A dock is an enclosed water basin, usually closeable with a lock or dock gate, in which vessels can be built, repaired, loaded or unloaded without being affected by tides or currents. Docks are essential elements of ports and shipyards.
Types of docks
Several types of docks are recognised in hydraulic engineering:
Dry dock
A dock that is pumped dry after a ship has entered. The vessel rests on keel blocks so the hull becomes accessible for maintenance, painting or repairs.
Wet dock
A dock kept permanently at a high water level, independent of tides. Common in ports with a large tidal range so ships always sit level with the quay.
Floating dock
A pontoon with hollow walls that can be submerged by filling ballast tanks. The vessel sails in, the dock is pumped out and rises with the ship dry on its deck.
Building dock
A temporary or permanent dock used for constructing large concrete elements such as caissons, tunnel segments or immersed-tube sections, which are then floated to their destination.
Construction aspects
Building a dock combines several disciplines:
- Watertight enclosure — usually reinforced concrete with diaphragm walls
- Dewatering — pumping systems to keep the dock dry
- Gates — sealing off the water basin
- Keel blocks — supports for vessels during drydocking
- Cranes and quays — for loading, unloading and repairs
Applications
Famous examples include the dry docks at Rotterdam and Portsmouth shipyards, and the building docks used to construct elements of the Maeslantkering and Eastern Scheldt storm surge barriers.
Related terms
- Lock
- Caisson method
- Diaphragm wall
- Dewatering
- Excavation pit
Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.