Following a recent SHE-ALT notice issued by Morgan Sindall it has been proven that Morgan Sindall's sub-contractor installed x3 of the wrong Excalibur product on this particular edge protection safety barrier system. The picture of the bracket shows the wrong product would only leave under 40mm of Excalibur Screwbolt embedded in the concrete which is below our recommended embedment depth of 60mm. All other edge protection barriers on this site were fixed using the correct product - Excalibur Screwbolts HSB 16x150, with no reported failures.
The sub-contractor concerned acknowledges that 3x HSB 12x100’s should not have been used at this location for the fixing of safety barriers and there have been no other failures of any of Excalibur's products.
The 1x Excalibur Screwbolt which then subsequently failed in service two months after installation (HSB 12x100) was used beyond its performance limits (see 12mm data sheet) and installed incorrectly in this application.
We believe that this was the root cause of failure in this instance especially as this is a combined load situation/application which is beyond our recommended loadings. There are also other site specific issues including abuse of product which we are looking into further. One such abuse witnessed was a sub-contractor, striking the safety barrier post with a hammer, in order to “ease” it over, such that an aluminium cleat could be fastened to the floor slab.
The Makita impact wrench used for installation had a maximum torque value of 1,000Nm when Excalibur recommend an impact wrench of up to 250Nm for our 12mm Excalibur Screwbolts. Consequences of which could over stress the bolt.
Regarding this matter we were provided with limited/late information on this incident so we could not express our opinions on this issue and no formal contact was made to Excalibur Screwbolts about this complaint by Morgan Sindall prior to release of their safety alert, which is against industry complaint protocol.
Excalibur Screwbolts are a proven and safe anchor which have been used extensively for all types of temporary and permanent applications in the construction industry for many years and are mechanically zinc finished as standard to specifically address and remove the risk of hydrogen embrittlement (see data sheet). Excalibur Screwbolts are manufactured in the UK to ISO 9001 quality standards with full material, heat treatment and finishing traceability plus sample batch testing prior to release to the marketplace.
We would also wish to make it known that Morgan Sindall confirmed to Excalibur Screwbolts that safety alerts of this type are meant to be internal documents only and not for external circulation.