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On the sunset limited, why does Amtrak uses 2 engines when 1 engine is strong enough and would save on fuel cost?
Kiernan Member # 3828
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Provide electricity for the cars?
notelvis Member # 3071
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To avoid a stranded train in the event of an engine failure?
There are lots of remote places along that route where a train stranded without air-conditioning would be a very bad thing very quickly.
Southwest Chief Member # 1227
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Amtrak has a power surplus and it's smarter to have two locos instead of one.
Many of my Desert Wind trips were cut short because the single F40 died. Some times the HEP worked but we needed a freight helper for motive power, and with the freight gearing we could never get up to track speed. And if you think UP is bad to Amtrak now, imagine back then how long it took them to send helper locos. One trip took close to six hours just to get a helper loco!
So one loco is never a good idea.
gp35 Member # 3971
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Yeah I thought it was for in case an engine die. However before Katrina and Rita, didn't sunset use single engine east of New Orleans?
CG96 Member # 1408
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Another reason to have two engines is the acceleration. Two engines make it easier to speed up when leaving the station.
PaulB Member # 4258
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I doubt that 1 locomotive would handle the train. Beaumont Hill is a grade to be reckoned with. There are also grades through Arizona and into Texas. You don't want to make this train any later than it already is.
PaulB Member # 4258
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quote:Originally posted by gp35: Yeah I thought it was for in case an engine die. However before Katrina and Rita, didn't sunset use single engine east of New Orleans?
Yes they did. I think that's because there weren't any significant grades between Orlando and New Orleans.
Geoff M Member # 153
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quote:Originally posted by PaulB: I doubt that 1 locomotive would handle the train. Beaumont Hill is a grade to be reckoned with. There are also grades through Arizona and into Texas. You don't want to make this train any later than it already is.
I agree with your latter point, but surely 1x 4000hp+ engine ought to be able to pull 9-10 cars (let's say 600 tons) up a 2% grade without breaking too much of a sweat? Our toy trains in the UK do that, and we have much smaller engines!
Geoff M.
jgart56 Member # 3968
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Being neither an electrician nor an engineer and being more than willing to be corrected:
I think it has something to do with the fact that one locomotive would be providing both the electricity for the entire train as well as the tractive effort. I would imagine that providing the HEP lessens the tractive effort somehow? Am I on the right track here or am I way off?
gp35 Member # 3971
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Is it possible for 1 engine to power the coaches and 1 to power the trucks. I was just thinking of ways to cut fuel use and cost.
Eric Member # 674
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quote:Originally posted by jgart56: Being neither an electrician nor an engineer and being more than willing to be corrected:
I think it has something to do with the fact that one locomotive would be providing both the electricity for the entire train as well as the tractive effort. I would imagine that providing the HEP lessens the tractive effort somehow? Am I on the right track here or am I way off?
You're on the right track! A certain amount of available horsepower (HP) is 'stolen' when the HEP is engaged. There have been occasions, such as engine failure on a unit, when the crew turns off the HEP to gain more HP out of their remaining unit(s), especially on steep grades, or to maintain schedule.
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