Almond Aqueduct | |
|---|---|
 | |
| Coordinates | 55°55′16″N 3°26′01″W / 55.9212°N 3.4337°W |
| OS grid reference | NT105707 |
| Carries | Union Canal |
| Crosses | River Almond |
| Locale | West Lothian/City of Edinburgh |
| Maintained by | British Waterways |
| Characteristics | |
| Total length | 420 feet (130 m) |
| Height | 76 feet (23 m) |
| Location | |
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The Almond Aqueduct, also known as the Lin's Mill Aqueduct, is a navigable aqueduct that carries the Union Canal over the River Almond in Scotland, west of Ratho, Edinburgh.
The aqueduct was built to a design by Hugh Baird, with advice from Thomas Telford, in tandem with the Slateford Aqueduct and Avon Aqueduct, with which it shares its design.[1] Baird had originally proposed to have only a single span, with embankments carrying the canal the rest of the way, but eventually decided to use the same design as the other two aqueducts.[2]
Telford was not convinced that the stone arches were necessary in conjunction with the iron trough, but Baird used both on all three major aqueducts.[1] Construction was carried out by Messrs. Craven, Whitaker and Nowell between 1819 and 1821, their success in building a stone bridge over the River Ouse making their tender for the contract "by far the most eligible."[3]
In 1970 it was designated as a scheduled monument[4] and in 1971 it was given Category A status, being individually listed for each local authority (the river denotes the boundary between West Lothian and Edinburgh).[5][6] In 2003 the Union Canal became a scheduled monument[7] thus causing the aqueduct to be scheduled twice and leading to the original designation being removed in 2019.[4]
The Barton Aqueduct of 1761, and subsequent canal aqueducts in the United Kingdom, used large quantities of masonry and puddling to obtain watertightness.[3] After the success of The Iron Bridge in 1789, however, cast iron was used by Telford on aqueducts such as Chirk and Pontcysyllte.[3] Aqueducts built in the early part of the 19th century use either puddle clay or an iron trough in no particular pattern.[8] The Almond Aqueduct uses an iron trough to achieve watertightness, as well as containing the outward pressure of the water, allowing it to be of more slender construction than a purely stone aqueduct such as the Kelvin Aqueduct.[9]
Measuring 420 feet (130 m) long, it carries the Union Canal 76 feet (23 m) above the River Almond, from Edinburgh into West Lothian.[10] A sluice into the Almond allows regulation of the water level in the canal, and near to the aqueduct is a feeder from Cobbinshaw Reservoir.[2] The aqueduct can be reached by car by way of a track and by walkers and cyclists on the Union Canal towpath.
