The gates of the barrier were fabricated in sections at Cleveland Bridge's Darlington works and assembled at Port Clarence on the River Tees. The gates, gate arms and rocking beams were transported from the Tees to the Thames by barge and lifted into position by two very large floating cranes operated by Neptun of Hamburg (now part of Smit International). The mechanical and hydraulic machinery was built by Davy Loewy, Henry Berry and Vickers and trial assembled in Davy's Darnall works. Delays to the civil works required changes to the construction and installation sequence, but commissioning was relatively uneventful and the first trial operation of all the gates together was carried out on 31 October 1982.