The Store Street Aqueduct in central
Manchester, England, was built in 1798 by
Benjamin Outram on the
Ashton Canal. A
Grade II* listed building it is built on a
skew of 45° across Store Street, and is believed to be the first major aqueduct of its kind in
Great Britain and the oldest still in use today.
Aqueduct
The
aqueduct was constructed to cross
Shooters Brook A shooter is someone who shoots something.
Shooter or Shoota may also refer to:
People
* Rod Beck (1968–2007), American baseball pitcher nicknamed "Shooter"
* Shooter Jennings (born 1979), country music singer
* Evan McPherson (born 1999) ...
. It is built of stone with large
voussoirs and retaining walls of coursed masonry and is wide with triangular
buttresses. The brook was
culvert
A culvert is a structure that channels water past an obstacle or to a subterranean waterway. Typically embedded so as to be surrounded by soil, a culvert may be made from a pipe, reinforced concrete or other material. In the United Kingdom ...
ed in about 1805 and Store Street was built over it. The canal is about wide and deep. The arch has a square span and a skew span rising above road level.

Generally, where a canal (or later a railway) crossed a road, or vice versa, the road would be diverted to cross at right angles. It had not always been acceptable but attempts to build masonry
arch bridges at an angle, or "skew" of greater than about 15 degrees, had proved unsatisfactory. The method up to that time had been to build the
voussoir arch with the stone course work parallel to the
abutments. This transmitted the load outward from the crown in a straight line to the foundations, parallel to the faces of the arch. If a skew was attempted, it threw the lines of force outside the abutments, leading to weakness in the structure.
William Chapman had partially solved the problem in 1787
when building bridges for the Kildare Canal, the first being the Finlay Bridge near
Naas.
The Kildare was part of the
Grand Canal Company
Grand may refer to:
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* Grand (surname)
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* Grand, Oklahoma
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, for
William Jessop had been the engineer. Jessop would no doubt have discussed it with Outram, his partner, and he experimented with the idea on the
Rochdale Canal
The Rochdale Canal is in Northern England, between Manchester and Sowerby Bridge, part of the connected system of the canals of Great Britain. Its name refers to the town of Rochdale through which it passes.
The Rochdale is a broad canal beca ...
. Examples are Gorrell's Lane and March Barn road bridges, though it is possible that they were built later.
The method used was to build timber falsework parallel to the proposed arches. Planks were laid on the falsework parallel to the abutments. The position of the courses at the crown were marked out, then those across the remainder of the arch.
Although the aqueduct still exists, and is structurally sound, years of neglect led to water leakage through the joints, and the spiral construction can no longer be seen, the surface of the
intrados having been rendered.
Later railway engineers improved on the system, producing what became known as
helicoidal construction that became the norm in English
skew bridge building. An exact solution to the problem was determined in the form of the French, or
orthogonal
In mathematics, orthogonality is the generalization of the geometric notion of ''perpendicularity''.
By extension, orthogonality is also used to refer to the separation of specific features of a system. The term also has specialized meanings in ...
, design. However this was complicated and expensive to build.
See also
*
List of canal aqueducts in the United Kingdom
*
Grade II* listed buildings in Greater Manchester
*
Listed buildings in Manchester-M1
References
{{Manchester B&S
Grade II* listed buildings in Manchester
Bridges in Greater Manchester
Bridges completed in 1798
Navigable aqueducts in England
Grade II* listed bridges in England
Grade II* listed canals