timeline item
Here is the information we have
on the item you selected
This entry was funded by
More like this
© 2020 Engineering Timelines
engineering timelines
explore ... how   explore ... why   explore ... where   explore ... who  
home  •  NEWS  •  search  •  FAQs  •  references  •  about  •  sponsors + links
Berriew Aqueduct
Montgomery Canal, Berriew, Powys, Wales, UK
Berriew Aqueduct
associated engineer
John Dadford
Thomas Dadford jnr
Thomas Dadford snr
George Watson Buck
date  23rd August 1794 - 1796, opened 1797, 1889
UK era  Georgian  |  category  Aqueduct  |  reference  SJ187006
ICE reference number  HEW 1465
photo  © John M and licensed for reuse under this Creative Commons Licence
Grade II listed Berriew Aqueduct carries the Montgomeryshire Canal's Eastern Branch over the River Rhiw. It has four segmental arches and is the second-largest masonry structure on the canal. It was largely rebuilt in the 19th century and fully restored in the 20th century.
John Dadford (1769-1809) was engineer for the Eastern Branch, assisted by his elder brother Thomas Dadford junior (c.1760-1801). Problems experienced during the construction of the four original aqueducts along the route contributed to John Dadford’s resignation in 1796, his duties were then undertaken by his father Thomas Dadford senior (1730-1809).
Two of Berriew Aqueduct's arches span the river, flanked by subsidiary arches over roadways. The central river pier is founded on timber piles and capping beams. The weight of the structure, from its masonry and puddled clay canal liner, coupled with its location on soft alluvial soil meant the aqueduct was prone to distortion and leaks.
In 1828, the canal’s then engineer George Watson Buck (1789-1854) installed iron railings on the towpath (south east) side of the aqueduct.
However, the aqueduct’s original masonry is now obscured behind the cladding of blue engineering brick that was added as part of extensive repair and rebuilding work in 1889, carried out by the Shropshire Union Railways & Canal Company.
The two main arches each span 9.1m and rise 2.5m. Arch rings, 460mm thick, have four brick courses with a 110mm stone course above. The central pier is 2.4m wide with stone ashlar up to the springing level and stone cutwaters.
The two roadway arches are of 3m span and 1.1m rise, with two-course brick arch rings springing from vertical walls 1.7m high. The south arch crosses a minor road and the north arch is over the access to a small sewage works.
The aqueduct is 10.1m wide overall and has a maximum height of about 8.5m above river level. It carries a canal trough 2.6m wide and 44.8m long, with stop plank slots at each end. The channel's towpath is some 3.3m wide to its south east side, with a similar width of turf on the north west side.
The side walls have stone copings 610mm wide and 280mm deep topped by 1.2m high cast iron parapet railings. The abutments feature curved vertical wing walls with similar copings.
To tie the aqueduct together, preventing the 19th century work peeling away from the 18th century original, three red-hot iron rods were inserted right through the structure above each of the main arches. The end fixings can still be seen on the aqueduct's elevations.
To prevent scour around the central pier and main arches, the river bed below the aqueduct and about 15m downstream is paved with stone blocks laid to arch inverts.
In 1948, the aqueduct's water was piped across the river after the closure of the canal following the 1944 Act of Abandonment.
In 1985, the canal at this point was restored to navigation. The aqueduct trough was reconstructed in concrete with blue brick coping, and adjacent car parking and visitor facilities were created.
In 2002, water leakage was found in one of the road arches.
Contractor: John Holbrook, Oswestry
Research: ECPK
"The Canals of Britain: A Comprehensive Guide" by Stuart Fisher, A&C Black, 2013
"The Archaeology of the Montgomeryshire Canal" by Stephen R. Hughes, Royal Commission on Ancient and Historical Monuments in Wales, 1989
reference sources   CEH W&WCEH Wales

Berriew Aqueduct