KBCpresidentDiesel engines are built and designed at lower elevations generally, and are air-breathing, so I'm guessing they could experience the mechanical equivilant of altitude sikness" at such high elevations a--slight decrease in efficiency.
I recall watching a British-made TV series on trains around the world back in the 1980s where they visited a line in South America that (IIRC) crossed the Andes mountains. They noted that the railroad dieselized by buying diesels with the same horsepower as the steam engines, but then found they had to buy bigger locomotives (FM TrainMasters I think?) with greater horsepower, because the diesels didn't work as well in the thin mountain air.
Given the fact that turbines had a relatively short life on real railroads, I'd have to assume there were no situations where they proved to be more efficient than either diesel or electric locomotives however.
wjstixI recall watching a British-made TV series on trains around the world back in the 1980s where they visited a line in South America that (IIRC) crossed the Andes mountains. They noted that the railroad dieselized by buying diesels with the same horsepower as the steam engines, but then found they had to buy bigger locomotives (FM TrainMasters I think?) with greater horsepower, because the diesels didn't work as well in the thin mountain air.
Many hotroders put "blowers" on their engines. Would this work on diesels at high altitudes?
KBCpresident The thing would look like a frigging B-17 on rails, it'd be awesome! It'd require a lot of scratchbuilding, but still...
More realistic... push an armored gun car in front of the locomotive, and armor the locomotive.
The Polish, Germans, and Soviets did this in World War 2.
The gun car can be armor clad, or just a flat car with lots of sandbags. Both are realistic.
davidmurrayMany hotrodders put "blowers" on their engines. Would this work on diesels at high altitudes?
Basically, no.
The vast majority of diesel engines manufacturerd since 1984 have been turbocharged. Some stationary engines remained naturally aspirated for a while, but now nearly 100% of all diesel engines are turbocharged.
Installing a roots type blower (supercharger) on a diesel that is already turbocharged is pointless. A roots type blower is a positive displacement mechanical air pump. When the air coming in is thinner and below 14.7 PSIA it becomes less efficient.
A turbocharger, which is a centrigufal air pump, becomes faster as air to the inlet decreases, so it stays efficient at "lower" high altitudes, but there are problems if the altitude becomes too high.
Detroit Diesel manufactured some 53 and 92 series engines after 1984 that were both turbocharged and equipped with blowers. Their design needed the positive displacement blower to start and idle. Once under load, and the turbocharger built up pressure, the blower provided no performance benefit. This design was dropped in the early 1990s.
There were some bizarre experiments with different types of air pumps for diesel engines at high altitudes. These were mainly to address issues when heavy trucks operated in the American and Canadian Rocky Mountains back in the 1960s. One of these involved a mechanical "barrel type" supercharger driven by a second driveshaft from the transmission. I have seen drawings. It was crazy.
All electronically controlled diesel engines that I know of derate at high altitude, usually about 5,000 feet. There are "ambient air pressure" sensors installed on these engines so the control module can calculate operating altitude.
Mechanically controlled diesel engines also had provisions for high altitude derate of several designs. If these derates failed, the turbocharger would overspeed in the thin air and fail.
Beyond that... NDA!
-Kevin
Living the dream.
The giant railway layout, Miniatur Wunderland in Hamburg, Germany has a bridge between two buildings that connects Europe with the U.S, and South America. Anything is possible.
NDA, my rear end.
Very well-established precedent in reciprocating aircraft motors is to use multiple-speed supercharging to maintain constant intake-tract pressure at altitude. A similar approach could easily be used on a locomotive since the actual peak boost pressure can be almost ridiculously small by comparison with 'high performance' supercharging (as e.g. with the diesel-sourced 6-71 Roots blower design used in drag racing, or on the turbocharging side the sequential twins used in truck or tractor pulling).
All you're assuring is that the engine performance at higher altitude matches specs at sea level.
In practice, it can be cheaper just to do as Kevin indicated and derate a 'standard' locomotive operating at a known range of altitude. But that's very different from saying that it's hard, let alone impossible, to do.
Steam locomotives, by contrast, lose comparatively little effective combustion heat release at up to 15K altitude but their cylinder efficiency can go up dramatically as you get into lower air pressure.