Took a look at the online version of the Subway track maps,doesn't show where the loop was connected to the leads to the
Kamen Rider wrote:there's a bellmouth for it just before the North side manhattanbound track leaves the tunnels, and that's all I've seen.The existence of a blind bellmouth makes sense. such an arrangement has been done several times in subway history to provide for uncertain future construction. The history of the BRT includes that originally, the lcoal and express tracks on Broadway in Manhattan were going to go to City Hall, and the tracks across the North side of the Manhattan Bridge would run along Canal Street and begin/end on the West side. but that was changed for reasons unknown to me into having the Broadway express tracks go over the bridge, and discontinuous "express" tracks providing space for car storage between Cith Hall and Canal Street. It makes sense that space was allowed for a loop in Brooklyn, between Dekalb and the bridge, but without building such a loop until the arrangement in Manhattan was resolved.