both.

Sec. 236.825  System, automatic train control.

    A system so arranged that its operation will automatically result in 
the following:
    (a) A full service application of the brakes which will continue 
either until the train is brought to a stop, or, under control of the 
engineman, its speed is reduced to a predetermined rate.
    (b) When operating under a speed restriction, an application of the 
brakes when the speed of the train exceeds the predetermined rate and 
which will continue until the speed is reduced to that rate.

Sec. 236.826  System, automatic train stop.

    A system so arranged that its operation will automatically result in 
the application of the brakes until the train has been brought to a 
stop.

Sec. 236.827  System, block signal.

    A method of governing the movement of trains into or within one or 
more blocks by block signals or cab signals.

Sec. 236.828  System, traffic control.

    A block signal system under which train movements are authorized by 
block signals whose indications supersede the superiority of trains for 
both opposing and following movements on the same track.

Sec. 236.829  Terminal, initial.

    The starting point of a locomotive for a trip.

Sec. 236.830  Time, acknowledging.

    As applied to an intermittent automatic train stop system, a 
predetermined time within which an automatic

[[Page 531]]

brake application may be forestalled by means of the acknowledging 
device.

Sec. 236.831  Time, delay.

    As applied to an automatic train stop or train control system, the 
time which elapses after the onboard apparatus detects a more 
restrictive indication until the brakes start to apply.

[49 FR 3388, Jan. 26, 1984]

Sec. 236.831a  Track, main.

    A track, other than auxiliary track, extending through yards and 
between stations, upon which trains are operated by timetable or train 
orders, or both, or the use of which is governed by block signals.

Sec. 236.832  Train.

    A locomotive or more than one locomotive coupled, with or without 
cars.

Sec. 236.833  Train, opposing.

    A train, the movement of which is in a direction opposite to and 
toward another train on the same track.

Sec. 236.834  Trip.

    A movement of a locomotive over all or any portion of automatic 
train stop, train control or cab signal territory between the terminals 
for that locomotive; a movement in one direction.

    Cross Reference: Trip-arm, see Sec. 236.744.

Sec. 236.835  Trunking.

    A casing used to protect electrical conductors.

Sec. 236.836  Trunnion.

    A cylindrical projection supporting a revolving part.

Sec. 236.837  Valve, electro-pneumatic.

    A valve electrically operated which, when operated, will permit or 
prevent passage of air.

Sec. 236.838  Wire, shunt.

    A wire forming part of a shunt circuit.

               Appendix A to Part 236--Civil Penalties \1\

------------------------------------------------------------------------
                                                               Willful
                    Section                      Violation    violation
------------------------------------------------------------------------
             Subpart A--Rules and Instructions--All Systems

------------------------------------------------------------------------
General:
236.0 Applicability, minimum requirements.....       $2,500       $5,000
236.1 Plans, where kept.......................        1,000        2,000
236.2 Grounds.................................        1,000        2,000
236.3 Locking of signal apparatus housings:
    (a) Power interlocking machine cabinet not        2,500        5,000
     secured against unauthorized entry.......
    (b) other violations......................        1,000        2,000
236.4 Interference with normal functioning of         5,000        7,500
 device.......................................
236.5 Design of control circuits on closed            1,000        2,000
 circuit principle............................
236.6 Hand-operated switch equipped with              1,000        2,000
 switch circuit controller....................
236.7 Circuit controller operated by switch-          1,000        2,000
 and-lock movement............................
236.8 Operating characteristics of electro-           1,000        2,000
 magnetic, electronic, or electrical apparatus
236.9 Selection of circuits through indicating        1,000        2,000
 or annunciating instruments..................
236.10 Electric locks, force drop type; where         1,000        2,000
 required.....................................
236.11 Adjustment, repair, or replacement of          2,500        5,000
 component....................................
236.12 Spring switch signal protection; where         1,000        2,000
 required.....................................
236.13 Spring switch; selection of signal             1,000        2,000
 control circuits through circuit controller..
236.14 Spring switch signal protection;               1,000        2,000
 requirements.................................
236.15 Timetable instructions.................        1,000        2,000
236.16 Electric lock, main track releasing
 circuit:
    (a) Electric lock releasing circuit on            2,500        5,000
     main track extends into fouling circuit
     where turnout not equipped with derail at
     clearance point either pipe-connected to
     switch or independently locked,
     electrically.............................
    (b) other violations......................        1,000        2,000
236.17 Pipe for operating connections,                1,000        2,000
 requirements

Roadway Signals and Cab Signals--

236.21 Location of roadway signals............        1,000        2,000
236.22 Semaphore signal arm; clearance to             1,000        2,000
 other objects................................
236.23 Aspects and indications................        1,000        2,000
236.24 Spacing of roadway signals.............        2,500        5,000

