After its introduction at the IFAT show in Munich (Germany), in mid-July came the first performance test for the new Rope Bursting Systems manufactured by RBS Germany. Furthermore by this technology overdriving of larger doglegs and bended at the old pipes is possible, at that the special rope is being conducted by return pulleys.
The Burster is operated of only one employee by use of a radio remote control. This one doesn't have to work in the pit, but controls everything from a safe distance at his position above the machine.
In addition to the safe handling the new rope pull technology makes the work much easier for the operator, because he doesn't have to move no more the 10-15 kg weighty rods.
In Stuttgart, one of Germanys larger towns, the local utility company EnBW Regional AG had to rehabilitate a water line (steel pipe ID 600 mm), built in 1954. Into the old pipe should be installed a new one with 508x 6,3mm and a concrete coating so that the outer diameter of new pipe was 520,6 mm, the weight of new coated steel pipe was nearly 142 kg/m.
At this job it was important, that the obstruction of traffic and residents should be as low as possible by minimizing number of pits and open cuts. Therefore trenchless technologies are being favored and planners choosed to use an approved method, the sliplining process developed and patented by GELSENWASSER.
The company which awarded the contract was Josef Pfaffinger Bauunternehmung GmbH, based in Passau/Berlin and one of Germanys most experienced companies in the rehab area.
Since their own Pipe Burster was not usable at all this job’s construction stages, at the most difficult part a RBS-1000 was employed: This part with a total length of nearly 380 m overcame a knoll crest and a height difference of some meters - with the pile string was to pass through a constantly upward sloping way the first 200 meters then came the vertex underneath a broad crossing road with tram tracks followed by the last part which was sloping with a bend just before the end.
As it was inoperable to weld the complete string of pipe before starting the job, every single of the concrete coated pipes with corrosion protective coating was connected with the pipe string at the insertion pit (breaks for welding and Densolit-coating of the welded joints of the steel pipes) and the work had to be made cycle-wise.
During pulling operations the pulling forces necessary were monitored permanently (this data’s are storaged in a special memory with the ability to print out a protocol). Once as the pipe string have reached the bend near the end of line a maximum pulling force of 40 tons was required (at a pipe strings weight of around 52 tons).
After whole 7 days the pope string arrived at the pit with the Burster and all involved were mightily impressed