# If railroads want to save fuel..



## MIrailfan (May 2, 2014)

They need to stop leaving their locomotives on overnight.


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## Green Maned Lion (May 2, 2014)

You know nothing about large Diesel engines.


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## XHRTSP (May 2, 2014)

Green Maned Lion said:


> You know nothing about large Diesel engines.


Neither do I, edumacate me please!


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## MetraUPWest (May 2, 2014)

They are left running in cold weather because the radiators are filled with water. The water will freeze if the engine is shut down too long. Antifreeze is too expensive since most locomotives take 300+ gallons to fill the radiators. It's cheaper to just leave them idle. A locomotive only uses 2-3 gallons of fuel to idle anyway.

It also takes a good amount of fuel to get an engine thay big started. Unless you are going to have it shut down for more than a half hour you're better off leaving it running.

There are other reasons they are left running too. Many times one locomotive will be left running to keep the air brakes on a train charged. On a passenger trains they may leave the HEP on as well. Locomotive batteries do go bad, too, just like a car, so you leave the engine running until the batteries are changed.

A major source of wear and tear on engine components is all of the heat cycling. The metal expelands and contracts as it heats and cools. The less heat cycles the engine goes through the longer some components last- especially the turbocharger. Diesel engines are designed to idle forever without causing much wear on them.


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## Green Maned Lion (May 2, 2014)

Thank you for saving me most of the trouble. Also, due to the amount of battery power and related weight, wear and tear, and cost, really large Diesel engines (generally anything bigger than a 16 liter OTR) do not have glow plugs.

Diesels operate by in taking only air, compressing it to insane pressure and heat, and then power misting the fuel into that environment, which causes it to explode violently (much more so than gas). In fact, diesel fuel is essentially non combustible in regular air and burns slow and relatively cool.

A cool experiment is to soak paper towels in both gas and diesel and see the difference in how they burn. (GML is a professional idiot and does not condone doing this at home and is not responsible for the results)

Anyway, in cold environments, smaller diesels use a device known as a glow plug to preheat the relatively small combustion chambers sufficiently to cause auto ignition within a second or two of spinning. Larger ones don't, and can result in the engine spinning for up to several minutes before it ignites, pumping raw diesel into its exhaust system, which can sometimes ignite if it gets stuck in the wrong place, and is certainly not good for the environment. The ignition requires a vet rich mixture. It can take a gallon or more of fuel to start a prime mover.

In cold climates it needs to be done with the unit plugged in and is something of a production. 18 wheelers sit idling for long periods for much the same reason.

A cool problem on older mechanical diesel Benzes, (almost every car I've ever owned) is that the engine directly drives the fuel pump. To shut off the engine, they used a valve controlled by the extensive vacuum system (it also controlled windows, door locks, and in the W140 S-class the glove box and center console locks), which had a hundred feet of tubes, any inch of which could and did spring leaks. The failure of vacuum in the system caused this automatic valve to become inoperative, so the car would not shut off. As a result, diesel Benzes used to have a cool anti theft feature: a valve under the hood that you manually closed to shut off fuel to the engine.


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## MIrailfan (May 2, 2014)

yes I do. they can be shut off if the temperature is 45 degrees or higher outside.


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## SarahZ (May 2, 2014)

MIRAILFAN said:


> yes I do. they can be shut off if the temperature is 45 degrees or higher outside.


How often, during the past eight months, have Pontiac and Chicago been over 45 degrees at night? I still have our radiators running, and I'm in southern Michigan.

Also, read the rest of the thread. Metra and GML gave you some very good information.


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## rrdude (May 3, 2014)

However.......(Isn't there ALAWAYS a however"?)

There are sev manfacturers who make Diesel engine "heaters" that use far less fuel that the 2-3 gals per hour, and IN THE LONG RUN, will be cheaper, and better for the environment, than idling a big Diesel all night, or in the case of Michigan, ALL WINTER"

http://www.hotstart.com/

EDIT: Lion is correct on the "wear n tear" issue. Diff maint plans will however, debate what is Excessive


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## Green Maned Lion (May 3, 2014)

They still cause excessive wear and tear from heat cycling.


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## MIrailfan (May 9, 2014)

csx agrees with me.check their site.


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## SarahZ (May 9, 2014)

MIRAILFAN said:


> csx agrees with me.check their site.


That site has a million billion links/pages. Which section are you talking about, specifically? Do you have a link?


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## TinCan782 (May 9, 2014)

You guys and gals are talking about diesel fuel usage. Spotted this over on Trainorders...

"a Big Boy under full load burned about 22,000 pounds or 11 tons of coal an hour, which gave them a fuel range of a little over about 2 hours".

I guess usage while "idling" would be somewhat less, LOL!


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## jebr (May 9, 2014)

MIRAILFAN said:


> csx agrees with me.check their site.


What do they agree with you on? Where on their website do they agree with you?

This isn't Twitter...posts can be longer than 140 characters.


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## Eric S (May 9, 2014)

MIRAILFAN said:


> csx agrees with me.check their site.


Come on. Without more information (as others have asked for - what are you referring to? where on their site?) this is little more than useless drivel.


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## MetraUPWest (May 10, 2014)

^Agreed. What are you trying to say? Lion and I have both already listed several reasons why locomotives are left running. I have no idea what you are trying to say about CSX.

Metra uses an electric Hotstart (or other brand) system on all their locomotives. We just call it layover protection. They plug the trains into 480VAC ground power at night, and that power runs the layover protection system which heats and circulates the engine water, oil, and charges the batteries while the engine is shut down.

The electric system only works if you park the locomotive in a spot where it can be plugged in, however, and that's not even remotely practical for freight or even Amtrak locomotives. The diesel powered Hotstart systems are called APUs. Some freight locomotives have them, but they are expensive to retrofit and it is an added cost to maintain them as well. I have seen NS units with APUs, not sure what other freight railroads have them, though I can tell you that UP doesn't have any so far. When you add up the cost of retrofitting, maintaining, and of course the fact that the APU still burns fuel, I bet you aren't really saving any money. The railroads employ people to crunch the numbers and figure this out. Trust me, if the APU was really that much cheaper than letting a locomotive idle they would be installing them like crazy.


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## neroden (May 20, 2014)

Actually, Amtrak has electric layover power at a lot of its yards. And so do a lot of the class Is at a large number of yards. Such power was generally installed specifically to stop overnight idling of diesel engines in populated areas, often with municipal grants.

But it's never going to be *every possible* layover location.


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## MetraUPWest (May 24, 2014)

Amtrak does, but I've never heard of any Class 1 having layover power in a yard let alone any Class 1 locomotive with the ability to plug in.


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## railiner (May 31, 2014)

This is interesting.....I wonder if the diesel APU's mentioned are similar to the "Webasto" pre-heater's we use in our buses during overnight layover's in location's away from our garages? The Webasto's use diesel fuel from the main tank, and keep the main engine water and oil warm in frigid climates. The one's in our Van Hool's even circulate hot water in radiators to keep the coach warm overnite.

Our buses also have plug-in electric heaters that do the same at locations where we have plug-in access.

It is interesting that more and more locations are requiring cruise ships to shut down (or perhaps run at lowest idle speed) their huge diesel power plants, and instead use newly built shore-line power connections, while the ship is in port. Location's in places like Alaska are especially sensitive to that....


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