Carillion Civil Engineering were awarded the project and Shay Murtagh Precast were contracted to design and manufacture the precast concrete deck and bridge beams to replace the arch including L-shaped ballast retention units at the four corners of the bridge. Steel walkways were to be attached to the outside of the precast elements with steel ramps bridging over the existing wing walls to the embankment.
The bridge superstructure consisted of four number skewed reinforced concrete deck units. The two edge portal units also incorporated a robust kerb.
Bridge Beam Specifications:
- All portals had a 300mm section thickness and 900mm down stand.
- The internal units weighed 10.1t while the edge units weighed 19t. The portal units beared onto four number 4.5m long precast cill beam units each weighing 5.2t.
- Ballast retention and ramp base units also formed part of the contract and the maximum weights of these units were 4.6t and 3.6t respectively.
Due to the constrained nature of the site the deck units could not be lifted into place individually. Therefore the bridge deck had to be assembled on trestles remote from its final location and then moved into place on a transporter. Shay Murtagh also designed the temporary works details which enabled the cill beams to hang from the portal downstands using structural steel braces while being moved into place on the transporter.
A trial erection was held in our factory with sign off from Carillion and Network Rail teams. Logistics were managed and delivery and installation were handed over a strict time frame. On this project Shay Murtagh Precast worked with Carillion Scotland, Design, Contract and Installation teams and as always we extend our thanks.
Follow us on Linkedin:
Gillian is the Marketing Director for Shay Murtagh Precast. The company's problem solving capacities allow us to give off site solutions to once insitu contracts which in turn speeds up project completion.
Working in conjunction with all divisions of the company she challenges industry norms in marketing.
Latest posts by Gillian Murtagh (see all)Posted by Gillian Murtagh Posted on 14 Dec 2012