Four reasons why the US should revisit the GT-EL locomotive units

August 16 2013 - William E. Forsthoffer

In the third part of this series, the author pointed out that natural gas proved to be a good fuel in larger locomotive units and they ran well for long periods of time between overhauls. In this article, he talks about the prospects of the GT-EL locomotives in this era.

There are four very good reasons why the time is right today to revisit the GT-EL. Times have indeed changed and gas turbine sales are on a roll, to be sure, for power plants, ships and other applications. Why not the RRs too? The four pushers are listed here:

Natural gas is now being produced in large amounts and is relatively low in cost, being about $4.50 a million BTU. The United States is in a unique position now regarding natural gas as a result of fracking that started the natural gas boom and is also increasing our crude oil production. The supply and price of natural gas is projected to be stabilized at this price level, giving the gas turbine a decided cost advantage over the diesel engine. Why think about exporting our surplus natural gas when we can more profitably use it here in the USA? There are three major shale gas fields in the US – one in Texas, one in North Dakota and one in Pennsylvania – that the RRs can call upon.

There have been many improvements in both the aero-derivative and the HD gas turbines over the years – especially in the past decade. There are several simple cycle aero and HD units in the 10000 to 20000 HP range that are suitable for large GT-ELs and which have simple cycle efficiency levels of around 35 percent or better burning natural gas fuel to compete favorably with the diesel engine. When considering passenger service, and possibly freight as well, heat recovery could be easily installed to provide heating and cooling. GE has dropped out of the lower power end of the GT market, but others like solar for instance, are filling in this low-end power gap.

Natural gas is an ideal fuel for today's gas turbines providing low maintenance costs and long TBOs. These costs should be lower than those for the diesel. The gas is clean burning and produces less CO2 than diesel fuel.

Low sulfur diesel fuel burned in the present diesel engines for locomotives is expensive and cuts into our US supply of crude oil.  Switching to natural gas would help considerably in achieving crude oil and energy independence in 8-10 years as some of our experts are presently predicting.

The T. Boone Pickens approach

T. Boone Pickens has been quite successful in promoting the use of natural gas to power large freight trucks across our interstate highways and to power fleets of vehicles for cities, schools, and delivery companies. Inroads in these areas are being realized to take advantage of our newly found and abundantly produced shale natural gas. Natural gas filling points are springing up all over the US. The natural gas producers need another Pickens to sweep the country promoting the GT-EL to absorb our excess natural gas production instead of trying to export it.  The TV GT-EL ad machine should be started up by the natural gas industry.

Converting existing railroad diesel engines in existing locomotives might be done but it would be expensive to do. However, if the savings are great enough between the price of diesel fuel and the price of natural gas, then conversions can be made. If filling points along the chosen routes are established, some of the diesel engines could be changed over to burn natural gas.

The UPRR found it an advantage to add diesel locomotives to their GT 4500 HP locomotives to form a hybrid power system. Once filling points along the line are established, then it becomes possible to convert diesels to burn natural gas. It is the old chicken or the egg story. We should listen to what Pickens has to say about the railroads burning natural gas now that there seems to be plenty of it to go around for trucks, power plants and railroads.

In his next article, the author discusses where the GT-EL can be applied in the US, considering the low cost of natural gas.

(This article is the fourth part of a series by the author.)

Can the gas turbine-electric locomotive make a comeback?

How rising fuel costs forced the retirement of Frame 3 and 5 units in U.S. locomotives

Ivan G. Rice was past chairman of the South Texas Section of ASME (1974 - 75), past chairman of the ASME Gas Turbine Division (now IGTI) (1975 - 76). A Life Fellow Member of ASME and Life Member of NSPE/TSPE, he has authored many articles and ASME papers on gas turbines, inter-cooling, reheat, HRSGs, steam cooling and steam injection.