Dry Dock

An artificial basin into which ships are floated, then the entrance to the basin closed by a gate and the water pumped out, leaving the vessel resting dry, her keel on keel-blocks, and her sides supported by bilge-shores. Also a huge platform which is sunk so as to allow a vessel to be floated over it, then the dock raised by different appliances, lifting the vessel entirely out of the water, and supported as explained above. Dry docks are described under the following heads:

A Graving Dock, strictly speaking may be either a basin or platform, but the name is employed principally in connection with basin or stationary docks. The word "graving" means the cleaning of a vessel's bottom, and this may be done as well on a floating as on a basin dock.

A Sectional Dock is a platform on which a vessel is raised out of water by a series of air-tight boxes.

A Floating Dock is another name for a sectional dock.

A Balance Dock is a platform so-called owing to the means provided for retaining it perfectly level by pumping water into or out of the side chambers as required.

A Box Dock is the name sometimes given to a basin dock.

A Basin Dock is the name at times applied to a stationary dock.

A Stationary Dock is a basin dock.

A Portable Dock is a floating dock.

A Screw Dock is constructed specially for small vessels, being a platform which is raised and lowered by means of large iron screws connecting the platform and the stationary frame above it.

An Hydraulic dock is a platform which is lifted clear of the water by means of chains pasing over pulleys in the side frames of the dock and connecting with a hydraulic engine. (See Gridiron: Wet Dock.)