The Thompson Dock and Gate
The Thompson Dock is essentially Titanic’s footprint.. ‘Graving’ docks were used to check the part of a ship that is usually under water. The name Graving Dock is an old one and originates back in the mists of time. It is thought it might have come from an old naval term to ‘grave’ or clean a ship’s bottom by burning off attached debris and then retarring. A graving dock is also the only dock within a shipyard that has stepped sides (called Arches or Alter Courses).
At the time of its construction The Thompson Dock was the biggest Dry Dock in the world, built for the biggest ships in the world. RMS Olympic was the first ship dry-docked here in April 1911, followed later by her sister ships Britannic and Titanic. The Dock was named after Robert Thompson who was Chairman of the Harbour commissioners at the time. The Dock was always left dry, in readiness for the next ship. It would then be flooded and the gate ‘stabled’. Next, the ship would be hauled in, the gate replaced in position and the dock pumped until the ship rested on the keel blocks down the centre of the dock floor. When work was completed on the hull of the ship, the process would be reversed.
The gate of the dock is a piece of high quality Edwardian engineering. As it moves the gate clears the head of the stable by inches and only the horns which lock it into the closed position on the other side of the dock protrude. Greenheart wood made the seal with the concrete wall of the dock… to stop the very occasional leak. The gate was hauled out or into position by massive chains powered by a three cylinder brass hauling engine located on the east side of the dock entrance. The gate also had a second position which allowed vital maintenance to the elaborate running gear which would normally have been under water or under the gate. The designers of the Olympic Class Liners took maximum advantage of this additional length. The gate is riveted steel and the fact that it can be closed or opened in 5-7 minutes is a credit to the tenacity and innovation of its designers & builders.