155th St Subway Station by Urbahn Arch (Photo: Ola Wilk Photography)

USA: Urbahn Architects and Zafra Minhas Construction have completed a $1·8m flood mitigation and storm resilience programme at New York City Transit’s 155th Street/8th Avenue Subway station in Harlem, served by B and D Local trains.

After the extensive flooding and damage caused by storm Sandy in 2012, NYCT designated this station as one of seven on the Subway network that needed to be storm-proofed to reduce disruption to operations and minimise future repair costs. The work was carried out as part of a $32m federally funded programme of works covering stations, tunnel portals, ventilation shafts and other critical assets.

155th Street Subway Station Flood Logs pressure testing (Photo: Zafra Minhas Construction)

The 155th Street station is just 100 m from the Harlem River, in an area that was completely flooded by Sandy and is vulnerable to storm surges, which have in the past often left it temporarily unusable.

Work carried out included rebuilding the perimeter around the entry stairs as a see-through but flood-resilient wall. This comprised panels of structural glass overlaid with an architectonic railing of 6 mm thick protective stainless steel blades made from modular, interlocking 1·8 m tall aluminium sections. These are designed to be carried from storage by station staff and installed rapidly across the 8·5 m wide mouth of the main stairwell in the event of a flood, forming a barrier capable of resisting the pressure from a 1·5 m storm surge. Watertight doors at the platform level have also been installed to protect power supply and other operational assets.

The upgrading took eight months to complete. The station has only one entrance/exit, which had to remain open throughout the modernisation work. A quadruple-width staircase leads down from the street to a full-length mezzanine that spans the platform and tracks.

155th St Subway Station by Urbahn Arch (Photo: Ola Wilk Photography)