Shiel Bridge is a three-span masonry arch bridge built in 1900. The masonry foundations were founded on soft silt which was stabilised by driving timber cofferdams to allow excavation of soft material and filling with concrete hearting. Deterioration of the timber piles and subsequent scouring had resulted in larges voids below the masonry foundations endangering the stability of the bridge.
This contract was to form a new concrete filled greenheart timber cofferdam around the existing timbers. Subsequent filling of voids by drilling and grout injection. Lower sections of masonry were also injected with grout and repointed during the works.
In order to complete the works a large portable fabric cofferdam was placed around one pier and abutment to divert the river flow and allow the works to be completed in the dry.
The River Shiel is a first class salmon fishing river and careful consideration to possible water pollution was the main driver behind the use of the non-intrusive portable dam system. After successfully completing the works on the south side of the river the dam was relocated on the north side where the operation was repeated.
The overall project involves the off-site fabrication and installation of a new linkspan structure at Oban Ferry Terminal for client Caledonian Maritime Assets Ltd (CMal).
12th February 2019
GL making a return visit to the Sound of Kerrera off Oban, to undertake substantial repairs to the breakwater which suffered collision damage following an altercation with a workboat earlier this year.
14th December 2018
Michael Matheson MSP and Cabinet Secretary for Transport, Infrastructure and Connectivity covered all his portfolios at the official opening of the new Polmadie Footbridge giving pedestrian and cycle transport access,
18th September 2018