CONSTRUCTION IS due to start this month on Norway's 'doomsday' vault, being built over 120m deep into a mountainside on an island, nearly 1000km north of the mainland.
The Svalbard International Seed Vault has been designed to protect seeds from worst case scenarios for the next 200 years.
A 100m tunnel will be carved into the rock with two 15m by 25m and about 6m high storage halls for the seeds at its end. However, Statsbygg, the Norwegian government's Directorate of Public Construction and Property, is still to award the NOK30M (£2.5M) construction contract.
'This will essentially be a rock excavation project, ' said Statsbygg project manager, Magnus Bredeli Tveiten. 'The process of creating the whole facility will be based on traditional tunnelling techniques of boring and blasting.'
Tveiten told GE the about 5m diameter access tunnel is likely to be dug out using traditional tunnelling techniques and should not pose much of a problem to the eventual contractor - likely to be from the local community - because local rms have a high level of tunnelling and mining competence.
He said the challenge will come from working to tight timeframes - the vault is due to be nished by September - because of seasonal changes. Svalbard lies in darkness for nearly four months between October and February and the fjords freeze over, making it impractical to ship in plant equipment during those periods.
The sandstone mountain chosen as the location for the fail safe vault, about 3km from Longyearbyen village on Svalbard, is covered in a layer of between 3m and 20m of loose rock. The plan is for site workers to excavate this before blasting to create a vertical face for the vault entrance. Then tunnelling will begin.
This excavated rock can be used to ll the annulus between the steel portal and rock tunnel. The tunnel will be reinforced with sprayed concrete and a steel casing will run down its length. There are plans for a separate of ce and administrative space about halfway down the tunnel.
A new 100m long access road is planned to lead from the vault entrance to an existing mountain road serving a nearby weather station. Tveiten said locating the vault here will help preserve the vulnerable landscape on Svalbard because only a small stretch of new road is required.