Distance between RR car wheels/axles per truck?

[Semper Vaporo]

Is there a Standard distance between the axles on a 2 axle truck?

[cacole]

I doubt that there's a standard distance because different types of trucks would have differences -- an Andrews truck would probably be different than an ASF Ride Control, for example.

[edblysard]

If you mean a ACF standard 70 ton two axel freight truck, check the AAR manual of interchange for diagrams and requirements.

[dehusman]

Typically 5' 6".

[CShaveRR]

There were standards.  It was 5'0" back in the days of Andrews trucks and their contemporaries (40-ton and 50-ton, and probably 70-ton), but increased to 5'6" when the wheel diameter increased from 33" to 36" in the 100-ton trucks.

[gopherstate]

I don't have any information on old trucks, but the present standards are:

5 1/2 x 10 bearing (50 ton) - 66" with 33" wheels

6 x 11 bearing (70 ton) - 68"  with 33" wheels

6 1/2 x 12 bearing (100 ton) - 70" with 36" wheels

7 x 12 bearing (125 ton) - 72" with 38" wheels

I don't have the numbers for a 6 1/2 x 9 bearing, but I would guess they would be the same as the 6 1/2 x 12.

Matt

[CShaveRR]

If the truck length is dependent on wheel diameter (not entirely, as we can see), does anyone know if the truck with 28-inch wheels for installation under certain trilevel auto racks is shorter?

[AgentKid]

CShaveRR

If the truck length is dependent on wheel diameter (not entirely, as we can see), does anyone know if the truck with 28-inch wheels for installation under certain trilevel auto racks is shorter?

On another thread someone observed that it seemed like not too many people go to page two, or further back, to check on older threads, so I thought I would do exactly that. And I recalled I was very curious to hear if anyone had an answer to this question.

I am going to go out on a limb here and suggest the axle spacing may be on the wider end of the spectrum, considering the number of times you see autoracks mixed in with intermodal cars. This would seem to be a higher speed service. Even though the wheel diameter on autoracks is smaller than most, it seems like the axle spacing would be wider, to prevent "hunting" or whatever the correct term is, at the higher speeds you see these cars being used at.

I am hoping that by moving this thread back to the front page on a Sunday night, on Monday someone will be bright eyed and bushy tailed enough to provide an answer to this question.

Thank you,

Bruce

[Paul_D_North_Jr]

How standardized - or the opposite, interchangeable - are freight car truck side frames ? 

Can they accept more than one bearing size, as long as the bearing adapter fits the mating surfaces on both the side frame and the bearing ?  Obviously, a 70-ton truck shouldn't be carrying bearings for a 100-ton truck - but what about the other way around ?

The 28" wheels that Carl mentions are mainly to keep the car's overall height down, not because of light weight (although that's also true), or a short length, so a more standard length might still be used ?

- Paul North.      

[gopherstate]

Axle spacing on low profile (28" wheels) autorack trucks are 63".  These smaller wheels use the standard 70 ton bearings (6 x 11).

Different size rated truck components can not be mixed and are not interchangeable.  Even components on the same size trucks have limited interchangability depending on style of truck (Barber, Ride Control, or National among others) and even the number of buttons on each side frame.  The side frame buttons are used to indicate the precise distance of the wheelbase.  A side frame may have from 1 to 5 buttons and a side frame on any truck must be within one button of its mate.