Brooklyn Navy Yard's 350-ton hammerhead crane for installing turrets and guns aboard the new battleships. This crane, like its counterpart at Norfolk, was of the turn-table type, rather than a pintle frame. The crane was provided with two main 175-ton trolleys, arranged in tandem on a single track, which could be operated independently or jointly, an auxiliary 50-ton trolley, with a reach of 190 feet, and an auxiliary crane of 15-ton capacity traveling on top of the main rotor or hammerhead. These installations gave these cranes a capacity of 350 tons at 115 feet reach, 175 tons at 150 feet, 50 tons at 190 feet, and 15 tons at an extreme reach of 240 feet[10].

The crane was used for placing turrets and massive gunbarrels on the decks of big warships. According to a page at today's Brooklyn Navy Yard website[1], the Hammerhead Crane was paid for out of an appropriation of $20 million dollars of public works funds through the Naval Appropriation Act of 1938. This is not super-clear or super-reliable information, but it's a lead to be followed up. The 1938 Times article[2] includes the crane in a list of other projects that are known to be New Deal, e.g. turret assembly facility and improve shipbuilding ways: both WPA. Also, bear in mind: this is 1938, when congress was still reluctant to appropriate big military budgets.

1. Yard Guardian: The 350-ton Hammerhead Crane, brooklynnavyyard.org (accessed 14 June 2018)
2. Navy Equips Yards to Build 40 Ships in Huge Program, New York Times, 20 Nov 1938, pp.1,26: "... The expansion construction work currently under way in the nine navy yards is shown in the following table, which is official ... The list, involving only funds being currently expended for shore facilities contributing directly to the expansion and omitting minor sums, is as follows: ... NEW YORK—$5.283,406—Turret assembly facilities, $750,000; improving shipbuilding ways, $1,190,000; addition to structure shop, $1,218,180; hammerhead crane, $1,112,234." The source of funding (Navy or New Deal agency) is not specified (it only says "government"), but the other items listed are identified elsewhere (e.g. here) as New Deal projects.
3. Navy Yard Here Dooms Big Crane, New York Times, 25 Nov 1962, p.239: "The big crane was built at a cost of $938,000 in 1941 ... It was erected on 1,700-foot-long Pier G — the best and longest pier at the yard — for one specific reason; to lift gun turrets and barbettes (turret bases) for battleships." Here again, no mention is made of the original funding source.