As I understand it, K brakes were banned in interchange on tank cars as of October 1, 1953 and had a final ban (returning cars)by January 1, 1954.
Is there evidence that there was a large scale rebuilding of tank cars to equip them with AB brakes at this time or were many of the cars scrapped then?
Was there any "grace" period?
By 1954-55 should I expect to be running only AB equipped tank cars (since interchanged privately owned cars predominate)?
