In the Swiss city Zufikon (canton Aargau) four 108 m (360 ft) deep double-U-earth probes (4x32 mm, 4x1.25”) were drilled for two neighboured residential buildings. The access to the drilling places was blocked by hedgerow, the space in the gardens very narrow. These were typical circumstances for the TERRA-DRILL TD 150x7 V. With its weight of only 3.5 tons (7’700 lbs) it could be lifted into the area by a truck crane. Then it drove around the house into the drilling position (transportation width = 0.92 m / 36”).
The drilling contractor Bohrfix AG from Härkingen is specialized for geothermal bores. They drilled these special bores. They drilled down the casings for the first 14 m (42 ft) until the rock top edge, then the DTH hammer continued drilling down to the final deep of 108 m (360 ft). The DTH hammer was pulled out and the earth probe (double-U-sonde) was lowered into the bore. Afterwards the bores were refilled.
The TERRA-DRILL TD 150x7 V was lifted into the drilling area by a truck crane. Then the drill rig could drive with its rubber crawler around the houses into the drilling position.
The TERRA-DRILL was lifted by the truck crane onto the second estate, because the height difference between both estates was too high.
Below the rock top edge the bore continued without casings.
The two earth sondes for this building are finally installed. Now they are connected horizontally with the heat pump in the cellar of this building.