Paraslim composite bridge system used to support the construction of the Catthorpe Viaduct Replacement
Replacing the existing Catthorpe Viaduct at the intersection of the M6/M1 motorways, M1 JN 19, in the Midlands, the new ‘M6 Catthorpe Viaduct Replacement is being constructed by Skanska at a similar level to the existing structures, using RMD Kwikform’s Paraslim product.
Commenting on the use of RMD Kwikform’s Paraslim, Neil Davison, sub agent for Skanska said: “Having to construct the viaduct right next to the existing structures Between the M1 and M6 Motorways whilst they are still active made the project very challenging.”
“With safety paramount for the travelling public and our workforce, as live traffic moves underneath the viaduct, we looked for a proven system that could be used to create a safe working platform, whilst being able to be installed simply onto the main beam sections of the structure.
“Having used RMD Kwikform’s Paraslim product before on a number of similar projects, we felt that this was the best solution for the viaduct construction. Probably the most important reason why we selected Paraslim was the simplicity of the design and the way in which RMD Kwikform were able to support us and deliver to site on a ‘just in time’ basis.
In practical terms, what this meant was we were able to schedule delivery to our compound at a convenient time. Our fitters were then able to erect the Paraslim directly onto the beam sections in the compound at ground level, in a controlled and safe environment. This eliminated almost all of the need for working at height as the beam sections were then lifted onto a low loader, transported to site and lifted into place in a simple operation.
“All that remained was to fix together sections once the beams were in place, an operation that could be achieved using MEWPS. This approach was not only much safer for our operatives, it proved to be a very swift safe and cost effective process.”
Commenting on the selection and use of Paraslim by Skanska, Stuart Grant, senior sales representative for RMD Kwikform for the Midlands said: “Paraslim has been a trusted product for this kind of composite bridge work ever since it was launched .The product has since been continuously developed and there are now a number of options available, including a pre-assembled solution.
“Because Paraslim uses standard equipment that is part of the RMD Kwikform range, it provides a safe and cost effective solution for a whole variety of composite bridge projects. On this particular job, Skanska had a spacious compound, where safe erection of Paraslim could take place, which proved to be the best option.”
Commenting on the Paraslim system, chief engineer Andrew Jones said, “RMD Kwikform were the first company to bring this product into the market having developed it in 1996. It has been used in many structures in the UK and overseas since then.
“On this structure we are using a solid hording ideal for use over live railways or in this instance over a live motorway. The Paraslim itself consists of triangulated frames that are hung from the bridge girders by a single tie. The frames are ganged together in modules, which can then be readily lifted up and placed onto the bridge. In this instance the modules were attached to the bridge prior to the girders being put into place, then the girders and modules were brought up on to the bridge as a single lift. This gave the advantage that they were able to have a continuous handrail and platform in place immediately, giving extra health and safety benefits.