Summary
Highlights
Construction of the Hardanger Bridge began in winter 2009 with blasting work. Tunnel engineers achieved a breakthrough in the fjord at Valavik in late April. Work continued on both sides of the fjord throughout 2009 and 2010, featuring roundabouts within the tunnels. The Valavik tunnel broke through in November 2009, and the Bu tunnel in February 2010. Ground excavation for bridge foundations also started in spring and summer 2009.
The first concrete for the Hardanger Bridge pylons at Buu was poured on October 7, 2009, requiring 50 hours of continuous concreting. Each of the four bridge foundations used 900 cubic meters of reinforcement and concrete. Concreting for the pylon foundation in Valavik began on January 26, 2010. Pylon construction started in autumn 2009 and finished in spring 2011, incrementally built in 4-meter sections using a climbing formwork system.
On August 24, 2010, the pylon at Buu reached 100 meters. An anchorage system, including a splay chamber below the pylons and an anchorage chamber deeper in the mountain, was built concurrently. Pylon saddles were installed in early spring 2011. By May 2011, both pylons reached their full height of 202.5 meters above the fjord, and the formwork was removed. The angled pylon top walls are 12 meters high.
The next step involved installing four 23-ton solid steel splay saddles at the front of the splay chambers, requiring millimeter precision. Before steelwork across the fjord, both pylons were pulled back half a meter towards the anchorage. They would eventually return to their natural vertical position once all steel was in place.
In July 2011, workers began installing the catwalk, a suspended work platform spanning the entire bridge, essential for the final year of construction. A man basket was used for transport. The catwalk was ready by September 5, 2011, allowing mayors and guests to walk across the fjord for the first time.
Cable spinning commenced in November 2011. A spinning wheel carried four bundles of galvanized steel wires across the bridge from Buu to Valavik, adding eight wires per trip. All wires were fixed to strand shoes in the anchorage blocks. Each wire measured 5.3 mm in diameter, with cables consisting of 19 strands, each made of 528 wires. This demanding process, including interruption by 'Dagmar' storm on Christmas Day 2011, was completed on July 18, 2012, after nine months.
Much of the steelwork, including 23 steel box girder sections, was fabricated in Shanghai. Mass production began in 2010, and surface treatment in 2011. The next stage was cable compaction, shaping the cable into its circular form. This machine-driven process also required manual input. Subsequently, 44 cable clamps were attached, 40 to the side spans.
The cable was then fitted with hanger clamps, with 130 clamps, each made of two hoisted and joined parts. The hangers, varying in length from 2 to 127 meters, were lifted into place from vessels below the bridge in pairs, with the shortest at mid-bridge and the longest near the pylons. On September 20, 2012, the vessel carrying the steel box girders arrived in Hardanger after a 46-day journey from Shanghai.
On September 28, 2012, hoisting of the steel box girder sections began. The total weight of all 23 girders was 7,850 tons, with most sections weighing 370 tons each. Cranes attached to the cables lifted the sections, which were then attached to hangers and bolted to the previously installed girders. The 23rd and final section was hoisted on November 7, 2012, marking a significant milestone.
During the first half of 2013, the steel box girders were welded together, and cable work was completed. Cable strands were wound with steel wire and wrapped in tape under canvas to maintain stable temperatures and prevent moisture. Painting of the bridge and hangers was ongoing throughout 2013, requiring dry and calm weather. Railings were also installed, including a pipe railing for the foot and cycle path on the eastern side.
After the opening, public interest in the bridge was high, and it served as an important diversion. Remaining work included removing the last crane from the pylon top at Buu using a large helicopter. The Norwegian Public Roads Administration built a picnic area with service facilities and parking at Buu. All remaining work was expected to be completed by summer 2014. The project manager, I Servik, was asked about the bridge's lifespan.