Ludwig Pfeiffer

Horizontal Directional Drilling

Ludwig Pfeiffer Horizontalbohrung

Using HDD to cross an airfield [Cambodia]

With Horizontal Directional Drilling (HDD), the pipelines are laid in three stages. First of all, the HDD rig powers a drill bit mounted on a rotating drill rod. A pilot hole is drilled from the start towards the end point. The drilled hole is supported with a bentonite suspension, which conveys excavated material to a separation plant. In the second stage, the hole is reamed by withdrawing the drill rod; it is then gradually expanded until it reaches the required diameter. Finally, the prefabricated pipeline is connected to the drill string at the exit point and pulled into the tunnel.


  • Requires little space
  • Short set-up and construction times
  • Low costs
  • High degree of precision
  • No groundwater conservation required
  • Diameters 0.2 m –2.0m
  • Lengths over 1,000 m possible
  • No shaft required
  • Pipes can be laid in curves
  • Minimal environmental impact