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2 Engines

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Guest Sandra

On long distance trains like the Empire Builder, do both engines pull even when on flat terrain? Or just on inclines? Also, how is the second engine controlled? I could ask the question why second engine is always backwards but I'm guessing it's because the "hook ups" are in the back...no way to hook the back of one engine to the front of another.

 

I hope these aren't stupid questions

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1349232496[/url]' post='397355']

On long distance trains like the Empire Builder, do both engines pull even when on flat terrain? Or just on inclines? Also, how is the second engine controlled? I could ask the question why second engine is always backwards but I'm guessing it's because the "hook ups" are in the back...no way to hook the back of one engine to the front of another.

 

I hope these aren't stupid questions

 

I'll try and take these one at a time-first, usually both engines are "on line" and putting out power when needed, though the engineer can certainly isolate or shut one down en-route for fuel conservation. With both running however, the train will accelerate out of stations faster, among a few other benefits.

The second engine is controlled via the engineer in the lead controlling locomotive. The engines have electrical connections to "MU" (Multiple Unit operation) the locomotives, usually two, sometimes three, occasionally more. The engines all respond to the engineers commands just like the lead locomotive. As in, when he notches up the throttle from 1 to 2, all locomotives respond the same way, turning multiple locomotives into one big locomotive.

The second engine is not always facing the other direction. It can hook up in any manner,either back to back, back to front, front to front, etc-both ends of locomotives have connections to hook up regardless of which way the engine actually faces. It is desirable though, to have them back to back, so there is an engine facing the other way, so the engineer can operate from the other engine if they need to "swap ends" and run the opposite direction. It helps speed the process at the end of the line, that way they won't need to turn the engines around to face the other direction.

 

 

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On long distance trains like the Empire Builder, do both engines pull even when on flat terrain? Or just on inclines? Also, how is the second engine controlled? I could ask the question why second engine is always backwards but I'm guessing it's because the "hook ups" are in the back...no way to hook the back of one engine to the front of another.

 

I hope these aren't stupid questions

 

I'll try and take these one at a time-first, usually both engines are "on line" and putting out power when needed, though the engineer can certainly isolate or shut one down en-route for fuel conservation. With both running however, the train will accelerate out of stations faster, among a few other benefits.

The second engine is controlled via the engineer in the lead controlling locomotive. The engines have electrical connections to "MU" (Multiple Unit operation) the locomotives, usually two, sometimes three, occasionally more. The engines all respond to the engineers commands just like the lead locomotive. As in, when he notches up the throttle from 1 to 2, all locomotives respond the same way, turning multiple locomotives into one big locomotive.

The second engine is not always facing the other direction. It can hook up in any manner,either back to back, back to front, front to front, etc-both ends of locomotives have connections to hook up regardless of which way the engine actually faces. It is desirable though, to have them back to back, so there is an engine facing the other way, so the engineer can operate from the other engine if they need to "swap ends" and run the opposite direction. It helps speed the process at the end of the line, that way they won't need to turn the engines around to face the other direction.

 

 

Shortline, good, detailed answer. There is another consideration in assembling two-unit consists 'elephant style' (both facing in the same direction) and that is if the lead unit becomes damaged or otherwise incapable of operating as a controlling unit due to a mechanical issue.

 

Here, the second unit is switched to the lead, the defective unit placed in trail, and the train is on its way again. On most RRs, it's getting more & more difficult to find places to turn locomotives. Having both facing the train's direction of travel seems to be a good hedge against line-of-road problems. I have recently (within the last six months) observed both SIlvers, the A-T, and SWC operating with both units facing in the direction of travel.

 

And Sandra, your questions are in no way stupid. Its one of those things that on its face should appear obvious... until you start actually pondering it! :hi:

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Thank you. You have explained perfectly something I have wondered watching 3 or 4 engines hauling rice trains past my house. Obviously

engines in 2, 3 or 4 configurations are able to be controlled to go the same way, no matter which way they are facing. In other words forward

and reverse doesn't matter whichever way the engines are facing? If that makes sense.

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Thank you. You have explained perfectly something I have wondered watching 3 or 4 engines hauling rice trains past my house. Obviously

engines in 2, 3 or 4 configurations are able to be controlled to go the same way, no matter which way they are facing. In other words forward

and reverse doesn't matter whichever way the engines are facing? If that makes sense.

