A waste weir on a navigable canal is a slatted gate on each canal level or pound, to remove excess water and to drain the canal for repairs or for the winter shutdown. [1] This differs for a dam or reservoir, for which a waste weir is another name for a spillway, i.e. not having the boards to adjust the water height nor the paddles to drain all the water as on a canal, only to drain the excess.
A canal will often need some means to maintain a water level. A canal constantly consumes water due to leakage, evaporation, and the operation of lift locks. Nevertheless, excess water from storms or emptying locks [2] could cause problems by eroding the banks of a canal, causing washouts, and flooding buildings or adjacent properties. Waste weirs were one of several measures used to remove surplus water. The waste weir also functioned as an opening to drain the entire canal prism of water for repairs, or for winter (to avoid damage from freezing water), or in anticipation of flooding. [3] [4]
In some cases when a creek was used to feed the canal, a waste weir was necessary for excess water from the creek. For instance, on the Morris Canal, the Lopatcong Creek went into the canal to feed it, but it had a tendency to flood, hence the need for a couple of waste weirs in the area around the bottom of Inclined Plane 9 West near Port Warren, New Jersey (near Strykers Road today). [5]
Reservoirs and tanks also use a waste weir for flood discharges. [6]
The maximum flow output in cubic meters/sec over the top of the waste weir with a length and height of water above the crest can be calculated by the formulas:
and
where g=gravitational constant of and Cd is the coefficient of discharge over the weir. [7] Various values of Cd can be given as follows: [8]
Crest type | |
---|---|
Weir with crest up to one meter in width | 0.625 |
Weir with crest greater than one meter in width | 0.562 |
Rough stone sloping escape | 0.500 |
Flush escape (no drop) | 0.437 |
Construction methods varied depending on the canal. On the Erie Canal and the Chesapeake and Ohio Canal, waste weirs were often constructed from masonry or concrete.
Since a waste weir was part of canal property, it would sometimes be explicitly protected by law. On the Morris Canal, New Jersey Statue 136 section 61 stated that for willfully and maliciously opening the gates of waste weirs the penalty was $25. [9]
The Erie Canal is a historic canal in upstate New York that runs east–west between the Hudson River and Lake Erie. Completed in 1825, the canal was the first navigable waterway connecting the Atlantic Ocean to the Great Lakes, vastly reducing the costs of transporting people and goods across the Appalachians. In effect, the canal accelerated the settlement of the Great Lakes region, the westward expansion of the United States, and the economic ascendancy of New York State. It has been called "The Nation's First Superhighway."
A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is the chamber itself that rises and falls.
The Chesapeake and Ohio Canal, abbreviated as the C&O Canal and occasionally called the Grand Old Ditch, operated from 1831 until 1924 along the Potomac River between Washington, D.C. and Cumberland, Maryland. It replaced the Potomac Canal, which shut down completely in 1828, and could operate during months in which the water level was too low for the former canal. The canal's principal cargo was coal from the Allegheny Mountains.
The Hiram M. Chittenden Locks, or Ballard Locks, is a complex of locks at the west end of Salmon Bay in Seattle, Washington's Lake Washington Ship Canal, between the neighborhoods of Ballard to the north and Magnolia to the south.
The Morris Canal (1829–1924) was a 107-mile (172 km) common carrier anthracite coal canal across northern New Jersey that connected the two industrial canals in Easton, Pennsylvania across the Delaware River from its western terminus at Phillipsburg, New Jersey to New York Harbor and New York City through its eastern terminals in Newark and on the Hudson River in Jersey City. The canal was sometimes called the Morris and Essex Canal, in error, due to confusion with the nearby and unrelated Morris and Essex Railroad.
Bingley Five-Rise Locks is a staircase lock on the Leeds and Liverpool Canal at Bingley. As the name implies, a boat passing through the lock is lifted or lowered in five stages.
The Gatun Dam is an earthen dam across the Chagres River in Panama, near the town of Gatun. The dam, constructed between 1907 and 1913, is a crucial element of the Panama Canal; it impounds the artificial Gatun Lake, which carries ships 33 kilometres (21 mi) of their transit across the Isthmus of Panama. In addition, a hydro-electric generating station at the dam generates electricity which is used to operate the locks and other equipment in the canal.
A canal pound, reach, or level, is the stretch of level water impounded between two canal locks. Canal pounds can vary in length from the non-existent, where two or more immediately adjacent locks form a lock staircase, to many kilometres/miles.
