Old West Bridge - Leicester

Metalock Engineering has been using its cast iron metal stitching expertise to repair and refurbish parapetpanels, copings and cornices on the Old West Bridge that carries three lanes of traffic out of the centre ofLeicester. The Grade II listed wrought and cast iron bridge is one half of a dual carriageway, another bridgehaving been constructed alongside some 25 years ago.

The Old West Bridge, on the A47, was surveyed four years ago and found to be in need of extensive repair andrefurbishment. Vibration from levels of traffic that it was never designed to carry had caused damage to thewrought iron support beams and the cast iron decorative arches, parapets and copings. In some places sectionsof cast iron were missing.

Dew Construction was contracted by Leicester City Council to undertake the repairs and refurbishment of themain structural elements. Dew brought in Metalock Engineering, with whom they had worked on two otherbridges in Leicester, to carry out the cast iron repairs, a task in which Metalock has specialist expertise.

The Metalock process is accepted as a method of repairing cracked and broken castings across a wide range ofindustries. One of the main advantages of the process is that it is heat free and can be carried out in-situ or oneof the company’s workshops. Apertures are jig drilled across the crack to accept multi-dumbell shaped keysmanufactured from a ductile high tensile nickel alloy. The keys are peened into the apertures to become integralwith the parent metal. Holes are then drilled and tapped along the line of the fracture and filled with studs, eachone positioned to overlap its neighbour. This combination of keys and studs produces a rigid and pressure tightrepair and final peening and hand dressing completes the operation. Once the repair has been dressed, aprimer applied and finish painted it is practically undetectable.

Where pieces of cast iron section were missing from decorative plaques and panels on the bridge, Metalockmachined replacements from cast iron blanks and stitched them into place to restore the original design.

Metalock used its cast iron stitching expertise torepair and refurbish parapet panels, copings andcornices on Leicester’s Old West Bridge whichcarries three lanes of traffic out of the city centre.