Horizontal Directional Drilling

Sometimes, there are obstacles in the ground you need to work around. The HDD method makes that possible. The cutter head is equipped with an emitter. That way, we can direct it from above. The starting and target pits are much smaller with this method. The jet, which sits in the starting pit, drives the cutter head ever further into the ground via the pilot rods. At the tip of the cutter head are nozzles that spray out high-pressure water and a bentonite/water mixture. This displaces the earth, where some of the soil is flushed out. It also lubricates the borehole.

Bores several hundred metres in length can be achieved using the HDD method. For large-scale projects, we work together with partners or rent appropriately larger machinery. Our in-house Mini-Jet reaches 50 m with no problems.

Once the cutter head has reached its destination, it is replaced with an expansion head, which is drawn back by the Mini-Jet. We can repeat this process as many times as necessary until the tunnel has the desired diameter (with the Mini-Jet, max. 300 mm). Once the bore channel is large enough, the medium or product pipe can be pulled in. Bentonite mixture is injected until the very end. This material lubricates and at the same time fills the hollow spaces in the bore channel.

Electric, gas, telecommunication, district heating and water lines can thus be laid even beneath creeks and rivers.

Using DTH methods, we can drill tunnels in ground up to soil class 8.

Phase 1 : PILOT RODS

microtunnel_ag_horizontalbohren1.jpg

1 STARTING PIT
3 MINI-JET
4 PILOT RODS
5 CUTTER HEAD WITH EMITTER

Phase 2 : EXPANSION , Phase 3 : PULLING IN PRODUCT LINES

microtunnel_ag_horizontalbohren2.jpg

2 TARGET PIT
6 EXPANSION HEAD
7 PRODUCT PIPE

8 While drilling, water and a bentonite/water mixture are injected. This displaces the earth and flushes out soil.
At the same time, the bentonite mixture lubricates and fills the hollow spaces in the bore channel.