Consist Question

[AlanB]

In the case of the Auto Train example given, it is technically possible to short loop the 480 power cables halfway through the consist. That would avoid the phase problem mentioned by GG-1, since the lead engines would provide power to the front half of the train, while the engine in front of the auto racks would provide power to the rear half of the train. This would avoid the problem whereby the 480 cables can't carry anymore power than they do.
The problem with this rather simple solution is that as noted by Hokie, FRA regs require that the engineer must be able to control HEP for the entire train. In this case, or if one placed some type of power generation car in the middle, is that the engineer would not be in control of HEP for the entire train. The engineer would only have control over the HEP supplied by the front locos. This could lead to someone requesting that HEP be turned off to uncouple cars, having the engineer respond positively, and forgetting that the engineer doesn't control the entire train and getting electrocuted.

I think I'm confused. I've never seen a loco between the coaches and the auto racks on the Auto Train...

Hi confused, I'm Alan. :lol:

Seriously though, I don't believe that anyone has ever seen a loco between the coaches and the racks. It was simply a suggestion on someone's part as a way to solve the power problem, that perhaps Amtrak could slip an extra loco into the consist. And I was explaining why that wouldn't work.

 

[AlanB]

In the case of the Auto Train example given, it is technically possible to short loop the 480 power cables halfway through the consist. That would avoid the phase problem mentioned by GG-1, since the lead engines would provide power to the front half of the train, while the engine in front of the auto racks would provide power to the rear half of the train. This would avoid the problem whereby the 480 cables can't carry anymore power than they do.
The problem with this rather simple solution is that as noted by Hokie, FRA regs require that the engineer must be able to control HEP for the entire train. In this case, or if one placed some type of power generation car in the middle, is that the engineer would not be in control of HEP for the entire train. The engineer would only have control over the HEP supplied by the front locos. This could lead to someone requesting that HEP be turned off to uncouple cars, having the engineer respond positively, and forgetting that the engineer doesn't control the entire train and getting electrocuted.

We have managed to develop MU cables that provide for controlling an entire second engine at the back of a train. I'm sure there is a simple way to run a control mechanism that would allow the engineer to control the HEP for a rear-located locomotive. Actually, it wouldn't surprise me if push-pull trains already have such a function.

I'm far from being an expert on all the why's and wherefore's on this topic, much less fully understanding what the FRA regs state precisely and why they don't like the idea of a short lopped train.

However, in the case of the AT, the Superliner cars don't have MU cables. In fact none of the Superliner cars had MU cables when delivered and the ones used on the Heartland Flyer had to be retrofitted for use on the Flyer.

 

[Green Maned Lion]

I'm far from being an expert on all the why's and wherefore's on this topic, much less fully understanding what the FRA regs state precisely and why they don't like the idea of a short lopped train.
However, in the case of the AT, the Superliner cars don't have MU cables. In fact none of the Superliner cars had MU cables when delivered and the ones used on the Heartland Flyer had to be retrofitted for use on the Flyer.

If they've been added before, they can be added again.

 

[jis]

We have managed to develop MU cables that provide for controlling an entire second engine at the back of a train. I'm sure there is a simple way to run a control mechanism that would allow the engineer to control the HEP for a rear-located locomotive. Actually, it wouldn't surprise me if push-pull trains already have such a function.

Of course anything can be developed. The current setup in engines and control cabs is enough HEP controls to control a single active unit at a time. The way HEP is wired through the train, apparently can also get fed from a single source. That is the way things are today. With appropriate amount of moolah anything else can be done naturally. The desire to spend for that specific purpose at the present time may be lacking. I wish Dutch was around since he can fill in with first hand knowledge about the nuances of HEP wiring and looping requirements for both US and Canadian HEP, which BTW are different.

 

[Joel N. Weber II]

If all you're concerned about is dropping HEP for the rear half of the train if HEP fails on the front half of the train, I think there's a straightforward way to do it with a single relay and a couple extra connectors at the border between the two HEP systems.

On the car on the front half of the system, you need a unit that plugs into one of the big HEP connectors, and provides a receptable for the HEP plug from that same car. That unit may need a transformer and an internal fuse, and it needs to have the 480V power from the front half of the train ultimately controlling a relay.

Then you need a pair of small guage wires running to an externally similar looking adaptor on the trailing car which will intercept the small gauge control wires on the rear half of the system, with the relay controlled by the front half's 480V set up to open the connection between the control wires whenever there's no HEP on the front half of the train.

