Being carried out by main contractor AF Gruppen, the Stockholm Bypass is one of Sweden's largest infrastructure projects, creating a series of underground motorway tunnels between the Kungens Kurva interchange in the south of Stockholm and the Häggvik interchange north of Stockholm. Most of this bypass, more than 17 out of 21 kilometres, is being built underground.

The bypass will become the world's third longest urban road tunnel, after the Westconnex Tunnel in Sydney and the Yamate Tunnel in Tokyo. Some 140,000 vehicles a day are expected to use it.

The 8.9-tonne Bobcat E88 at work in Stockholm was originally adapted to meet the special regulations of underground works in the mining region of Kiruna in the north of Sweden. The Bobcat E88 was adapted and supplied by Luleå-based Nordkust Maskin AB, the local Bobcat dealer, in collaboration with Bobcat Sverige AB, the main distributor for Sweden.

The heavily modified E88 excavator was delivered to Bergteamet AB, a specialist shaft and tunnel contractor, based in Boliden. Nordkust Maskin is working on another E88 adapted for the mining industry that will also be used for a drilling application.

As part of the modifications needed on the E88, it was decided that the ability to control the excavator remotely was needed. The excavator also needed to be protected for working in the harsh environment of the underground vertical shafts.

Bergteamet has been using the Bobcat E88 to sink ventilation shafts for the Stockholm Bypass project. One of the first was at Lovön at Drottningholm outside Stockholm. The process used to construct the shafts begins with making a circular hole at ground level, using blasting, and hauling the material away.

The next step is to lift the E88 into the hole at the top of the shaft, where the articulated boom allows the machine to fit, from where it can be remote controlled to manoeuvre into a better position if needed. This includes the use of on-board cameras, again driven from a control room, away from any hazardous areas. The E88 is fitted with a tiltrotator allowing it to be used with a breaker to remove loose material as well as an attachment for rock scaling work. It also has water connections for dust control.

Other attachments/features on the modified E88 include:

• Åkerströms radio control
• ABL buckets
• Hammerglass explosion proof windows
• Lincoln lubrication
• Forrex automatic fire extinguisher.