No-Dig Techniques » Auger Boring » Guided Auger Boring » Directional Drilling » HDD Rock Drilling » Pipe Ramming

HDD Rock Drilling [Rock Boring]

Sometimes referred to as Horizontal Directional Rock Drilling.

With years of experience specialising in difficult rock crossings, Allen Watson designs, builds and operates a versatile range of rock drilling equipment, including maxi to mini-drill rigs with pullback forces from 300te down to 14te.

When used in conjunction with our range of mud mixing, pumping and recycling systems, mud motors, TCI and Mill tooth reamers, this specialised equipment gives us the confidence to successfully install pipelines in the toughest ground conditions.


  • Surface technique, steered both horizontally and vertically
  • Ideal for boring in rock formations where it is impractical to open cut
  • Pipes can be installed either straight or curved to steer clear of obstacles
  • By boring underground the working area is confined to points of entry and exit only
  • No disruption to road, river or rail traffic and no scarring of the landscape
  • Equipment works from surface with no need for deep excavations or blasting
  • HDRD is unaffected by surface obstacles
  • Sea outfalls can be drilled with minimal marine works

Below: HDD Rock Drilling [Rock Boring]
- click images for larger versions in pop-up window

For more images of HDD Rock Drilling, see our Gallery page

What is Rock Drilling?

Content on this page requires a newer version of Adobe Flash Player.

Get Adobe Flash player

Horizontal rock drilling provides a safe system of installing pipes, ducts and cables where conventional open cut methods are not permitted, practical, environmentally or economically viable.

Using specially designed and manufactured equipment including TCI or Mill tooth bits, rock and overburden is crushed, allowing the cutting head to pass and form the bore.

Typical Applications

  • Steel or polyethylene pipes from 25mmØ up to 1,200mmØ in distances from 25 metres up to 1,500 metres have been successfully drilled under areas such as rivers, estuaries, roads, railways, airports, contaminated landfill sites and Sites of Special Scientific Interest (SSSI).
  • Crossings can be for water, oil, gas, electricity, sewerage, chemicals, communication ducts and outfalls.

Mill tooth bit on mud motorCompleted pullDriller's consoleUnder Falmouth harbour installationEntry loacation on Falmouth harbourMill tooth bitMud motor prep for pilot borePilot bore exit

For more images of HDD Rock Drilling, see this Gallery page