wheelset question

[AllenB]

What is the difference between a 33" and a 36" HO wheelset? Probably a stupid question when I hear the answer (and I can hear it now..."3 inches").
Thanks!

 

[D&J RailRoad]

It represents the two wheel sizes on the prototypes. Regular freight cars, i.e. tanks, gondolas, flats use the 33" wheels while the TOFCs and COFCs use the 36" wheels. I think passenger cars use 36" as well for a smother ride.

 

[wheeler1963]

when looking at them, you'll see the difference in the side profile in height.

 

[diburning]

It represents the two wheel sizes on the prototypes. Regular freight cars, i.e. tanks, gondolas, flats use the 33" wheels while the TOFCs and COFCs use the 36" wheels. I think passenger cars use 36" as well for a smother ride.

Most but not all passenger cars use 36" wheels. Some used odd sizes that are not standard. Also, modern tank cars use 36, modern gondolas use 36, and TOFC/COFCs can use 28, 33, and 36

 

[Scordicus]

Regular freight cars, i.e. tanks, gondolas, flats use the 33" wheels while the TOFCs and COFCs use the 36" wheels.

Why do TOFC's and COFC's use the 36" wheels??

Is this because of weight of the cargo carried or the smoothness of the ride because of what's being carried, or something else??

 

[D&J RailRoad]

Why do TOFC's and COFC's use the 36" wheels??

Is this because of weight of the cargo carried or the smoothness of the ride because of what's being carried, or something else??

I don't know. Just from observation.

 

[diburning]

TOFCs and COFCs generally use 33" wheels unless they are articulated. On the ones where the truck is the articulation, they use 36" wheels as the truck is bearing half the weight of each car.

 

[Cjcrescent]

Wheel size on the cars is mostly determined by the amount of cargo in tons the cars can carry. Most cars that carry 70 tons or less, get 33". Cars that carry more than 70 tons generally get the 36". There are some exceptions, as in some articulated cars get 28" wheels due to height restrictions.

 

[LoudMusic]

What other standard wheel sizes are actively in use for modern freight and passenger cars? And modern locomotives?

What wheel sizes are available in HO?

Larger wheels are used on heavier loads, but what actual purpose does this serve? Is it simply a smoother ride, or is it because the weight is distributed over a larger patch? It also seems like larger wheels would create less friction heat in the bearings because the axle would be rotating less quickly (10% less in 33" vs 36").

But larger wheels weigh more, and even those it's minimal in comparison to the rest of the car it still has to be accounted for since it's a minimum of 8 x Number_Of_Cars. I can't find examples of 'weight of train wheels' on the web. Does anyone have those numbers? I realize it varies, but something within 10 pounds for each diameter?

 

[diburning]

Larger wheels will give a smoother ride, and the smoother ride will damage the rail less when going over switches, joints, etc. The larger wheels are also more durable because of the added load.

The wheel size also depends on how long the car is, and how many trucks it has as they also have to take into account the weight on the rails per axle. This is why schnabel cars have many trucks, but only have 33" wheels.