The Kethel Tunnel is a land tunnel between Schiedam and Delft with 2 separate tunnel tubes that are 1.6 kilometers (east tube) and 1.9 kilometers (west tube) respectively. The tunnel is managed by the A4all consortium, consisting of Boskalis, Heijmans and VolkerWessels. Several times a year maintenance is carried out on various aspects of the tunnel. Saval has been involved in fire protection since the tunnel opened in 2015.
Every 50 meters in the tunnel, there is a cupboard on both sides of the road with a water / foam reel and a frost-free Bioclass foam extinguisher that can be reached in the event of a fire. These extinguishers are maintained annually in accordance with NEN2559 for fire extinguishers and EN671-3 for fire hose reels. Every 5 years a foam extinguisher falls into a special maintenance year. Extensive maintenance will then take place in accordance with NEN 2559. The 150 extinguishers have to undergo extended maintenance within a limited period of time, therefor it has been decided to replace all extinguishers with a new one.
All 150 extinguishers in both tunnel tubes of the Kethel tunnel were replaced within 12 hours. The high-quality extinguishing foam in these 9 liter IFP constant pressure extinguishers has been specially developed for use in extremely low temperatures (frost-free up to 30 degrees below zero!).
With a long spray time of 55 seconds and an excellent extinguishing rating on solids of 27A and liquid fires of 233B, the tunnel meets the strictest fire safety requirements again.