I know it has been talked about before but I want to know is why haven’t natural gas locomotive found mass market use while other markets have seen mass adoption of either CNG or LNG powered vehicles for example many bus fleets are powered and not to mention garbage trucks are powered by locally made bio-natural gas. Wouldn’t Liquid natural gas being liquified be able to ignite with air in a diesel engine and couldn’t LNG filled use the same fueling infrastructure or am I missing something? With such a massive price difference between the price of Natural GAS and diesel fuel it seems obvious thing to adopt Natural GAS vehicles or at least experiment with them, plus wouldn’t natural gas allow rail companies to meet emissions standards for a long time?
First of all a diesel being compression ignition engine, methane (natural gas) is not the perfect fuel in that it needs a separate ignition source. This is achieved 2 ways ; either with a small squirt of diesel fuel, called pilot fuel, that auto-ignites setting off the methane charge,or using a spark ignition using a spark plug as in your car. Converting an engine that will operate on methane is much simpler using the “dual fuel” approach as was done over twenty years ago on a couple of BN SD40’s. I think the problem with that set up was that there was an enormous tank-car full of LNG between the locomotives instead of a safer spot, say the other end of the train in case of a derailment. IF the LNG delivery is late this units can run on straight diesel fuel. On spark ignited engine you have to control the air/fuel ratio precisely and you have to have a throttling system with turbo boost control and so forth.
CN railroad has announced a project with Westport fuel injection system (high pressure) and EMD to develop an engine in the not too distant future meanwhile CN has contracted with Energy Conversions to convert 2 SD40’s to dual fuel operation with their low pressure system. The first one was tested last week and both units will be in operation soon.
The Chicago Transit Authority ran a sizable percentage of its bus fleet on propane into the early 1970’s. Specialized fueling facilites were required. Liquefied natural gas is a cryogenic substance and as such would require speciaized storage and fueling facilities. It also requires spark ignition if used as a fuel. Conversion to natural gas fuel would require new fuel facilities and rebuilding of engines.
A growing percentage of the North American Transit bus fleet is running on Natural Gas. I would bet that the current bus authority in Chicago has some CNG buses…
The major locomotive builders seem to be taking a serious look at LNG as a fuel for future locomotives. Caterpillar/Progess/EMD (all one entity now) just began a joint venture with a company that specializes in Natural Gas fuel systems for diesel engines and GE bought an austrian company that maufactures a line of NG fueled engines…
Creepycrank:
" I think the problem with that set up was that there was an enormous tank-car full of LNG between the locomotives instead of a safer spot, say the other end of the train in case of a derailment."
I’ve been wondering how they could get away with that considering the requirement for buffer cars between locomotives and hazardous material cars.
You design the fuel tender to be more like a locomotive than a tank car - even more collision-proof than a standard tank car. They you go get an FRA waiver. Then, you pray.
One thing working against LNG/LPG for locomotive fuel is the need for long range with infrequent fuel stops. You just can’t compare a diesel locomotive to a city bus or trash truck - and I haven’t seen/heard of many over-the-road rigs running on LNG.
Because of density, LNG contains a lot fewer BTU/Cubic Foot - so the size of the fuel tank for equivalent energy content goes up. That’s why the separate fuel tender on those experimentals - the usual fuel tanks were just too small (even if they hadn’t been in use for the diesel `starter, spark and backup’ fuel.)
As several spectacular past events have demonstrated, LNG is a prime candidate for turning a disaster into a catastrophe. Diesel fuel may spill and leak. LNG in the presence of an ignition source will BLEVE. You don’t even want to be in the same Zip code when that happens.
Chuck (recent spectator at a propane dealership fire - including several BLEVEs)
The BN SD 40-2s with the tender were converted back to diesel, the tank cars were/are also converted to diesel only.
One of the major factors that worked against the concept was the simple one….it’s not like you can order up a fuel truck to run out and fuel your LNG tank car and locomotives and installing system wide LNG fueling facilities would cost many times more that the LNG would save in fuel cost.
The LNG set up worked fine, it saw helper service in Nebraska, and as a diesel set all over the BN system, the tank cars used are still in diesel fuel service today, they carry fuel to Needles from Houston on a regular basis.
BN’s custom made fuel tender was not one of the converted tank cars. I was very insulated and can be seen in the picture at this link:
http://crudeoilpeak.info/solutions/lng-locomotive-conversion
I saw this car still sitting in the yard at Staples, MN. This was the ‘refueling station’ for the LNG powered pair of locomotives.
Jim
Very neat info. I wonder how far (if at all) the two units will roam on CN.
Worked fine? I guess that depends on your idea of fine. Sure it ran, pulled trains, probably reliable. BUT you only have 60% of the btu content of diesel fuel. So your 4000hp locomotive is now 2400 hp. OR you can burn 66% more fuel than before IF the induction system can get that much air into the engine.