|
Madison Co. Virginia | Kooiker - 9/10/2024 11:16
Its "insurance".
Kind of like taking a 2024 cell phone along in your pocket when you go out cruising in your 50's, 60's or 70's car.
Two other reasons I can think of -- UP would rather not use the railcar brakes any more than necessary, since it's expensive to replace brake shoes on that many axles. They, like everyone else, use electric resistive braking on the locomotive whenever possible, to convert excess rolling energy into heat energy, with no wearing parts involved in the conversion. Steam locomotives have no way of providing resistive braking, so there's an economic advantage to keeping a diesel-electric locomotive in the consist.
Another reason is to take some of the load off of the steam locomotive, and conserve water and fuel. the extensive infrastructure needed to fuel and water those locomotives is gone now, and extra logistics are needed to keep it going. At least one of the yellow cars between the Big Boy and the diesel-electric is an additional tender car, which helps, but doesn't completely eliminate the fuel/water logistics problem.
It wouldn't surprise me if the diesel is doing most of the work while the train is in remote areas. The steamer would still be providing some aid all the time, since steam is needed to carry lubricating oil throughout the cylinders. But then while rolling through towns, they dial back the diesel, and give the crowds the bark and smoke they expect to see from the steamer. | |
|
Big Boy
