Summary
Two road bridges. 1904-5 by Samuel Sydney Platt, Borough Engineer of Rochdale, in association with L.G Mouchel and Partners, with the work undertaken by Yorkshire Hennebique Contracting Co. Ltd. of Leeds. Ferro-concrete with Stanicliffe sandstone parapets from quarries near Rowsley, Derbyshire.
Reasons for Designation
The two Mellor Street bridges, of 1904-5 by Samuel Sydney Platt, Borough Engineer of Rochdale, and L.G Mouchel and Partners, are listed at Grade II for the following principal reasons:
* Technological Innovation: the bridges were at the cutting edge of concrete bridge construction in England, being amongst the very first bridges to be constructed entirely of ferro-concrete and also using vault-slab arches in their design. They clearly demonstrated the advantages of reinforced concrete over traditional construction practices in terms of the material costs, the ease and rapidity of construction, even in a geologically difficult location, and the reduced maintenance liability;
* Influence: the technical success of the Mellor Street bridges was well publicised and there was a rapid expansion in the use of reinforced concrete in bridgeworks from around 16 known bridges in 1905, to 40 bridges built, strengthened, or widened by 1907, and well over 400 bridges, viaducts, and similar structures by 1915, when the First World War brought a virtual halt to construction;
* Engineers: the bridges were designed by Samuel Sydney Platt, Borough Engineer of Rochdale and advocate of ferro-concrete, in association with L.G Mouchel and Partners, who were notable bridge and concrete engineers and British agents for the proprietary reinforced concrete system known as 'ferro-concrete' developed in France by Francois Hennebique.
History
The two reinforced concrete bridges were constructed in 1904-5 to carry a new road over the River Spodden; the road, named Mellor Street, was built as part of the infrastructure for Rochdale's new tram system. The former tramway offices, which are dated 1904, are located to the north of the northern bridge. The bridges were constructed by Samuel Sydney Platt, the Borough Engineer of Rochdale, in association with L.G Mouchel and Partners, with the work undertaken by Yorkshire Hennebique Contracting Co. Ltd of Leeds.
Reinforced concrete comprising concrete with embedded steel rods, bars, or mesh first began to be used by European engineers in the early 1870s. It was not generally used in Britain until after 1897 when the agents L.G Mouchel and Partners introduced the proprietary reinforced-concrete system known as 'ferro-concrete' which had been developed by the French engineer Francois Hennebique.
Ferro-concrete was used for the Mellor Street bridges because of the presence of colliery workings in the Royley mine at a depth of 30-40 feet (9-12 m) below the river level. The workings contained water which was then being pumped out and used for industrial purposes. The ground was therefore badly honey-combed and would not support a traditional masonry bridge. Platt, writing in the October 1904 edition of Hennebique Ferro-Concrete Construction, described how ferro-concrete piles 14 inches (36 cm) square and 40-60 feet (12-18 m) deep were placed in bore-holes through the colliery workings and driven at least 2 1/2 feet (0.76 m) into the solid stratum below. The pile foundations were calculated to give a resistance equal to a dead load of over 90 tons and held the abutments of the bridge. A shallow-arched ferro-concrete slab was rested upon the abutments, with further strengthening at the springing point to resist the pressure of the arch. Platt stated that the bridges were the first in the country constructed entirely of ferro-concrete from the foundations to the superstructure, and that they were in addition the first to have been built with slab-arches without ribs or beams. These facts were reiterated by the Manchester Geological and Mining Society journal of October 1904.
It is known that the earliest English bridges to use reinforced concrete were a bridge strengthening scheme in Hampshire, completed in 1901, and a road bridge over the former Foredyke Stream, New Cleveland, Kingston upon Hull, of 1902, which has a plaque stating that it is the first bridge built of ferro-concrete in Great Britain; however in both cases only the bridge deck is reinforced, with masonry or mass concrete foundations and abutments. The 1904-5 Mellor Street bridges were certainly at the forefront of a new approach to bridge construction which used reinforced concrete throughout the structure.
Platt also used ferro-concrete in 1904-5 to cover the River Roch in the centre of town between the Rochdale and Wellington bridges, thus forming a central open space for the distributing centre of the electric tramways. He used both these structures to highlight the advantages of ferro-concrete construction, stating a saving in initial cost of about twenty percent on steel construction, together with an ongoing economy in maintenance as the concrete did not need to be painted. Such economies led to a rapid expansion of the use of reinforced concrete in bridgeworks to the extent that by 1907 it was reported that 40 bridges had by then been built, strengthened, or widened. By 1915, when the First World War brought construction to a virtual halt, well over 400 reinforced concrete bridges, viaducts, and similar structures had been built in Britain of which about 80 percent used the Mouchel/Hennebique system.
Details
Two road bridges. 1904-5 by Samuel Sydney Platt, Borough Engineer of Rochdale, in association with L.G Mouchel and Partners, with the work undertaken by Yorkshire Hennebique Contracting Co. Ltd. of Leeds. Ferro-concrete with Stanicliffe sandstone parapets from quarries near Rowsley, Derbyshire.
DESCRIPTION: the two shallow-arched skew bridges are built to carry Mellor Street over a bend in the River Spodden. The abutments, slab arches, and battered buttresses are constructed of reinforced concrete; at a later date the original concrete was sprayed with concrete render which has now been partially removed. The sandstone parapets have chamfered plinths and are pierced with vertical rectangular, chamfered openings, with chamfered coping stones. They are flanked by panelled rectangular piers with chamfered plinths and deeply chamfered cap stones. The right-hand pier of the east parapet of the south-east bridge has a mason's mark. The south-east bridge also has short stone walls to the outer sides of the piers with chamfered plinths and flat coping stones. The north-west bridge has similar short stone walls to the outer sides of the piers, though lacking the cap stones; the exception is the right-hand pier of the west parapet, where the stone blocks return. An iron strap protruding from the stonework suggests that there may have been a gateway or an earlier fence in the position of the modern fence.
The brick walls and metal fencing abutting the stone parapets of the bridges are later and not part of the original construction. They are not of special interest.
