The huge dock gates that govern the flow of Thames into West India Dock are undergoing a £920,000 repair, providing a challenge for river-borne engineers.

At 160 tonnes each, they needed to be floated out of position as they were too heavy for a crane to handle.

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The gates, which date back to 1929, have seen the arrival and departure of cruise lines, luxury yachts, naval vessels and barges which have used South Quay as a berth.

The Canal & River Trust – the charity that looks after the docks – has been upgrading the gates to withstand corrosion from the salt water in the Thames; improving the pintel – a top hat shaped steel object which the gate stands on – on the lock bed; and relining the seals between the bottom of the gates and the lock bed to make the lock watertight.

At 160 tonnes each, the gates are so heavy that they have to be floated out of position, rather than being craned out

The project, which costs £920,000, is the single largest part of the Trust’s programme to repair waterways across the country. In London this has already included repairing lock gates in Mile End and in Kentish Town, where over 3,000 people took the opportunity to walk along the bottom of the drained Regent’s Canal.

Canal & River Trust project manager Colin Perkins said: “At other locks around the country we crane the gates out for repairs but the ones in West India Dock are so big that we have to float them off.

“It’s certainly an unusual sight to see the water pumping out of a gate and it slowly rising out of the water and tilting flat: it’s like it has a life of its own. The work is very technical, particularly because of the size of the gates and weight of thousands of cubic metres of water, as well as the tidal pressure of the Thames.

“Ships from all over the world come to London and these are the only gates that enable access into Docklands, so it’s vital they are in top condition.”

West India Docks Lock

  1. The gates each weigh 160 tonnes - the equivalent of two Boeing 737s
  2. Each gate is 11.6m high by 15.1m wide
  3. The lock is 178m long. It is also 24m wide and 12m deep, holding up to 51,264 cubic metres of water – more than 20 Olympic swimming pools
  4. An average of 150 vessels come through the lock each year. This includes luxury yachts, cruise liners, navy vessels, cruisers, tall ships, historic boats - the majority of which stay in South Dock.