[[Page 532]]


236.26 Buffing device, maintenance............        1,000        2,000

Track Circuits--

236.51 Track circuit requirements:
    (a) Shunt fouling circuit used where              2,500        5,000
     permissible speed through turnout greater
     than 45 m.p.h............................
    (b) Track relay not in de-energized               2,500        5,000
     position or device that functions as
     track relay not in its most restrictive
     state when train, locomotive, or car
     occupies any part of track circuit,
     except fouling section of turnout of hand-
     operated main-track crossover............
    (c) other violations......................        1,000        2,000
236.52 Relayed cut-section....................        1,000        2,000
236.53 Track circuit feed at grade crossing...        1,000        2,000
236.54 Minimum length of track circuit........        1,000        2,000
236.55 Dead section; maximum length...........        1,000        2,000
236.56 Shunting sensitivity...................        2,500        5,000
236.57 Shunt and fouling wires:
    (a) Shunt or fouling wires do not consist         2,500        5,000
     of at least two discrete conductors......
    (b) other violations......................        1,000        2,000
236.58 Turnout, fouling section:
    (a) Rail joint in shunt fouling section           2,500        5,000
     not bonded...............................
    (b) other violations......................        1,000        2,000
236.59 Insulated rail joints..................        1,000        2,000
236.60 Switch shunting circuit; use restricted        2,500        5,000

Wires and Cables--

236.71 Signal wires on pole line and aerial           1,000        2,000
 cable........................................
236.73 Open-wire transmission line; clearance         1,000        2,000
 to other circuits............................
236.74 Protection of insulated wire; splice in        1,000        2,000
 underground wire.............................
236.76 Tagging of wires and interference of           1,000        2,000
 wires or tags with signal apparatus..........

Inspections and Tests; All Systems--

236.101 Purpose of inspection and tests;              2,500        5,000
 removal from service or relay or device
 failing to meet test requirements............
236.102 Semaphore or search-light signal              1,000        2,000
 mechanism....................................
236.103 Switch circuit controller or point            1,000        2,000
 detector.....................................
236.104 Shunt fouling circuit.................        1,000        2,000
236.105 Electric lock.........................        1,000        2,000
236.106 Relays................................        1,000        2,000
236.107 Ground tests..........................        1,000        2,000
236.108 Insulation resistance tests, wires in
 trunking and cables:
    (a) Circuit permitted to function on a            2,500        5,000
     conductor having insulation resistance
     value less than 200,000 ohms.............
    (b) other violations......................        1,000        2,000
236.109 Time releases, timing relays and              1,000        2,000
 timing devices...............................
236.110 Results of tests......................        1,000        2,000
-----------------------------------------------
                Subpart B--Automatic Block Signal Systems

------------------------------------------------------------------------
236.201 Track circuit control of signals......        1,000        2,000
236.202 Signal governing movements over hand-         1,000        2,000
 operated switch..............................
236.203 Hand-operated crossover between main          1,000        2,000
 tracks; protection...........................
236.204 Track signaled for movements in both          1,000        2,000
 directions, requirements.....................
236.205 Signal control circuits; requirements.        1,000        2,000
236.206 Battery or power supply with respect          1,000        2,000
 to relay; location...........................
-----------------------------------------------
                         Subpart C--Interlocking

------------------------------------------------------------------------
236.207 Electric lock on hand-operated switch;
 control:
    (a) Approach or time locking of electric          2,500        5,000
     lock on hand-operated switch can be
     defeated by unauthorized use of emergency
     device which is not kept sealed in the
     non-release position.....................
    (b) other violations......................        1,000        2,000
236.301 Where signals shall be provided.......        1,000        2,000
236.302 Track circuits and route locking......        1,000        2,000
236.303 Control circuits for signals,                 1,000        2,000
 selection through circuit controller operated
 by switch points or by switch locking
 mechanism....................................
236.304 Mechanical locking or same protection         1,000        2,000
 effected by circuits.........................
236.305 Approach or time locking..............        1,000        2,000
236.306 Facing point lock or switch-and-lock          1,000        2,000
 movement.....................................
236.307 Indication locking:
236.308 Mechanical or electric locking or             1,000        2,000
 electric circuits; requisites................
236.309 Loss of shunt protection; where
 required:
    (a) Loss of shunt of five seconds or less         2,500        5,000
     permits release of route locking of power-
     operated switch, movable point frog, or
     derail...................................
    (b) Other violations......................        1,000        2,000
236.310 Signal governing approach to home             1,000        2,000
 signal.......................................

