Canal lock in the context of "Canal pound"

The head of navigation is the farthest point above the mouth of a river that can be navigated by ships. Determining the head of navigation can be subjective on many streams, as the point may vary greatly with the size or the draft of the ship being contemplated for navigation and the seasonal water level. On others, it is quite objective, being caused by a waterfall, a low bridge that is not a drawbridge, or a dam without navigation locks. Several rivers in a region may have their heads of navigation along a line called the fall line.

Longer rivers such as the River Thames may have several heads of navigation depending on the size of the vessel. In the case of the Thames, that includes London Bridge, which historically served as the head of navigation for tall ships; Osney Bridge in Oxford, which has the lowest headroom of any bridge on the Thames that generally restricts navigation to smaller vessels such as narrowboats and cabin cruisers, and the long reach above St John's Lock, the first lock downstream of the river’s source, on the outskirts of Lechlade, where the river can become treacherously narrow and shallow for anything but small motorboats and human-powered vessels.

The Rhine–Herne Canal (German: Rhein-Herne-Kanal) is a 45.6-kilometre-long (28.3 mi) transportation canal in the Ruhr area of North Rhine-Westphalia, Germany, with five canal locks. The canal was built over a period of eight years (5 April 1906 – 14 July 1914) and connects the harbour in Duisburg on the Rhine (51°26′59″N 6°46′1″E / 51.44972°N 6.76694°E / 51.44972; 6.76694) with the Dortmund-Ems Canal near Henrichenburg (51°37′1″N 7°19′19″E / 51.61694°N 7.32194°E / 51.61694; 7.32194), following the valley of the Emscher. It was widened in the 1980s. The Rhein-Herne canal ship was designed specifically for this canal; normally of about 1300–1350 ton capacity, it has a maximum draft of 2.50 metres (8.2 ft), a length of approximately 80 metres (260 ft), and maximum beam of 9.50 metres (31.2 ft).

Originally the Rhine-Herne canal ended in Herne, where it met a branch of the Dortmund-Ems-Kanal running from Henrichenburg to Herne, the intersection situated just above the East Herne lock.

The Grand Union Canal in England is part of the British canal system. It is the principal navigable waterway between London and the Midlands. Starting in London, one arm runs to Leicester and another to Birmingham. The Birmingham canal is 137 miles (220 km) with 166 locks. The Birmingham line has a number of short branches to places including Slough, Aylesbury, Wendover, and Northampton. The Leicester line has two short arms of its own, to Market Harborough and Welford.

It has links with other canals and navigable waterways, including the River Thames, the Regent's Canal, the River Nene and River Soar, the Oxford Canal, the Stratford-upon-Avon Canal, the Digbeth Branch Canal and the Birmingham and Fazeley Canal.

A boat lift, ship lift, or lift lock is a machine for transporting boats between water at two different elevations, and is an alternative to the canal lock.

It may be vertically moving, like the Anderton boat lift in England, rotational, like the Falkirk Wheel in Scotland, or operate on an inclined plane, like the Ronquières inclined plane in Belgium.

The John Day Dam is a concrete gravity run-of-the-river dam spanning the Columbia River in the northwestern United States. The dam features a navigation lock plus fish ladders on both sides. The John Day Lock has the highest lift (at 110 feet or 34 meters) of any U.S. lock. The reservoir impounded by the dam is Lake Umatilla, and it runs 76.4 miles (123.0 km) up the river channel to the foot of the McNary Dam. John Day Dam is part of the Columbia River Basin system of dams.

Panamax and New Panamax (or Neopanamax) are terms for the size limits for ships traveling through the Panama Canal. The limits and requirements are published by the Panama Canal Authority (ACP) in a publication titled "Vessel Requirements". These requirements also describe topics like exceptional dry seasonal limits, propulsion, communications, and detailed ship design.

The allowable size is limited by the width and length of the available lock chambers, by the depth of water in the canal, and by the height of the Bridge of the Americas since that bridge's construction, along with the clearance under the Atlantic and Centennial Bridges since their constructions in 2019 and 2004 respectively. These dimensions give clear parameters for ships destined to traverse the Panama Canal and have influenced the design of cargo ships, naval vessels, and passenger ships.

Delph Locks or the Delph Nine are a series of eight (originally nine) narrow canal locks on the Dudley No. 1 Canal in Brierley Hill, in the West Midlands, England. They were opened in 1779, and reopened in 1967 following restoration of the Dudley Canal and the Stourbridge Canal in a joint venture between the Staffordshire and Worcestershire Canal Society and the British Waterways Board.

The Trent–Severn Waterway is a 386-kilometre-long (240 mi) canal route connecting Lake Ontario at Trenton to Georgian Bay, Lake Huron, at Port Severn. Its major natural waterways include the Trent River, Otonabee River, Kawartha Lakes, Lake Simcoe, Lake Couchiching and Severn River. Its scenic, meandering route has been called "one of the finest interconnected systems of navigation in the world".

The canal was surveyed as a military route, but the first lock was built in 1833 as a commercial venture. This connected a number of lakes and rivers near the centre of the waterway, opening a large area to navigation by steamship. The government had begun construction of three additional locks when the Upper Canada Rebellion of 1837 broke out. This led the government to re-examine the project, concluding that the route would have too many locks to allow rapid movement for military purposes. They decided that the locks under construction would be completed, but the rest could be turned into timber slides. This left the completed inland section with no outlet, which business interests addressed by connecting to the route with a number of new toll roads, plank roads, and later, railways.