Lock (water transport)

A ship lock - for small vessels: Boot lock - just called lock, is an Engineer building that watercraft permits, such as barrages for navigability of a watercourse or channel levels induced water level differences between sections to overcome a waterway. The process of the passage of a vessel through a lock is called smuggling. From the linked through the sluice water sections one who is designated by the higher water level than the upper hand, the one with the lower water level than underwater.

With modern navigation locks is usually to chamber locks. After construction or operating principle, a distinction different lock types. For example: double lock, sluice, sluice twin, shaft lock or Koppelschleuse. Depending on the location, a distinction between internal locks, sea locks or port locks. On a sluice building several of these distinguishing characteristics may apply. In the designation of a single lock is limited usually to one or two features. Two or more structurally independent of each other shipping locks step a case be referred to as a lock group; Example: Lock Group Münster of the Dortmund- Ems Canal.

Locks are also known as descent structures. In this term, however, it is a generic term, with the other technical solutions are referred to Overcome water level differences, such as the rather the functional principle of an elevator -like boat lifts.

Construction and principle of operation

A lock consists of a lock chamber with a double lock design in a building of two interconnected lock chambers, and each chamber of two or more lock heads with sluice gates, of which generally never more than one is open at a time. Locks with more than two goals can be found for example at intersections of channel systems, the boiler lock in Emden and the round lock at Agde, or to divide a long lock chamber with a central gate as am Main. With closed lock gates can be the water level in the lock chamber, and with him raise floating in the lock chamber ships through water inlet from the headwater to the level of the upper or lower water flow through the lower water. If the respective water level is reached, the delimiting floodgate opens, and the ships can move out of the lock chamber in the waters adjacent section or retract from it into the lock. For inlet and outlet no pumps are needed in running waters; the water flows from the upper water in the lock chamber and the lowering of the lock chamber into the bottom water. For shipping canals is lost in smuggling water from the upper to the lower stance. To compensate for water is pumped back or it becomes a part of the smuggling water directed at saving locks when emptying the lock chamber in lateral saving basins and used for the next fill again. Examples include the double sluice Anderten the Mittelland Canal and the sluice Henrichenburg of the Dortmund- Ems Canal. A variant is the twin lock, in which a part of the smuggling of water is used to fill a lock chamber of the other lock chamber of a double lock; Example: Lock Herne -east of the Rhine- Herne Canal.

For filling and emptying the chamber serve slider ( plate contactors, radial gates, etc.). These are located in older locks directly into the lock gates or in the Torumläufen. With modern navigation locks the slide sit in longitudinal channels. To minimize turbulence during filling of the sluice chamber, the water is supplied through the longitudinal passages in the chamber walls or in the bottom chamber (basic cycles ) which are distributed over the entire length of the chamber. The slides were previously moved by hand with winds, today the slides are moved hydraulically or with Elektrohubzylindern.

Locks are now used for a drop height of about 25 meters; for greater heights boat lifts are usually required. For economic reasons, it is trying to get by with as few giant steps that it have a greater height of fall. Navigation locks with high head, the lock chamber are completed through the passage opening to bottom water out with a transverse wall (mask) are referred to as bay locks; Example: double shaft lock Anderten the Mittelland Canal. Locks, which must overcome high heads can also be realized as a lock staircase with many contiguous navigation locks along with their Schleusenvorhäfen. Examples include the Nine Locks in France, the lock staircase Niederfinow the Havel - Oder waterway in Germany (36 m drop height, 1934 replaced by a boat lift ), the flight of locks at the Three Gorges Dam in China or the Vytegra - lock staircase in the Volga Sea-Baltic Canal (80 m head ) in Russia. With several directly behind the other lock chambers, where the Untertor one is also Obertorplatz the next lower lock chamber, one speaks of a Koppelschleuse.

Locks in rivers jammed with closed lock gates the water and therefore need a parallel weir over which the accumulated water can drain as far as it is not used for smuggling.

