What railroads use gas locomotives instead of diesel now?

Since gasoline is cheaper than diesel right now I was just wondering what railroads have gas locomotives? Also what are some of the bigger gas locomotives? I only know of small industrial switchers.

It's not about the price per gallon. It's about the price per mile of freight pulled. Gasoline may not be cheaper than diesel by that criteria.

Gasoline engines are generally less efficient than diesel engines of comparable size. Diesel fuel has more energy (BTUs) than gasoline.

Thanks guys, I didn't know that. I'm sure on a cost per mile basis it must be getting very close though right?

No. It might be getting closer, but it's not close enough to make a difference.

The other posters are also correct: diesel works much better in these heavy freight applications.

Dave Becker

To answer the other part of your question, I'm not aware of any "big" gasoline-powered locomotives in the U.S. There are still a few little "critter"-type locomotives that run on gasoline... usually these are in the 25-ton or smaller category, and only capable of moving one or two cars at a time.

Gasoline is not cheaper than diesel. The railroads as any off road entity buy off road dyed fuel,plus many roads as airlines do hedge there fuel. The railroad i spoke to yesterday is paying 3.26 per gallon and my bill last week was 3.68
Thanks, Tom

To my knowledge, there is no gasoline internal combustion engine anywhere in the realm of what a mainline locomotive would require. There is nothing better suited to the application then a Diesel engine.

And don't forget the volitility of the fuel. Gasoline is extremely dangerous. The vapors alone can cause an explosion. I highly doubt any railroad would use a fuel that dangerous when Diesel fuel is so safe.

slashmaster wrote:Thanks guys, I didn't know that. I'm sure on a cost per mile basis it must be getting very close though right?

Not even close! Let's look at some numbers:

1 - Energy content of gasoline averages about 125,000 BTU/gallon. For diesel fuel it’s around 138,300.

2 - The best gasoline engines have a thermal efficiency (percent of the energy contained in the fuel converted to mechanical energy/delivered at the flywheel) of about 29%. Modern railroad-sized diesels are about 44% efficient.

Thus mechanical output per gallon of fuel burned for each engine type is:

Gasoline: 125,000 BTU x 29% = 36,250 BTU/gal

Diesel: 138,300 BTU x 44% = 60,850 BTU/gal

In other words, on a per gallon of fuel consumed basis the diesel engine is about 68% more efficient than the gasoline engine. Consequently the energy delivered to the locomotive's drawbar - hence the ton-miles of train that is moved - is 68% higher.

This means that for gas and diesel locomotives types be equivalent on fuel cost basis, the price of diesel fuel would have to be 68% HIGHER than gasoline. (For comparison, this morning's wholesale gas/diesel price spread is $3.24 vs $3.83 - about an 18% difference)

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Other considerations:

- A gasoline fueled locomotive would require fuel tanks 68% larger than an equivalent diesel to achieve the same range.

- Gasoline engines reject more heat into the coolant than do diesels. A gas locomotive would thus need larger radiators and cooling fans - also more power engine power diverted to run cooling fans

- Gasoline engine efficiency is poor at idle/light load. It also drops off as it approaches maximum power. The diesel OTOH maintains very high efficiency across its entire load range.

- Fuel fire safety issue already mentioned. (Imagine a derailment involving several locomotives each spilling a couple thousand gallons of gasoline….)

- No railroad-sized (3,000 – 6,000 HP) gasoline engine design even exists right now.

Bottom line is it seems unlikely you will see gasoline-powered mainline or switching locomotives anytime soon!

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Incidentally with the exception of very small industrial “critters”, no locomotives with gasoline prime movers have been built since the early 1930’s. And even then only a handful of relatively low HP gas-electrics were ever constructed – mostly experimental switchers and a couple streamliner trainset power cars.