norwegian meter long double track railway tunnel line norway built state line construction started february tunnel opened august tunnel built conducted drilling blasting method easternmost meters built cut cover method tunnel opened problems leaks damaging superstructure tunnel double track electrified allows maximum speed kilometers hour mph cost build tunnel excluding superstructure million norwegian nok tunnel accelerate regional traffic west oslo free capacity oslo commuter rail specifications meters long cross section varying square meters tunnel consists meter long section meter long cut cover section easternmost tunnel carries double tracked line tunnel runs slate limestone local occurrences rock meter long section stable rock tunnel cover way meters lower margin laying meters meters line runs meters open entering line electrified allows maximum speed kilometres hour mph tunnel frost meters tunnel form end tunnel frost fans ensure air stays middle tunnel cold air flowing past frost isolation history runs municipalities line built allow increased railway traffic main corridor west oslo previously railway west oslo limited capacity mix local regional freight trains caused delays poor tracks trains stops allows regional trains pass local stations east local freight trains remain line line built stages constructed second stage constructed tunnels line meter long kilometer long awarded contract build cost nok million including open section excluding superstructure main tunnel built drilling blasting method points entry work started concluded february construction included removal cubic meters laying tonnes long tons short tons ballast laying tracks signaling power supply cost entire section nok million work completed november opening tunnel rest section took place august concern people living tunnel subject low frequency noise originally municipalities demanded residents subject maximum appealed requirements permitted allow march test tunnel requirements met low frequency sound difficult predict measurements opening tunnel showed background noise subject higher nearly impossible measure passing trains major concerns leaks construction year delay severe cost improper leak handling methods main focuses project avoid similar leaks contract specified maximum imp gal gal minute meters contractor attempted achieve extending time pre injection concrete water tunnel caused types damage places water track causing places water electrical equipment issues water running walls collecting cable water limestone ballast mixing ballast limestone emergency lighting system replaced high humidity stated savings specifications water frost methods caused higher maintenance costs small leaks present lot harm addition areas leaks suffer national trend older tunnels nearly maintenance free newer tunnels incurred high maintenance costs
Tanum Tunnel