the breakthrough took place on 2 September, five months before schedule. Sixty people participated in a course to master fear of tunnels organized by the toll company. When it opened, the tunnel was the longest and second-deepest subsea tunnel in Europe and Norway, after the Hitra Tunnel. The Stord and Bømla Bridges were both constructed using the same method and by the same contractors, Arbeidsfellesskapet Triangle Contractor, a joint venture between NCC Eeg-Henriksen and HBG Steel Structures. Construction started on the Stord Bridge on 20 February 1999. After the pylons were completed, two catwalks were erected between them, with the constructors choosing a continual catwalk instead of three separate ones. The cables were spun on-site using a reel; this also allowed for cost savings, as the reels could be used two times. The cables were spun using the air spinning with controlled tension, which allowed spinning with little space use and with a crew with limited experience with spinning. The two bridges were the first time that on-site spinning was used in Norway. The fastening poles were delivered five weeks after schedule; a new mounting method was developed which allowed them to be installed in a quarter of the time, in part by using a helicopter, and the whole five-week delay was eradicated. This allowed the deck sections to be installed as scheduled. The decks were produced in Schiedam, Netherlands, for the Stord Bridge and in Italy for the Bømlo Bridge. These were sent by barge to Sunnhordland. The section length was different between the two bridges, the Stord Bridge having them in lengths of and the Bømla Bridge in sections of . This was to accommodate the latter's smaller vertical curvature. The entire project cost NOK 1,814 million. The costs were distributed to NOK 476 million for the Bømlafjord Tunnel, NOK 433 million for the Stord Bridge, NOK 336 million for the Bømla Bridge, NOK 46 million for the Spissøy Bridge, NOK 36 million for the Digernes Tunnel, NOK 325 million for roadways and NOK 172 for administration and common costs. The investment cost was split between state grants and NOK 1,036 million in debt taken up by the toll company. When the project was passed by Parliament it had a budget of NOK 1,260 million. The Office of the Auditor General of Norway criticized the Western Norway Public Roads Administration in 2001 for a total cost overrun of