By rosebell
On July 18, the final blast, that is a landmark on the challenging project Fámjin tunnel in the Faroe Islands, has officially been fired and this event has been celebrated with almost everyone on the island attending.
As one of the most difficult projects Metrostav Norge has undertaken,this 1.2km road tunnel is located on Suðuroy, the southernmost island.
According to Metrostav Norge project manager Anton Vido: “The whole project was challenging and with a lot of surprises along the tunnel excavation.”
Considering that the geology created complications from the outset a delay was faced in the commence of construction and due to the poor geology excavators were used instead of vertical drill and blast method for pit excavation.
“We realised the geology in the tunnel, at least in the first meters, would be more difficult than we expected. We have a lot of experienced people in our team and even they were surprised how difficult the geology could be.The project was calculated to use standard Scandinavian method, drill and blast process. We went through several demanding situations in relation to the geology, having to adapt as it was changing nearly every round,” said Vido.
Two partial collapses were accoured due to this variable geology, whereas during these events, Vido said the team had to adapt to new collapse conditions on a daily basis, and planning was reduced to no more than 24 hours ahead.
He also added: “Eight per cent of production was out of any contractual processes and in many situations we had to improvise. When you are in a collapse you can’t use standard process and this made everything even more difficult.”
Because of this type of geology led Metrostav changed its approach on nearly a third of the tunnel length.
“The tunnel was designed to be blasted in 5m rounds but, for safety, for 380m we chose to blast in 3m rounds,” stated Vido.
Currently the tasks about the water and frost protection before J&K Petersen starts work on the road, as well as electricity and drainage system for the tunnel is completing by Metrostav Norge.
Following inauguration of the project \ in the fourth quarter of next year, the Fámjin Tunnel is due to shorten journey times between the villages of Ørðavík and Fámjin and improve road safety as vehicles will no longer have to drive over a wind-exposed mountain ridge.
