Siemens Nederland N.V. equiped all tunnels of the Dutch Betuwe project with the FibroLaser II® linear heat detection system developed and manufactured by LIOS Technology. The Betuweroute is a 160km long double-track freight railway. It is the largest infrastructure project in the Netherlands. Construction officially started on 3 June 1997, and on its completion in 2005, it will link the Mainport Rotterdam with Zevenaar on the Dutch/German border. The tunnels are designed for double-stacked trains and safety had a major influence on the design. Major safety features are a sprinkler system - controlled by FibroLaser II® - that is designed to stop LNG (Liquefied Natural Gas) tankers exploding in the event of an accident and heat resistant cladding that will protect the tunnel interior for two hours.