The Helgeland Bridge
The Helgeland Bridge – Connecting Sandnessjøen with Leirfjord and mainland
This unofficial website is dedicated to all those who at one time or another need to cross Helgelandsbrua (The Helgeland Bridge), and who want information about the weather conditions or other traffic conditions prevailing on the bridge.
Helgelandsbrua ties Alstahaug and Sandnessjøen with Leirfjord and mainland. Because of strong winds from vulnerable direction is the bridge occasionally closed for traffic.
Therefore we have made this simple website that provides information both from Storm.no and Statens Vegvesen, so that most people can get updated information about conditions on the bridge.
For information: The bridge closes when the measured wind speeds exceed 32 m/s (62 Knots). The information boards on both sides of the bridge shows wind speeds in m/s.
Weather information from Storm.no:
About Helgelands Bridge:
«The bridge is 1065 meters long cable-stayed bridge which connects the municipals Alstahaug with its city center Sandnessjøen with Leirfjord. The bridge crosses the sea between the island Alsten, and provides a ferry-free main land connection.
The bridge is built as a two-lane road with a pedestrian crossing. Construction of the bridge started in 1989, it was opened in July 1991 and was a toll road until it was repaid on 27 May 2005. It is part of the county road number 17″
The Helgeland Bridge is a concrete bridge made of cable-stayed cables and measuring 12 m in width, spans 425 m. The towers were built on top of a 30 m deep rock. The bridge is vulnerable to strong storms and winds up to 77 m/s. An analytical time-history analysis in the ultimate limit state was done to determine the governing load ‘wind’. This took into consideration aerodynamic damping and geometrical and material nonlinearities.
After a two-year construction, the bridge was completed by cantilevering free from both towers. It was finally opened in July 1991. CIP concrete was used to build the beam. This has the advantage of not having to transport and lift heavy precast elements. CIP construction takes approximately one to two weeks to build each section of the beam, while precast elements allow construction progress to be made in one to two days.
Long beam sections measuring 12 m were used to shorten the construction time. The unsupported weight of this new section would have created too many bending moments at beam tip. The formwork carriage needed to be tied back. It is time-consuming and tedious to use auxiliary tiebacks for the lengthening of the beam sections. The final cables were used for support during casting of the Helgeland Bridge. These cables were bolted to form traveler by being anchored in precast elements.
The Helgeland Bridge crosses the Leirfjord, which connects the island of Alster with the mainland. It is found on the west coast in Norway near Sandnessjoen. Granite is part of the geology surrounding the bridge. It has been partially eroded by ice-age glaciers. The fjord measures 130m deep and nearly 400m wide. It has steep slopes on both sides. To remove enough tower foundations from the fjord edges, the original main span of 400m had to be extended to 425m to prevent granite slopes from sliding.
Although the Gulf Stream keeps temperatures from dropping below freezing on site, severe storms are a problem. The wind blows in the direction of the wind, causing turbulence intensity levels of 21 percent and a high gust speed of 77 M/s at beam (plus 50 m) To allow ships to access the hinterland’s industrial harbor of Mosjoen, they must have a 45-meter vertical navigational clearance.
The towers were built for ship impact and carry a static load equivalent to 5 000 t. All the construction was made of regular high-strength concrete, B 65. The construction contract was awarded to a Norwegian contractor in April 1989 after an international tender. It cost approximately EUR 25 million.
Webcam towards Helgeland Bridge. Provided by Statens Vegvesen.