Creating a highway while saving the salmon

Trelleborg - Case Study -Creating a highway while saving the salmon
The biggest integrated seal ever


In the fjords of Norway, just south of the city of Trondheim, the Public Roads Administration planned a new motorway. They encountered multiple challenges, such as streams carrying salmon and fluctuating water levels, due to the open connection to the sea. Rivers could not be blocked to allow fishing trips in the area and any solution would need to accommodate large volumes of water.

Consultants were hired, who wondered if it was possible to make 3 meter tubes.

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Pipe manufacturer LOE Nord was up to the challenge. Together with Trelleborg, they designed a large pipe and sealing system that diverted five streams with a total length of 595 meters. Loe bought moulds for wet casting of 3-meter concrete pipes and asked Trelleborg to produce a seal for this size, as he had good experiences with the F-102.5 seal on pipes up to 2 meter.

Lars Loe, Managing Director of LOE Nord says: "We have worked with Trelleborg on previous projects and know they can produce high quality, tailor made seals suitable for even the most complex of environments".

In total, 350 pipes with a 3 meter diameter and a 1,75 meter length were produced and Trelleborg supplied the seals that were integrated into the cast.

These are the biggest concrete tubes made in Norway ever!

Product details

Trelleborg 102.5 seal was originally designed for the Nordic market. It is based on our Trelleborg 103 integrated sealing system, but it has an undercut behind the lip which reduces the jointing force when laying the pipes.

Trelleborg 102.5 is an integrated sealing system, meaning the seal is cast into the socket of the pipe during manufacture. The benefits are multiple: pipe layers cannot misplace the seal, select the wrong seal or position it incorrectly. During transport and handling a protective strip remains in the pipe socket. This prevents sand, clay or ice entering the sealing area, keeping the seal in optimal condition.

The Trelleborg 102.5 is a tailor made sealing system. It was developed together with Basal, the technical and marketing association for concrete pipes and manholes in Norway. Loe is a member of this association.