I'm not 100% sure I understand how the control wires on the HEP connectors work, but I think if you open up the control wire loop at any point, power will be dropped, on the theory that the reason for the open circuit could be that one of the plugs has exposed contacts, and you don't want to risk a person coming in contact with energized, exposed 480V power connectors.

 

[Crescent ATN & TCL]

Alan explained that CSX requires 2 loco's south of Richmond so they don't have trains lying dead on there mainline. I just can't imagine that running 2 loco's costs that much more.

But it does cost more, ties up a very valuable asset, and quite frankly isn't needed. When was the last time the single loco on a TE just 'died' enroute? Not to mention, there is 3x as much AMTRAK traffic on the CSX that could bump a dead train into the next station if CSX didn't want to get their little locos dirty. Much more double tracking on the CSX to navigate around a dead train as well, leaving the likelyhood of being stranded on a single track stretch much less.

CSX should be a little more considerate. :angry:

Last summer on the SWC, both locos died. Fortunately, one was still able to keep HEP so a BNSF unit pulled it the rest of the way to LAX. It can and does happen. I would much rather be on a train with two, especially if I am trying to make a connection.

A few months ago the NB Crescent lost a motor at Meridian, the second one 20mi later, stole one from the SB and lost it before the crossed AL, they got one to do HEP and NS to tow with a dilapidated yard engine for the rest of the trip.

 

[amtrakwolverine]

Alan explained that CSX requires 2 loco's south of Richmond so they don't have trains lying dead on there mainline. I just can't imagine that running 2 loco's costs that much more.

But it does cost more, ties up a very valuable asset, and quite frankly isn't needed. When was the last time the single loco on a TE just 'died' enroute? Not to mention, there is 3x as much AMTRAK traffic on the CSX that could bump a dead train into the next station if CSX didn't want to get their little locos dirty. Much more double tracking on the CSX to navigate around a dead train as well, leaving the likelyhood of being stranded on a single track stretch much less.

CSX should be a little more considerate. :angry:

Last summer on the SWC, both locos died. Fortunately, one was still able to keep HEP so a BNSF unit pulled it the rest of the way to LAX. It can and does happen. I would much rather be on a train with two, especially if I am trying to make a connection.

A few months ago the NB Crescent lost a motor at Meridian, the second one 20mi later, stole one from the SB and lost it before the crossed AL, they got one to do HEP and NS to tow with a dilapidated yard engine for the rest of the trip.

3 locos dead on one train. amtrak never heard of preventive maintenance.

 

[Crescent ATN & TCL]

It is interesting to read this post and then compare how many locomotives Amtrak uses to haul x number of coaches vs. Indian Railways, for example. I have watched many videos of them on Youtube, and am amazed how many cars they haul with their locomotives. They often use one WAP4 electric locomotive to haul 24 coaches. The WAP4 is 5000 horsepower and is rated to haul up to 26 coaches at 160 kph (100 mph). Amtrak's AEM 7 is 7000 hp; I don't know how many coaches they are rated to haul, but I don't think they haul anywhere near that number anywhere on the NEC.
Maybe one reason is (I think) the WAP4 uses an extra power car where the AEM 7 generates HEP itself?

India doesn't have FRA rules in effect, therefore their cars weigh less than Amtrak cars do, that allows their engines to pull more cars.

I believe that an AEM-7 can haul around 15 to 16 cars without too much trouble. And the AEM-7 doesn't generate HEP power, it just converts the catenary power to HEP. Unlike with a diesel engine, you're not stealing power from the traction motors to provide HEP. A P42 is rated for 4,200 HP. However if it's providing HEP, you're probably only getting around 3,700 to 3,800 HP in tractive effort, the remainder is going into HEP.

With an AEM-7 you're getting 7,000 HP regardless of whether or not the motor is also providing HEP. You've got a very large power comany at the other end of that long wire, so you can draw as much power as you need provided that you don't overload the electronic equipment in the locomotive.

When the Metroliners were still the cream of the crop, Amtrak ran 1 AEM-7 per 6 Am fleets for optimal performance. So apparently performance begins to drop after 6.

 

[MattW]

Alan explained that CSX requires 2 loco's south of Richmond so they don't have trains lying dead on there mainline. I just can't imagine that running 2 loco's costs that much more.

