The bored tunnels have an inner diameter of 10.1 metres, approximately 6.5 km long and reaches to a maximum depth of 60 metres below sea-level. The total length of the crossing is about 7.0 km long. Transportation of hazardous goods is acceptable according to the category I tunnel classification. For safety reasons both tubes are connected with cross connections every 250 metres.
Scope of work
Reviewing the contractors detailed design of the bored tunnel, cross connections and access ramps; reviewing work method statements, quality plans and construction planning; monitoring of investigations for the design (fire-tests, freezing test for cross connections); advice with respect to local damage of lining during construction.