Working with American Bridge over 4 months in Tintagel, Cornwall
CAN delivered specialist anchoring works for the new footbridge at Tintagel Castle, providing critical support for the bridge foundations and adjacent cliff face. The project was completed during the tourist off-season, helping minimise disruption.
As part of the installation of the new footbridge at the spectacular Tintagel Castle in Cornwall, CAN was enlisted to install high-capacity rock anchors to support the bridge abutment foundations, and strand anchors to stabilise an adjacent rock face. Works were undertaken over winter during the tourist off-season, ensuring minimal disruption.
To support the bridge, 57.5mm double corrosion-protected support anchors were specified to be drilled up to 17m deep, with 6 anchors grouped in the mainland upper foundation and 4 in the island upper foundation, and a pair on each side at the lower abutments. A further 30 strand anchors were required to stabilise the cliff face adjacent to the mainland side of the bridge.
With a cable crane installed for plant access, limited to lifting items weighing up to 5 T into difficult-access worksites, the plant was restricted to small, manoeuvrable items. CAN provided the solution to this drilling plant weight limit by undertaking the drilling on the rock faces and lower abutment using A-frame drill rigs, suspended from bespoke kentledge-based crest access systems, a temporary works system designed specifically for this contract to avoid drilling into the historically sensitive ground of the castle courtyards.
A bespoke lightweight drill mast was also developed to fit on a 5T excavator, which was lifted into the works area by the cable crane, with a double hydraulic rotator built to achieve the extremely tight angle tolerances required for drilling the upper abutment anchors. Following initial suitability anchor installation and testing, the main bridge anchors were installed and underwent a rigorous acceptance testing regime, with load checking using a load cell within the testing system carried out. The bridge abutment foundations were then cast around these, ready to receive the bridge, which was lifted in sections using the cable crane.
