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GCOR - Blocks


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9.1 Signal Aspects and Indications

Distant, block, and interlocking signal aspects and indications are shown in the special instructions.

Signal aspects are identified by the position of semaphore arms, color of lights, flashing of lights, position of lights, or any combination. Aspects may be qualified by marker plate, number plate, letter plate, or marker light.

Signals may display color light aspects or semaphore arms and color lights.

9.2 Location of Signals

When viewed from the train, block and interlocking signals are generally to the right of the track. However, they may be located to the left or above the track. To display indications for two tracks, two bracketed signals may be located on a supporting mast. The signal to the right governs the track to the right, and the signal to the left governs the track to the left.


9.3 What Signals Govern

Block signals, cab signals, or both govern the use of blocks.

Interlocking signals govern the use of interlocking routes. Where a track is signaled beyond the interlocking limits in the direction of movement, the interlocking signal is also a block signal.

Image All other rules, where required, remain in effect when complying with the indication of block and interlocking signals.

9.4 Improperly Displayed Signals or Absent Lights

Except as shown in block, cab, and interlocking signal aspects in the special instructions, if a light is absent or a white light is displayed where a colored or lunar light should be, regard a block or interlocking signal as the most restrictive indication that the signal can give. However, when the semaphore arm position is plainly seen, that aspect will govern.

9.5 Where Stop Must Be Made

When movement is being made beyond a block signal requiring a train to be prepared to stop at the next signal, the stop must be made before any part of a train passes the block signal requiring the train to stop.

If a train overruns any block signal that requires it to stop, the crew must:


9.5.1 Changing Established Route

Except to avoid an accident, after a controlled signal has been cleared for a closely approaching train, the control operator must not change the signal before the approaching train's engineer has assured the control operator that he can comply with the signal change. Do not establish or authorize a conflicting route until communicating with the approaching train's crew and ensuring that the train has stopped clear of the conflicting route.

The control operator must not establish a conflicting route into an occupied block or interlocking limits, or authorize a conflicting movement, unless it is safe to do so.

The control operator must avoid operating the device controlling a switch, derail, movable point frog, or lock when any portion of a train is on or closely approaching the equipment.

9.5.2 Protection if Signal Appliance or Track Is Damaged

If a signal or signal appliance functions improperly or the track is damaged, signals that govern movements on affected routes must display a Stop indication. No movements on such routes may be permitted until track and signal appliances are examined and movement can occur safely.

9.5.3 Protection During Repairs

Within CTC limits or within manual interlocking limits (unless track bulletin Form B is in effect), when a switch, movable point frog, derail, or signal is under repair or is disconnected, or when the track is obstructed or removed from service, display Stop indications for all affected routes. In addition, block or mark any controls to prevent their operation.

Maintenance forces must contact the control operator before beginning repairs, disconnecting equipment, obstructing the track, or removing the track from service. Switches, movable point frogs, and derails must be spiked or secured in the required position if any movement over them occurs before repairs are complete.

9.5.4 Authority to Proceed

Except when a signal is used to provide protection within CTC limits or at manual interlockings, control operators must not give hand signals or verbally authorize movement beyond a Stop indication when a proceed indication can be displayed for the movement.

At manual interlockings, control operators must give hand signals so that crew members can understand the signals and know which train they are intended for.

9.5.5 Reporting Delays

When a controlled signal displays a proceed indication, notify the control operator immediately if movement cannot occur promptly.

9.5.6 Track Occupancy Indicator

Where track occupancy indicators are located, employees must observe the indication before fouling a circuit or changing the derail or a main track switch.

When an occupied indication is displayed, trains or equipment must not foul the main track unless movement is properly protected.

Track occupancy indications do not authorize movement or relieve employees from protecting movements as required by the rules.

9.6 Change of Signal Indication

If a signal displaying a proceed indication changes to an indication requiring a train to stop, the train must stop at once. Report such a signal change to the train dispatcher.

9.7 Failure to Display Most Restrictive Indication

When a block is occupied, or when a switch protected by a signal is changed from its normal position and that signal fails to display its most restrictive indication, regard the signal as displaying Stop. The train must stop immediately, and employees must warn others by radio of the exact location and status of the train. Contact the train dispatcher or control operator and do not move the train without permission.

9.8 Next Governing Signal

A train may comply with the next signal's indication when its aspect can be clearly seen and the signal governs the track where movement is occurring or will be made. This does not apply when a rule or previous signal indication requires movement at restricted speed.

9.9 Train Delayed Within a Block

If a train has entered a block on a proceed indication that does not require restricted speed, and the train stops or its speed is reduced below 10 MPH, the train must:


Proceed at restricted speed. The train must maintain this speed until the next signal is visible, that signal displays a proceed indication, and the track to that signal is clear.

