Buderus Manual on Trenchless Installation of Ductile Cast ... - Duktus

The rocket plough technique
6. Installing ductile cast iron pipes by the
rocket plough technique
6.1 General
For quite some time now, it has been the practice in rural areas for cables and plastic
pipelines to be ploughed in from a drum provided there was no existing infrastructure
or other obstacles along the path of the run. Where this is preferably done is along
farm roads at the edges of areas used for agricultural purposes. The technique was
successfully tried out for the first time using ductile cast iron pipes in 2000, as part of
a research project, and it has now developed into a standard technique which has now
been covered in the sets of rules issued by the DVGW and DWA. What is used for the
installation of ductile cast iron pipes is the trailing plough procedure detailed in ATV
DVWK Merkblatt M 1 0 [ .1] and DVGW Arbeitsblatt GW 32 (draft of /0 ) [ .2].
6.2 A description of the technique
A cavity is produced by a widening body shaped like the nose of a rocket at the bottom
end of a ploughshare. A pipe string, which is attached to the widening body, is pulled
into this cavity in the same stage of the operation. Fig. .1 shows the principle of the
technique. So far it has been used with pipes of nominal sizes from DN 80 to DN 300.
The machinery required consists of the traction vehicle (Fig. .2) and a plough (Fig. .3)
carrying a ploughshare. To ensure that the vertical position of the path followed by the
run remains constant when the profile of the terrain varies, the depth of penetration of
the share can be controlled hydraulically.
Fig. 6.1 The rocket plough technique
8
Launch
pit
Pipe string with
traction-resistant joints
Warning strip
Widening
body
Ploughshare
Rocket plough Traction vehicle
Pilling
rope
Winch
Support
plate