Metro-North cab signals

[Messhead]

Hello,

my apologies if this has been covered here previously; I searched but couldn't find the answers.

I am trying to understand more about the cab signal system used on the Harlem Line; as I am working on a visual representation of it. Of interest to me particularly is how the system relates to the ACMU and M7 cab interiors.

I am aware that the states are displayed to the driver inside the cab somehow; and that there are wayside signals installed at interlockings. I am interested to know what are the aspects displayed on both the in-cab and wayside signals.

What does the driver see?

Anyone know of a good online resource for this kind of information?

Thanks!

Messhead

[DutchRailnut]

First there is no driver on American trains, we got locomotive engineers.

The Way side signal only has 3 aspects:
Green flashing = proceed by cab signal indication.
Red/red = stop
Red/reg alternate flashing with green = Absolute block (for cab signal failures)

The engineer has 4 cab signal aspects in cab near speedometer:
Red = restricting (15 pass/15 freight.
Yellow= Medium (30 mph pass/ 15 freight)
Yellow/green = limited (45 passenger/30 freight)
Green= normal cab ( max auth speed for pass/ 40 mph for freight)

[Messhead]

Engineers, of course. My apologies.

Excellent information, DutchRailnut, thanks a lot for that quick reply!

[Messhead]

Actually. Sorry if this is a silly question but is there no "stop" aspect on the cab signal?

[Terminal Proceed]

There is no stop indication in the cab signals.

[Messhead]

Thanks.

Hm... just trying to understand how that works. Are the trains scheduled or maybe signalled so there is always an empty block between them?

What's to stop a train entering an occupied block?

Thanks again.

~R~

[MNRR_RTC]

[quote="Messhead] What's to stop a train entering an occupied block?
~R~[/quote]

As a train gets to a closer to a block that is occupied, the cab signals downgrade in order. Everytime the cab signal downgrades, the engineer must hit the acknowledge button and slow down to the corresponding speed. Failure to do so will cause the train to go into emgency brakes and stop on its own. Once the train enters an occupied blocker, the engineer must procceed at restricted speed which is to be able to stop within one-half the range the vision of whats in front of the train. I believe with Amtrak, their ACSES (Advanced Civil Speed Enforcement System) allows for a full stop in their cab signal apparatus.

[Penn Central]

As a train gets to a closer to a block that is occupied, the cab signals downgrade in order. Everytime the cab signal downgrades, the engineer must hit the acknowledge button and slow down to the corresponding speed. Failure to do so will cause the train to go into emgency brakes and stop on its own. Once the train enters an occupied blocker, the engineer must procceed at restricted speed which is to be able to stop within one-half the range the vision of whats in front of the train. I believe with Amtrak, their ACSES (Advanced Civil Speed Enforcement System) allows for a full stop in their cab signal apparatus.

Failure to adhere to the cab signal speed will not put the train in emergency (unless there is a slip slide situation, but that's another topic), the automatic train control (ATC) will apply a penalty application which is the same as full service. The penalty application on M-series cars can be quickly reset without stopping by going to b-max or coast (M-7). Even on a Genesis engine, a running recovery is possible except at slow speeds.

Nothing stops a train from entering an occupied block, unless there is a control point with a signal at the entrance to that block. The following train will get a restricted cab in the previous block so that it will follow the first train at restricted speed prepared to stop. It would look like this:

TRAIN2 Normal | Limited | Medium | Restr. | TRAIN1

Another correction: While the maximum ATC freight speed on Metro-North equipment is 45, the top freight speed on the Hudson Line is 50. CSX and CP equipment can and do operate at 50 on Metro-North tracks.

[abaduck]

As a train gets to a closer to a block that is occupied, the cab signals downgrade in order. Everytime the cab signal downgrades, the engineer must hit the acknowledge button and slow down to the corresponding speed. Failure to do so will cause the train to go into emgency brakes and stop on its own. Once the train enters an occupied blocker, the engineer must procceed at restricted speed which is to be able to stop within one-half the range the vision of whats in front of the train.

