Fire water supply and drainage of the Bikoš tunnel

The fire water supply system is designed as a water-filled system made of ductile cast iron, DN 150 profile, with electric heating and thermal insulation. It consists of a fire tank, an automatic pressure station, fire water distribution pipes with the necessary fittings as well as automatic control and regulation of the system. The fire water supply system is located under the sidewalk in the tunnel. In front of the portals, it runs underground where there are fire hydrants that can also serve as filling points for firefighting equipment if necessary. An automatic air vent and bleed valve is located at the highest point of the fire water supply system.

The drainage system drains rock water located in the rock mass near the tunnel lining into a DN 250 drainage pipe, which is located behind the tunnel lining at the portal and then into the recipient. The drainage system includes cleaning drainage shafts located in cleaning niches and pre-portal sewage. The drainage of the tunnel roadway is solved by a slotted gutter. The drainage of the roadway includes fire barriers at a maximum distance of 50 meters – siphon components that prevent the spread of burning liquid in the channel. In standard mode, water is drained into the motorway sewerage system at the northern portal of the tunnel. In the event of a fire or tunnel cleaning, the drainage of dirty water in the sluice shaft will be diverted and collected in an emergency tank.