[[Page 533]]


236.311 Signal control circuits, selection            1,000        2,000
 through track relays or devices functioning
 as track relays and through signal mechanism
 contacts and time releases at automatic
 interlocking.................................
236.312 Movable bridge, interlocking of signal
 appliances with bridge devices:
    (a) Emergency bypass switch or device not         2,500        5,000
     locked or sealed.........................
    (b) other violations......................        1,000        2,000
236.314 Electric lock for hand-operated switch
 or derail:
    (a) Approach or time locking of electric          2,500        5,000
     lock at hand-operated switch or derail
     can be defeated by unauthorized use of
     emergency device which is not kept sealed
     in non-release position..................
    (b) other violations......................        1,000        2,000

Rules and Instructions--

236.326 Mechanical locking removed or                 1,000        2,000
 disarranged; requirement for permitting train
 movements through interlocking...............
236.327 Switch, movable-point frog or split-          1,000        2,000
 point derail.................................
236.328 Plunger of facing-point...............        1,000        2,000
236.329 Bolt lock.............................        1,000        2,000
236.330 Locking dog of switch and lock                1,000        2,000
 movement.....................................
236.334 Point detector........................        1,000        2,000
236.335 Dogs, stops and trunnions of                  1,000        2,000
 mechanical locking...........................
236.336 Locking bed...........................        1,000        2,000
236.337 Locking faces of mechanical locking;          1,000        2,000
 fit..........................................
236.338 Mechanical locking required in                1,000        2,000
 accordance with locking sheet and dog chart..
236.339 Mechanical locking; maintenance               1,000        2,000
 requirements.................................
236.340 Electromechanical interlocking                1,000        2,000
 machine; locking between electrical and
 mechanical levers............................
236.341 Latch shoes, rocker links, and                1,000        2,000
 quadrants....................................
236.342 Switch circuit controller.............        1,000        2,000

Inspection and Tests--

236.376 Mechanical locking....................        1,000        2,000
236.377 Approach locking......................        1,000        2,000
236.378 Time locking..........................        1,000        2,000
236.379 Route locking.........................        1,000        2,000
236.380 Indication locking....................        1,000        2,000
236.381 Traffic locking.......................        1,000        2,000
236.382 Switch obstruction test...............        1,000        2,000
236.383 Valve locks, valves, and valve magnets        1,000        2,000
236.384 Cross protection
236.386 Restoring feature on power switches
236.387 Movable bridge locking................        1,000        2,000
-----------------------------------------------
              Subpart D--Traffic Control Systems Standards

------------------------------------------------------------------------
236.401 Automatic block signal system and
 interlocking standards applicable to traffic
 control systems:
236.402 Signals controlled by track circuits          1,000        2,000
 and control operator.........................
236.403 Signals at controlled point...........        1,000        2,000
236.404 Signals at adjacent control points....        1,000        2,000
236.405 Track signaled for movements in both          1,000        2,000
 directions, change of direction of traffic...
236.407 Approach or time locking; where               1,000        2,000
 required.....................................
236.408 Route locking.........................        1,000        2,000
236.410 Locking, hand-operated switch;
 requirements:
    (a) Hand-operated switch on main track not        2,500        5,000
     electrically or mechanically locked in
     normal position where signal not provided
     to govern movement to main track,
     movements made at speeds in excess of 20
     m.p.h., and train or engine movements may
     clear main track.........................
    (b) Hand-operated switch on signaled              2,500        5,000
     siding not electrically or mechanically
     locked in normal position where signal
     not provided to govern movements to
     signaled siding, train movements made at
     speeds in excess of 30 m.p.h., and train
     or engine movements may clear signaled
     siding...................................
    (c) Approach or time locking of electric          2,500        5,000
     lock at hand-operated switch can be
     defeated by use of emergency release
     device of electric lock which is not kept
     sealed in non-release position...........
    (d) other violations......................        1,000        2,000

Rules and Instructions--

236.426 Interlocking rules and instructions           1,000        2,000
 applicable to traffic control systems........
236.476 Interlocking inspections and tests            1,000        2,000
 applicable to traffic control systems........
-----------------------------------------------
  Subpart E--Automatic Train Stop, Train Control and Cab Signal Systems
                                Standards

------------------------------------------------------------------------
236.501 Forestalling device and speed control.        1,000        2,000
236.502 Automatic brake application,                  1,000        2,000
 initiation by restrictive block conditions
 stopping distance in advance.................
236.503 Automatic brake application;                  1,000        2,000
 initiation when predetermined rate of speed
 exceeded.....................................
236.504 Operations interconnected with                1,000        2,000
 automatic block-signal system................

