To comply with the new legislation set out by the European Community Directive the Tay Road Bridge required strengthening to cope with the ever-increasing volume of traffic crossing it on a daily basis. This strengthening involved the installation of additional internal and external brackets to the main box girders.
Millar Callaghan personnel carried out a detailed survey of each bracket location on the 22 spans to be strengthened. Once the survey was complete and detailed fabrication drawings were submitted and approved by the client our fabrication department went into production on the brackets.
Fabrication jigs were used to keep the brackets within a tolerance of 0.75mm and magnetic hinged drilling jigs were used on site to compensate for any change of shape or level to existing steelwork.
Additional strengthening plates had to be welded to the steelwork to compensate for the material being removed by the drilling process.
With all the holes drilled and the new knee-brace brackets bolted into position using tension controlled bolts, a central bracket was then lifted into position using a pneumatic ram. This bracket was then welded to the ring frame knee brace.
At the end of the contract Millar Callaghan’s quality department presented the client with a package containing all material certificates, welder qualifications, welding procedures, N.D.T. test results and paint specifications.
This contract was nominated for the Saltire Award for engineering excellence.
