The Direct Pipe® -method enables to lay a prefabricated pipeline in one single, continuous working operation into the ground with the aid of the innovativ thrust unit “Pipe Thruster”. As with Pipe Jacking, earth excavation is executed by means of a navigable Direct Pipe® -machine, which is directly coupled with the pipeline. The Pipe Thruster is fixed horizontally and vertically in the launch pit and clampes the pipeline with its clamping device and pushes the pipeline forward into the borehole.
October 2007 saw the successful world premiere for the Herrenknecht Direct Pipe® technology installing a 464 m (1,522 ft) long culvert underneath the Rhine River near Worms in Germany. The pipe was planned to serve as conduit for a water pipeline and several ducts for power and telecommunication cables. The jobsite team realized maximum advance rates of 90 m (295 ft) in 24 hours.
For the second time the Direct Pipe® -method was chosen in July 2009 for a outfall project in Emden, Germany. Like in Worms a 48” pipeline was installed to provide the necessary thrust force to push the pipeline forward.
After the first two successful Direct Pipe®-projects in 2010 several projects in the Netherlands will be realised with Direct Pipe®. During the first crossing a 362m long 48”-pipeline will be laid under a historical monument. The client is the Dutch gas supplier “Gasunie”. The next project will also be part of the same PP-coated gas pipeline of the Gasunie.