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236.505 Proper operative relation between             1,000        2,000
 parts along roadway and parts on locomotive..
236.506 Release of brakes after automatic             1,000        2,000
 application..................................
236.507 Brake application; full service.......        1,000        2,000
236.508 Interference with application of              1,000        2,000
 brakes by means of brake valve...............
236.509 Two or more locomotives coupled.......        1,000        2,000
236.511 Cab signals controlled in accordance          1,000        2,000
 with block conditions stopping distance in
 advance......................................
236.512 Cab signal indication when locomotive         1,000        2,000
 enters blocks................................
236.513 Audible indicator.....................        1,000        2,000
236.514 Interconnection of cab signal system          1,000        2,000
 with roadway signal system...................
236.515 Visibility of cab signals.............        1,000        2,000
236.516 Power supply..........................        1,000        2,000

Rules and Instructions; Roadway--

236.526 Roadway element not functioning               2,500        5,000
 properly.....................................
236.527 Roadway element insulation resistance.        1,000        2,000
236.528 Restrictive condition resulting from          1,000        2,000
 open hand-operated switch; requirement.......
236.529 Roadway element inductor; height and          1,000        2,000
 distance from rail...........................
236.531 Trip arm; height and distance from            1,000        2,000
 rail.........................................
236.532 Strap iron inductor; use restricted...        1,000        2,000
236.534 Rate of pressure reduction; equalizing        1,000        2,000
 reservoir or brake pipe......................
236.551 Power supply voltage..................        1,000        2,000
236.552 Insulation resistance.................        1,000        2,000
236.553 Seal, where required..................        2,500        5,000
236.554 Rate of pressure reduction; equalizing        1,000        2,000
 reservoir or brake pipe......................
236.555 Repaired or rewound receiver coil.....        1,000        2,000
236.556 Adjustment of relay...................        1,000        2,000
236.557 Receiver; location with respect to            1,000        2,000
 rail.........................................
236.560 Contact element, mechanical trip type;        1,000        2,000
 location with respect to rail................
236.562 Minimum rail current required.........        1,000        2,000
236.563 Delay time............................        1,000        2,000
236.564 Acknowledging time....................        1,000        2,000
236.565 Provision made for preventing                 1,000        2,000
 operation of pneumatic brake-applying
 apparatus by double-heading clock;
 requirement..................................
236.566 Locomotive of each train operating in         5,000        7,500
 train stop, train control or cab signal
 territory; equipped..........................
236.567 Restrictions imposed when device fails
 and/or is cut out en route:
    (a) Report not made to designated officer         5,000        7,500
     at next available point of communication
     after automatic train stop, train
     control, or cab signal device fails and/
     or is cut en route.......................
    (b) Train permitted to proceed at speed           5,000        7,500
     exceeding 79 m.p.h. where automatic train
     stop, train control, or cab signal device
     fails and/or is cut out en route when
     absolute block established in advance of
     train on which device is inoperative.....
    (c) other violations......................        1,000        2,000
236.568 Difference between speeds authorized          1,000        2,000
 by roadway signal and cab signal; action.....

Inspection and Tests; Roadway--

236.576 Roadway element.......................        1,000        2,000
236.577 Test, acknowledgement, and cut-in             1,000        2,000
 circuits.....................................

Inspection and Tests; Locomotive--

236.586 Daily or after trip test..............        2,500        5,000
236.587 Departure test:
    (a) Test of automatic train stop, train           5,000        7,500
     control, or cab signal apparatus on
     locomotive not made on departure of
     locomotive from initial terminal if
     equipment on locomotive not cut out
     between initial terminal and equipped
     territory................................
    (b) Test of automatic train stop, train           5,000        7,500
     control, or cab signal apparatus on
     locomotive not made immediately on
     entering equipped territory, if equipment
     on locomotive cut out between initial
     terminal and equipped territory..........
    (c) Automatic train stop, train control,          5,000        7,500
     or cab signal apparatus on locomotive
     making more than one trip within 24-hour
     period not given departure test within
     corresponding 24-hour period.............
    (d) other violations......................        2,500        5,000
236.588 Periodic test.........................        2,500        5,000
236.589 Relays................................        2,500        5,000
236.590 Pneumatic apparatus:
    (a) Automatic train stop, train control,          2,500        5,000
     or cab signal apparatus not inspected and
     cleaned at least once every 736 days.....
    (b) other violations......................        1,000        2,000
-----------------------------------------------
   Subpart F--Dragging Equipment and Slide Detectors and Other Similar
                      Protective Devices; Standards

------------------------------------------------------------------------
236.601 Signals controlled by devices;                1,000        2,000
 location.....................................
------------------------------------------------------------------------
\1\ A penalty may be assessed against an individual only for a willful
  violation. The Administrator reserves the right to assess a penalty of
  up to $22,000 for any violation where circumstances warrant. See 49
  CFR part 209, appendix A.


[53 FR 52936, Dec. 29, 1988, as amended at 63 FR 11624, Mar. 10, 1998]

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