Dry dock reopened to boost warship engineering support

The arrival of a new caisson at Portsmouth Naval Base has enabled a former dry dock to be reopened for the first time since 2002.

This multimillion pound uplift will increase the level of engineering support and warship maintenance on the base, boosting operational capability.

Reopening this dock takes the base capability up to 11 dry docks which can support ships up to the size of a Type 45 destroyer.

Captain Bill Oliphant, Captain of the Base said: “Today is a significant moment in the regeneration of Portsmouth Naval Base. 14 Dock has been unavailable since 2002 so the arrival of this new caisson to give us access to this dock once again is a huge shift in capability.

“A caisson is like a tailor made plug which fits into the end of the dry dock, forming a seal so that the dock itself can then be pumped empty of water, giving access to the underside of the ship that is in for maintenance.”

The new caisson is designed to remain in service for 25 years without the need for servicing, boasts a new paint finish and has an operating system involving electric pumps to pump out the ballast water rather than being blown out by compressed air. Routine maintenance and inspections can also be undertaken without the need to remove the caisson from service.

The caisson has already been put to the test with a full drain-down of the dry dock for maintenance crews to assess how much cleaning needs to be done to it before the first ship will be brought in for works.

Getting a warship into a dry dock is essential to carry out crucial underwater maintenance that otherwise would be expensive or impractical to be completed in the water by divers or in a habitat.

All ships incur wear and tear from deployments and regular maintenance work is necessary to continue our operational capabilities. This improved facility enables Portsmouth Naval Base to regenerate warships with greater speed and efficiency.