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Operation Deadlight

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Operation Deadlight was the code name for the Royal Navy operation of November 1945 – February 1946 to scuttle German U-boats surrendered to the Allies after the defeat of Germany near the end of World War II . After the surrender, political discussions continued between the Allies concerning the final disposal of the surviving German naval vessels, the result of which was an agreement to retain 30 U-Boats in total, to be divided equally between the UK, the USA and the USSR. The remainder would be scuttled.

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46-450: Of the 156 U-boats that surrendered to the allies at the end of the war, 116 were scuttled as part of Operation Deadlight. The Royal Navy carried out the operation, and planned to tow the submarines to three areas about 100 miles (160 km) north-west of Ireland and sink them. The areas were codenamed XX, YY, and ZZ. They intended to use XX as the main scuttling area, while towing 36 boats to ZZ to use as practice targets for aerial attack. YY

92-445: A combination mooring line. The two-headed mooring bitts is a fitting often-used in mooring. The rope is hauled over the bitt, pulling the vessel toward the bitt. In the second step, the rope is tied to the bitt, as shown. This tie can be put and released very quickly. In quiet conditions, such as on a lake, one person can moor a 260-tonne ship in just a few minutes. Quick release mooring hooks provide an alternative method of securing

138-402: A concrete foundation was raised 50 feet (15 m). above low water of neap tides . A small tidal rise spreading tidal water over a large expanse of lagoon or inland backwater causes the influx and efflux of the tide to maintain a deep channel through a narrows no longer confined by a bank on each side, becomes dispersed, and owing to the reduction of its scouring force, is no longer able at

184-606: A definite channel and protecting the mouth from being blocked up by littoral drift. This system was long ago applied to the shifting outlet of the river Yare to the south of Yarmouth , and has also been successfully employed for fixing the wandering mouth of the Adur near Shoreham , and of the Adour flowing into the Bay of Biscay below Bayonne. When a new channel was cut across the Hook of Holland to provide

230-411: A fixed length of pier as they occupy only their width of pier rather than their length. The disadvantages of Mediterranean mooring are that it is more likely to result in collisions and that it is not practical in deep water or in regions with large tides. A mooring used to secure a small boat (capable of being beached) at sea so that it is accessible at all tides. Making a Travelling Mooring involves (1)

276-473: A hundred of them. Because the U-boats were constructed in the pre-atomic age, the wrecks contain metals that are not radioactively tainted , and are therefore valuable for certain research purposes. The ministry awarded no salvage rights, due to objections from Russia and the U.S., and potentially from Great Britain. Between 2001 and 2003, nautical archaeologist Innes McCartney discovered and surveyed fourteen of

322-411: A little above low water of neap tides , on which open timber-work is erected, provided with a planked platform at the top raised above the highest tides. In other cases, they consist entirely of solid material without timber-work. The channel between the jetties was originally maintained by tidal scour from low-lying areas close to the coast, and subsequently by the current from sluicing basins; but it

368-466: A means of constricting a channel. The term derives from the French word jetée , "thrown", signifying something thrown out. One form of jetties, wing dams , are extended out, opposite one another, from each bank of a river, at intervals, to contract a wide channel , and by concentration of the current to produce a deepening. Jetties have been constructed on each side of the outlet river of some of

414-414: A moderate distance from the shore effectually to resist the action of tending to form a continuous beach in front of the outlet. Hence a bar is produced that diminishes the available depth in the approach channel. By carrying out a solid jetty over the bar, however on each side of the outlet, the tidal currents are concentrated in the channel across the bar, and lower it by scour. Thus the available depth of

460-418: A mooring by smaller, weighted heaving lines. Once a mooring line is attached to a bollard , it is pulled tight. Large ships generally tighten their mooring lines using heavy machinery called mooring winches or capstans . The heaviest cargo ships may require more than a dozen mooring lines. Small vessels can generally be moored by four to six mooring lines. Mooring lines are usually made from manila rope or

506-449: A rode (a rope, cable, or chain) running to a float on the surface. The float allows a vessel to find the rode and connect to the anchor. These anchors are known as swing moorings because a vessel attached to this kind of mooring swings in a circle when the direction of wind or tide changes. For a small boat (e.g. 22' / 6.7 m sailing yacht), this might consist of a heavy weight on the seabed, a 12 mm or 14 mm rising chain attached to

