With its veritable labyrinths of fjords penetrating the coast and running deep into the mountains, Western Norway is known as “Fjordland”. All in all, Norway has over 1,700 fjords! Not surprisingly, to create a convenient road network the country had to build a large number of bridges, some of which are truly spectacular. For example, the famous Atlantic Ocean Road, almost nine kilometres of bridges snaking among the fjords of Averøy, on what is one of the world’s most stunning and dangerous roads… When it comes to Norway’s bridges, Hardangerbrua (Hardanger Bridge) is well worth a mention: a particularly long, recently-built suspension bridge stretching for more than 1,380 metres over the waters of Hardanger fjord, it is Norway’s longest suspension bridge and one of the longest in the world.
Let’s dive into the unique features of this grandiose engineering feat.
The Bridge over Hardangerfjord’s Records
As we have seen, Hardangerbrua is Norway’s long suspension bridge, its single-span 1,310-metre length making it the world’s 16th longest. The world record-holder is Japanese, the Akashi Kaikyō Bridge, with a span of 1,991 metres, built in 1998. In Europe, the record belongs to the Great Belt Bridge, which in Denmark connects the islands of Zealand and Funen: also built in 1998, it is 6.7 kilometres long overall, with a span width of 1,624 metres.
There is, however, one record that Hardangerfjord, in the Hordaland region, is likely to hold for some time: Hardangerbrua is the world’s longest suspension bridge between tunnels. Interestingly, the tunnels were built to actively enhance the view for motorists as they arrive at the Hardanger and admire this engineering marvel. The vault of the Vallavik tunnel on the final hundred metres of the bridge is a heady 23 metres in height, compared with six metres elsewhere, making it one of the world’s tallest tunnels. Similarly, the Bu tunnel ceiling was raised to 15 metres, to enhance the magnificent bridge’s perspective and beauty.
A Brief History of Hardanger Bridge
The Hardangerbrua bridge is extremely useful to travellers between Oslo and Bergen, significantly reducing journey times. Before the bridge, the trip required a ferry ride, but that does not always run when the weather is bad. The idea of building a bridge across Hardangerfjord, Norway’s third longest fjord, was first mooted back in the 1930s by local inventor Aamund K. Bu, who came up with a plan for a suspended link between Vallavik and Bu.
The idea made some progress: in 1938, an engineer working at the Hordaland County Roads Department called Ødegard confirmed that the work was indeed feasible. However, the project ran aground, and fell into oblivion for thirty years. Only in 1969 was the bridge plan resurrected, this time as multiple works: a tunnel between Kjerland and Vallavik, and a bridge between Vallavik and Bu. Work began years later on constructing the tunnel, which opened in April 1985. Without the bridge, however, the work was incomplete, and the idea of building the bridge rose to the top of the municipal agenda. Councils in the Hardanger Fjord area came up with a scheme adopted officially in 1986. The Norwegian Public Roads Administration publically announced the work in 1988. Many more years would pass before the scheme won approval, and that was only granted on condition of a transit toll being levied. Construction work began in 2009, and was completed in August 2013.
Features of the Bridge over Hardangerfjord
The bridge carries two 4.5-metre travel lanes and a 3.25-metre bike/pedestrian path. To the north, the bridge leads into an underground traffic circle and then into the Vallavik tunnel; the same applies to the south, towards the Bu tunnel. The road carries on average 2,000 vehicles daily at a maximum speed of 80 kilometres per hour.
A number of different companies worked on the Hardanger Bridge. Veidekke, for example, was responsible the concrete work. Just to build the foundations on the Bu side, in October 2009, a total of 1,800 cubic metres of reinforced concrete for the bases of the two piers was cast for fifty hours straight. The completed bridge has two pairs of piers 185 metres high, made using 44-section formwork, featuring a section of 8.6 metres by 7 at the base, and 4.5 metres by 4.5 metres at the top. Each pair of piers has its own internal maintenance elevator.
In 2011, work began on installing the cable mountings on top of the pylons, which reach an overall height of 201 metres. The metal caissons for building the deck were made by Zhenhua Port Machinery, in Shanghai, and shipped to Hordaland in 2011; the cables, on the other hand, were produced by Bridon, of Doncaster. Each cable is made up of 19 bundles of wire, inside of which are 528 strands of 5.3 millimetre diameter wire. The anchor plates were made in Poland and Vietnam, while the mountings were made by British Goodwin Steel Castings Ltd.; O.M.E. of Como manufactured the anchor bars.
As is so often the case with such works, the Hardangerbrua Bridge is the result of an international effort, coordinated in this case by Danish contractor MT Højgaard.
