Crazy question to ask about commuter trains

[tjemartin]

Hello,

I've never been on a commuter rail train except for a GO train in Toronto, ON. I usually take Amtrak from Niagara Falls, ON to Wilmington, DE to visit friends and family in that area. When going through the NYC area, sometimes I'll see a commuter train go overly fast in reverse.

I know trains can go in either direction, but if a commuter train is going so fast in reverse, how is it the engineer/conductor(sorry I'm a little rusty on the exact terminology) can see where the train is going with so many cars that hooked up behind (or in this case in front of the engine). To me it looks like an accident waiting to happen

 

[SarahZ]

When trains run like that, it's called "push-pull". They use a control car/cab car.

http://en.wikipedia.org/wiki/Control_car_(rail)

 

[TinCan782]

Many commuter trains (and Amtrak's Pacific Surfliner) operate in "push-pull" operation. When in "reverse" the engineer is controlling the train from the front in a cab car. He can see ahead of the train just like when he is in the locomotive going "forward".

 

[the_traveler]

When you see a commuter train going fast in the opposite direction, most times it will have a locomotive on one end (say the north) and a "cab car" on the other(say the south). If the train is going north, the engineer operates the train from the locomotive. If the train is going south, the engineer controls the train from the cab car.

 

[fairviewroad]

Many commuter trains (and Amtrak's Pacific Surfliner) operate in "push-pull" operation. When in "reverse" the engineer is controlling the train from the front in a cab car. He can see ahead of the train just like when he is in the locomotive going "forward".

Some other Amtrak "push-pull" routes include the Keystone corridor trains and the New Haven/Springfield shuttles.(I'm sure there

are others)

The Cascades Corridor train use a variation on the "push-pull" method, but in those cases the cab control car has the outward appearance of an engine...so it doesn't look like the train is going in reverse. In this photo, the "engine" on the left is actually a cab control car.

Another variation on the "push-pull" method is where both ends of the train are cab control cars. This photo is old, but the principal holds

true today for some commuter operations. This method is usually used with electric power, but can also be found on so-called Rail Diesel

Cars. In these cases, there is no "engine" as such...the motive power is either gathered from the overhead electric wires or from a motor embedded in the RDC car.

 

[MikefromCrete]

GO Transit uses a push-pull operation, so you should be familiar with that. As every has said when the train is in push mode, the engineer sits in a cab control on the last passenger car and runs the train from there.

 

[Bob Dylan]

While not a Commuter Train, Amtrak's State Supported (Texas and Oklahoma)Heartland Flyer between FTW and OKC operates with a P-42 on each end of the consist since there is no Y to turn the train on its daily runs between the 2 Cities!

 

[tjemartin]

GO Transit uses a push-pull operation, so you should be familiar with that. As every has said when the train is in push mode, the engineer sits in a cab control on the last passenger car and runs the train from there.

I was only on a GO train once and wasn't paying much attention, I know maybe I should have been though.

 

[TinCan782]

Another version of push-pull that does not involve a cab car is the use of a "cabbage"...a locomotive that has been gutted of the power but still has the controls in the cab. The space where the diesel engine was is now used for baggage. A conventional locomotive is used at the other end. At first glance, the train appears to have a locomotive at each end.

 

[TinCan782]

Cab+baggage = cabbage. Formal name Non-powered Control Unit or NPCU

 

[Anderson]

As has been said, most of those trains will have a cab car on the non-locomotive end, and are operating in "push" mode where the cab car has the engineer (who is controlling the engine from it). This is distinct from a "shove" move where the engineer is in the locomotive and is moving the train in reverse under the direction of the conductor (who will be near the other end of the train, usually leaning out a door). This can only be done at a fairly low speed, usually with special permission from dispatch, and that's what you were probably thinking of when you were wondering how the trains were moving so fast in "reverse". So when push comes to shove...

*rimshot*

 

[MetraUPWest]

If you look between the passenger cars, there is an electric cable called an MU cable which runs between each one of them. The MU cable allows the locomotive to be controlled from the cab car at the "rear" of the train. There are also brake hoses which send air the engine produces to the cab car for the braking system.

Here is the cab of a Metra cab car- our cabs are on the upper level- you can see the door leading into the cab if you sit up there. The cab car controls are very similar to the locomotive- the cab is just a lot smaller.

 

[George Harris]

If you look between the passenger cars, there is an electric cable called an MU cable which runs between each one of them. The MU cable allows the locomotive to be controlled from the cab car at the "rear" of the train. There are also brake hoses which send air the engine produces to the cab car for the braking system.

