|
Navigation Transit Markers
Navigation Transit Markers are posts placed alongside a navigation to allow powered craft to check their speed. Examples of these markers can be found at several locations along the River Thames in England. A navigation marker consists of a black and white ringed pole surmounted by a red open triangle. The configuration of the markers is made up of two pairs, each pair having one pole behind the other, and the pairs being separated by a set distance along the bank. Timing starts when the first two markers line up, and ends when the second pair line up. For a craft to be within the speed limit, it should take a minute or more to reach the second pair of markers after passing the first pair of markers. On the upper reaches of the Thames, the speed limit is 8 km per hour or 133.3 m per minute, and so the markers are set 133.3 m apart. On the River Thames, there are markers on the reaches above Teddington Lock, Sunbury Lock, Cookham Lock, Sonning Lock, Day's Lock and O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Thames
The River Thames ( ), known alternatively in parts as the The Isis, River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the Longest rivers of the United Kingdom, second-longest in the United Kingdom, after the River Severn. The river rises at Thames Head in Gloucestershire and flows into the North Sea near Tilbury, Essex and Gravesend, Kent, via the Thames Estuary. From the west, it flows through Oxford (where it is sometimes called the Isis), Reading, Berkshire, Reading, Henley-on-Thames and Windsor, Berkshire, Windsor. The Thames also drains the whole of Greater London. The lower Reach (geography), reaches of the river are called the Tideway, derived from its long Tidal river, tidal reach up to Teddington Lock. Its tidal section includes most of its London stretch and has a rise and fall of . From Oxford to the estuary, the Thames drops by . Running through some of the drier parts of mainland Bri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teddington Lock
Teddington Lock is a complex of three locks and a weir on the River Thames between Ham and Teddington in the London Borough of Richmond upon Thames, England. Historically in Middlesex, it was first built in 1810. The limit of legal powers between the Port of London Authority, the navigation authority downstream to the North Sea and that upstream to small headwaters of the river, the Environment Agency, is marked nearby by an obelisk on the "Surrey" (towpath, right) bank. The weir named Teddington Weir marks the river's usual tidal limit and is the lowest on the Thames. This lock is the lowest full-tide lock and second lowest of all-tide locks on the Thames. The complex of civil engineering or infrastructure in essence consists of a large long weir and three locks: a conventional launch lock in regular use, very large barge lock and a small skiff lock. The barge lock was made to accommodate long barges, steamers or passenger ferries and has an additional set of gates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunbury Lock
Sunbury Lock is a lock complex of the River Thames in England near Walton-on-Thames in north-west Surrey, the third lowest of forty four on the non-tidal reaches. The complex adjoins the right, southern bank about downstream of the Weir Hotel. The complex is two locks, old and new, and a narrow concrete divide, which are downstream of the original lock built in 1812. The older, hand-operated, was originally built in 1856, seldom used. The newer was opened in 1927 by Lord Desborough. Rollers and a slope adjoins for the portage (hauling) of small boats. The lock adjoins Sunbury Lock Ait. The lock has three associated weirs, upstream. The main weir is between Sunbury Lock Ait and Wheatley's Ait (north); the latter has two other weirs, one is a small part-time weir used in high flows. History The earliest major weir locally was built in 1789 specifically to divert water to create a deeper channel for navigation. Other such weirs locally were in place since medieval times ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cookham Lock
Cookham Lock is a Lock (water navigation), lock with weirs situated on the River Thames near Cookham, Berkshire, about a half-mile downstream of Cookham Bridge. The lock is set in a lock cut which is one of four streams here and it is surrounded by woods. On one side is Sashes Island and on the other is Mill Island connected to Formosa Island, the largest on the non-tidal Thames. There are several weirs nearby. Hedsor weir was placed across the old navigation channel in 1837, seven years after the lock was opened. There is a lower weir, and Odney weir is on the channel next to Formosa Island. A short distance away from the lock is Odney, with the Odney Club situated on an ait. Navigation to the Odney Club by boat is possible, but is extremely difficult due to the shallow waters. It is thought that this is deliberate - to disallow non-members from entering the club site without paying the entrance fees. History The navigation route was formerly down Hedsor Water and the only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonning Lock
