Multiple Drilling System first time used

On the occasion of the 2009 STUVA Conference the Hilti Deutschland GmbH presented a new multiple drilling system to the public for producing drill holes for anchors and subsequent reinforcement fasteners. In January 2010 the Strabag Rail Fahrleitungen GmbH used the new system for the first time to produce attachment points by means of anchors for overhead line components at a tunnelling site in Germany.

Contractors and construction companies in tunnelling can now lease a partly automated multiple drilling system from Hilti, which has already been used successfully by the Strabag Rail Fahrleitungen GmbH. The system comprises a drilling, a power and a drive module. The core of the drilling module is formed by a crane arm, whose drill head can swivel 360 °. The drill head is fitted with 4 automatically operating electro-pneumatic drill hammers TE 70, which result in a variably adjustable drilling pattern of 100 to 560 mm. However, other drilling patterns such as 4 drill hammers mounted in a row are possible.

In the power module a sound-proofed generator with particle filter and a compressor provide the drilling module with power and a dust exhaust unit including a container is integrated here. It removes all the dust resulting from drilling thus preventing contamination as well as dust development in the tunnel which can jeopardise health.

The drilling module’s crane arm is installed on a 10 foot Euro Container frame just like the power supply. The multiple drilling system as well as fastening operations can take place from a lorry or from flatbed or work cars.

The cars can by moved through the tunnel at a speed of up to 10 km/h by a specially developed hydraulic drive module without a separate traction unit. The drive module was classified by the Federal Railways Office as a technical work unit and can be applied on a standard or narrow gauge. In this way the assembly fitters can reach the workplace and the erection point quickly. When drilling the anchoring holes they no longer needed to exert themselves and as a result a uniformly high work rate over the entire period was possible. Reinforcements were avoided through measures and aids that are easily handled under on-site conditions. Further­more automation of the drilling process ensures that the tools in the drill hammers of the multiple drilling system enjoy considerably longer service life thus also increasing productivity in this respect.

An extremely precise drilling pattern resulted following 9 days of work during which some 500 anchors were unproblematically attached for the return conductor without any time-consuming rectification work having to be carried out. With this system Hilti offers a wide service programme, embracing technical consultation right up to on-site support.

Thomas Lützow, Technical Manager for Civil and Structural Engineering, Hilti Deutschland GmbH