Okay, knowing nothing about railroads except what the local hobby shop has, and obviously roller bearing are better, but why can't friction bearings be used, fire?
Also, is the 240K the weight of the crane, or the lifting capacity of the crane?
One more, what's the difference in railroad classes?
Precisely, friction bearings rely on a half bronze babbit that sits in the journal box, with the wheelshaft riding direcly on it, in the old days if the journal box ran out of oil the friction would heat the box up soo fast that it would ignite the wadding material and residual oil.
I couldnt quite see the lift specs on that , can't see the boom, but would suspect 240k.
Railroads classes are just a designation, such as your bigger railroads , such as Union Pacific, CSX , Norfolk Southern.
Class 2's wouild be regional rr's , for example, my area is the Reading And Northern, Lycoming Valley,
3's would be really small switching operation.