Sonning Lock is a lock (water transport), lock and associated weir situated on the River Thames at the village of Sonning near Reading, Berkshire, Reading, Berkshire, England. The first lock was built by the Thames Navigation Commission in 1773 and it has been rebuilt three times since then. There is a weir a little upstream at the top of the island where Sonning Backwater separates from the main course of the river. History A weir at Sonning is recorded as belonging to the Blunte family in the 15th century. This was associated with the mill and fisheries and mention is made of a "Locke-heise" at this time. The flash lock was replaced in 1773 by the pound lock. This was the highest upstream of the eight locks constructed after the Thames and Isis Navigation Act 1750 (24 Geo. 2. c. 8). It was commissioned in 1771 but took two years to build. Fir wood was originally used for these locks, but this decayed very quickly and was replaced at Sonning by oak in 1787. Repairs took pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Day's Lock
Day's Lock is a lock on the River Thames near Dorchester-on-Thames, Oxfordshire, England on the Dorchester side of the river. The pound lock was built in 1789 by the Thames Navigation Commissioner. The lock is across the river from the small village of Little Wittenham and is overlooked from the south by the hills of Wittenham Clumps, with a particularly good view from Round Hill. The weir runs straight across the river from the other side of the lock island. Day's Lock is the main gauging station for the measurement of the water flow in the River Thames. The Thames Path crosses the river here. The ''World Poohsticks Championships'', on behalf of the Royal National Lifeboat Institution, RNLI, have taken place annually here since 1983. History The name ''Day's Lock'' comes from the Day family, local Roman Catholic, Catholic yeomen since the 17th century. During the 16th century, there was a flash lock here. The pound lock was staked out in August 1788. It was judged best ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osney Lock
Osney Lock is a lock on the River Thames in Oxford Oxford () is a City status in the United Kingdom, cathedral city and non-metropolitan district in Oxfordshire, England, of which it is the county town. The city is home to the University of Oxford, the List of oldest universities in continuou ..., England, where the village or island of Osney is next to the river. The first lock was built of stone by Daniel Harris for the Thames Navigation Commission in 1790. Across the weir pool is a large Environment Agency complex which monitors the River Thames, while a small office building exists on the front lawn opposite from the lock house. The weir is upstream of the lock alongside the navigation channel in two parts and feeds the Osney pool. The Osney Lock Hydro hydro-electric plant occupies a building beside the weir. To the south and southwest are Osney Mill Marina and Osney Cemetery. Oxford railway station on the Botley Road is close by to the northwest. Histor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locks On The River Thames
The England, English River Thames is navigable from Cricklade (for very small, shallow boats) or Lechlade (for larger boats) to the sea, and this part of the river falls 71 meters (234 feet). There are 45 lock (water navigation), locks on the river, each with one or more adjacent weirs. These lock and weir combinations are used for controlling the flow of water down the river, most notably when there is a risk of flooding, and provide for navigation above the tideway. History From ancient times there were many obstructions across the Thames, for fish-pounds and millers' weirs. They are referred to by Asserius Menevensis in the ninth century and Magna Carta (1215) states that "weirs, for the time to come, shall be demolished in the Thames and Medway, except on the sea coast." It appears this never happened. In the Middle Ages, the fall on the river in its middle and upper sections was used to drive watermills for the production of flour and paper and various other purposes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautical Measured Mile
A nautical measured mile is a nautical mile which is marked by two pairs of towers. A mile is measured by sailing on a given bearing and lining up the pairs of towers. The start of the mile is recorded when the first pair of towers line up and the end of the mile recorded when the second pair line up. To accurately measure performance ships must make at least four to six runs in both directions to allow for the wind and tide. There are several nautical measured miles around the British Isles: * Between Talland Bay and Hannafore, West Looe, Cornwall. * At Skelmorlie, North Ayrshire, Scotland, between Skelmorlie Pier and Skelmorlie Castle. * Lower Hope Reach, near Gravesend on the Thames Estuary, between Cliffe Creek coastguard station and Lower Hope Point. *Four Admiralty day beacons (unlit) were installed on Maplin Sands, adjacent to The Warp channel. Buoys in the channel marked the course and vessels under test were required to fly a blue-and-white swal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Transport In England
Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, despite not providing food energy or organic micronutrients. Its chemical formula, , indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. In liquid form, is also called "water" at standard temperature and pressure. Because Earth's environment is relatively close to water's triple point, water exists on Earth as a solid, a liquid, and a gas. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