Hmmm. So just to get this straight (for the benefit of an ignorant foreigner), there's no absolute block (based on a fixed space interval) on US railroads - or at least MNCR anyway? That is, unless the stationary train happens to be under protection of fixed lineside signals, the only protection against a train coming up the rear is the engineer of the rear train correctly obeying the 'restricted' rules and stopping in time?

Not criticising the US way of doing things (since it obviously works from the number of people you move safely every day), just trying to learn

Mike

[Penn Central]

Hmmm. So just to get this straight (for the benefit of an ignorant foreigner), there's no absolute block (based on a fixed space interval) on US railroads - or at least MNCR anyway? That is, unless the stationary train happens to be under protection of fixed lineside signals, the only protection against a train coming up the rear is the engineer of the rear train correctly obeying the 'restricted' rules and stopping in time?

Not criticising the US way of doing things (since it obviously works from the number of people you move safely every day), just trying to learn
Mike

We are only talking about Metro-North here, Mike. In Manual Block territory, trains have an absolute block, and trains with a train control apparatus (cab signal) failure get an absolute block. In their last rulebook, Metro-North allowed trains to proceed into an occupied block with a train control apparatus failure at restricted speed with the permission of the RTC. This proves very helpful at points where there are short blocks and trains bunch up. Remember that it is the block before the occupied block that displays the restricting signal, so trains are separated in that manner. There are no "lineside" signals on Metro-North except at control points.

Another thing that makes this a safe system is that restricted speed on Metro-North is not exceeding 15 mph, not 20 like on other systems. Engineers know that at restricted speed, they are "holding the bag" and are responsible for stopping short of a train or obstruction.

In the US, there are four types of signal systems:

Manual Block or DCS; movement of trains by written orders
Automatic Block or TCS; movement of trains by wayside signals
Automatic Block with CABS; movement of trains by wayside signals and CABS
CABS without wayside signals; movement of trains by cab signals only with wayside signals at control points (Metro-North system)

New systems being developed include a moving block that allows following trains to proceed faster with real-time information on the train in front of it. The lead train slows down, the brakes on the following train apply.

[Erie-Lackawanna]

And, keep in mind that on railroads with fixed wayside signals at locations other than interlockings (automatic signals, we call 'em), an all red aspect is called "Stop and Proceed", and conveys the indication "Stop, then proceed at restricted speed". So even with a wayside signal system, usually only at controlled points (interlockings) do you have to stop and stay.

Obviously, there are exceptions, but that's the general rule in North America.

Jim

[Noel Weaver]

This does NOT apply anywhere on Metro-North but is generally related to
the topic at hand, on CSX in territory controlled by automatic block signals
and CTC, at an automatic signal (of course not interlocking, home or CP
signals) trains no longer stop for red automatic signals. They are now
shown as "RESTRICTED PROCEED" and a "G" marker no longer will
change nor affect the indication of the signal.
I haven't heard of any other railroads doing this yet.
Noel Weaver

[abaduck]

Thanks guys, this is really interesting - though starting to drift off-topic for MNCR. 'Stop and Proceed' is a phrase known to Brit railroaders too - but only in the context of passing a *failed* automatic signal, not as an everyday rule for working.

SPAD (Signal Passed At Danger) is a phrase that's been much-used in the UK recently due to a couple of bad accidents resulting from engineers not observing signals and proceeding anyway - though the worst of these was at an interlocking where it would have been a 'stop means STOP and STAY' on any railroad in the world. This has led to an emphasis on ATC systems which take control and won't let a train pass a signal at danger - seems kinda the opposite of the MN/CSX approach, which is to give the engineer ultimate responsibility for driving safely.

Mike

[Stephen B. Carey]

Just a random question that seems on topic, I have always been wondering "about" how long is a track block? For this instance I am just asking about Metro-North since I know that the blocking distance changes on other railroads.

[Erie-Lackawanna]

The quick answer is, it depends.

On location, physical characteristics, traffic density.

Can't make a one-size-fits -all rule, even on one railroad.