But it does cost more, ties up a very valuable asset, and quite frankly isn't needed. When was the last time the single loco on a TE just 'died' enroute? Not to mention, there is 3x as much AMTRAK traffic on the CSX that could bump a dead train into the next station if CSX didn't want to get their little locos dirty. Much more double tracking on the CSX to navigate around a dead train as well, leaving the likelyhood of being stranded on a single track stretch much less.

CSX should be a little more considerate. :angry:

Last summer on the SWC, both locos died. Fortunately, one was still able to keep HEP so a BNSF unit pulled it the rest of the way to LAX. It can and does happen. I would much rather be on a train with two, especially if I am trying to make a connection.

A few months ago the NB Crescent lost a motor at Meridian, the second one 20mi later, stole one from the SB and lost it before the crossed AL, they got one to do HEP and NS to tow with a dilapidated yard engine for the rest of the trip.

3 locos dead on one train. amtrak never heard of preventive maintenance.

That's one thing they never heard of, the other is "not run the p-42s into the ground by not mothballing the p-40s so many years ago." Perhaps if they had kept their other locomotives up and running, the p42s wouldn't be breaking down every few miles

 

[Crescent ATN & TCL]

I'm not sure what the maximum amount of HEP that an AEM-7 can put out actually is. However, there is also a finite limit on just how much HEP can be pushed through the 480 cables on the cars. This limit in fact prevents Amtrak from adding still more passenger carrying cars to the Auto Train than it currently runs with at peak times.

Wouldn't an extra P40 *between* the superliners and the autoracks solve that problem? The superliners would then get power from the front as well as the end of the consist?

Aloha

This wold allow the "current" to be distributed but adds the issue of generator phase, which probably make the gains not worth the headache.

Is there any reason that all the HEP systems needs to be connected together? Could one stick some form of 'generator wagon' in there to produce HEP for some of the coaches, with the others being fed from the loco, but not connect the two HEP sets together.

In the case of the Auto Train example given, it is technically possible to short loop the 480 power cables halfway through the consist. That would avoid the phase problem mentioned by GG-1, since the lead engines would provide power to the front half of the train, while the engine in front of the auto racks would provide power to the rear half of the train. This would avoid the problem whereby the 480 cables can't carry anymore power than they do.

The problem with this rather simple solution is that as noted by Hokie, FRA regs require that the engineer must be able to control HEP for the entire train. In this case, or if one placed some type of power generation car in the middle, is that the engineer would not be in control of HEP for the entire train. The engineer would only have control over the HEP supplied by the front locos. This could lead to someone requesting that HEP be turned off to uncouple cars, having the engineer respond positively, and forgetting that the engineer doesn't control the entire train and getting electrocuted.

Why don't they split the Auto-Train into a passenger section and an Auto-rack section? Then operate the passenger section with 2 p-42's one on the front and one on the rear with with short looped HEP via MU cables or Radio dpu like the freights do. Then they could let the freight section leave early ahead of the passenger section while passengers are being settled into rooms, dinner reservations are being made, etc. then depart. Due to the fact that the passenger section would be allowed 79vs 70 it would gain up to the freight section, once they got to an AT terminal the passenger section could proceed straight to the platform and the freight section to the loading ramps. It would make the assembly and the breakdown of the train much simpler.

 

[AlanB]

In the case of the Auto Train example given, it is technically possible to short loop the 480 power cables halfway through the consist. That would avoid the phase problem mentioned by GG-1, since the lead engines would provide power to the front half of the train, while the engine in front of the auto racks would provide power to the rear half of the train. This would avoid the problem whereby the 480 cables can't carry anymore power than they do.

The problem with this rather simple solution is that as noted by Hokie, FRA regs require that the engineer must be able to control HEP for the entire train. In this case, or if one placed some type of power generation car in the middle, is that the engineer would not be in control of HEP for the entire train. The engineer would only have control over the HEP supplied by the front locos. This could lead to someone requesting that HEP be turned off to uncouple cars, having the engineer respond positively, and forgetting that the engineer doesn't control the entire train and getting electrocuted.

Why don't they split the Auto-Train into a passenger section and an Auto-rack section? Then operate the passenger section with 2 p-42's one on the front and one on the rear with with short looped HEP via MU cables or Radio dpu like the freights do. Then they could let the freight section leave early ahead of the passenger section while passengers are being settled into rooms, dinner reservations are being made, etc. then depart. Due to the fact that the passenger section would be allowed 79vs 70 it would gain up to the freight section, once they got to an AT terminal the passenger section could proceed straight to the platform and the freight section to the loading ramps. It would make the assembly and the breakdown of the train much simpler.

