Four graving docks were also formed, opening out of the first (Upnor) basin.
There are two large fish-docks, and, for general traffic, the Royal dock, communicating with the Humber through a tidal basin, the small Union dock, and the extensive Alexandra dock, together with graving docks, timber yards, a patent slip, &c. These docks have an area of about 104 acres, but were found insufficient for the growing traffic of the port, and in 1906 the construction of a large new dock, of about 40 acres' area and 30 to 35 ft.
Depth of water, and floating and graving docks.
Parliamentary powers were obtained to construct a graving dock capable of accommodating the largest class of warships.
In 1880 the graving dock accommodation consisted of one double dock at the extremity of Dockyard creek, known as Nos.