Five workers have been removed from HS2’s London tunnelling project after an air rifle was brought onto a West Ruislip site and fired by night-shift workers.
The site is operated by the Skanska, Costain and Strabag joint venture, known as SCS. The incident was investigated by SCS and HS2 after a whistleblower raised concerns in May 2025.
HS2 said the incident took place around 18 months ago and described the behaviour as “unacceptable” and isolated. It said individuals involved had been dismissed and that health and safety processes had been overhauled.
Changes to site controls
HS2 said it had also reviewed how SCS handled the incident. Measures introduced by SCS include more searches and monitoring of compliance with the prohibited-items list, including checks on people and vehicles entering and leaving sites.
The joint venture has also introduced workplace culture interventions and updated its health and safety and whistleblowing policies. HS2 said there had been changes to SCS’s leadership.
“We very much regret that a prohibited item made it onto site despite the extensive security protocols in place,” an SCS spokesperson said.
SCS said its security team attended the site and contacted police after being alerted to the rifle’s presence, but that it had already been removed. The company said it conducted a full investigation using the evidence available and took appropriate action once the evidence had been established.
“The actions of the individuals involved were not in line with our values or policies and therefore they were removed from the project,” SCS said.
HS2 urges workers to report concerns
HS2 urged workers to report incidents directly through its confidential Speak Out channels so that it or its contractors can take prompt action.
“HS2 Ltd takes all allegations of dangerous and unethical behaviour on our worksites extremely seriously, and incidents of this nature will not be tolerated,” the organisation said.
SCS is delivering HS2’s 13.5km Northolt Tunnel between West Ruislip and Old Oak Common and the 7.2km Euston Tunnel under a £4.2bn main works civil contract.
Last month, Costain announced that Rohan O’Grady would take over leadership of the team delivering the London tunnels section of the SCS joint venture.