as opposed to?
Saw this on a flat car on an inbound freight. And it was full of wheels - (must have been freight wheels).
What are my options on sizes?
Mookie,
There is a bunch of different sizes…two that come to mind are the 36" wheels under auto racks…(at least I think they are 36s) and the larger 44" wheels on most other freight cars.
Passenger car wheels are different than freight car wheels, although I would assume there are a few different sizes there too.
Locomotive wheel sets are handled differently also, due to the gear on the axle.
Because of the difference is sizes and the way the wheels have to handled, each is shipped in dedicated cars, often home made things, but designed for one type of wheel only.
I have seen freight car wheels shipped on flats in racks, in mill gondolas and in old converted steel coil cars…the SP had quite a few of these.
What do you mean what are your options? Gonna get a set on your car? lol
there is not just diameter issues. different cars and there trucks have different weight ratings. the wheels under an autorack or spine car do not need to be rated(thickness/strenght) the same as a coal gon/hopper rated at almost two and a times the weight but with the same number of wheels. Stay happy. RMR
Most common wheel sizes :
28" Tri- level and some Bi-level auto racks
33" Bi-level autoracks and other assorted cars with 70 ton truck sets
36" & 38" on most freight cars carrying heavier loads
Thank you…
Millie will take the 28’s…with baby moon spinners.
…Autos in general: 15 to 22". Now many standard from 16 to about 17 or 18". Width is an issue too. Some on autos up to 8". Some special applications a bit wider. My little Xtreme has 8" wide wheels and the lexus has 6".
While it doesn’t occur with any great frequency, I have seen cars with mis-matched wheel diameters installed on the same truck. Sing me the ‘Somebody, done somebody wrong’ song.
I can only imagine the damage that could be done if some one didn’t catch that for some time.
And another add on here - since it is so tiny, and don’t want to open another thread for it - for all the ICE fans - your # 6215 SD40 (well, it sure looked like one to me) is running around down here in Lincoln today. This is the first one we have ever seen. But we don’t watch every day, either. Looked great to me! Nice to have something different. He was keeping two of our 40’s company.
Maybe one of the working Rails will comment, but I don’t know that it would damage anything, assuming that the axle fit in the truck properly. If a 33" wheel-set was put into a truck designed for a 36" wheel-set that end of the truck would only sit 1.5" not 3" low again assuming that the mounting doesn’t already account for this difference, as I am not familiar with this type of mechanical detail. I wouldn’t think, but I could be wrong that the bolster would be damaged by that combination. Putting 33" wheels in a truck for 36" wheels the brake rigging may not have the travel to properly apply. Putting 36" wheels in place of 33" inch wheels may not work, because of insufficient clearance for the brake rigging, but those are just my best guesses, maybe Railway Man, or someone else more knowledgeable on the topic will pipe in with more accurate info.
The carknocker has the proper diameters for freight car wheels. Ed might be right, too, since they do everything bigger in Texas! [;)]
Wheel diameter has a lot to do with the tonnage rating of the cars. As has been discussed here often enough, the main determinant of a car’s gross rail load is the bearing size, measured in width and diameter. But the wheel sizes go along with this.
50-ton (if you can find ‘em any more) and 70-ton cars use 33-inch wheels, normally. For certain low-deck flat cars (these could be intermodal flats as well as auto racks, though you don’t see many conventional pig flats any more), 28-inch wheels are used just to lower the cars’ clearance profiles. These are still nominally 70-ton wheels and bearings, but gross rail loads are often limited on an individual-car basis by altering the springs in the trucks.
100-ton cars (preceded for a few years by 85-ton cars) use 36-inch wheels. Wheels of this size are also what you’ll find under the 286K Gross Rail Load cars.
38-inch wheels are generally found only under 125-ton (315K GRL) cars, or the intermediate trucks on articulated stack cars.
Because of the different bearing sizes associated with the different wheel diameters, it would be hard to have a mismatched pair of wheelsets get very far.
Better quit for now, in spite of the fact that I’m on a roll…
So…it could cause some kind of wear or damage or problem if it was allowed to go a little distance w/o notice? Or would it be very noticeable right away?
The apparent difference in diameter is likely a new wheel installed with worn wheels. I cannot imagine anyone putting different wheels in a freight car truck !
If it’s physically possible, I can imagine it’s been done. Can’t be a good thing, though.
…I agree with Larry, if it’s possible…it’s been done. I wonder if the side support parts {of the truck}, have that much travel for uneven rail as designed…I’d think they might.
Same size brake shoes used at both axles would not conform properly at the wrong axle…{until worn to fit}…
Just my thoughts…not being a RR specialist.
At least you say them on a freight car; what gets me is when I see the wheel sets riding on a flatbed tractor trailer on the interstate.
I think that Randy’s right–a worn wheel could be an inch or more smaller in diameter than a new one. And with the differences in bearing sizes, a bearing either wouldn’t fit or would fit 'way too loosely into the truck sideframes of the wrong size.
Yes, Quentin, it is possible to agree with Larry–I’ve done it a time or two myself! (Couldn’t resist that golden opportunity! [}:)])
Carl and Randy are on the money.( a worn wheel can be an inch or smaller in diameter ).
Also a 6 x11 adaptor would not fit on top of a 6 1/2 x 12 wheel and also the adaptor
would not fit in the pedestals a 100 ton side frame.
Carl and Randy are on the money.( a worn wheel can be an inch or smaller in diameter ).
It is possible to fit a smaller bearing into a larger adaptor , and it is possible get a 7X12 bearing under a 6 1/2 X12 adaptor it will wear out the bearing fairly quick , I have seen it done , but if a wheel were to wear as much as an inch in diameter smaller the wheel would be bad anyhow .
All the tank cars that come into my work have 36" wheels