TBM for Hallandsås

The Skanska/Vinci consortium has been awarded the US$409M 4.5km long Hallandsås rail tunnel contract by the Swedish Rail Administration (SRA). The award will see the restart of work on a project surrounded by controversy following the pollution disaster in 1997 that suspended the tunnel's previous construction.

"We are proud to be assigned this trust," Mats Williamson, president of Skanska Sweden, said. "It is proof that we have learned from prior mistakes."

Providing the Environmental Court approves the Rail Administration's water leakage request, and that Båstad Municipality grants building permission, construction on the 4.5km long twin tube tunnel will begin in spring 2003.

Skanska was fined US$300,000 for its part in the 1997 environmental pollution disaster, during the tunnel's original construction. Work was halted when groundwater was contaminated by sealant used to reduce leakage.

Commenting on Skanska's win, SRA's general director, Bo Bylund, said: "It was the best bid overall and meets the very high safety and environmental demands placed by the Rail Administration."

"The level of environmental awareness in today's Skanska is very high and we are well aware of the risks," Williamson said. "At the same time, we have great respect for the task ahead. Valuable expertise is also being provided through Vinci's participation in the project."

This time, a TBM will be used – a first for Sweden. As a result, the tunnels will be lined with pre-cast concrete segments, and sealed directly behind the machine, to ensure minimal water leaking.

Over the last 50 years Vinci has constructed 670km of tunnels, with 50 projects similar in size to Hallandsås.

In 1997, the miners working on the Hallandsås tunnel project suffered throat and eye irritation. Subsequent tests showed that the grout used, Rhoca Gil, was affected by temperature and dilution, and caused neurological damage.

Skanska has since developed its own chemical database, resulting in the company being the first international construction group to be certified with the ISO14001 standard.

An alternative to the tunnel would have been an upgrade of the existing railway line, at a cost of US$88.8M. The increased capacity would not have been sufficient, resulting in more road traffic and the resulting pollution.

"The environment and ethics are the guiding principles for how the Hallandsås project shall be managed," Williamson said.