Here is the cab of a Metra cab car- our cabs are on the upper level- you can see the door leading into the cab if you sit up there. The cab car controls are very similar to the locomotive- the cab is just a lot smaller.

Generally engineers prefer these upper level cabs instead of one at the normal level it is on single level equipment. Main reason: That way if you hit something you are more likely to be going over it instead of wearing it.

 

[MetraUPWest]

^Absolutely!!!

 

[strangebrew]

UTA's FrontRunner is also push pull. The train arriving at this station in the begining is in push operation. The operator is at the very front of the first car coming into the platform. I didnt look, but you might be able to see the operator if you can get past the light glare.

https://www.youtube.com/watch?v=aZfszZqR7i4

 

[VentureForth]

I would have thought that "push" mode would be inherently unstable. I'm sure that it is certainly dangerous if there is something that the cab car would get stuck on and the loco kept going...

But GO has been operating these for decades without any issue, so I suppose they're safe. But I still contend that it is more efficient, and perhaps faster, to distribute the power like a DMU or EMU.

 

[MetraUPWest]

Cab cars weigh over 100,000 pounds- nothing is going to get them stuck

That being said, if I were given a choice I would MUCH rather hit something with the locomotive.

 

[BCL]

I would have thought that "push" mode would be inherently unstable. I'm sure that it is certainly dangerous if there is something that the cab car would get stuck on and the loco kept going...

But GO has been operating these for decades without any issue, so I suppose they're safe. But I still contend that it is more efficient, and perhaps faster, to distribute the power like a DMU or EMU.

I remember for a Metrolink collision, the push configuration was sometimes cited as a reason why the damage was so high.

Any obstruction on the track can be pretty destructive. I remember the San Joaquin train that collided fell on its side, and that was in pull mode.

As for what these things look like, I found a photo of an Amtrak California cab car next to a Caltrain cab car:

The horn on the California car is under the door and the engineer is visible in this photo.

 

[Green Maned Lion]

Those Metrolink cars were Bombardier bi levels. Their structural integrity is questionable. Other cab cars not so much.

 

[MetraUPWest]

That Caltrain car posted is a Nippon Sharyo which are what Metra in Chicago uses. They're built pretty sturdy. The cab photo I posted earlier in the thread is the same type as the Caltrain.

 

[Green Maned Lion]

Iunno about you, but I prefer my Sharyos to be kinki.

 

[fairviewroad]

Interesting that both of the cab cars in that photo appear to be configured to allow them to be hooked up end-to-end with another coach car.

That would seem to be unnecessary if they were always used as cab cars. But I suppose it gives the operator the flexibility when using the

train in pull mode to hook up additional cars at the end of the train. Wonder how often that happens, that a cab car is stuck in the middle

of a series of non-cab-car coaches?

 

[Green Maned Lion]

NJT frequently runs trains loco-cab-trailers-cab

 

[MattW]

Interesting that both of the cab cars in that photo appear to be configured to allow them to be hooked up end-to-end with another coach car.

That would seem to be unnecessary if they were always used as cab cars. But I suppose it gives the operator the flexibility when using the

train in pull mode to hook up additional cars at the end of the train. Wonder how often that happens, that a cab car is stuck in the middle

of a series of non-cab-car coaches?

It gives the railroad a lot more flexibility when sizing consists for demand. Let's say a railroad rain 8-car trains during the rushes, but 4-car trains off-peak. If they ran them cab-coach-choach-coach-coach-coach-coach-coach-locomotive, they would have to switch around he whole consist either at the terminal or the yard. If instead they ran them cab-coach-coach-coach-cab-coach-coach-coach-locomotive, all they have to do is uncouple the connection between the middle cab car and "trailing" coach. There's really no reason not to enable them to interface with other cars, I doubt it adds any to the cost, and may actually cost more to have it removed, but I'm guessing here.

 

[BCL]

NJT frequently runs trains loco-cab-trailers-cab

BART in the San Francisco Bay Area used to only operate "A cars" (with a slanted cab and only one linking door) and "B cars" which were only meant as middle cars. So a setup had to be two A cars on the ends and anywhere from one to eight B cars in the middle. When new orders came out in the 80s, they decided that they would only be "C cars" which had a cab on one side and a door on the other. It still got complicated because two C cars wouldn't couple unless the cabs were pointed in the same direction. There was also controversy over the manufacturers, where Morrison-Knudsen was selected as a second source.