Shiplift

Submarine HMS Astute on a shiplift, being brought out of the building hall towards the water

A shiplift is a modern alternative for a slipway, a floating dry dock or a graving dry dock. A shiplift is used to dry dock and launch ships. It consists of a structural platform that is lifted and lowered exactly vertically, synchronously by a number of hoists. First, the platform is lowered underwater, then the ship is floated above the support, and finally the platform with support and ship is lifted and the ship is brought to the level of the quay.