Direct by Design
In-tunnel service vehicle fire on UK HS2 under investigation TunnelTalk reporting
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vacuation of the tunnel, retreat of the crew into the TBM refuge chamber for 13 hours, and call of fire services to the site were all part of a recent fire incident on the Align JV Chilterns tunnel contract on the HS2 high speed railway project in the UK. The fire occurred at about 7.30pm on Tuesday evening 10 May, on a personnel carrier service vehicle carrying supplies and a crew change to the TBM heading. A flame in the engine bay was noticed by the driver when the vehicle was stopped at about 2.5km into the tunnel to drop off an MSV operator to take over a production MSV vehicle, before continuing to the TBM about 1.4km ahead. The established fire safety procedures were followed by the workers and the fire was extinguished using a portable fire extinguisher. Unfortunately, the fire reignited and overcame any possible intervention control. The tunnel was evacuated and the crew at the TBM were ordered to start operation of the refuge chamber on gantry three of the trailing backup and take shelter in it until the fire was fully under control and access back into the tunnel was possible the next morning for their rescue. It is a credit to the fire safety procedures on the site, and of the operation of the refuge chamber, that there was no injury or need for anyone to attend a hospital for treatment or observation. In response to the risk and the emergency, all was handled and managed according to
23 May 2022 risk management procedures. Up to 18 workers were involved with the incident. Nevertheless, a full investigation of the incident has been opened by the UK HSE Health & Safety Executive and the fire authorities. The Align JV, led by Bouygues Travaux Publics, with VolkerFitzpatrick and Sir Robert McAlpine, has confirmed that it will cooperate fully with the enquiry and to make the full report available to the industry to share the findings. The enquiry report will also be awaited by the UK representatives of the CEN European Committee for Standardization who, together with their European counterparts, are currently studying the safety and operating standards of multi-service vehicles. MSVs, with their operator cabins and electric or diesel drive trains at both ends of the vehicles, are finding wider use in the international underground construction and tunnelling industry. Align JV operates a large fleet of diesel powered, wheeled based service vehicles on its twin 16km long x 10.26m o.d. TBM drives through the Chiltern Hills. The length of each tunnel prohibited the use of electric powered vehicles including production MSVs for transporting segments; MSVs for concrete delivery; and Hiab and side loading MSVs. The personnel service vehicle (PSV) involved in the fire was transporting the new shift team to the TBM and dropping a production MSV driver at his vehicle. Electric power was said to be impractical for MSVs travelling up to 16km fully loaded with the 64 tonne of seven precast segments of each ring of
Examples of different types of rubber-tyre service vehicles with operator cabins at both ends for travelling in either direction
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