Until the 1930s, there were tide gates here separating the fully tidal section of the Bow Back Rivers from the semi-tidal level of the Lee Navigation. There were pairs of pointing gates, one pair each side of the central island. Vessels could only pass through the gates when the tide made a level with, or was above, the maintained level of the navigation. The tide gates were replaced in the 1930s by Carpenters Road lock (see separate pictures) to the East. The pillars in this picture used to support a footbridge.