spaced every . Additional columns between the tracks, spaced every , support the jack-arched concrete station roofs. The ceiling height varies based on whether there are utilities in the ceiling. There is a gap between the trough wall and the platform walls, which are made of -thick brick covered over by a tiled finish. The walls along the platforms consist of a pink marble wainscoting on the lowest part of the wall, with bronze air vents along the wainscoting, and white glass tiles above. The platform walls are divided at intervals by green and rose pilasters, or vertical bands, with brown and buff-colored swags. In the original portion of the station, each pilaster is topped by blue, green, and yellow faience plaques with the letters "BH". White-on-green tile plaques with the words "Borough Hall", containing red, green, blue, buff, violet, and pink mosaic borders, are also placed on the walls. The platform extensions contain similar decorative elements. The ceilings contain plaster molding. At the extreme east end of the platforms, where they were extended in the 1950s to accommodate the current standard "A" Division train length, there is a brown trim line on beige tiles with "BOROUGH HALL" in white sans serif lettering. BMT Fourth Avenue Line platform The Court Street station on the BMT Fourth Avenue Line has two tracks and one island platform. The R stops here at all times; some rush-hour W trains stop here; and the N stops here during late nights. A single staircase from the western end of the platform goes up to the elevators to the western BMT mezzanine. Two staircases from the eastern end of the platform go up to the escalators and stairs to the IRT passageway. West of the station, the line goes through the Montague Street Tunnel under the East River to connect to the BMT Broadway Line and the BMT Nassau Street Line. All trains use the former connection; the latter was last used by the M train in June 2010 before it was rerouted to run via the IND Sixth Avenue Line. Design Since the tunnel descends to go underneath the East River, it was constructed with a deep-bore tunnel, making both track walls curved. The walls also still have their original Dual Contracts mosaic tablets and trim line. The name tablets have "COURT ST." in serif lettering, and tablets showing scenes of Borough Hall are located