Answer
A- 1. Graving Dock – Constructed on land near coastal waters. The Vessel is shifted inside the DD and rested
on the blocks. After the ship is in required position, the g ate is closed & the water is removed.
2.Floating Dock – It is in the form of a U structure, mainly used in salvage to carry ships that have met with an accident & are damaged to an extent that has made them unable to sail further to a coastal dock.
The ship is brought near the channel where the floating will partly submerge itself & the ship slides inside the dock. Once the ship is in position , the dock is deballasted to drain the water from its hollow floors & walls, which support the vessel on the blocks arranged on the dock’s floor.
3.Marine Rail dock or Marine Railway or patent slips – A sloped ramp where ships are pulled out of the water using winches. It is usually employed for smaller vessels. These are inclined planes that extend from the shoreline into the water with a geared hauling machine used to pull vessels out of the water through a combination of horizontal & vertical movements. It is less expensive, fast, convenient, eco method.