 

That is correct. And the engine's computers are smart enough to know which way its facing and they run the traction motors in the correct direction to make the engine move in concert with the rest. So an engine facing backwards to us, knows to run its traction motors in reverse which of course moves it forward.

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Thank you. You have explained perfectly something I have wondered watching 3 or 4 engines hauling rice trains past my house. Obviously

engines in 2, 3 or 4 configurations are able to be controlled to go the same way, no matter which way they are facing. In other words forward

and reverse doesn't matter whichever way the engines are facing? If that makes sense.

Doesn't matter which way the engines face, they just have to be set to run that way. Remember, the engines' traction motors are electric, there is no mechanical drive train. So they will run either way, just set them.

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It helps speed the process at the end of the line, that way they won't need to turn the engines around to face the other direction.

 

Don't they wye most LD trains? In which case they don't need to detach the engines and run them around the train?

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Lately, on the freight railroads, first UP and now BNSF, there are remote-controlled pusher engines at the far end of the train that are co-controlled with the leading 2 engines - they all work together for efficiency.

Edited by NW cannonball

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It helps speed the process at the end of the line, that way they won't need to turn the engines around to face the other direction.

 

Don't they wye most LD trains? In which case they don't need to detach the engines and run them around the train?

 

That is correct, Amtrak tends to wye most LD's at the end of their runs. But occasionally there isn't time for that, or again if there is a problem while enroute, it can make it easier to double back in the other direction.

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On long distance trains like the Empire Builder, do both engines pull even when on flat terrain? Or just on inclines? Also, how is the second engine controlled? I could ask the question why second engine is always backwards but I'm guessing it's because the "hook ups" are in the back...no way to hook the back of one engine to the front of another.

 

I hope these aren't stupid questions

 

I've noticed some long distance trains (Texas Eagle, City of New Orleans) use only 1 engine pulling sometimes 8 cars. Am I guessing correctly there are no significant inclines on either of these routes and that's the reason 2 engines aren't needed?

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I've noticed some long distance trains (Texas Eagle, City of New Orleans) use only 1 engine pulling sometimes 8 cars. Am I guessing correctly there are no significant inclines on either of these routes and that's the reason 2 engines aren't needed?

In a short answer, yes!

 

Figured I'd post this link for all of you too, shows you sort of how the engines "talk" to each other. You hook the 27-pin cable in between the engines, so whatever is done from one control stand will be done by all engines on the train.

 

http://www.railway-technical.com/us-musp.shtml

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Guest Nathanael

I've noticed some long distance trains (Texas Eagle, City of New Orleans) use only 1 engine pulling sometimes 8 cars. Am I guessing correctly there are no significant inclines on either of these routes and that's the reason 2 engines aren't needed?

 

Those are certainly quite flat routes. I personally don't know if that's *why* they don't have two engines. :-)

 

The Coast Starlight, Empire Builder, California Zephyr, Southwest Chief, and Pennsylvanian are routes with very significant grades.

 

But the Lake Shore Limited, Silver Star, Silver Meteor, Palmetto, and Crescent are pretty flat routes too. And they usually run with two engines, though, if I'm not mistaken. (Though I guess some of them are pulling a lot more than 8 cars! So maybe that's why.)

 

(I'm not sure about the grades on the Capitol Limited or the Sunset Limited. Anyone know?)

 

Now, another couple of thoughts. Elephant-style and back-to-back aren't the only two possible ways to arrange two engines; it would seem to be efficient and flexible to put one in front of the train and one behind the train, push-and-pull. Is there a reason this is done so rarely? Perhaps lack of push-pull wiring on the carriages? (Apparently the entire single-level fleet will have push-pull wiring done by the end of the year -- there's only one cafe left to convert -- but the bilevel fleet probably won't.)

 

Also, it seems apparent that the need to "turn" the engines is due to having a cab only on one end. The new Siemens electric engines appear from the mockups to have cabs on both ends, so I suppose they won't need to turn -- they'll be operable in both directions. Will Amtrak order double-ended diesels for its next order to eliminate the 'turning'/wyeing requirements for the diesel fleet?

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The Coast Starlight, Empire Builder, California Zephyr, Southwest Chief, and Pennsylvanian are routes with very significant grades.

The Pennsylvanian runs with one engine all the way, but it has only 6 or 7 cars.

But the Lake Shore Limited, Silver Star, Silver Meteor, Palmetto, and Crescent are pretty flat routes too. And they usually run with two engines, though, if I'm not mistaken. (Though I guess some of them are pulling a lot more than 8 cars! So maybe that's why.)

