The project involved the construction of a sea lock between the existing Old Quay and Old North Wall, with closure structures to connect the existing structures to the lock body, which formed an inner marina consisting of floating pontoons, restraint piles, support facilities and a slipway extension. A piled Approach Berthing Structure to the seaward side of the lock was installed to allow approaching vessels to moor in the Outer Harbour.
Navigation equipment, lighting and gate control equipment was also provided and housed in a Control Building constructed to the north side of the lock body. Masonry repair, permeation grouting and the installation of a steel sheet piled cut off wall along the length of the Old Quay and Old North Wall was required to reduce the permeation of water into and out of the Inner Harbour. The Masonry repair was undertaken in-house working off floating pontoons and was programmed around tide levels. The work consisted of repointing, crack sealing and other general repairs.
The Old Quay was a Grade II listed structure and stringent requirements had to be met.
All associated dredging work and harbour services infrastructure was also included.