What is the maximum grade that a modern (can motor) Sunset steam engine or pair of diesels will pull an 8 car passenger train up?
Original Post
Replies sorted oldest to newest
Depends on a few situations. Here are some of the factors which will affect maximum grade:
1) stock pulling power of the engine steam or diesels
a) what sized steam? 4-6-4, 4-8-4, 2-6-6-4? etc
b) diesels A-1-A, B or C trucks on each?
2) will steam engines or diesels be modified with added weight
3) what kind of passenger cars? brass, plastic, aluminum – which mainly affects weight for the train
4) what kind of trucks, friction bearing or ball bearing?
5) are there pickup wipers on the trucks? which will introduce drag
In most cases I've seen Sunset steam–unless heavily modified with tuned drive and added weight–will have trouble pulling and average weight 8 car passenger train. (average going by 8 GGD aluminum cars). Sunset Diesels the newly delivered units I've seen have no problems without modifications. Partially to answer I would say 2.5% for the diesel pair, likely more and almost 1% for unmodified Sunset Steam. On flat they are ok but once they get on a grade they have trouble.
I try not to exceed 2.5%.
If you are interested, we have a video recently taken by a videographer of the O Scale Union Connecting RR at NYSME. Most of the footage is taken on the 2.5%, of what I call triple whammy–Grade+SuperElevation+Curve.
Descrption of some trains
Prospector : Key ABBA (repowered by Jerry Snow) and 9 PRB passenger cars
MT Vernon: Kohs GG1, Jerry Snow powered R50B and various brass passenger cars
NYC: Sunset E7 AB 6 GGD Aluminum cars
Broadway: Sunset E7 AB (extra A not needed) and 8 GGD Aluminum cars + 1 Atlas Plastic
CoalDrag: MTH F7 ABA
Originally Posted by pitogo:
Depends on a few situations. Here are some of the factors which will affect maximum grade:
1) stock pulling power of the engine steam or diesels
a) what sized steam? 4-6-4, 4-8-4, 2-6-6-4? etc
b) diesels A-1-A, B or C trucks on each?
2) will steam engines or diesels be modified with added weight
3) what kind of passenger cars? brass, plastic, aluminum – which mainly affects weight for the train
4) what kind of trucks, friction bearing or ball bearing?
5) are there pickup wipers on the trucks? which will introduce drag
In most cases I've seen Sunset steam–unless heavily modified with tuned drive and added weight–will have trouble pulling and average weight 8 car passenger train. (average going by 8 GGD aluminum cars). Sunset Diesels the newly delivered units I've seen have no problems without modifications. Partially to answer I would say 2.5% for the diesel pair, likely more and almost 1% for unmodified Sunset Steam. On flat they are ok but once they get on a grade they have trouble.
Thanks MP,
So stay under 1" of rise for every 48" of run to get these up an incline with passenger cars in tow? If my math is correct to rise 12" would require 50' to be safe? (By length it will include two curves also.)
JD,
Is that 2R or 3R on that 2.5%?