Palmetto usually runs with a single engine. The others have two. LSL is the longest single level train.

(I'm not sure about the grades on the Capitol Limited or the Sunset Limited. Anyone know?)

Capitol Limited crosses the same Alleghanies that the Pennsylvanian does. The Cap goes through Cumberland Gap and then climbs the Sand Patch grade. The Sunset should have some grades since the profile of the route has it go below sea level and then climb to couple of thousand feet. I don't know the exact profile of that route enough to know what the ruling gradient is.

 

Ironically, the steepest grade that the Silvers and Crescent and Palmetto etc. have to climb is done with a single engine. It is the climb through the Hudson Tunnel.

 

The Silvers do not really absolutely need two engines to keep to their schedule, but CSX likes them to have two.

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The Coast Starlight, Empire Builder, California Zephyr, Southwest Chief, and Pennsylvanian are routes with very significant grades.

The Pennsylvanian runs with one engine all the way, but it has only 6 or 7 cars.

But the Lake Shore Limited, Silver Star, Silver Meteor, Palmetto, and Crescent are pretty flat routes too. And they usually run with two engines, though, if I'm not mistaken. (Though I guess some of them are pulling a lot more than 8 cars! So maybe that's why.)

Palmetto usually runs with a single engine. The others have two. LSL is the longest single level train.

(I'm not sure about the grades on the Capitol Limited or the Sunset Limited. Anyone know?)

Capitol Limited crosses the same Alleghanies that the Pennsylvanian does. The Cap goes through Cumberland Gap and then climbs the Sand Patch grade. The Sunset should have some grades since the profile of the route has it go below sea level and then climb to couple of thousand feet. I don't know the exact profile of that route enough to know what the ruling gradient is.

 

Ironically, the steepest grade that the Silvers and Crescent and Palmetto etc. have to climb is done with a single engine. It is the climb through the Hudson Tunnel.

 

The Silvers do not really absolutely need two engines to keep to their schedule, but CSX likes them to have two.

Sunset is far from flat. It has to go up 2% grades at Beaumont Pass, more grades around Vail, AZ and has to climb through Paisano Pass in Texas, which also has some 2% grades.

 

Also, Southwest Chief has the worst grades, with 3%+ grades at Raton and if they use the 3% "South" track in Cajon Pass (which often do, as they can get up that grade better than a frieght can). Most mainlines grades held to around 2 - 2.2%. I think the ex-GN the Empire Builder uses holds the grades down to around 1%.

 

Superliners generally do not have push-pull cabling in the cars. There are a couple of exceptions, the damaged ones that CalTrans paid to have fixed up and are being used on the San Joaquins and the Surfliners have the necessary equipment for push-pull operation.

Edited by zephyr17

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Our Heartland Flyer carries an engine on both ends to eliminate having to turn the entire train in OKC or FTW. Lately is has been a P42 on both ends but for about a year P32 #500 was a regular since it was testing the Biofuel. With her normal consist of 3 cars, it almost looks like overkill with 2 engines.

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Our Heartland Flyer carries an engine on both ends to eliminate having to turn the entire train in OKC or FTW. Lately is has been a P42 on both ends but for about a year P32 #500 was a regular since it was testing the Biofuel. With her normal consist of 3 cars, it almost looks like overkill with 2 engines.

But both probably are not working, since the there are no control lines through the train. It may on but idling (the practice of letting locomotives sit and idle, I frankly do not understand) So it is likely pulling the engine at the end as just part of the train.

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Our Heartland Flyer carries an engine on both ends to eliminate having to turn the entire train in OKC or FTW. Lately is has been a P42 on both ends but for about a year P32 #500 was a regular since it was testing the Biofuel. With her normal consist of 3 cars, it almost looks like overkill with 2 engines.

But both probably are not working, since the there are no control lines through the train. It may on but idling (the practice of letting locomotives sit and idle, I frankly do not understand) So it is likely pulling the engine at the end as just part of the train.

 

In the case of the Flyer, the Superliners allow train control to pass through and whenever I have gotten off in Norman and been standing near the trailing locomotive, you can hear it throttle up in synch with the lead.

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Our Heartland Flyer carries an engine on both ends to eliminate having to turn the entire train in OKC or FTW. Lately is has been a P42 on both ends but for about a year P32 #500 was a regular since it was testing the Biofuel. With her normal consist of 3 cars, it almost looks like overkill with 2 engines.

