- Client: The Highways Agency
- Architect: Jacobs Engineering
- Construction Manager: Connect Plus
- Fire Protection: 9,300m² Promat Promatect®-T Board
- Support Structure: 9,300m² Stainless Steel Framing System
- Drainage: 9,300m² Stainless Steel Water Ingress Management System
Overview
The Dartford Thurrock Crossing is a vital section of the UK’s strategic road network, forming a key trunk road link between Junctions 2 and 31 of the M25 London Orbital Motorway. Following the introduction of European Directive 2004/54/EC, which sets minimum safety requirements for tunnels on the Trans-European Road Network, it became necessary to upgrade the fire protection performance of the West Tunnel to meet stringent new standards.
Given the high volume of heavy goods vehicles using the crossing, a high-performance passive fire protection solution was required. The design was based on the RWS (RijksWaterStaat) fire curve, demanding protection against extreme temperatures of up to 1350 °C for a minimum duration of two hours. In addition, the system was required to accommodate static pressures of ±1.5 kPa caused by wind and traffic movement, while providing a maintenance-free design life of 40 years.
What we did
Sharpfibre was awarded the project to design and install the new passive fire protection package in March 2009. Due to the short timeframes involved in this scheme, meticulous planning and preparation prior to the start of works on site represented the key to the successful delivery of the works. Working from first principles, Sharpfibre engaged its specialist project delivery team consisting of Ancon Building Products (Stainless Steel Systems), Promat UK Limited (Fire protection boards) and Industrial Marine Coatings (Surface finishes). This project delivery team helped establish a robust design solution which was independently tested and approved prior to the installation programme on site.
Once on site, all installation works were carried out over a five day shift pattern under strictly controlled road traffic management closures between the hours of 22.00 and 05.00. Whilst the installation of the passive fire protection system was underway, Sharpfibre had to accommodate unplanned and emergency maintenance works without effect on the overall completion date. Following the meticulous planning both pre-construction and while on site, the passive fire protection works were successful delivered 26 weeks after commencement.
Fire protection
Built-in or “passive” fire protection measures are used in most modern constructions.
With road tunnels, the extent of passive fire protection is determined by assessment of the risk to those travelling within this environment, or the potential value placed on the goods carried and the value of the overall asset.
Safety
Minimum safety requirements for tunnels in the Trans-European road network
The European Directive 2004/54/EC on minimum safety requirements for tunnels in the Trans-European road network became effective in 2004. In almost all EU member states, the EU Directive considerably changed the legislative background of road tunnel safety as well as the relevant national technical guidelines. The EU Directive thus initiated an impetus towards harmonisation of regulations in Europe to improve the safety of the road tunnel users and the protection of the tunnel structure from failure in a fire.
Standards
British Standards for fire protection
Although there are no specific British Standards for fire protection in tunnels, a great deal of research has been carried out in recent years into fire development and temperatures. Hydrocarbon fires will develop quickly and reach much higher temperatures than less flammable materials. Throughout Europe, two fire curves are commonly specified as the base curves for modern tunnel fire protection designs; RWS (RijksWaterStaat) and HCM (HydroCarbon Modified – France).
Get a Quote
From initial planning to seamless post-installation support, Sharpfibre offers an all-encompassing solution that spans a wide range of products, effectively addressing the majority of passive fire-related concerns.
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