Our observations of available photos, while far from comprehensive, shows at least three versions of the stern aircraft crane base. One was used on the battleships that were modernized in the late 20s and early 30s, the other two types were basically the same but with some small differences in the base casting. The strongback bracing could be either open or filled in. The booms of these cranes were mostly constructed of rounded pipe save for the Baltimore class and some later Cleveland class ships which had a more solid, girder-like construction. I believe all were designed to lay flat on the deck when necessary.

The catapults of the Omaha class were different than those of other cruisers and I believe the three installed on Fletcher class destroyers were also of this type.