At sea locks at the entrance of the harbor or from Seekanälen with connection to tidal waters, the lake is dependent on tides times the upper hand and sometimes under water, while the water level of the harbor or channel is kept constant. Such barrier or protection locks are also used in the internal area junctions of navigation channels in rivers with flood to be expected; Example: sluice Hanekenfähr of the Dortmund- Ems Canal.

A sea lock consists only of a main lock (like a dry dock, hence the name). This lock type was often built in the 19th century. Since it does not require lock chamber, space and money is saved. The smuggling is done only with the same water level before and after the main lock (with tidal sea ports ), the time window for this amounts to about 1 hour, a serious disadvantage of this lock type. Even with lift-locks, a Dockschleusung be carried out, this is required if the length of the hull exceeds that of the lock chamber.

History

The word lock is derived from the Medieval Latin sclusa ( weir), which has its origin in the Latin excludere ( exclude ).

The Greek historian Diodorus, in the restoration of the ( begun under Pharaoh Necho II, but probably only under the Persian king Darius I in 498 BC completed ) Bubastis - canal between the Nile and the Red Sea to 280 BC have the Egyptian Diadochenherrscher Ptolemy ( 284-246 BC ) at its eastern end a double (?) let II Philadelphus install - lock. This channel fell in the 1st century BC, but was restored under the Roman emperor Trajan in the 2nd century AD. With restrictions on the channel until the late 8th century AD in use.

In China, the channel lock for ships 984 by Qiao Weiyue, Deputy Commissioner for Transport was invented in Huainan. Until then Gradients were overcome by slides or ramps in the local channels, which the ships repeatedly damaged and led to the theft of cargo. In addition, you had very drought affecting the operation of the slides. Qiao Weiyue now had two "hanging gates" at a distance of 50 paces (76 m) building, the space roofed over, secure the shores and so built a sluice. Henceforth were differences in height of 1.2 to 1.5 m per gate no longer a problem.

1325 the first ship lock was built as a chamber lock in Germany. Technical precursor were jam locks and weirs with boat slip. Weirs were weirs that were opened after the damming; the barges floated then downhill on the tidal wave. For weirs with boat slip the boat was lowered on a ramp or; such boat slides were commercially used on small watercourses until the 19th century in use. At the High Rhine between Rheinfelden Eglisau and there are several boat slides ( officially: Slipp plants) and transport carts for motor boats up to 20 m, sometimes even 30 meters in length. Also at locks of other waters can be found, for example, a fish Canoe or boat pass lanes as spillway chute for pleasure boats.

Records

The largest lock in Germany and second largest lock in the world is the outer harbor for the navy belonging Seeschleuse IV entrance to Wilhelmshaven. She has two lock chambers with a length of 390 m, a width of 60 m and a threshold depth of 14.75 m below middle harbor water level (volume 320,000 m³). A gate ( sliding ) with a clearance width of 60 m weighs about 1700 tons. For comparison with a single lock: The Main lock in Ottendorf has a length of 301 m at 12 m width (volume of about 27,500 m³).

The three locks savings Hilpoltstein, Eckersmühlen and Leerstetten of the Main- Danube Canal have with 24,67 meters height the largest heads of all built in Germany locks.

The biggest lock in the world is the 1989 on the right bank of the Scheldt opened " Berendrecht lock " the port of Antwerp in Belgium. It is 500 m long, 68 m wide and 17.7 m deep (volume 600,000 m³). With a smuggling it can be funneled with a maximum draft of 11.85 m and several barges up to four ocean-going vessels. The mean tidal range is 4.94 m in front of the lock.

On the left bank of the Scheldt arises to a new area of the port of Antwerp, the Deurganckdock lock the same width and length but with greater depth of 4 m to accommodate post-Panamax ships with 2016 to 12,000 TEUs in March can.

The Panama Canal is expanded in 2007; 2014 new locks with 427 m length and 55 m width be built ( scheduled completion: 2015; details here).

Heraldry

An exceptional Common figure, the lock dar. in the arms of Kleinmachnow