Craigellachie Bridge
Encyclopedia
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
arch bridge
Arch bridge
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side...
located at Craigellachie which is near to the village of Aberlour
Aberlour
Aberlour , is the name of a place in Moray, Scotland, 12 miles south of Elgin on the road to Grantown. A burn , a tributary of the River Spey, and surrounding parish, are both named Aberlour, but the name is most commonly used in reference to the village which straddles the stream and flanks the...
in Moray
Moray
Moray is one of the 32 council areas of Scotland. It lies in the north-east of the country, with coastline on the Moray Firth, and borders the council areas of Aberdeenshire and Highland.- History :...
, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
. It was designed by the renowned civil engineer
Civil engineer
A civil engineer is a person who practices civil engineering; the application of planning, designing, constructing, maintaining, and operating infrastructures while protecting the public and environmental health, as well as improving existing infrastructures that have been neglected.Originally, a...
Thomas Telford
Thomas Telford
Thomas Telford FRS, FRSE was a Scottish civil engineer, architect and stonemason, and a noted road, bridge and canal builder.-Early career:...
and built from 1812–1814. The bridge has a single span
Span (architecture)
Span is the distance between two intermediate supports for a structure, e.g. a beam or a bridge.A span can be closed by a solid beam or of a rope...
of approximately 46 metres (151 ft) and was revolutionary for its time, in that it used an extremely slender arch which was not possible using traditional masonry
Masonry
Masonry is the building of structures from individual units laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, stone, marble, granite, travertine, limestone; concrete block, glass block, stucco, and...
construction. The ironwork was cast at the Plas Kynaston iron foundry
Foundry
A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal in a mold, and removing the mold material or casting after the metal has solidified as it cools. The most common metals processed are aluminum and cast iron...
at Cefn Mawr
Cefn Mawr
Cefn Mawr is a large village in the community of Cefn within the County Borough of Wrexham, Wales. Its name translates as "great ridge".The community of Cefn comprises the villages of Cefn Mawr, Cefn-bychan , Acrefair, Penybryn, Newbridge, Plasmadoc and Rhosymedre and is situated on the northern...
, near Ruabon
Ruabon
Ruabon is a village and community in the county borough of Wrexham in Wales.More than 80% of the population of 2,400 were born in Wales with 13.6% speaking Welsh....
in Denbighshire
Denbighshire (historic)
Historic Denbighshire is one of thirteen traditional counties in Wales, a vice-county and a former administrative county, which covers an area in north east Wales...
by William Hazledine
William Hazledine
William Hazledine was a pioneering English Ironmaster whose talent for casting structural ironwork helped to realise the designs of engineers such as Thomas Telford and architects including Henry Goodridge and Charles Bage...
, who cast a number of Telford bridges. The ironwork was transported from the foundry through the Ellesmere Canal
Ellesmere Canal
The Ellesmere Canal was a canal in England and Wales, originally planned to link the Rivers Mersey, Dee, and Severn, by running from Netherpool to Shrewsbury. The canal that was eventually constructed was very different from what was originally envisioned...
and Pontcysyllte Aqueduct
Pontcysyllte Aqueduct
The Pontcysyllte Aqueduct is a navigable aqueduct that carries the Llangollen Canal over the valley of the River Dee in Wrexham in north east Wales....
then by sea to Speymouth, where it was loaded onto wagons and taken to the site. Testing in the 1960s revealed that the cast-iron had an unusually high tensile strength
Tensile strength
Ultimate tensile strength , often shortened to tensile strength or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before necking, which is when the specimen's cross-section starts to significantly contract...
. This was likely specified by Telford because, unlike in traditional masonry arch bridges, some sections of the arch are not in compression under loading.
At each end of the structure there are two 15 m (49.2 ft) high masonry mock-medieval towers, featuring arrow slits and miniature crenellated battlements.
Spandrel
A spandrel, less often spandril or splaundrel, is the space between two arches or between an arch and a rectangular enclosure....
members were replaced with new ironwork fabricated to match the originals. A 14 ton
Ton
The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.It is derived from...
restriction was placed on the bridge at this point. This, along with the fact that the road to the north of the bridge takes a sharp right-angled turn to avoid a rock face, made it unsuitable for modern vehicles. Despite this it carried foot and vehicle traffic across the River Spey
River Spey
The River Spey is a river in the northeast of Scotland, the second longest and the fastest-flowing river in Scotland...
until 1972, when its function was replaced by a reinforced concrete
Reinforced concrete
Reinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...
bridge built by Sir William Arrol & Co.
Sir William Arrol & Co.
Sir William Arrol & Co. was a leading Scottish civil engineering business founded by William Arrol and based in Glasgow. It built some of the most famous bridges in the United Kingdom including the Forth Bridge and Tower Bridge in London.-Early history:...
which opened in 1970 and carries the A941 road today. Telford's bridge remains in good condition, and is still open to pedestrians and cyclists. The bridge has been given Category A listed status by Historic Scotland
Historic Scotland
Historic Scotland is an executive agency of the Scottish Government, responsible for historic monuments in Scotland.-Role:As its website states:...
and has been designated a civil engineering landmark by the Institution of Civil Engineers
Institution of Civil Engineers
Founded on 2 January 1818, the Institution of Civil Engineers is an independent professional association, based in central London, representing civil engineering. Like its early membership, the majority of its current members are British engineers, but it also has members in more than 150...
.
The bridge inspired a popular Strathspey
Strathspey (dance)
A strathspey is a type of dance tune in 4/4 time. It is similar to a hornpipe but slower and more stately, and contains many dot-cut 'snaps'. A so-called Scotch snap is a short note before a dotted note, which in traditional playing is generally exaggerated rhythmically for musical expression...
, written by William Marshall
William Marshall (Scottish composer)
William Marshall is regarded as one of the greatest composers of Scottish fiddle music.Marshall was born in Fochabers, Scotland. He entered the service of the Duke of Gordon, eventually becoming the Factor to the Gordon Estate. James Hunter's The Fiddle Music of Scotland credits Marshall with...
in 1814.
It was also the site of a parade upon the amalgamation of The Gordon Highlanders
The Gordon Highlanders
The Gordon Highlanders was a British Army infantry regiment from 1794 until 1994. The regiment took its name from the Clan Gordon and recruited principally from Aberdeen and the North-East of Scotland.-History:...
and The Queen's Own Highlanders (Seaforth and Camerons)
Queen's Own Highlanders (Seaforth and Camerons)
The Queen's Own Highlanders , officially abbreviated "QOHldrs," was an infantry regiment in the Scottish Division of the British Army. It was formed on 7 February 1961 at Redford Barracks, Edinburgh, with the amalgamation of 1st Battalion, Seaforth Highlanders and 1st Battalion, Queen's Own Cameron...
to form The Highlanders (Seaforth, Gordons and Camerons)
The Highlanders (Seaforth, Gordons and Camerons)
The Highlanders, 4th Battalion, Royal Regiment of Scotland is an infantry battalion of the Royal Regiment of Scotland.Prior to 28 March 2006, the Highlanders was an infantry regiment in its own right; The Highlanders , part of the Scottish Division...
in 1994. A plaque has been fitted to the bridge parapet
Parapet
A parapet is a wall-like barrier at the edge of a roof, terrace, balcony or other structure. Where extending above a roof, it may simply be the portion of an exterior wall that continues above the line of the roof surface, or may be a continuation of a vertical feature beneath the roof such as a...
to commemorate this. Another plaque records the bridge's restoration in 1964.