The first three photos show the BMT Q cars as they were rebuilt by the museum into something close to their original configuration as BU gate cars. When originally constructed in 1904 , the cars had a higher clerestory roof.
The last photo is interesting as it shows three of the first convertibles used on the Brooklyn system. The cars had removable side panels which were removed during the warm months. There were curtains which could be pulled down when it rained. These cars date to the turn of the century and usually worked the likes of the Culver line to the Beaches. The train in the photo is on the 5th Ave El heading towards downtown Brooklyn . Since the panels are still in place, its probably just before or after summer. These cars survived until 1947 or so. None were preserved.
