Savannah Station Questions (For the Technical Folks)

[cuppb001]

First off I want to apologize if I am starting too many new posts as a new member. I have been reading these forums for quite a while and never signed up until just recently. I have been excited since I have been able to get answers to all the questions I have always wanted to ask but didnt know who to ask. Any way about Savannah:

Ive noticed that the Savannah station has at the stub end of a few of its tracks ground connections for 480. Are these deactivated and non functional? I ask since I have noticed that when the Palmetto is parked the P42 idles all night generating HEP for the entire consist. I would think that it may be more efficent to just plug the whole trainset in. Is there a reason that they dont? Also when PVs are parked they are always running their own generator. If you look in the Amtrak Manual for PV's it shows Savannah as not offering 480. Clearly though the system is in place. Tampa even offers 480v ground and its connections look nowhere near in good as shape as Savannah.

 

[battalion51]

I would venture to guess it has something to do with the contractor working on the train at night. I'm not 100% on that, but it would make sense to me. With the engine in standby you're not having to mess with any HEP cables, and you also ensure that the engine will be live when they come to pick the train up in the morning. That would not be a good thing if the engine were shut down and wouldn't come back up when the road crew showed up.

 

[Ryan]

What he said.

Don't worry about all the n00b questions, that's what we're here for. It's a pleasant distraction from arguing about Amtrak cost allocations. Again. And again. And again.

 

[VentureForth]

On the contrary, when I've seen the Palmetto back into the stub, the first thing I see the crew do is plug in the power.

 

[cirdan]

I would venture to guess it has something to do with the contractor working on the train at night. I'm not 100% on that, but it would make sense to me. With the engine in standby you're not having to mess with any HEP cables, and you also ensure that the engine will be live when they come to pick the train up in the morning. That would not be a good thing if the engine were shut down and wouldn't come back up when the road crew showed up.

I'm not familar with the Savannah location. But I would assume that the whole point of having a ground power supply is to not leave the engine idling all night. Ground electricity is cheaper than diesel fuel and assuring there are staff on location who have been trained in the correct handling of the cables, actually doing it can't be too great a challenge either. With old fashioned diesels, there certainly was a risk that they wouldn't start in the morning and even if they did start, that the thermal cycling of letting an engine go cold and then heat up again on a regular basis was bad for its lifetime. But modern diesels should be more reliable than that.

My guess is that if the 480 is not being used, it's because there's something wrong with it. If Amtrak didn't think ground supply was a good idea. they wouldn't use it anywhere. If it is used in some locations and not in others the only explanation can be differences in local conditions. In some cases these can be ordnances or pollution concerns, in others they can be the availability of the ground supply itself.

 

[the_traveler]

A diesel locomotive (or especially a steam locomotive) takes hours to get ready for use from a cold start. It is not like your car or truck that you just turn the key and you're ready to go. That is why they leave it running all night long. That's why you sometimes see cut-off locomotives sitting parked on a siding running.

 

[VentureForth]

As true as that is, I would make the following assumption. Maybe I'll just have to suck it up and go ask the crew in Savannah. I think they shut off the HEP - it's isn't near as big a load to start back up as the main. I have seen them hook up shore power, so I think that's what they do. Despite the hours it takes to start a diesel, I think in the 10+ hours it's stopped, it's still more efficient to shut it down and restart for the morning run.

 

[SP&S]

Possible silly thought.

• An idling diesel uses X amount of fuel per hour.
• An idling diesel providing HEP whould use more than X amount of fuel per hour.
• It takes time and effort to restart a big diesel.
• Some times it might be more economical to keep the loco idling but draw HEP from the ground power.

Or am I completely missing something here?

 

[battalion51]

Also, don't forget, in the period that the engine is in SAV they're going to have to perform the calendar day inspection, do a load test, etc. so it is possible that it won't be put on ground power until all of that is accomplished.

 

[Shortline]

A diesel locomotive (or especially a steam locomotive) takes hours to get ready for use from a cold start. It is not like your car or truck that you just turn the key and you're ready to go. That is why they leave it running all night long. That's why you sometimes see cut-off locomotives sitting parked on a siding running.

Not true at all. Steam, yes they take a while to start, diesels, no its just minutes from cold. Flip the battery switch, blow out the test cocks if necessary, prime the engine, crank it up, and go. Starting a diesel is a 2 minute process, 6 if you have to blow down the engine. (which I doubt is required on those P40/42's). By the time you're done with your daily inspection, it's warmed and ready to go. Many railroads even do it automatically using "smart starts" that shut the engine down if it's not being used, such as when sitting in a siding. When you're ready to go, just notch out on the throttle, and it kicks over automatically. It really is almost as easy as starting your car in the morning.