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552-430: A straighter and deeper outlet channel for the river Meuse , forming the approach channel to Rotterdam , low, broad, parallel jetties, composed of fascine mattresses weighted with stone, were carried across the foreshore into the sea on either side of the new mouth of the river, to protect the jetty channel from littoral drift, and cause the discharge of the river to maintain it out to deep water. The channel, also, beyond

598-471: A synthetic material such as nylon . Nylon is easy to work with and lasts for years, but it is highly elastic . This elasticity has advantages and disadvantages. The main advantage is that during an event, such as a high wind or the close passing of another ship, stress can be spread across several lines. However, should a highly stressed nylon line break, it may part catastrophically, causing snapback , which can fatally injure bystanders. The effect of snapback

644-408: A weak spot of the beach, which along a low coast may be at some distance off; and this new outlet in its turn may be blocked up, so that the river from time to time shifts the position of its mouth. This inconvenient cycle of changes may be stopped by fixing the outlet of the river at a suitable site, by carrying a jetty on each side of this outlet across the beach, thereby concentrating its discharge in

690-429: Is a technique for mooring a vessel to pier. In a Mediterranean mooring the vessel sets a temporary anchor off the pier and then approaches the pier at a perpendicular angle. The vessel then runs two lines to the pier. Alternatively, simple moorings may be placed off the pier and vessels may tie to these instead of setting a temporary anchor. The advantage of Mediterranean mooring is that many more vessels can be connected to

736-619: Is analogous to stretching a rubber band to its breaking point between your hands and then suffering a stinging blow from its suddenly flexing broken ends. Such a blow from a heavy mooring line carries much more force and can inflict severe injuries or even sever limbs. Mooring lines made from materials such as Dyneema and Kevlar have much less elasticity and are therefore much safer to use. However, such lines do not float on water and they do tend to sink. In addition, they are relatively more expensive than other sorts of line. Some ships use wire rope for one or more of their mooring lines. Wire rope

782-402: Is hard to handle and maintain. There is also risk associated with using wire rope on a ship's stern in the vicinity of its propeller. Mooring lines and hawsers may also be made by combining wire rope and synthetic line. Such lines are more elastic and easier to handle than wire rope, but they are not as elastic as pure synthetic line. Special safety precautions must be followed when constructing

828-413: Is located), (c) attaching to the mooring line to the boat, and (d) then pulling the boat out and away from the beach so that it can be accessed at all tides. A mooring used to secure a narrowboat (capable of traversing narrow UK canals and narrow locks) overnight, during off boat excursions or prolonged queuing for canal lock access. Water height with minimal exceptions, remain constant (not-tidal); there

874-446: Is now often considerably deepened by sand-pump dredging . It is protected to some extent by the solid portion of the jetties from the inroad of sand from the adjacent beach, and from the levelling action of the waves; while the upper open portion serves to indicate the channel and to guide the vessels, if necessary (see harbor ). The bottom part of the older jetties, in such long-established jetty ports as Calais , Dunkirk and Ostend ,

920-641: Is secured to a mooring to forestall free movement of the ship on the water. An anchor mooring fixes a vessel's position relative to a point on the bottom of a waterway without connecting the vessel to shore. As a verb, mooring refers to the act of attaching a vessel to a mooring. The term likely stems from the Dutch verb meren (to moor ), used in English since the end of the 15th century. These moorings are used instead of temporary anchors because they have considerably more holding power. They cause lesser damage to

966-420: Is used in the following explanation in a generic sense. Mooring is often accomplished using thick ropes called mooring lines or hawsers . The lines are fixed to deck fittings on the vessel at one end and to fittings such as bollards, rings, and cleats on the other end. Mooring requires cooperation between people on a pier and on a vessel. Heavy mooring lines are often passed from larger vessels to people on

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1012-439: Is water height variance in close proximity to locks . Types of canal moorings: Mooring pin (boat operator supplied) driven into the ground between the edge of the canal and the towpath with a mooring-line rope to the boat. Mooring hook (boat operator supplied) placed on the (permanent) canal-side rail with either (boat operator supplied) rope or chain-and-rope to the boat. Mooring ring (permanent) affixed between

1058-559: The Great Barrier Reef off the Australian coast, a vast number of public moorings are set out in popular areas where boats can moor. This is to avoid the massive damage that would be caused by many vessels anchoring . There are four basic types of permanent anchors used in moorings: A vessel can be made fast to any variety of shore fixtures from trees and rocks to specially constructed areas such as piers and quays . The word pier

