Case Study - Crossrail installs the PlusBolt

Excalibur's PLUS bolt was tested in over 11,000 hours' worth of salt spray and revealed no significant signs of corrosion. In addition, a UKAS accredited test house tested the bolt for 6,200 hours, sufficient for their evaluation purposes. The Ford Motor Company also evaluated the bolt through their nine week accelerated cyclic corrosion test. Results showed no signs of corrosion. An unofficial comment was made that "they had seen nothing better."

The Excalibur PLUS Hexagonal Head Screwbolt was launched at a tunnelling exhibition in London. Following the success of Excalibur's installations in the Channel Tunnel Rail Link project, Crossrail consultants expressed an interest in using Excalibur's screwbolts.

Tunnels being subjected to C5 environmental conditions meant any anchors fixing into the tunnel lining needed to have a life of 120 years: the new Excalibur PLUS Screwbolt was ideal.


Particularly long bolts however were required to fix the platform edge steelwork to the tunnel lining. Excalibur manufactured a small quantity of longer bolts for testing that combined the anti-corrosion specification of the PLUS bolt with a 120-year design life. Vinci Technology provided mock up sections of the tunnel lining into which the Excalibur samples were installed and rigorously tested at Imperial College London.

In July 2015 Excalibur PLUS Screwbolts were first used in the installation of the platform edge screens at Tottenham Court Road station. Four further Crossrail stations have since been commissioned; Bond St., Farringdon, Liverpool St. and Whitechapel.

Excalibur has now produced a range of M12, 16 and 20 Hexagonal Head PLUS Screwbolts for the tunnelling and marine industries. Not only are the concrete screw anchors highly resistant to corrosion, they have all the advantages of the standard anchor for ease of use and speed of application.