 

[George Harris]

A diesel locomotive is a fairly efficient electricity generator. It could well be that the saving by using shore based power ws so small it was not worthwhile.

That diesel generator efficiency is a major reason for the complete lack of enthusiasm for electrification of freight lines. By the time you consider line losses between power plant and user using oil or gas to power a central generating plant, I would suspect that it would prove rediculous. Oil and gas should be burned much closer to the user. Particularly for railroads, with freight the ability to start a train and to lug it up a grade depends more on weight on powered axles than anything else. Since you need the weight, might as well have part of it be the generator of the electricity spinning the motors. That is much cheaper than stringing and maintaining overhead power lines and providing all the associated substations, etc. plus paying every jurisdiction higher property taxes on the fixed facilities.

 

[Phil S]

A diesel locomotive is a fairly efficient electricity generator. It could well be that the saving by using shore based power ws so small it was not worthwhile.
That diesel generator efficiency is a major reason for the complete lack of enthusiasm for electrification of freight lines. By the time you consider line losses between power plant and user using oil or gas to power a central generating plant, I would suspect that it would prove rediculous. Oil and gas should be burned much closer to the user. Particularly for railroads, with freight the ability to start a train and to lug it up a grade depends more on weight on powered axles than anything else. Since you need the weight, might as well have part of it be the generator of the electricity spinning the motors. That is much cheaper than stringing and maintaining overhead power lines and providing all the associated substations, etc. plus paying every jurisdiction higher property taxes on the fixed facilities.

George -- Thanks. Thoughts on how natural gas fired road units might change this? Thanks. -- Phil

 

[X]

I would venture to guess it has something to do with the contractor working on the train at night. I'm not 100% on that, but it would make sense to me. With the engine in standby you're not having to mess with any HEP cables, and you also ensure that the engine will be live when they come to pick the train up in the morning. That would not be a good thing if the engine were shut down and wouldn't come back up when the road crew showed up.

Yep, Probably.

http://www.justice.gov/usao/vt/press/releases/20120302_drummac.html

 

[X]

Many railroads even do it automatically using "smart starts" that shut the engine down if it's not being used, such as when sitting in a siding. When you're ready to go, just notch out on the throttle, and it kicks over automatically. It really is almost as easy as starting your car in the morning.

No Smart Start, but they will shutdown automatically when placed in standby mode, restarting as necessary to keep the engine warm, air pressure up and batteries charged.

 

[Shortline]

Many railroads even do it automatically using "smart starts" that shut the engine down if it's not being used, such as when sitting in a siding. When you're ready to go, just notch out on the throttle, and it kicks over automatically. It really is almost as easy as starting your car in the morning.

No Smart Start, but they will shutdown automatically when placed in standby mode, restarting as necessary to keep the engine warm, air pressure up and batteries charged.

Smart Start is just the trademarked name of one company that makes them, thats exactly what a Smart Start does, shuts it down when engaged and not being utilized, and firing back up to maintain temp/pressure within pre-set parameters. Calling it a smart start is kinda like calling a tissue a Cleanex, generally it's all the same.

 

[Nathanael]

If you look in the Amtrak Manual for PV's it shows Savannah as not offering 480. Clearly though the system is in place.

In that case, there's most likely something wrong with it. Just because the hookups are there doesn't mean they work... someone could have severed a wire decades back, or disconnected the supply in a payment dispute, or something.

Of course, it's always possible that there's a misbehaving contractor, as in the Drummac case (Drummac was required to turn the trains off and plug them into shore power, didn't, and ended up paying a penalty).

But the fact that Savannah isn't listed as having 480 in the PV manual means I bet they don't work. I'd suggest taking your own PV down there and testing the connections, if you're rich enough to have your own PV

 

[xyzzy]

Thoughts on how natural gas fired road units might change this?

There's no doubt that LNG is less expensive, BTU for BTU, than diesel fuel. Whether LNG will turn out to be a safety issue, time will tell. Grade crossing accidents come to mind. The other question is storage. Many Amtrak trains can finish their runs without having to be refueled en route. LNG range is likely to be less, unless we see a return to the fuel tender. Old-timers may remember that Amtrak turned an E9 into a fuel tender in the late 1970s.