Notwithstanding the other issues of why you can't short loop the train, there is no reason that they have to seperate the auto racks from the rest of the train just to put a third engine at the end of the passenger section.

However, seperating the train would dramatically up the expenses of operating the train, as you now need to double the number of operating crews, you're using 4 engines instead of two (or maybe three), incurring extra charges from CSX to run 4 trains instead of 2, and there really is nothing to be gained by doing so.

Passenger make their dinner reservations inside the terminal when they check in, have their tickets taken, and are given their seat assignments if in coach. Additionally the passengers are usually boarded around 3:00 to 3:15 and are already settled in, perhaps even at the wine tastings, long before the train leaves the station.

 

[sentinal]

and can you imagine if the section with all the personal cars broke down somewhere along the way or any number of other things went wrong. the passengers arrive , and thier vehicals ... somewhere . i'd be willing to bet i could hear the complants here in chicago

 

[jis]

Seems to me that this proposal to run the Auto Train in two sections is trying to solve a non-existent problem, sometimes what we call "a solution looking for a problem"

 

[Long Train Runnin']

Seems to me that this proposal to run the Auto Train in two sections is trying to solve a non-existent problem, sometimes what we call "a solution looking for a problem"

:lol: :lol: Good point. I think having your car right behind give you all kind of peace of mind. Even if they sent the Auto Racks first and something happens, and you pass by your car while on your way to the terminal I think that would cause quite a stir.

 

[battalion51]

Ok, unless I missed something I didn't see anything from Dutch. So I'll throw this in. The idea that the engineer has to have full control of the HEP is incorrect. What about every train in the US that runs with a cab car? The HEP is always run from the engine, and that's unmanned. AFAIK the rule states the engineer has to have the ability to do an MU shut down on each engine, unless it is being carried dead in tow. There is a difference between dead in tow and being shut down. When you are being hauled dead in tow there is a series of systems that have to be shut down for this to occur. Typically if an engine dies it has to be MU controlled because it is just shut down, not dead in tow. With the advances in modern technology it is very common for HEP to be run off of a rear motor, rather than the lead engine. Part of this is to create a better ride for the engine crew, but also to create redundancy. If the HEP dies for whatever reason en route, you can fire up the HEP on the leader and address the HEP on the trailer at a later point in time. Like I said, AFAIK you just need MU control of each engine in consist, not HEP control.

 

[jackal]

In all reality one of the motors is very rarely "along for the ride." They'd have to take the leader offline, and for the most part it's not very practical to do so. Rather than running in a cruising notch of 5 or 6 you're more likely to be in 3.

Maybe Dutch can clarify this but somewhere in the cob webs I seem to remember an FRA reg that stated that the lead unit HAS to be on line if it is running and operable.

Not unless that's a new rule.

Going back several years ago I was on a Silver Palm coming north with two units. All the sudden there was considerable heavy smoke coming from the second engine and we lost HEP. I'm guessing that the unit blew the rectifier stack, but I never heard the real reason. We ran for almost two hours till we reached a point where we could stop and allow the engineer to walk back to the second engine and flip some switches that would allow him to give us HEP from the lead engine.

The Alaska Railroad has a rule that if a train has four SD70MACs in a row, only three can be online. Therefore, the train crew will usually isolate the lead unit to provide a quieter ride and let the three behind it do the work. (This is usually on empty northbound oil trains where the third and fourth units will be put in DP to help with the loaded southbound.)

 

[AlanB]

Ok, unless I missed something I didn't see anything from Dutch. So I'll throw this in. The idea that the engineer has to have full control of the HEP is incorrect. What about every train in the US that runs with a cab car? The HEP is always run from the engine, and that's unmanned. AFAIK the rule states the engineer has to have the ability to do an MU shut down on each engine, unless it is being carried dead in tow. There is a difference between dead in tow and being shut down. When you are being hauled dead in tow there is a series of systems that have to be shut down for this to occur. Typically if an engine dies it has to be MU controlled because it is just shut down, not dead in tow. With the advances in modern technology it is very common for HEP to be run off of a rear motor, rather than the lead engine. Part of this is to create a better ride for the engine crew, but also to create redundancy. If the HEP dies for whatever reason en route, you can fire up the HEP on the leader and address the HEP on the trailer at a later point in time. Like I said, AFAIK you just need MU control of each engine in consist, not HEP control.

