As part of a renewal project for power cables in the Ravensteyn Street in the city of Koblenz, (Germany) new house connections were also installed. Due to their age as well as dampness the protection coat of the power cables had started to become brittle there, thus causing concern regarding the safety of these lines.
The KEVAG utility company planned the installation of house connections with a 1 KV Cable from the main line beneath the footpath up to a small connection pit at the house inside a protection pipe ND 50 x 4,6 mm. The new installation of the house connection proved to be tougher than would have been expected under normal circumstances, as many of the houses and villas in the Ravensteyn Street are only accessible via stairways and are situated on steep slopes, which are partially bordered off with high vineyard walls. 4 house connections had a very special degree of difficulty, which required the application of modern technology. The open trenching method was out of the question as the expenditure in these steep slopes would have been immense.
The GRUNDOPIT Power was the tailor made solution as it could be installed in a small construction pit suiting the width of the footpath and on a level with the service line. There was no need to access the road, which was tight enough as it was. The traffic was not influenced at all. The hydraulic power unit TTB20 and the mixing system MA 09 for operation and supply of the small, compact bore rig with water were installed on the loading surface of a small truck.
From the main service line underneath the footpath right in front of the vineyard wall up to a small target pit, directly in front of the house, a distance of 15 m had to be overcome. Not a long bore, but one with a certain level of complexity. Behind the wall, which was 2 m high, the bore head with the attached drill rods had to overcome a height difference of 12 m up to the target, which was a distance of 15 m away. This lead to an incredible inclination of up to 86 %, which was clearly visible when the bore head entered the target pit.
Another factor straining the bore rig and the drill rods to a degree above the normal level, was the partially filled in and worn, stony, sand-clay soil. The deepest measured point for the bore head was 2,75 m below the terrain surface. Interferences caused by an old power cable, which was still in operation, caused a minor interruption when trying to locate the bore head in the target area, but this passed by very quickly. Otherwise the pilot bore was completed without any problems whatsoever and arrived in the target pit spot on.
The bore, which was carried out without the application of Bentonite and only with water, only took around 2 hours to complete. Pipe installation did not even take half an hour (pure boring times).
Wolfgang Schulz, one of the brothers and managing director of the contracting company
Schulz GmbH from Koblenz commented: “This application was part of an instruction session for our bore team beforehand. It was a steep case and our first bore with the steerable bore unit, which worked out tremendously well. We are very happy with the result, as this proves that we can help quickly and cost-effective, even in such “problem” cases”.
Last but not least, it is worth noting that the beautiful garden remained untouched thanks to the application of the GRUNDOPIT and the owner was really impressed.
This was also a special occasion for the manufacturer TRACTO-TECHNIK, as it was the 400th GRUNDOPIT to come out of TT production and the presentation was made by the TT subsidiary manager Walter Schad. He congratulated both company owners on making the right decision and wished the Schulz company numerous successful bores with this machine for years to come.