River Weaver - Structures

Structures

The navigation has a number of structures which, because of their age, have historic value and are listed on the Listed Building register. At Vale Royal, the lock built in 1860 was retained as a sluice channel when a new lock was built in the 1890s. A swing bridge crosses the chamber. The sluice at the upstream end is supported by two cast iron arches on rusticated piers. A swing bridge, made of wood and iron, crosses the small lock, which was the large lock until the construction of the new large lock in the 1890s. This has three sets of gates, and could accommodate a train of four barges when the outer gates were used. Again, a swing bridge crosses the lock. The gates are opened by a Pelton water turbine mechanism, and other features include a water levelling mechanism and a system for removing rubbish from behind the gates using jets of water which are controlled mechanically. The lock keeper's cottage is also grade II listed. It was built in the 1850s, but was moved northwards by 20 yards (18 m) during the 1890 reconstruction.

Below the locks, a five-arched red sandstone viaduct, constructed in 1837, crosses the valley. It was built by Joseph Locke, and carried the Grand Junction Railway. Hunt's locks also consist of a pair, the smaller one from the 1860s and the larger one, with three sets of gates, from the 1890s. Steel semaphore signals control access to the locks, and again the movement of the gates employs a Pelton turbine. The weir to the east of the locks has a walkway supported by rusticated piers and five cast iron arches, which also support the floodgates. The structure is Baroque in style.

Northwich railway viaduct spans both the lock cut and the weir stream, and was built in the 1860s. It consists of 48 round arches, constructed of blue bricks and red sandstone, with iron spans over the channels. It is around 980 yards (900 m) long, provides 39 feet (12 m) of headroom over the navigation, and also crosses the River Dane. Hayhurst swing bridge carries the A5509 road over the navigation, and was manufactured by A Handyside and Co. Ltd., of Derby and London, in 1899. It is an asymmetric bowstring lattice girder bridge, and its timber-framed weatherboarded control cabin is also listed. This and Town bridge, which is located a little further downstream and is of a similar design, are believed to be the two earliest swing bridges in Britain to be powered by electricity. Both bridges were designed by J. A. Saner, who was the Navigation's engineer, and incorporate a sectional pontoon, which is immersed in the river and carries about 80 per cent of the weight of the bridge. Because of the risk of subsidence from the salt workings, the bridges are fitted with screw jacks which allow the deck level to be maintained. Hayhurst bridge was refurbished in 2004 at a cost of £33.5 million. Winnington bridge, the next downstream, was built between 1908 and 1909, to replace the first bridge which was built in 1901. The original design was flawed, and hence the bridge was replaced after only 7 years. A pedestrian walkway was later fitted on the downstream side of the new bridge.

Saltersford locks were built in 1874, using red sandstone and limestone, and replaced a lock built on the Barnton cut between 1832 and 1835. The Pelton turbines which control the gates were built to Stoney's patent, and carry plates which indicate that they were manufactured by Hanna, Donald and Wills of Paisley. Acton Bridge is a symmetrical bowstring girder swing bridge, which was built in situ between 1931 and 1933, on an island in the centre of the river. It was first swung across the channel on 10 August 1933. J. A. Saner was again the designer. Dutton locks are of a similar design and age to those at Saltersford, and the Pelton turbines were made by Northern Foundry Co. Ltd. of Oldham, who are described as turbine makers on the cast-iron covers. Dutton sluice, some 160 yards (150 m) to the north-east of the lock, was built in the 1870s, in a similar Baroque style to Hunt's weir, but is larger, with eight arches each carrying a sluice gate. Where the weir stream rejoins the main channel, the towpath is carried over it on Horse bridge, which was designed by J. A. Saner, the Navigation's engineer, in 1915, and erected in 1916. It is one of the earliest surviving laminated timber structures, and consists of two arches, both over 100 feet (30 m) long. Below the locks, Joseph Locke and George Stephenson built another viaduct for the Grand Junction Railway, which was completed in 1836 and is grade II* listed. It has 20 arches, and was built at a cost of £54,440 by a London civil engineering contractor called David McIntosh. A civic celebration was held on its completion, as there had been no deaths and no serious injuries to the workers during its construction. The navigation has since been re-routed, and now passes through a different arch of the structure.

The weir at Frodsham was built in 1785, although it has been altered subsequently. The main curved section is 49 yards (45 m) wide, and there are two 16-foot (5 m) sluices at the southern end. The adjacent lock, which was designed by Robert Pownall and George Leigh in 1781, was modified in 1830 and later, but most traffic was using the Weston cut by the time of the 1890s upgrade, and so it retained some of its original features. It is derelict, and water flow is controlled by a concrete and steel sluice erected in the mid 20th century. A red sandstone and limestone bridge carries the A56 road over the channel below the lock. It was built in 1850, and has three 27-yard (25 m) arches. The A56 crosses the main channel on Sutton swing bridge, which was built in the 1920s. There have been problems with the stability of the road surface, and options to secure its long term future and appearance were discussed in 2010. Frodsham viaduct, completed in 1850 and built in brown bricks with a cast-iron central arch, was built for the Birkenhead, Lancs & Cheshire Junction Railway by the contractor Thomas Brassey. The engineer for the project was Alexander Rendel.