Wheel Size for Auto Racks

Model Railroader Prototype information for the modeler
1

Hello,

Could someone please advise on the prototypically correct wheel sizes for the following modern cars

  1. Double Deck Auto Racks These seem to have 33" from Walthers

  2. Triple Deck Auto Racks These seem to have 33" from Walthers

  3. Articulated Auto Racks These seem to come with 36" from Athearn and Atlas

I thought they were smaller for vertical clearance reasons??

Thanks

2

Don’t know but since no one has tried to answer this I’ll take a stab at it. Autoracks don’t haul a lot of weight. If an autorack has twenty cars at 4000# each the car could still be in regulations if it had one axle since the weight restriction is 80,000# per axle. I supect that the smaller wheels also help reduce weight and keep the car lower and the weight of the load is inconsequential. I also suspect with articulated cars that the 36" wheels are a result of the articulaton sizing and need to carry additional weight on the trucks since there are three axles per section instead of four. This is all speculation however.

3

Vertical clearance is only a problem for prototype tri-levels, so they roll on 28-in wheels.

4

Even with a full load of automobiles, you have to remember that each auto only carries a minimal amount of fuel, no cargo and obviously no passengers so in terms of train tonnage, autoracks are very light. In fact, some autorack trains are pulled by just a single locomotive.

To my knowledge all modern autoracks run on 28" wheels. The manufacturers stick on the 33" wheels because they’re off-the-shelf parts which are obviously used on their other products, and most people can’t really tell.

That’s also what aftermarket parts manufacturers are for…

5

Thanks to all. I have spent considerable time on manufactuerers(Thrall for example) websites, etc. to find out. I believe all the responses are helpful and correct as far as I can tell. I have gone to 28" on the triple deck. I am not certain on the double, nor the articulated truck on those units. Typically that truck holding two units has larger wheels–at least on well cars.

6

Tri-Level and Bi-Level autoracks are relatively the same height; the tri-level racks are meant to hold small cars while the bi-level racks are meant to hold minivans, SUVs, etc - vehicles that have a taller vertical height.

Ergo, a tri-level autorack would carry Toyota Corollas while bi-level autoracks would carry Honda Elements.

7

What is the overall height of these HO cars in inches,…for clearance in tunnels and on a helix?

Are these cars taller than a double stack container load?