Metro North Train Control Systems

[Gilbert B Norman]

While likely this inquiry has been made elsewhere at the Forum, but in light of Spuyten Duyvil, could someone with knowledge outline what train control systems presently exist through the MNR system, so that such is all available at one topic. Also of interest would be to what extent, if at all, would an existing system be considered compliant with 'Positive Train Control' under RSIA 08.

Example (and this may no longer be the case) New Canaan Branch is 'Timetable' and not compliant with PTC.

Thanks for the help; especially if such comes from those around here who are Rules Qualified and have access to an ETT.

Oh and a final off topic note. To 'graduate' from Third Grade at Cos Cob School, one was required to properly spell 'Spuyten Duyvil'.

[Jersey_Mike]

While likely this inquiry has been made elsewhere at the Forum, but in light of Spuyten Duyvil, could someone with knowledge outline what train control systems presently exist through the MNR system, so that such is all available at one topic.

Signaled portions of Metro North are equipped with a continuous Cab Signaling System (CSS) that makes use of coded track circuits 4 possible cab signal indications (3+no code) to trains. The indications are Restricting, Medium Speed, Limited Speed and Normal Speed. An on board Automatic Train Control device takes the cab signal inputs and applies speed limits of 20, 30, 45 and 90mph for each of the cab signal indications respectively which is enforced by means of a penalty brake application if an overspeed state persists. Moreover any change in cab signal indication from a less to a more restrictive state requires the Engineer to acknowledge an audible alarm. The Cab Signaling System and ATC are designed to prevent train to train collisions and enforce speed restricted routes at interlockings.

Also of interest would be to what extent, if at all, would an existing system be considered compliant with 'Positive Train Control' under RSIA 08.

It wouldn't as it does not (normally) enforce permanent or temporary speed restrictions or enforce a full stop at Stop signals. However the current CSS is a necessary component for the intended ACSES PTC system to be compliant as a PTC system.

The remaining branch lines which are not signaled are run under track warrant control which other people can get into.

If you want full details here is a copy of MNRR's PTC implementation plan from 2010 which also contains a complete signaling and line schematic for the entire railroad.

[lirr42]

Mr. Norman, I quickly whipped up this map showing (*more or less*) what territory is what.

Basically, there's only three different types:
BLUE == Centralized Train Control/Cab Signal System (CTC/CSS)
GREEN == Interlocking Rules/Cab Signal System (IR/CSS)
YELLOW == Manual Block Signaling

(Click for slightly larger image)

[EDM5970]

So, the radar speed detection alarm system feeding into the CSS that I suggested maybe six pages ago on the other thread is feasable; should not be too much of a problem for a good C&S engineer to put together. I would imagine that if it worked well in test the FRA would certify it in a heartbeat.

[Clean Cab]

The current cab signal system only downgrades if a train is being switched to another track, following another train or approaching the end of a main line track.

[EDM5970]

So its not really continuous, but the code can only be changed at specified points? I guess I misunderstood the term continuous... An attorney friend said something the other day about returning to smashboards; maybe its time.

[RearOfSignal]

So its not really continuous, but the code can only be changed at specified points? I guess I misunderstood the term continuous... An attorney friend said something the other day about returning to smashboards; maybe its time.

No it's continuous, a cab signal can change at any point in CSS territory. Upgrade or downgrade.

[Head-end View]

On Metro-North, will the train dump if the engineer either fails to acknowledge the audible alarm for a code-drop, and/or if he fails to slow the train as required by the code-drop? I assume it will dump as on LIRR, but I don't want to take anything for granted as different systems operate differently.

[truck6018]

On Metro-North, will the train dump if the engineer either fails to acknowledge the audible alarm for a code-drop, and/or if he fails to slow the train as required by the code-drop? I assume it will dump as on LIRR, but I don't want to take anything for granted as different systems operate differently.

You will get a penalty brake application. It's not dumping the brake pipe.

[Clean Cab]

On Metro-North, will the train dump if the engineer either fails to acknowledge the audible alarm for a code-drop, and/or if he fails to slow the train as required by the code-drop? I assume it will dump as on LIRR, but I don't want to take anything for granted as different systems operate differently.

Once the engineer gets a cab signal downgrade, they have 6 seconds to acknowledge and apply the brakes at a rate sufficient to achieve the appropriate amount of deceleration. Failure to either acknowledge of get on enough brakes will result in a penalty brake application.

[Jersey_Mike]

So its not really continuous, but the code can only be changed at specified points? I guess I misunderstood the term continuous... An attorney friend said something the other day about returning to smashboards; maybe its time.

It's continuous, but the logic uses fixed blocks. You can rig up some things with timers and the LIRR has a few of those, but that is considered to be a less optimal solution.

[RearOfSignal]

On Metro-North, will the train dump if the engineer either fails to acknowledge the audible alarm for a code-drop, and/or if he fails to slow the train as required by the code-drop? I assume it will dump as on LIRR, but I don't want to take anything for granted as different systems operate differently.

You will get a penalty brake application. It's not dumping the brake pipe.

Not so sure about that... I've had the air dump plenty of times because the engineer can't get down in time. Ever see BL20's moved light at night by passenger crew with interior cab lights on. Took me a while to figure out why the lights came on and how to turn them off the first time that happened.

"The engine is going crazy, it keeps dumping and the lights won't turn off!"

[truck6018]

Ever see BL20's moved light at night by passenger crew with interior cab lights on. Took me a while to figure out why the lights came on and how to turn them off the first time that happened.

"The engine is going crazy, it keeps dumping and the lights won't turn off!"

Ok, you got me there. Been there done that!