 

[VentureForth]

A diesel locomotive is a fairly efficient electricity generator. It could well be that the saving by using shore based power ws so small it was not worthwhile.
That diesel generator efficiency is a major reason for the complete lack of enthusiasm for electrification of freight lines. By the time you consider line losses between power plant and user using oil or gas to power a central generating plant, I would suspect that it would prove rediculous. Oil and gas should be burned much closer to the user. Particularly for railroads, with freight the ability to start a train and to lug it up a grade depends more on weight on powered axles than anything else. Since you need the weight, might as well have part of it be the generator of the electricity spinning the motors. That is much cheaper than stringing and maintaining overhead power lines and providing all the associated substations, etc. plus paying every jurisdiction higher property taxes on the fixed facilities.

As true as this is with traditional power plants, nuclear plants would do away with most of those concerns. The cost of the electricity should be lowered enough to pay for the rest of the cost liabilities incurred.

 

[xyzzy]

Most people agree that nuclear is cheaper than coal or oil. There's an argument these days about whether nuclear is cheaper than natural gas. Duke Power in the southeast just withdrew its plans for additional nuclear because natural gas is so attractive. Nuclear is not cheaper than hydro, in terms of hydro that is already in place.

That said, the losses from transporting the electricity after it has been generated are substantial -- regardless of the source of the electricity. It's why the conducting cables in high-voltage transmission lines are often 250 degrees in temperature. If you can generate electricity where it is needed with reasonable efficiency and safety, you will almost always do better than importing your electricity from several hundred miles away -- such are the lengths of transmission lines that an electrified railroad in the western states would face -- even if generation is as cheap as hydro.

 

[Ryan]

That said, the losses from transporting the electricity after it has been generated are substantial

I'm not sure if I would agree with that, high voltage transmission lines have losses in the single digits of percent.
You pay a far higher penalty for having to carry both your electricity source and fuel with you.

 

[National Limited]

Just a point of clarification. The Savannah Amtrak Station does indeed have 480V service available but ONLY on the north stub track on which the Palmetto rests at night. There is a south stub track on which PV cars would be parked but it does not now have 480V service. Someone correct me if I am wrong, but there are two "through" tracks at Savannah and two stub tracks (north and south) all of which are sidings to the main line which runs immediately to the west of the platform tracks.

 

[VentureForth]

Yes. Here is a rough diagram:

<-- NORTH S T A T I O N SOUTH -->

Palmetto Stub -> /-----| |----\ <- PV/Inspection Car Stub

Secondary Pax Track -> /-----------------\

/ P L A T F O R M \

Primary Pax Track -> /---------------------\

Mainline -> -----/-----------------------\---

Mainline -> ---------------------------------

 

[Nathanael]

That said, the losses from transporting the electricity after it has been generated are substantial

I'm not sure if I would agree with that, high voltage transmission lines have losses in the single digits of percent.
You pay a far higher penalty for having to carry both your electricity source and fuel with you.

(1) The weight penalty for carrying the diesel fuel and the diesel generator onboard is substantial.

(2) Very large generators are generally far more efficient than small, onboard generators. (I think this is true of every form of power generation except photovoltaic; it's certainly true of all thermal power generation.)

There's a reason why nobody ever removes electrification if they've already got it, apart from the Milwaukee Road, whose accounting was famously wrong. Electrified routes are cheaper to operate and cheaper to maintain. It is strictly a matter of whether it is worth the capital costs.

Accordingly, it's pretty nearly always a savings to plug into "shore power". Even if you have to use it to heat the diesel to prevent it from gelling! This is actually being done at some freight yards.

After seeing the detailed description of the Savannah layout, it sounds like the contractor is failing to plug into shore power when the contractor *should* be using shore power. This costs Amtrak extra money. As noted previously, Amtrak got a settlement from one contractor (in Vermont) over that particular abuse. Perhaps the original poster should contact someone at Amtrak management and give them a tip, as they may be unaware that one of their subcontractors is costing them unnecessary extra money in fuel.

 

[xyzzy]

No, the weight penalty of the diesel prime mover and diesel fuel is not a factor. The locomotive must be ballasted anyway in order to get enough weight on the axles to avoid slipping. Besides, the inevitable transformer and high voltage components in a pure electric are not lightweight, either. Between electrical equipment and ballast, the GG1 (which was highly successful in freight service) weighed 475,000 pounds.

Your statement that only the Milwaukee removed electric is incorrect. There are many examples of de-electrification such as the Great Northern (74 miles in mountainous territory). Wikipedia has a good list at http://en.wikipedia.org/wiki/Railroad_electrification_in_the_United_States

 

[VentureForth]

Any weight above that needed for traction is wasted energy. It can be assumed that a locomotive that is nearly empty should have enough weight for traction.