The Ohio and Erie Canal was a canal constructed during the 1820s and early 1830s in Ohio. It connected Akron with the Cuyahoga River near its outlet on Lake Erie in Cleveland, and a few years later, with the Ohio River near Portsmouth. It also had connections to other canal systems in Pennsylvania.
The Warren County Canal was a branch of the Miami and Erie Canal in southwestern Ohio about 20 miles (32 km) in length that connected the Warren County seat of Lebanon to the main canal at Middletown in the mid-19th century. Lebanon was at the crossroads of two major roads, the highway from Cincinnati to Columbus and the road from Chillicothe to the College Township (Oxford), but Lebanon businessmen and civic leaders wanted better transportation facilities and successfully lobbied for their own canal, part of the canal fever of the first third of the 19th century. The Warren County Canal was never successful, operating less than a decade before the state abandoned it.
The Schuylkill Canal, or Schuylkill Navigation, was a system of interconnected canals and slack-water pools along the Schuylkill River in the U.S. state of Pennsylvania, built as a commercial waterway in the early 19th-century. Chartered in 1815, the navigation opened in 1825, to provide transportation and water power.
The Panama Canal locks are a lock system that lifts ships up 85 feet to the main elevation of the Panama Canal and down again. The original canal had a total of six steps for a ship's passage. The total length of the lock structures, including the approach walls, is over 1.9 miles (3 km). The locks were one of the greatest engineering works ever to be undertaken when they opened in 1914. No other concrete construction of comparable size was undertaken until the Hoover Dam, in the 1930s.
The Locks on the Chesapeake and Ohio Canal, located in Maryland, West Virginia, and Washington, D.C. of the United States, were of three types: lift locks; river locks; and guard, or inlet, locks.
A flash lock is a type of lock for river or canal transport.
A lock keeper, lock tender, or lock operator looks after a canal or river lock, operating it and if necessary maintaining it or organizing its maintenance. Traditionally, lock keepers lived on-site, often in small purpose-built cottages. A lock keeper may also be the operator for the lock's Weir and, in many cases lock keepers play an important role in moderating and controlling water levels in response to drought and heavy rain. With the decline in commercial traffic the occupation is dying out on inland waterways, at least in Britain. Many previously staffed locks are now unstaffed.
The Whitewater Canal, which was built between 1836 and 1847, spanned a distance of 76 miles (122 km) and stretched from Lawrenceburg, Indiana on the Ohio River to Hagerstown, Indiana near the West Fork of the White River.
The Lehigh Canal is a navigable canal that begins at the mouth of Nesquehoning Creek on the Lehigh River in the Lehigh Valley and Northeastern regions of Pennsylvania. It was built in two sections over a span of 20 years beginning in 1818. The lower section spanned the distance between Easton and present-day Jim Thorpe. In Easton, the canal met the Delaware and Morris Canals, which allowed anthracite coal and other goods to be transported further up the U.S. East Coast. At its height, the Lehigh Canal was 72 miles (116 km) long.
The Selby Canal is a 6-mile (9.7 km) canal with 2 locks which bypasses the lower reaches of the River Aire in Yorkshire, England, from the village of West Haddlesey to the town of Selby where it joins the River Ouse. It opened in 1778, and provided the main outlet for the Aire and Calder Navigation until 1826, when it was bypassed by a new cut from Ferrybridge to Goole. Selby steadily declined after that, although traffic to York still used the canal.
Riley's Lock (Lock 24) and lock house are part of the 184.5-mile (296.9 km) Chesapeake and Ohio Canal that operated in the United States along the Potomac River from the 1830s through 1923. They are located at towpath mile-marker 22.7 adjacent to Seneca Creek, in Montgomery County, Maryland. The lock is sometimes identified as Seneca because of the Seneca Aqueduct that carried the canal over the creek to the lift lock. The name Riley comes from John C. Riley, who was lock keeper from 1892 until the canal closed permanently in 1924.
Violette's Lock is part of the 184.5-mile Chesapeake and Ohio Canal that operated in the United States along the Potomac River from the 1830s through 1923. It is located at towpath mile-marker 22.1, in Montgomery County, Maryland. The name Violette comes from Alfred L. "Ap" Violette and his wife Kate, who were lock keepers from the beginning of the 20th century through the permanent closure of the canal in 1924.