Image B. CTC or Manual Interlocking Limits

Proceed prepared to stop at the next signal until the next signal is visible and that signal displays a proceed indication.


Operate according to cab signal indication.

9.9.1 Passing Approach to Automatic Interlocking

A train must proceed prepared to stop at the interlocking signal when:

The train must continue to move prepared to stop at the interlocking signal until the train reaches a point approximately 1,000 feet from that signal. If the interlocking signal then indicates proceed, the train may resume speed.

9.10 Initiating Movement Between Signals

When one of the following occurs, move at restricted speed until the leading wheels have passed the next governing signal or the end of the block system:

Image Exception

If a train is within ACS territory and a cab signal device is cut in and operative, the train may operate according to the cab signal indication after moving a distance equal to its own length or to the next governing signal.

9.11 Movement from Signal Requiring Restricted Speed

When a train passes a signal requiring movement at restricted speed, the train must move at restricted speed until its leading wheels have passed the next goveming signal or the end of the block system.

9.12 Stop Indications

9.12.1 CTC Territory

At a signal displaying a Stop indication, if no conflicting movement is evident, the train will be governed as follows:


Conflicting Movement. When the control operator has stopped a conflicting movement, he may then authorize another train to proceed in the same limits, advising both crews of movement to be made. If the stopped movement is later permitted to proceed, that train must move at restricted speed until its leading wheels have passed the next governing signal or the end of the block system.

9.12.2 Manual lnterlockings

At a signal displaying a Stop indication, if no conflicting movement is evident, the train will be governed as follows:


Conflicting Movement. When the control operator has stopped a conflicting movement, he may then authorize another train to proceed, advising both crews of movements to be made. If the stopped movement is later permitted to proceed, that train must move at restricted speed until its leading wheels have passed the next governing signal or the end of the block system.

9.12.3 Automatic lnterlockings

At a signal displaying a Stop indication, the crew will be governed by instructions in the release box, special instructions, or other instructions.

If there is a conflicting movement, the train must not proceed until the movement has passed or stopped, and both crews agree on the next movement.

9.12.4 ABS Territory

At a signal displaying a Stop indication outside interlocking limits, the train will be governed as follows:

A. Main Track

On a main track, after stopping, a train authorized beyond the signal must comply with one of the following procedures:

  1. If authority beyond the signal is joint with other trains or employees, proceed at restricted speed.
  2. Proceed at restricted speed when a crew member has contacted the train dispatcher and obtained permission to pass the Stop indication. However, if the train dispatcher cannot be contacted, move 100 feet past the signal, wait 5 minutes, then proceed at restricted speed.

    B. Siding or Other Track

    If the signal governs movements from a siding or other track to the main track, comply with Rule 9.17 (Entering Main Track at Hand-Operated or Spring Switch).

    9.13 When Instructed to Operate Dual Control Switches by Hand

    If the control operator cannot line the dual control switch to the desired position, or the control machine does not indicate that the switch is lined and locked, the control operator must authorize movement past the Stop indication and instruct the employee to operate the switch by hand. Movement may then proceed to that switch.

    Before passing over the switch, the train must stop and the employee must operate the switch by hand as outlined in Rule 9.13.1 (Hand Operation of Dual Control Switches). After at least one unit or car has passed over the switch points, the employee must return the switch to power unless otherwise instructed by the control operator.

    9.13.1 Hand Operation of Dual Control Switches

    An employee must get permission from the control operator to operate a dual control switch by hand. Operate the switch as follows:

    • Unlock the switch lock.
    • Place the selector lever in the HAND position or remove the hand crank from the holder.
    • Operate the hand throw lever until the switch points are seen to move when the lever is operated, even if the switch is lined for the intended route.
    • Line the switch for the intended route, or insert the crank on the shaft and turn the crank as far as it will turn until the switch is in the desired position. Remove the crank from the shaft, but do not return it to the crank holder.
    • Return the switch to power by restoring the selector lever to the POWER or MOTOR position and lock. Or, return the crank to the holder and secure it with the switch lock. Notify the control operator after power to the switch is restored.

    When the selector lever is in the HAND position or the crank has been removed from the holder, signals governing movements over the switch will display Stop indication, and movements will be governed by hand signals. Notify the engineer, if possible, when the switch is in hand operation and when it has been restored to power operation.

    9.14 Movement with the Current of Traffic

    On tracks designated in the timetable, trains will run with the current of traffic, if the train dispatcher gives verbal authorization or a controlled signal indicates proceed.

