Atlas Copco’s new four-boom drill rig drives to success in Gothenburg rail tunnel
2010-12-07
A new four-boom drill rig developed by Atlas Copco in cooperation with Nordic tunneling contractor, Veidekke, is proving its worth at a major railway project near Gothenburg, Sweden. The rig, named Boomer XE4 C, is a fully computerized unit designed to drill all pre-grout holes as well as blast holes.
The Boomer XE4 C equipped with the rod handling system Auto RHS E is reaching all targets at the Hede-Älvängen railway project.
So far, with 50% of the tunnel completed, the rig has drilled approximately 280 000 meters of blast holes and 65 000 meters of grouting holes.
Anders Östberg, Plant and Machine Manager at Veidekke, says: “It’s early days yet but so far the Boomer XE4 C is achieving all the targets we set out to achieve in this project. We have had no major problems and we are especially pleased with the efficiency of the new Auto RHS E rod handling system. It’s working extremely well.”
Sweden is one of the few countries in the world where pre-grouted, unlined tunnels are consistently used for all civil tunnel works. As a result, pre-grouting has become a state-of-the-art skill with equipment from Atlas Copco at the forefront of development.
It therefore came as no surprise when Veidekke, the Nordic tunneling specialist, won a contract to drive a new railway tunnel in south-west Sweden and challenged Atlas Copco to produce the necessary equipment.
Veidekke knew what they wanted in order to get the job done as quickly and efficiently as possible – a four boom drill rig that could drill all of the required pre-grouting holes as well as the blast holes, and that would require only one operator.
The two companies cooperated for several months on the specifications and the result was Boomer XE4 C – a fully computerized drill rig with four booms, high performance COP 3038 rock drills, a specially developed automatic rod handling system – Auto RHS E – for drilling of up to 30 m long grout holes, and the Atlas Copco rig control system (RCS) enabling it to be handled by just one operator. The rig was built and delivered in mid-2010 and by December all indications showed that it is fully living up to expectations.
Veidekke’s assignment to build the Hede – Älvängen tunnel, through the Kattleberg mountain, is part of a major upgrade of a 70 km long railway that links Gothenburg with the city of Trollhättan in which the track is being rebuilt from a single track to a twin-track system to double the capacity and accommodate high speed trains.
The Hede – Älvängen tunnel section is 13.5 m wide, 10.8 m high and will be 1.8 km long. An emergency escape tunnel with a cross section of 35 m2 runs parallel to the main tunnel for 0.6 km and there will be a 500 m long adit for access to the emergency tunnel.
The Boomer XE4 C is proving clearly beneficial both economically, in terms of production speed and also from a safety perspective.
In developing countries, a three-boom rig is commonly manned by one operator per rock drill, while the norm in Europe is two operators operating a whole three boom rig. In Veidekkes case, they normally use only one operator. With the Atlas Copco Boomer
XE4 C, not only has Veidekke increased the number of booms from three to four – increasing productivity – but they still need only one operator. This reduces the risk of error in communication between operators, and increases safety as the fully mechanized rod handling system eliminates the need to stand on a platform, coupling and uncoupling threaded joints in order to extend drill rods.
Operator Niklas Karlsson says: “I think the Boomer XE4 C is a perfect solution for the work we are doing and I am convinced that this new technology will make the whole pre-grouting process much more efficient.“
The railway between Gothenburg and Trollhättan is planned to be completed in December 2012.