This same question came up on another forum, and Dutch specifically shot it down saying that FRA regs prohibited the idea of short looping the 480 and supplying half from a head engine and half from a engine trailing the consist.

You are correct though that many crews do run HEP out of the second engine in the consist, rather than the lead engine, but in that case the engines are MU'd and therefore the engineer remains in control of the 480. If a ground crew person asks the engineer to drop the HEP, the engineer can accomplish that task from the lead engine and without walking to the second engine and power goes out to the entire train. In the case of sticking an engine between the auto racks and the passenger cars, that engine would not be MU'd, which in and of itself is a problem, and dropping the HEP on the lead engines would not drop it on the imbedded engine.

 

[Green Maned Lion]

Why would they do this? The train only sells out around major holidays. Not worth the investment. They'd get more money for the train by increasing coach fare and swapping out coaches for sleepers.

 

[AlanB]

The Auto Train frequently sells out, and not just around the holidays.

It can often be difficult, if not impossible to get on the AT during the summer, during the snow bird commutes, and around the holidays.

 

[Green Maned Lion]

Honestly, Alan, I have never had a problem booking the Auto Train when I need it, Holidays excluded.

 

[AlanB]

Well I'm not suggesting that it's always sold out. But it does sell out more than on just the holidays. In fact, I've been on four AT runs that were either sold out, or almost entirely sold out and only one of those was a holiday weekened Memorial day.

On the near sellouts two of them, the sleepers were totally gone, and there were only a few seats left in coach. Had they eliminated a coach in favor of a sleeper, then they would have sold out coach.

 

[battalion51]

Ok, unless I missed something I didn't see anything from Dutch. So I'll throw this in. The idea that the engineer has to have full control of the HEP is incorrect. What about every train in the US that runs with a cab car? The HEP is always run from the engine, and that's unmanned. AFAIK the rule states the engineer has to have the ability to do an MU shut down on each engine, unless it is being carried dead in tow. There is a difference between dead in tow and being shut down. When you are being hauled dead in tow there is a series of systems that have to be shut down for this to occur. Typically if an engine dies it has to be MU controlled because it is just shut down, not dead in tow. With the advances in modern technology it is very common for HEP to be run off of a rear motor, rather than the lead engine. Part of this is to create a better ride for the engine crew, but also to create redundancy. If the HEP dies for whatever reason en route, you can fire up the HEP on the leader and address the HEP on the trailer at a later point in time. Like I said, AFAIK you just need MU control of each engine in consist, not HEP control.

This same question came up on another forum, and Dutch specifically shot it down saying that FRA regs prohibited the idea of short looping the 480 and supplying half from a head engine and half from a engine trailing the consist.

You are correct though that many crews do run HEP out of the second engine in the consist, rather than the lead engine, but in that case the engines are MU'd and therefore the engineer remains in control of the 480. If a ground crew person asks the engineer to drop the HEP, the engineer can accomplish that task from the lead engine and without walking to the second engine and power goes out to the entire train. In the case of sticking an engine between the auto racks and the passenger cars, that engine would not be MU'd, which in and of itself is a problem, and dropping the HEP on the lead engines would not drop it on the imbedded engine.

Alan, I think you took my terminology out of context. When I said rear motor I was referring to one of two scenarios, either you have 2+ motors up front and the HEP is being run from the last engine (the rear motor), or you have a train like the Vermonter with an engine on either end and you run the HEP off the engine on the bottom (the rear motor). I apologize for the confusion. When you talk to most engineers they recognize referring to the last motor in your consist as the rear motor. I'm not suggesting that the train should be short looped to provide HEP from either end. But it does bring up an interesting point. If you have to add a freight motor to the head end of a passenger train, regardless of whether it's Amtrak, commuter, or a Business car train, that motor is not going to have the ability to shut down the HEP AFAIK. You can most definitely kill all the traction via MU, but I don't know about HEP...

 

[jis]

If you have to add a freight motor to the head end of a passenger train, regardless of whether it's Amtrak, commuter, or a Business car train, that motor is not going to have the ability to shut down the HEP AFAIK. You can most definitely kill all the traction via MU, but I don't know about HEP...

I believe in those cases they have to place a live human being in one of the cabs from which HEP can be controlled, for the ride.