The project included design, calculation, fabrication and assembly of stair modules with cable support system for full profile drill cable shaft with diameter 2.6 m, length 164 m and 44 degree slope.
The cable support solution consists of a total of 28 prefabricated stair modules. The modules are assembled from fiberglass profiles and gratings steps which were then bolted to tunnel walls / floors with steel brackets.
For cabling, 3 cable ladders of 600 mm width and 1 piece of width 400 mm were installed. Furthermore, additional fire protection for cables and gratings has been added to provide additional protection against falling stones from the tunnel roof.
We would like to thank Lynet Engineering AS, Nordic Steel AS and Steis Mekaniske Verksted AS for the help of design, calculation, production of steel brackets and for installation at Tonstad.
A big thank to Risa AS who showed us confidence in this project.