Disk brakes Disc brakes on freight cars?

Are there AAR bogies with disc brakes?

From a fast survey of literature, the answer is very few to No us freight trucks are equipped for disc brakes.

I don't know much about the physical sizes and configurations of different types of brake. The standard freight-car truck frame is designed for use with clasp brakes (with places to mount brake cylinders and space for the brake rigging): would it have to be modified to accommodate the sorts of disk brakes often used on passenger rolling stock?
---
The North American freight railroad system depends on interchange: cars belonging to one railroad (or other company) operate on the track of other railroads, and can be repaired by other railroads' mechanical staff. Introducing disk brakes on freight cars would probably involve re-writing the agreements and conventions governing interchange: think in terms of years of lobbying and committee work. If there are disk brakes somewhere in use on otherwise conventional freight trucks, it might be on isolated systems that don't interchange with other rail carriers (something like, e.g., the Western Australian iron ore, mine to seaport, railways).

I understand that Europe is moving towards disk brakes on freight cars. There was a piece in Railway Gazette about a new truck using the standard design that would allow disk brakes on tank cars a few weeks ago (I’m traveling so on a phone or I’d have the link).

It is easy to weld brackets for disc brake calipers even to cast steel frames or bolsters. The car in the pic has 100 metric tons gross weight and 80 tons of brake force. With high speed, very cold whether and heavy braking there is a big problem with spalling wheel treads.
The use of disk brakes have easyed the problem. The cars also have an extra air feed pipe.

There are 1.6 million freight cars in service. From the DOT study I link to below, the 1980 cost per car was $11,700. Using a constant dollar calculator, the cost today would be $42,100 per car. Extending that cost , the total is $67.36 BILLION.

Bengt, do you really think the shippers will buy into that?

Link to pdf: https://railroads.dot.gov/sites/fra.dot ... ED%20B.PDF