the Follobanen (Follo Line) has opened with fanfare on 12 December 2022 by by King Harald V and the Crown Prince. And closed abruptly just after a week on 19 December after some fires and other problems. The 22km long high speed railway line connects the cities of Oslo and Ski. 19 Kilometers of the railway runs in the twin-tube tunnel called Blix Tunnel. 

The newspaper Aftenposten reports that the Follobanen struggles with water leakages in the tunnel.

The newspaper has seen the contract between Bane NOR (Norway's national railway management company) and the builders, the Acciona Ghella Joint Venture (AGJV). In the contract, the newspaper reports, Bane NOR specifically states that 'The contractor will provide a dry tunnel'.

Yet, the Aftenposten writes, the August 2022 inspection discovered 525 (five hundred twenty five) 'unacceptable' leakage points. This is a serious problem with electrical systems. The water leaking normally can easily be collected by the water collection system. But this is not a normal rainwater. When water is passing through the tunnel structure, it gets contaminated. Later, when the contaminated water dries our on the tunnel service, the remaining salt conducts the electricity causing short circuits. Fires starting because of such short circuits is given as one of the reasons the tunnel is abruptly closed.

Those 525 water leakage points discovered in August had to be sealed off until October 30 and from the responses of the Bane NOR official in the newspaper article, it is understood that that job has been deemed to have been done to an acceptable level. But obviously it was not enough which consequently caused the closure of the tunnel on 19 December. All leakages discovered after October 30 has to be sealed off until March 23, according to the report.

The newspaper writes "Density in the tunnel now becomes part of Bane NOR's complaint case against AGJV".

Aftenposten further reports that out of the 165000 segments mounted in the tunnel, 171 should never have been, as they were marked as faulty segments. Yet they are still there. Among those 171, 47 of them can now be considered approved, according to the newspaper report.

https://www.aftenposten.no/norge/i/dwklO1/bane-nor-lovet-en-toerr-tunnel-paa-follobanen-naa-sliter-de-med-lekkasjer