But both probably are not working, since the there are no control lines through the train. It may on but idling (the practice of letting locomotives sit and idle, I frankly do not understand) So it is likely pulling the engine at the end as just part of the train.

 

In the case of the Flyer, the Superliners allow train control to pass through and whenever I have gotten off in Norman and been standing near the trailing locomotive, you can hear it throttle up in synch with the lead.

Thanks for the correct info! I thought only the Superliners repaired for CalTrans use had control lines. Do all Superliners?

Edited by zephyr17

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In the case of the Flyer, the Superliners allow train control to pass through and whenever I have gotten off in Norman and been standing near the trailing locomotive, you can hear it throttle up in synch with the lead.

 

Thanks for the correct info! I thought only the Superliners repaired for CalTrans use had control lines. Do all Superliners?

 

Amtrak specially modified selected Superliner cars with the control cables to operate on the Flyer. But no, not all Superliners have been modified.

 

You can get at least a partial listing of the cars here.

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Ironically, the steepest grade that the Silvers and Crescent and Palmetto etc. have to climb is done with a single engine. It is the climb through the Hudson Tunnel.

 

True, but then that single engine has a huge power source behind it and at least 2,750 HP to work with.

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Those are certainly quite flat routes. I personally don't know if that's *why* they don't have two engines. :-)

 

The Coast Starlight, Empire Builder, California Zephyr, Southwest Chief, and Pennsylvanian are routes with very significant grades.

 

But the Lake Shore Limited, Silver Star, Silver Meteor, Palmetto, and Crescent are pretty flat routes too. And they usually run with two engines, though, if I'm not mistaken. (Though I guess some of them are pulling a lot more than 8 cars! So maybe that's why.)

 

(I'm not sure about the grades on the Capitol Limited or the Sunset Limited. Anyone know?)

 

 

I believe it's not just the load or gradient that determines how many engines you need but also questions of redundancy. If an engine fails in a remote location it could take several hours to get a rescue engine out there. In the meantime the line is blocked and a long tail of freight trains will build up behind it. That is why some freight railroads insist Amtrak uses two engines. On lines where it may be relatively easy to find a rescue engine, they may be prepared to relax that requirement.

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Also, it seems apparent that the need to "turn" the engines is due to having a cab only on one end. The new Siemens electric engines appear from the mockups to have cabs on both ends, so I suppose they won't need to turn -- they'll be operable in both directions. Will Amtrak order double-ended diesels for its next order to eliminate the 'turning'/wyeing requirements for the diesel fleet?

 

Electric locomotives have almost always had cabs t both ends. the GG1s did. the AEM7s do.

 

I'm not sure what the reason for the difference is.

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The Silvers do not really absolutely need two engines to keep to their schedule, but CSX likes them to have two.

 

One reason for having two units on what would seem as "easy" East Coast gradients is not strictly related to horsepower but horsepower per ton (hp/ton). The higher hp/ton rating with the second unit makes a sizeable difference in the way the train handles (and brakes, now that you are controlling two full D/B sets).

 

Trains powered up in this manner are much easier to keep on schedule not only due to the additional hp/ton, but also by giving the train dispatcher greater options when planning meets and passes. An 11-car passenger train that the train dispatcher knows can clear up one more siding ahead versus a single-engine train. That second unit makes the entire district run much smoothly.

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I've noticed some long distance trains (Texas Eagle, City of New Orleans) use only 1 engine pulling sometimes 8 cars. Am I guessing correctly there are no significant inclines on either of these routes and that's the reason 2 engines aren't needed?

 

Those are certainly quite flat routes. I personally don't know if that's *why* they don't have two engines. :-)

 

The Coast Starlight, Empire Builder, California Zephyr, Southwest Chief, and Pennsylvanian are routes with very significant grades.

 

But the Lake Shore Limited, Silver Star, Silver Meteor, Palmetto, and Crescent are pretty flat routes too. And they usually run with two engines, though, if I'm not mistaken. (Though I guess some of them are pulling a lot more than 8 cars! So maybe that's why.)

 

(I'm not sure about the grades on the Capitol Limited or the Sunset Limited. Anyone know?)

.....

 

I guess the limit for gradeless trains is about 7 cars. Those trains you mentioned all exceed that, while gradeless trains below that all have only one locomotive. The Palmetto now runs with only one locomotive.

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