Heavy stitch drillingPublished 29/10, 2014
In the UK a team from D-Drill have helped to remove a 4.4t concrete block during major works at Pembroke Power Station in south Wales.
D-Drill was called in by main contractor Woodenbale 2000 who were awarded the contract to open an existing sealed chamber at the power stations cooling water pump house.
With no access points, a block of concrete 1.65m in diameter had to be removed to create the opening. The sealed chamber was covered by pre-cast concrete lids with stitch anchors and lifting eyes glued in place to stabilise the concrete during the drilling stages.
Tests were carried out to ensure the anchors and eyes would be able to withstand the full weight of the concrete section being removed and once, they passed, it was hooked up to an overhead gantry crane to support it.
This allowed D-Drill to carry out stitch drilling with two Weka DK 22 coring rigs drilling 100mm diameter holes. D-Drill and Woodenbale 2000 worked together to devise a solution to remove the concrete section by crane, which took five days.