UK: The bespoke corrosion-resistant PLUS bolt was developed by screwbolt specialist Excalibur to meet the demanding requirements of the Crossrail project in London.

Crossrail Ltd requires anchors used in the tunnel lining to demonstrate a 120-year design life instead of the standard 50-year span of a standard fixing. The twin-helix Excalibur PLUS bolt also offers high-performance tensile and shear characteristics.

PLUS bolts have passed 11 000 h of salt spray tests, and were evaluated for nine weeks in an accelerated cyclic corrosion test undertaken by Ford Motor Co. Vinci Technology and Imperial College London’s Department of Engineering conducted stringent testing to ensure they can withstand the stresses of a long design life in a sprayed concrete tunnel lining.

Applications include fixing platform screen doors, a task which requires particularly long bolts to overcome variations in the depth of the concrete tunnel lining.