The tower is high, wide at the base, and tapers gradually to below the first projection; its walls are thick and narrow to at the string course under the corbels. The bricks of this plain brick tower were made from clay obtained from excavations in the marsh adjoining the docks, and are set in blue lime mortar. Hoop iron bond is used in the walls to a considerable extent. The foundation of the tower is a solid masonry wall built upon a timber bearer piling. Approximately one million bricks were used in its construction.