Northwich Town Bridge repaired
AFTER struggling to operate over four years, Northwich Town Bridge has been repaired.
This swing bridge is Britain’s first electrically-operated floating swing bridge, and is swinging again, thanks to a £300,000 repair by the Canal & River Trust.
Struggled to open for boat traffic
For the last four years, the two lane road bridge has struggled to open and close successfully for boat traffic, and has recently had to remain fixed in position to carry road traffic, so stopping the large vessels that use the Weaver.
The repairs on the bridge, that carries the Northwich Ring Road were to re-balance the original cantilever rotary mechanism enabling the 122 years old bridge to swing open again for boats.
Designed by the Weaver Navigation Company’s engineer Col J.A. Saner, the 1899 black and white, steel lattice girder bridge originally had wooden decking and weighed about 300 tons. Over the years there have been several modifications to the original design, including the addition of a tarmac road, which means the rollers and foundation piles are now having to support a moving deck of 460 tons—much more than they were designed for.
Ground-breaking technology
Simon Harding, project manager with the Canal & River Trust,explained:
“Town Bridge and its sister structure Hayhurst Swing Bridge in Northwich used ground-breaking technology when they first opened at the turn of the last century. The Weaver Navigation was in constant use by coastal steamers and barges transporting salt, coal and other goods to the River Mersey, Liverpool Docks and beyond.
“River transport was massively more important than road traffic, which was still dominated by the horse and cart at this time. The control cabin was manned 24 hours a day and the bridge was apparently operated more than 55,000 times in the first 15 years. Compare that with today’s largely leisure boating traffic, which requires the bridge to be swung less than 50 times a year, due to the smaller nature of most boats which can safely cruise underneath.
“The original engineers devised a series of clever adaptations to the bridge to cater for subsidence caused by collapsing salt brine mines. The bridge is partly floating and partly supported on adjustable cast iron screw piles. The water level is maintained by sluices, located away from the subsidence and the screw piles can be raised with adjustable screws. The bridge was powered by electric motors rather than steam to avoid pipes bursting due to the effects of corrosive, salty river water.
"The solution to the problem has involved the installation of new large sprung rollers and a circular metal rail. This should now help to keep the bridge swinging on its intended track, prevent further instability and ensure the historic bridge remains operational for many years to come.”
The six week repair project is now completed and the bridge is able to swing again to allow larger vessels to pass through Northwich up river towards Winsford or downstream towards Frodsham and Runcorn. Boat passage can be booked by ringing the Canal & River Trust on 0303 040 4040.