Text and photo: Sveinung W. Jensen, Tellus Communication

– Because the tank is square, we've used thinner plates and considerably more welding than on a round tank. We've also had to use a cooler welding method in several places to avoid structural material changes, says the production coordinator at the workshop, Chris Bjørklund.

The tank is made of Duplex, which is a stainless steel with good corrosion resistance and high mechanical durability. It is 3.5 metres high and wide, and 10.4 metres long, and has three internal chambers with a total volume of 120 cubic metres.

"It needs to stand out on the platform and must withstand seawater. Before we transport it to the customer, the tank will be acid-treated outside the workshop," says Bjørklund.

WORKING ON The refuelling started last autumn. Welders, fitters and platers have been hard at work.

– Representatives from Aker Solutions, who are the customer, are coming to inspect the weld. After that, the tank will be leak tested before it is ready to be picked up by truck and then by boat to Kleven quay, says Bjørklund.

OFF PLATFORM Will the square tank be installed, along with the five other tanks that Halvorsen will deliver to the same project.

– These other thoughts are all round and more like the ones we usually make here, says Bjørklund, who praises the work done so far.

– We have tremendously skilled people in the workshop. For this project, we have also hired labour from a local recruitment agency, and that has worked very well, he says.

HALVORSEN is one of several hundred Norwegian supplier companies contributing to Yggdrasil.

Aker BP is the operator for Yggdrasil. The client for Halvorsen is the alliance for fixed installations with Aker BP, Aker Solutions and Siemens Energy.