The onset of the Second World War increased activity in the industrial area considerably, resulting in the Winslow Marine Railway and Ship Building Company to be awarded navy contracts to build minesweepers on Bainbridge Island, Eagle Harbor Shipyard. World War II vintage shipyard crane, known as a "whirley crane" because it could rotate 360 degrees and Raidroad Tracked Portal Gantry/Whirley Cranes at the shipyard served as the principal hoisting devices of the shipyard. Whirley Cranes are also representative of the shipbuilding and repair machinery acquired by the shipyard during the 1940s to accommodate the increased urgencies of wartime naval ship production activity.

Whirley Cranes was first used to build Grand Coulee Dam in Washington state (Wirley Crane On display CW 3204 at Shipyard 3, project of the City of Richmond, National Park Service and Rosie the Riveter Trust) The use of Whirley Cranes was a major innovation in the mass production of maritime ship building industry. The cranes made it possible to turn huge ship structural pieces around and over during the pre-assembly process so that welders could complete relatively simple welding seams parallel to the ground. The cranes were also used in groups working together to move large pre-assembled parts of a ship into place in the basins so the ship could be fitted together, generally by welding. The result was a previously unimagined rate of astonishing production. Wirley Gantry Cranes are still utilized in many industries requiring heavy lifting, some are museum landmarks in many cities, as testmony to magnitude of this invention in ship building industry.