If you are driving between Eastern and Western Norway in the summer, you won't find a more beautiful mountain pass than the Sognefjellsveien road between Lom and Luster. Many people choose to stop at Sognefjellshytta, 1,410 metres above sea level, with magnificent views of some of Northern Europe's most beautiful glaciers and highest peaks.

However, if you want to go hiking from this point, you must first trudge along the main road. And if you use a wheelchair, you will have no chance of accessing the terrain. The management of Jotunheimen National Park has decided to do something about this. 

Easy access to grand outdoor experiences

From Sognefjellshytta a bridge is now being built across Lake Fantesteinvatnet, providing easy access to the alpine terrain.  Not only will the bridge and adjacent hiking trails be adapted for the movement-disabled, it will also be a slender, elegant and spectacular installation – the first of its kind in Norway.

"For many, the stressed ribbon bridge will be familiar from London, where the Millennium Bridge over the Thames has been built according to the same principle. The principle is only used for pedestrian bridges," says Tore Valstad, geotechnician at NGI.

The anchorings of the new bridge must take into account the bridge's natural oscillations and withstand the dynamic response that occurs when people walk over it. The bridge will hang in an arch, lowest at the centre and highest at the abutments, and must withstand enormous tension forces. With maximum volumes of snow and lowest temperatures it is designed for around 11 MN, (meganewtons), which correspond to 1,100 tonnes on each abutment.

Unspoilt mountain terrain

The national park administration has issued clear guidelines for the work.  It is not permitted to touch the rocks around the foundations and the terrain must appear completely unspoilt.  Thus, for each abutment a block must be carved out that has a surface of 2×3 metres.  A steel structure will be permanently cast in the hole, which will be tensioned with wire anchors in order to hold the bridge in place. 

A wire anchor consists of anchor wires that are inserted into the rock. In each abutment, six wire anchors will extend 18 metres into the rock. Each of these anchors comprises 22 wires.

"In order to disperse the forces down into the rock, the anchors will be installed in a fan shape. By dispersing the anchors, this will ensure synergy with a large rock volume. The requirements for what the bridge must be able to withstand and the guidelines for anchoring the abutments on each side, only make the job even more exciting and challenging," explains Tore Valstad.

The planned bridge and adjacent walkway system with universal design is expected to be a tourist attraction and will harmonise well with the National Tourist Road.

20161115 Fantestein Sognefjellshytta van bovenaf article
Sognefjellshytta is a great starting point for a treck in the magnificent mountains.
 

FACTS about Lake Fantesteinvatnet:

  • Sognefjellsveien, county road 55, has the status of a National Tourist Road between Lom in Oppland county and Gaupne in Sogn og Fjordane county.
  • The highest point of the road is 1,450 metres above sea level.  When the road opened in 1936, it was the highest stretch of road in Norway.
  • Sognefjellshytta is situated by Lake Fantesteinvatnet at 1,410 m above sea level in Jotunheimen National Park and is a popular stop for motorists. The views are wonderful: towards the east is the Smørstabbreen glacier and the surrounding peaks, to the south-west the view is dominated by the Fannaråken mountain and Fannaråkbreen glacier.
  • From Sognefjellshytta, you can walk to Skogadalsbøen, Nørdstedalseter, across Smørstabbreen glacier to Leirvassbu, or to Fannaråken mountain.

FACTS about the bridge and the project:

  • The bridge is 47 metres long and 1.9 metres wide. The load-bearing steel plate has a thickness of 25 mm.
  • The bridge was designed by Dronninga Landskap AS and Dipl.-Ing Florian Kosche AS.
  • The client is the National Park Administration, Oppland county.
  • NGI is rock engineering consultant and has been commissioned by the National Park Administration to design the foundations. NGI will also follow-up the work during the construction phase.
  • The abutments, i.e. the structures that form the transition between bridge and road, will be founded on six wire anchors on each side. Each anchor comprises 22 wires. Each wire is 15 mm thick and 18 m long.  Each anchor will be tensioned to a force of 4 MN (400 tonnes).
  • Scaffolding will be built across the strait in order to install the load-bearing steel plate.  Preparatory work was carried out in the summer and spring of 2016, while the rest of the work will take place in the summer of 2017 after the snow in the area has melted.
  • Read more about Jotunheimen National Park

The bridge will be completed in the summer of 2017.