1104-401: The "anchor", and a bridle made from 20 mm nylon rope, steel cable, or a 16 mm combination steel wire material. The heavy weight (anchor) should be a dense material. Old rail wagon wheels are used in some places (e.g. Clontarf, Dublin, Ireland) for this purpose. In some harbours (e.g. Dun Laoghaire, Ireland), very heavy chain (e.g. old ship anchor chain) may be placed in a grid pattern on

1150-579: The U-boat wrecks; including the rare Type XXI U-boat U-2506 , once under the command of Horst von Schroeter ; the successful Type IXC U-boat , U-155 commanded by Adolf Piening and the U-778 , which was the most promising salvage. In 2007, Derry City Council announced plans to raise the U-778 to be the main exhibit of a new maritime museum. On 3 October 2007, an Irish diver, Michael Hanrahan, died whilst filming

1196-601: The approach channels to Venice through the Malamocco and Lido outlets from the Venetian Lagoon have been deepened several feet (metres) over their bars by jetties of rubble, carried out across the foreshore into deep water on both sides of the channel. Other examples are provided by the long jetties extended into the sea in front of the entrance to Charleston harbour, formerly constructed of fascines weighed down with stone and logs, but subsequently of rubble stone, and by

1242-669: The bar by banks. Jetties prolonging the Sulina branch of the Danube into the Black Sea , and the south pass of the Mississippi River into the Gulf of Mexico , formed of rubble stone and concrete blocks, and respectively, have enabled the discharge of these rivers to scour away the bars obstructing the access to them; and they have also carried the sediment-bearing waters sufficiently far out to come under

1288-551: The boats before they reached the scuttling areas, and those that did reach the area were generally sunk by gunfire rather than explosive charges. The first sinking took place on 17 November 1945 and the last on 11 February 1946. Several U-boats escaped Operation Deadlight. Some were claimed as prizes by Britain, France, Norway, and the Soviet Union. Four were in East Asia when Germany surrendered and were commandeered by Japan. U-181

1334-530: The bottom of the rode, such as the use of a length of heavy chain, the angle of force can be dropped further. Unfortunately, this scrapes up the substrate in a circular area around the anchor. A buoy can be added along the lower portion of rode to hold it off the bottom and avoid this issue. Non-line mooring ("hands-free") is used where pier time is highly valuable, and includes suction cups or magnets . It can also be used between ships. Mediterranean mooring, also known as "med mooring" or "Tahitian mooring",

1380-410: The depth of the water running from the anchor to the mooring buoy, the longer the rode is the shallower the angle of force on the anchor (it has more scope ). A shallower scope means more of the force is pulling horizontally so that ploughing into the substrate adds holding power but also increases the swinging circle of each mooring, so lowering the density of any given mooring field. By adding weight to

1426-411: The edge of the canal and the tow path, with (boat operator supplied) rope to the boat. Mooring bollard (permanent) affixed canal-side on lock-approaches for the short-term mooring of advancing boats and lock-side to assist in ascent and descent. Jetty A jetty is a structure that projects from land out into water. A jetty may serve as a breakwater , as a walkway, or both; or, in pairs, as

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1472-781: The end of the war, she survived to become a war memorial at the Museum of Science and Industry in Chicago . U-995 was transferred to Norway by Britain in October 1948 and became the Norwegian Kaura . She was returned to Germany in 1965, to become a museum ship at Laboe in October 1971. In the late-1990s, a firm applied to the British Ministry of Defence for salvage rights to the Operation Deadlight U-boats, planning to raise up to

1518-403: The influence of littoral currents, which, by conveying away some of the sediment, postpone the eventual formation of a fresh bar farther out (see river engineering ). Where a river is narrow near its mouth, has a generally feeble discharge and a small tidal range, the sea is liable on an exposed coast to block up its outlet during severe storms. The river is thus forced to seek another exit at

1564-465: The line of quays at the side, to enlarge the accommodation; and they also serve, when extended on a large scale from the coast of a tideless sea under shelter of an outlying breakwater, to form the basins in which vessels lie when discharging and taking in cargoes in such a port as Marseille . The approach channel to some ports situated on sandy coasts is guided and protected across the beach by parallel jetties. In some cases, these are made solid up to

1610-400: The marine environment, and are convenient. Where there is a row of moorings they are termed a tier . They are also occasionally used to hold floating docks in place. There are several kinds of moorings: Swing moorings also known as simple or single-point moorings, are the simplest and most common kind of mooring. A swing mooring consists of a single anchor at the bottom of a waterway with

