Any steam expert out there?

[Jacktal]

I have developped a special interest for steamers lately and have started collecting different models.I already own five different and would like,with time,to own one of each available in "N" scale,with the exception of a Big Boy and a Challenger,which I'd love but call for completely unreal prices on eBay.

When I survey available steamers,I often see "Light Mountain" and "Heavy Mikado" as a designation for these two particular models,which raises a question to my mind.Are there any "Heavy Mountain's" and "Light Mikado's"?I already own a Mikado(a jewel by the way)but it's not identified as either "light" or "heavy".Just would like to know...thanks.

[andrechapelon]

QUOTE: Originally posted by Jacktal

I have developped a special interest for steamers lately and have started collecting different models.I already own five different and would like,with time,to own one of each available in "N" scale,with the exception of a Big Boy and a Challenger,which I'd love but call for completely unreal prices on eBay.

When I survey available steamers,I often see "Light Mountain" and "Heavy Mikado" as a designation for these two particular models,which raises a question to my mind.Are there any "Heavy Mountain's" and "Light Mikado's"?I already own a Mikado(a jewel by the way)but it's not identified as either "light" or "heavy".Just would like to know...thanks.

Yes, there are "Heavyy" Mountains and "Light" Mikados. The "Light" and "Heavy" designation usually refers to locomotives produced under the auspices of the United States Railroad Administration during WWI and copies built afterward to the same specifications. The USRA produced 12 designs. In some instances, there were "Light" and "Heavy" versions. The "Light" versions were built to a maximum axle load ot 55,000 punds and the "Heavies" to an axle load of 60,000 pounds. USRA designed locos of the following wheel configurations are as follows:

0-6-0
0-8-0
Mikado type:
2-8-2 (Light)
2-8-2 (Heavy)
Santa Fe type
2-10-2 (Light)
2 -10-2 (Heavy)
2-6-6-2
2-8-8-2
Pacific type:
4-6-2 (Light)
4-6-2 (Heavy)
Mountain type:
4-8-2 (Light)
4-8-2 (Heavy)

USRA 2-8-2 lights were made at one time by Rivarossi and marketed alternatively by Atlas and Con-Cor in N scale. The 2-8-2 offered by Kato is a USRA Heavy Mikado. The current 4-8-2 offering by Bachmann is a USRA light.

Hope this helps.

Andre

[ndbprr]

Light engines were designed to help when weight was an issues like light rail or bridges. Bridges in particular have a special rating called the Cooper rating that say's how heavy a load a bridge can handle. In fact one of the things that allows the railroads today to haul the cars they do is the fact that most bridges were designed to handle the weight of steam engines and have a Cooper rating far in excess of current loading. This factor is something most railroads are very grateful for since replacing all the bridges would be impossible today just from the cost perspective alone.