The refurbishment of Teddington Lock began in September 2007. The Lock had deteriorated significantly and the refurbishment, incorporated several elements.
These works, included the construction of a new floating pontoon as a tail lay by for the lock – Intermarine Ltd provided and fitted the pontoons. The pontoons were held in place by driven tube piles some 14m long.
A collapsing concrete wall was also replaced with a new pre-cast concrete wall and the revetment was replaced with pre-cast concrete slabs with stone inlay. Access for cranes and materials to the works was particularly challenging; achieved by installing a temporary bridge spanning one of the existing locks.
Barge Lock Works
Mackley’s assisted the Environment Agency with fitting new lock gates. Divers bolted on new stainless steel seals to the quoins and installed new service channels across the base of the lock. New hydraulics were also fitted to the lock gates and access to the services improved.
Launch Lock Works
This involved the replacement of 2 pairs of timber lock gates with new steel ones. Existing cills were removed and replaced with new concrete ones with stainless steel sealing plates, together with repairs to existing quoins. The tidal position of Teddington Lock has meant that the gate weights are different – 9.5 tonnes downstream, 8.5 tonnes upstream.
A cofferdam was designed to keep water out by transferring the load to the lock walls in the gate recess, but could work backwards by transferring the load onto the other end of the recess. The cofferdam weighing approx 25 tonnes at each end, was fabricated on site, and put together underwater by divers. Sheet piles were not driven, but scribed and cut to suit the irregular invert of the lock.