The King George V lock (KGV lock) is in the south-east of London’s Royal Docks and is managed by the Royal Docks Management Authority (RoDMA). It consists of three sets of mitre gates (16m x 17m each gate) in a lock approximately 243.8m long, 30.48m wide, and a cill depth below chart datum of 6.90m. The lock allows access into the Royal Docks from the River Thames.
The outer gates isolate the lock from the River Thames, the area between the outer and middle gates is described as the quarter lock, and the space between the middle and inner gates is described as the three-quarter lock.
When the gates are in the closed position the weight of the water behind them presses all the sealing faces together, creating the seal.
The whole of the Lock was refurbished in 1989 with new gates (manufactured by Ravestein BV of the Netherlands); new sluice paddles; and new control, hydraulic and electrical services.
The existing lock gates have dry buoyancy chambers in their base and tidal upper chambers and weigh 250 tonnes.
The outer gates form a public right of way with access across the top of the gates whilst also doubling as part of the Environmental Agency’s flood defence. It is planned for the existing outer lock gates to be replaced in approximately two years (circa 2022) as they would have been designed for a design life of 30-50 years, and fatigue of the steelwork is likely to be a limiting factor for what residual life there is. Even if the gates had a 50-year design life in 1989 there would need to be a significant amount of reassessment of the structures if they are to be modified to provide a flood gate with a working life of a further 50 years.