    9.14.1 Reporting Clear of a Track Having a Current of Traffic

    A train without a crew member on the rear and operating on a track having a current of traffic may report clear of the limits or report having passed a specific location only when it is known the train is complete. This must be determined by one of the following ways:

    • The rear of the train has a rear-end telemetry device, and air pressure on the head-end device indicates brake pipe continuity.
    • An employee verifies the marker is on the rear of the train.
    • A crew member can observe the rear car of the train on which the marker is placed.
    • The train is stopped and an inspection verifies that the marker is on the rear car of the train.
    • A trackside warning detector transmits an axle count for the train, and axle count duplicates the axle count transmitted by the previous trackside warning detector.

    In addition, a train clearing in a siding or other track must comply with requirements outlined in Rule 8.3 (Main Track Switches) before reporting clear of the limits.

    9.15 Track Permits

    On tracks designated in the timetable, a track permit will authorize a train, track car, machine, or employee to occupy the main track or tracks between specific points. The track permit must be issued by a designated control operator under the direction of the train dispatcher. Within these limits, movements may be made in either direction without flag protection.

    Except at interlockings, trains granted a track permit, after stopping, may pass a signal displaying a Stop indication to enter limits without further authority.

    9.15.1 Issuing Track Permits

    The track permit may only be issued when:

    • Limits are clear.
    • Limits are occupied by the train, track car, machine, or employee that will receive the track permit.
    • Limits are occupied by a train, track car, machine, or employee holding a track permit.
    • All trains moving on signal indication without a track permit have passed the location where the track will be fouled.

    The track permit limits must be protected by controlled signals. The designated control operator must know the following before issuing a track permit:

    • Each controlled signal protecting the limits displays a Stop indication.
    • Marking or blocking devices prevent displaying signals for movement into the limits.
    • The designated control operator and each control operator who controls signals to protect the limits understand the limits, have provided protection, and have recorded the track permit on the prescribed form.

    Track Permit Wording

    Track permits will be granted in the words, "Track permit granted on (track) between (limit) and (limit) until (time)."

    The employee requesting a track permit must repeat the permit and receive acknowledgment before acting upon it.

    More than One Track Permit

    If more than one track permit is in effect at any time within the same limits, all affected trains or employees must be notified.

    Trains must move at restricted speed within these limits

    9.15.2 Clearing Track Permits

    Marking or blocking devices must not be removed until the track permit has been released to the control operator. Other movements must not be authorized into the limits unless also granted a track permit.

    Track permit limits must be cleared and reported clear to the control operator before time expires. If the track permit is released before time expires, all equipment must be clear of the limits and reported clear to the designated control operator. However, if no other track permit has been granted within the same limits, the train may request release of the track permit. Signal indications will then govern the train if the control operator verbally authorizes the release, specifying direction of movement if required.

    The employee must request any additional time before the authorized time has expired. If the employee is not clear when the time expires or if the control operator cannot be contacted, authority is extended until the control operator is contacted.

    9.16 Stop and Proceed Indication

    At a signal displaying a Stop and Proceed indication, the train will be governed as follows:

    1. The train must stop, then proceed at restricted speed.
    2. The train may pass the signal at restricted speed without stopping to do any of the following:

      a. Leave the main track when the switch is lined for movement and the track is clear from the signal to the clearance point. Image

      b. Continue on the main track when meeting or passing a train, and the main track is clear to the opposite end of the siding where a train is fouling the main track. Image

      c. Permit an engine, with or without cars, to couple to its train or to a standing cut of cars, if the track between the engine and cars is clear. Image

      d. Enter a switch that is less than 1,000 feet beyond the signal, and the employee in charge of the switch has granted permission for movement. Image

      e. Proceed from a Stop indication in CTC territory, when authorized by the control operator as prescribed in Rule 9.12.1 (CTC Territory). This will apply to each succeeding signal displaying a Stop and Proceed indication. Image


      f. Move within track and time, work and time, work between, or track permit limits. Image

    9.17 Entering Main Track at Hand Operated or Spring Switch

    Within CTC territory and manual interlocking limits, the control operator must authorize the train to enter the main track at a hand-operated or spring switch where no governing signal exists. The control operator must verify that there are no conflicting movements before giving the authority.

    In ABS territory, when authorized to enter the main track, a crew member or switch tender must open the switch and wait 5 minutes at the switch to establish block signal protection. If at the end of 5 minutes the employee does not hear or see movement approaching, the train may enter the main track.

