Well dock

In modern amphibious warfare usage, a well dock or well deck, officially termed a wet well in U.S. Navy instructions when the well deck is flooded for operations, is a hangar-like deck located at the waterline in the stern of some amphibious warfare ships. By taking on water the ship can lower its stern, flooding the well deck and allowing boats, amphibious vehicles and landing craft to dock within the ship.

Evolution of structure and term

The structure on the modern naval amphibious ships does not exactly fit the traditional "well deck" definition of a weather, or open deck, that is lower than adjacent decks, surrounded by bulkheads that would, lacking proper drainage, form a catchment for water; however, the structure has its origins in such an exaggerated deep deck on World War II era tank landing craft (TLC) the British forces were considering. On July 19, 1941 Major R. E. Holloway, Royal Engineers, forwarded a design from a 1924 patent by Otto Popper of the Danube International Commission concerning a barge transporter for Danube barges. That evolved into the British TLC-C that would become the Dock Landing Ship (LSD) that had an open, very deep and special purpose well deck open to the elements and thus technically a "well deck" in the traditional definition.

Dock

Dock may refer to:

In transportation

In science

In computing

Places

People

Dock (maritime)

A dock (from Dutch dok) is either the area of water between or next to a human-made structure or group of structures involved in the handling of boats or ships, usually on or close to a shore, or the structures themselves. The exact meaning varies among different variants of the English language. "Dock" may also refer to a dockyard or shipyard where the loading, unloading, building, or repairing of ships occurs.

History

The earliest known docks were those discovered in Wadi al-Jarf, an ancient Egyptian harbor dating from 2500 BCE located on the Red Sea coast. Archaeologists also discovered anchors and storage jars near the site. A dock from Lothal in India dates from 2400 BCE and was located away from the main current to avoid deposition of silt. Modern oceanographers have observed that the Harappans must have possessed great knowledge relating to tides in order to build such a dock on the ever-shifting course of the Sabarmati, as well as exemplary hydrography and maritime engineering. This was the earliest known dock found in the world, equipped to berth and service ships. It is speculated that Lothal engineers studied tidal movements, and their effects on brick-built structures, since the walls are of kiln-burnt bricks. This knowledge also enabled them to select Lothal's location in the first place, as the Gulf of Khambhat has the highest tidal amplitude and ships can be sluiced through flow tides in the river estuary. The engineers built a trapezoidal structure, with north-south arms of average 21.8 metres (71.5 ft), and east-west arms of 37 metres (121 ft).

Rumex

The docks and sorrels, genus Rumex L., are a genus of about 200 species of annual, biennial and perennial herbs in the buckwheat family Polygonaceae.

Members of this family are very common perennial herbs growing mainly in the Northern Hemisphere, but various species have been introduced almost everywhere.

Some are nuisance weeds (and are sometimes called dockweed or dock weed), but some are grown for their edible leaves.

Rumex species are used as food plants by the larvae of a number of Lepidoptera species - see list of Lepidoptera that feed on Rumex.

Description

They are erect plants, usually with long taproots. The fleshy to leathery leaves form a basal rosette at the root. The basal leaves may be different from those near the inflorescence. They may or may not have stipules. There are minor leaf veins. The leaf blade margins are entire or crenate.

The usually inconspicuous flowers are carried above the leaves in clusters. The fertile flowers are mostly hermaphrodite, or they may be functionally male or female. The flowers and seeds grow on long clusters at the top of a stalk emerging from the basal rosette; in many species the flowers are green, but in some (such as sheep's sorrel, Rumex acetosella) the flowers and their stems may be brick-red. Each seed is a 3-sided achene, often with a round tubercle on one or all three sides.