The Slateford Aqueduct is a
navigable aqueduct
Navigable aqueducts (sometimes called water bridges) are bridge structures that carry navigable waterway canals over other rivers, valleys, railways or roads. They are primarily distinguished by their size, carrying a larger cross-section of wa ...
that carries the
Union Canal over the
Water of Leith
The Water of Leith (Scottish Gaelic: ''Uisge Lìte'') is the main river flowing near central Edinburgh, Scotland, and flows into the port of Leith where it flows into the sea via the Firth of Forth.
Name
The name ''Leith'' may be of Britt ...
at
Slateford,
Edinburgh
Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian ...
, Scotland. Completed in 1822, it has eight arches and spans a length of .
History

It was designed by
Hugh Baird with advice from
Thomas Telford
Thomas Telford FRS, FRSE, (9 August 1757 – 2 September 1834) was a Scottish civil engineer. After establishing himself as an engineer of road and canal projects in Shropshire, he designed numerous infrastructure projects in his native Scotla ...
and is modelled on Telford's
Chirk Aqueduct.
Different parts of the canal were tendered to contractors at different times, and the masonry for the Slateford Aqueduct was advertised to builders on 2 March 1818.
Baird wrote to Telford regarding the ironwork, as he had received a visit from James Thomson, representing the company of
William Hazledine, who had worked on the
Pontcysyllte Aqueduct. Baird was unsure about using a contractor based so far away, and also as to whether the contract should just be for the delivery of the plates or the delivery and assembly.
[ On 3 April 1818, Hugh McIntosh was chosen to construct the aqueduct, as he was the contractor for the east end of the canal.][ After Thomson sent an estimate to Telford for the iron on 30 April, a revised specification was chosen by Baird, the contract for which was advertised on 18 July, and tenders opened on 11 August.][ The offer by the partnership of Messrs. Craven, Whitaker and Nowell, riding on the success of their building a stone bridge over the River Ouse, was accepted as being "by far the most eligible."][
Construction had started by March 1819, after the laying of a foundation stone.][ It lasted until 1822, and the canal opened that year.][
It was listed as a category B ]listed building
In the United Kingdom, a listed building or listed structure is one that has been placed on one of the four statutory lists maintained by Historic England in England, Historic Environment Scotland in Scotland, in Wales, and the Northern I ...
in 1970.
Design
The Barton Aqueduct of 1761, and subsequent canal aqueducts in the United Kingdom, used large quantities of masonry and puddling
A puddle is a small accumulation of liquid on a surface.
Puddle or Puddles may also refer to:
* Puddle, Cornwall, hamlet in England
* ''Puddle'' (video game)
* Puddle (M. C. Escher), a woodcut by M. C. Escher
* Weld puddle, a crucial part of the ...
to obtain watertightness.[ After the success of ]The Iron Bridge
The Iron Bridge is a cast iron arch bridge that crosses the River Severn in Shropshire, England. Opened in 1781, it was the first major bridge in the world to be made of cast iron. Its success inspired the widespread use of cast iron as a str ...
in 1789, however, cast iron was used by Telford on aqueducts such as Chirk and Pontcysyllte.[ Aqueducts built in the early part of the 19th century use either puddle clay or an iron trough in no particular pattern.
The Slateford Aqueduct has eight arches of span, and is long and high above the Water of Leith.][ The piers are battered, giving a larger footprint at the base than the top, and the ]spandrel
A spandrel is a roughly triangular space, usually found in pairs, between the top of an arch and a rectangular frame; between the tops of two adjacent arches or one of the four spaces between a circle within a square. They are frequently fill ...
s are hollow, an innovation by Telford.[ The interior of the stone structure is essentially a setof 5/6? stone arches running in parallel along the length of the bridge, linked and braced laterally at the top of each arch. It is possible to walk the length of the bridge inside the stonework on the north side, from access apertures on the abutments ersonal experience
It carries the Union Canal across Inglis Green Road and the Water of Leith at Slateford.] To the north of the aqueduct, on the side of the accessible towpath, is the parallel Slateford Viaduct, which carries an operational railway.
See also
* List of canal aqueducts in Great Britain
References
External links
Video footage of the aqueduct
{{Buildings and Structures in Edinburgh
Bridges completed in 1822
Bridges in Edinburgh
Category B listed buildings in Edinburgh
Navigable aqueducts in Scotland
Listed bridges in Scotland
Listed canals in Scotland
1822 establishments in Scotland
Bridges across the Water of Leith