Store Street Aqueduct
Ashton Canal at Store Street, Manchester, UK
1798 - 1799
ICE reference number
photo Paul Dunkerley / ICE R&D Fund
The Grade II* listed Store Street Aqueduct carries the Ashton Canal over Store Street in central Manchester. This section of the canal — its last half mile — was designed by Benjamin Outram, who also laid out the canal's terminus and local warehousing. Most of the rest of the canal was completed when he came to the project in 1797.
The Ashton Canal runs from Aston under Lyne, westwards into central Manchester, through James Brindley Basin and terminating near Ducie Street (the basin there is now infilled).
The masonry arch carrying the aqueduct is one of the earliest examples of the helicoidal method of coursing in masonry — the courses being at right angles to the faces of the arch. It is the oldest remaining bridge of its type on the canal system. Unfortunately, the coursing is no longer visible under the rendering.
The helicoidal (or ‘English’) method is attributed to William Chapman, an engineer from Northumberland who worked at Naas in Ireland. William Jessop is said to have introduced the technique to Benjamin Outram, who designed this aqueduct.
The arch has a 7.6m square span and a 10.5m skew span and rises 1.8m from springing set 2.75m above road level. It has large voussoirs, with spandrels and retaining walls of block masonry set in courses.
Two types of stone were used in the structure, which is 7.4m wide excluding the triangular buttresses. The canal is some 4.6m wide and 1.45m deep at the aqueduct.
The aqueduct crossed Shooters Brook originally, which was later put into a culvert and Store Street was built over it circa 1805. The aqueduct overflies the street at about 45 degrees.
Research: PD and AJD
"A Guide to the Industrial Archaeology of Greater Manchester"
by Robina McNeil and Michael Nevell
Association for Industrial Archaeology, 2000