The BMT Sea Beach Line is a rapid transit line of the BMT division of the New York City Subway, connecting the BMT Fourth Avenue Line at 59th Street via a four-track wide open cut to Coney Island in Brooklyn. It has at times hosted the fastest express service between Manhattan and Coney Island, since there are no express stations along the entire stretch, but now carries only local trains on the N service, which serves the entire line at all times. During rush hours, select Q trains serve the full line in the northbound direction only, while several W trains serve the line north of 86th Street. Extent and service The following services use part or all of the BMT Sea Beach Line: Route description The modern line begins as a split from the BMT Fourth Avenue Line at a flying junction immediately south of 59th Street. Between the station and the split, crossover switches are provided between the local and express tracks of the Fourth Avenue Line, and then the express tracks curve east under the northbound local track to become the beginning of the Sea Beach Line. After emerging from the tunnel under Fourth Avenue, the two separate Sea Beach tracks rise on either side of a ramp which formerly connected to the original line to the Brooklyn shore at 65th Street in Bay Ridge. After passing the former junction with the line to the shore, the Sea Beach widens to the width of four tracks. All stations have two side platforms with no platform access to the express tracks anywhere on the Sea Beach right-of-way. Before and after Kings Highway, there are crossover switches to the southbound express track from the northbound express track. On both sides of Kings Highway, crossovers exist to allow express trains to switch to the local tracks before the station or local trains to switch to express after the station. The express tracks end south of 86th Street as the line becomes double-tracked, and cut diagonally adjacent to the Coney Island Yards. After several yard connections, the line ends at the Coney Island–Stillwell Avenue terminal. Express tracks The express tracks were originally intended to host the Coney Island Express. Service was carried on these tracks twice in the line's history — for summer weekend service to Chambers Street from 1924 to 1952 and again from 1967–1968 to provide a fast rush-hour