Diesel-stingy locomotives chug forth

Except for barges, the railroads use less fuel than any other form of transport. So they could be forgiven for expectting others to do all the work on fuel-saving.

However, railroads do want to save costly energy. The Association of American Railroads estimates railroads use about 4 billion gallons of diesel fuel a year. Thus, devices that have cut fuel consumption by 10 to 24 percent in tests have little trouble getting railmen's interest.

In the United States, the primary builder of railroad locomotives is the Electro-Motive Division of General Motors. Its newest offering -- a 3,500 horsepower, turbocharged diesel -- comes with 16 cylinders and 500 more horsepower than its predecessor with the same number of cylinders.

But the "new generation" locomotive, part of what Electro-Motive calls its new "50" series, comes with a number of features that should help it run more efficiently:

* The engine idles at a lower speed -- 250 instead of 315 r.p.m. (revolutions per minute).

* Higher-efficiency radiator cooling fans switch off when they are not needed. Their design lest them deliver more air from the same amount of horsepower, the company maintains, and also helps reduce noise.

* More highly refined controls allow the engines to be shut down at temperatures higher than 50 degrees F. Because of the difficulty in getting the huge diesel engines going, some rail yards allow their old engines to run much of the time.

The company has produced 23 test versions of the locomotive, which have been tried by four railroads, logging more than 5 million miles since 1978.

Even with lowered horsepower, trains are often carrying more power than they can use. For this reason, more railroads are installing "black boxes" with a toggle switch that allows the engineer to cut off one or more of the locomotives in multi-engined trains. These engines operate at idle while the others run at full speed, where they are most efficient. Semiautomatic and computer-controlled devices to accomplish the same purpose are being developed.

The railroads will also be the beneficiaries of another advance, but one that involves the trucking industry. Moves to deregulate the freight industry are expected to bring more cooperation between trucking companies and railroads in the 1980s. That's particulary so in "piggyback," where truck trailers are carried on railroad flatcars designed for this purpose.

Now, the Atchison, Topeka & Santa Fe Railway has improved on the concept with a system of trailers it claims will save the company 1.5 million gallons of fuel a year. Called the "Fuel Foiler," the rail car looks sort of like a capital "I, " the narrow middle making it much lighter. The cars are designed to be connected in units of 10, each unit carring a single trailer.

The Fuel Foiler's "trucks," or sets of wheels, are set between the cars, rather than underneath them. This means the truck trailers ride lower, reducing wind resistance. The truck arrangement also means the cars in "Ten Pack" units can be coupled together more closely, reducing slack action between the cars.

Santa Fe has put 10 of the "Ten Packs" together in a train carrying a total of 100 trailers. The lighter weight and lower profile, the railroad says, means that only three locomotives, instead of four, are needed for power. In tests, the railroad claims to have saved 6,000 gallons of fuel per 4,400-mile round trip between Los Angeles and Chicago.

Another use of truck trailers is an idea some 20 years old, but one that is getting renewed attention in these fuel-hungry days. Called the "road railer," it is a truck trailer with rubber tires for highway travel and flanged railroad wheels that can be lowered for the rails. On the railroad, the trailers are linked in much the same way an automobile and a trailer are hooked together.

The developers of the road railer -- Bi-Modal Corporation of Greenwich, Conn. , and the North American Car Company of chicago -- maintains that its fuel consumption is 75 percent less than highway trucking and 45 percent less than piggybacking.

Finally, the railroads are even getting into the solar power picture, though their trains are a long way from being run by the sun. The Southern Railway and Canadian Pacific are experimenting with solar power to operate grade crossing protective devices, like those flashing red lights that warn motorists of oncoming trains. The solar devices are used in place of commercial electric power and standby batteries. the solar devices use special batteries to store, literally, the sun's power "for a rainly day."