1656-405: The outlet of the river Nervion into the Bay of Biscay has been regulated by jetties; and by extending the south-west jetty out for nearly 0.5 miles (0.80 km) with a curve concave towards the channel the outlet has not only been protected to some extent from the easterly drift, but the bar in front has been lowered by the scour produced by the discharge of the river following the concave bend of

1702-450: The rivers flowing into the Baltic , with the objective of prolonging the scour of the river and protecting the channel from being shoaled by the littoral drift along the shore. Another application of parallel jetties is in lowering the bar in front of one of the mouths of a deltaic river flowing into a tide — a virtual prolongation of its less sea, by extending the scour of the river out to

1748-419: The rope to the quay: such a system "greatly reduces the need for port staff to handle heavy mooring ropes … means staff have to spend less time on exposed areas of the dock, and [reduces] the risk of back injuries from heavy lifting". The Oil Companies International Marine Forum recommend the use of such hooks in oil and gas terminals. The basic rode system is a line, cable, or chain several times longer than

1794-608: The sea bed to ensure orderly positioning of moorings. Ropes (particularly for marker buoys and messenger lines) should be "non floating" to reduce likelihood of a boat's propeller being fouled by one. Pile moorings are poles driven into the bottom of the waterway with their tops above the water. Vessels then tie mooring lines to two or four piles to fix their position between those piles. Pile moorings are common in New Zealand but rare elsewhere. While many mooring buoys are privately owned, some are available for public use. For example, on

1840-399: The sinking of a heavy weight to which a block ( pulley wheel) is attached at a place where the sea is sufficiently deep at low tide, (2) fitting a block / pulley wheel to a rock or secure point above the high tide mark, and (3) running a heavy rope with marker buoy between these blocks. Mooring involves (a) beaching the boat, (b) drawing in the mooring point on the line (where the marker buoy

1886-422: The slope for supporting coal-tips. Pilework jetties are also constructed in the water outside the entrances to docks on each side, so as to form an enlarging trumpet-shaped channel between the entrance, lock or tidal basin and the approach channel, in order to guide vessels in entering or leaving the docks. Solid jetties, moreover, lined with quay walls, are sometimes carried out into a wide dock, at right angles to

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1932-481: The southwest jetty. As the outer portion of this jetty was exposed to westerly storms from the Bay of Biscay before the outer harbour was constructed, it has been given the form and strength of a breakwater situated in shallow water. Where docks are given sloping sides, openwork timber jetties are generally carried across the slope, at the ends of which vessels can lie in deep water or more solid structures are erected over

1978-436: The wreck as part of the salvage project. In November 2009, a spokesman from the council's heritage museum service announced the salvage project had been cancelled for cost reasons. Moored A mooring is any permanent structure to which a seaborne vessel (such as a boat, ship, or amphibious aircraft ) may be secured. Examples include quays , wharfs , jetties , piers , anchor buoys , and mooring buoys. A ship

2024-438: Was composed of clay or rubble stone, covered on the top by fascine-work or pitching, but the deepening of the jetty channel by dredging and the need that arose for its enlargement led to the reconstruction of the jetties at these ports. The nes jetties at Dunkirk were founded in the sandy beach, by the aid of compressed air, at a depth of 22.75 feet (6.93 m). below low water of spring tides; and their solid masonry portion, on

2070-627: Was renamed I-501 , U-195 – I-506 , U-219 – I-505 , U-862 – I-502 , and two other boats, U-511 and U-1224 , had been sold to Japan in 1943 and renamed RO-500 and RO-501 . Two U-boats that survived Operation Deadlight are today museum ships. U-505 was earmarked for scuttling, but American Rear Admiral Daniel V. Gallery argued successfully that she did not fall under Operation Deadlight. United States Navy Task Group 22.3, under then-Captain Gallery, had captured U-505 in battle on 4 June 1944. Having been captured, not surrendered at

2116-493: Was to be a reserve position where, if the weather was good enough, they could divert submarines from XX to sink with naval forces. Submarines that were not used for target practice were to be sunk with explosive charges, with naval gunfire as a fall-back option if that failed. When Operation Deadlight began, the navy found that many of the U-boats were in poor condition from being moored in exposed harbours while awaiting disposal. These issues, combined with poor weather, sank 56 of

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