    A. When Hand Operation of a Spring Switch or 5 Minute Wait Is Not Required

    Waiting 5 minutes or operating the spring switch by hand is not required [unless prescribed by Rule 8.9 (Movement over Spring Switches)] under any of the following conditions:

    1. Switch is equipped with an electric lock.
    2. Track occupancy indicator indicates track is clear.
    3. Block signal governing movement to main track indicates proceed.
    4. Block signals governing movements on the main track indicate that no train is approaching from either direction. Image

    5. Block to be entered is occupied by a train, engine, or car that is standing or moving away from the switch to be used. Image

    6. Main track between siding switches is occupied by a train that has been met or a standing train that will be passed. Image

    7. Train is entering a main track outside of yard limits for authorized movement against the current of traffic.
    8. Rule 6.14 (Restricted Limits) is in effect, provided movement does not occur beyond restricted limits for 5 minutes after the main track circuit is fouled, unless a block signal displays a proceed indication.
    9. Work and time authority is granted within DTC.
    10. Track permit authorizes movement.
    11. Track warrant outside yard limits authorizes "WORK BETWEEN" two specific points.

      9.18 Electrically Locked Switches and Derails

      Special instructions or instructions posted near the switch will govern the operation of switches and derails equipped with electric locks.

      To enter a main track within interlocking or CTC limits, employees must not open the case door or unlock an electrically locked switch or derail without track and time or authority from the control operator. Emergency Release

      If the electric lock includes an emergency release, do not break the seal on the release or operate the release without permission from the control operator or train dispatcher. However, when communication has failed, the seal may be broken and/or the release operated:

      • To permit a train to leave the main track.
      • To permit a train that has authority to enter the main track. Train must not enter the main track until 5 minutes after the seal is broken and/or the release operated.

      Notify the control operator or train dispatcher when the seal has been broken and/or the emergency release operated.

      9.19 Leaving Equipment in Interlockings

      Engines, cars, or equipment must not be detached and left standing entirely between the opposing interlocking signals that govern movements at a railroad crossing at grade.


      9.20 Clear Track Circuits

      A train, engine, car, or equipment left standing on sidings or other tracks must be clear of insulated joints at clearance points.

      9.21 Overlap Circuits

      Overlaps may be identified by overlap signs. A train on the main track at a meeting point must not pass an overlap sign location or open a switch within the overlap until the opposing train has entered the block. Image A preceding train must clear the overlap as soon as possible to avoid delaying a following train.

      9.22 Standing on Sanded Rail

      Do not allow an engine with less than three cars, or cuts of four cars or less, to stand on a sanded rail.

      9.23 Suspension of Block System

      When authorized, a track bulletin may suspend the block system or sections of it.

      Do not suspend the block system or sections of it until all trains and control operators in the affected territory have been notified by track bulletin specifying the limits of the suspension.

      Track bulletins issued to suspend the block system must not be delivered to trains entering the affected territory until the affected limits are clear of trains, or until the track bulletin has been transmitted or delivered to all trains within the limits.

      9.23.1 Guidelines While Block System Is Suspended

      When the block system or sections of it are suspended, the following guidelines govern:

      • Employees must follow rules that apply to nonsignaled territory.
      • Trains must receive a track bulletin prescribing speed restrictions that do not exceed 59 MPH for passenger trains or 49 MPH for other trains.
      • Trains will disregard extinguished or illuminated block and interlocking signals except where:
        • Signals govern movements over railroad crossings at grade or drawbridges.
        • Signals are connected with trackside warning detectors.

      Trains must approach the block and interlocking signals excepted above and each end of the suspended limits prepared to stop. Trains that leave the limits and move into block system territory must move at restricted speed until they reach the first signal in service beyond the limits. Signals that govern movement over railroad crossings at grade and drawbridges must be regarded as displaying a Stop indication, regardless of the aspect displayed, unless the track bulletin specifies that the signals are in service.

      If the crew does not know that signals governing movement over railroad crossings at grade are in service, the crew must provide flag protection in each direction on conflicting routes before proceeding over the crossing. Crew members must not rely on time release or key controller operation as adequate protection while moving over the crossing, unless they are instructed otherwise.

      • On multiple main tracks, a track bulletin will designate the track or tracks the block system is suspended on. A track bulletin that specifies the track to be used will be issued to each train.
      • Where automatic crossing warning devices have been affected, action to be taken will be stated in the track bulletin.
      • Dual control switches on the main track will be lined and locked for main track movement. Switches equipped with selector levers will be locked in the HAND position. All other dual control switches will be spiked. All concerned will be notified. Until informed by the train dispatcher, trains must stop and inspect dual control switches, foul the circuit, and make sure the switch is properly lined before passing over it.

      A track bulletin must be issued that specifies which position dual control switches at the end of double track or multiple main tracks are to be left lined.

      If a crew member receives notification from the train dispatcher of the position of dual control switches, leave those switches in that position after use.

      • Spring switches that will be removed from service must be spiked and those concerned notified.

      If spring switches are left in service, trains making facing point movements must be prepared to stop, unless it is known that the switch is properly lined.

      9.24 Call Lights

      When a call light is on, any employee who sees it, unless the employee is on a moving train, must contact the control operator immediately.

      Next Chapter - CTC Rules

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