Code of Practice for Horizontal Directional Drilling Suiting Indian Condition

Table of Contents



Sewerage and water infrastructure and other utility services represent a significant investment on the part of most municipalities. For well over 100 years, the distribution networks for utility services have been located underground in pipes or ducts that are laid, repaired or replaced by trenching from surface. In cities and urban areas, these distribution networks are located underneath the roads. This often makes access difficult, particularly in areas congested with traffic and buildings. When pipeline infrastructure is not well maintained, inefficiencies occur. For example, in water distribution system, this can lead to leakage and possible water shortages. In sewage system, cracked and damaged pipes can cause wastewater seepage, leading to contamination of ground water apart from other host of problems. These problems often give rise to related health and environmental impacts and are needed to be corrected at an early age.

Horizontal Directional Drilling (HDD) is a steerable technique for the installation of pipes, conduits, and cables in an arc shape using a surface launched drilling rig. This method requires the execution of a pilot bore which is then enlarged with the use of a reamer prior to installation of the product pipe. Depending on the diameter of the product pipe, multiple enlargements may be required. The excavation is performed by the mechanical action of a fluid assisted cutting head.

This Code of Practice therefore addresses the following issues for a successful project:

  • Works should conform to general workplace safety
  • Works should conform to efficient work practices
  • They should stipulate conditions to prepare and set-up the plant and equipment
  • They should stipulate conditions to prepare the new pipe-work material
  • They should stipulate conditions assisting in drilling holes to desired requirements
  • They should be identifying tracking parameters for a successful drilling operations
  • They should be stipulating conditions for installing new pipe-work
  • They should help in developing as built / as installed drawings
  • They should help in managing drilling fluid/mud and related plants
  • Help in erecting and dismantling plant (cranes and rigs)
  • Assist in operating plant or machinery to lift and transfer loads
  • Assist in operating plant or machinery to extract material
  • Assist in operating plant or machinery to excavate
  • Assist in operating plant or machinery to receive and transport loads
  • Detailing slinging and signalling the movement of loads
  • Stipulating conditions for equipment de-commissioning.

As HDD provides a cost effective alternative for developing subsurface pipelines in the Trenchless way this code of Practice is expected to provide a useful benchmark for the user. Like all codes this code is also expected to grow with time and the Society invites the readers/users to provide their inputs to include additional issues to make the code more useful.

Dr. Niranjan Swarup
Director General
Indian Society for Trenchless Technology


Table of Contents








3.1      Pipe

3.2      Allowable forces

3.3      Pipe dimensions

3.4      Protective Coatings (Steel Pipe)

Subsurface Investigations
5.1      Minimum Allowable Depths
  5.2      Equipment
  5.3      Method
  5.4      Drilling Site
  5.5      Overcut Allowance
  5.6      Waterlight Joints
  5.7      Drilling Fluids
  5.8      Pipe Locating and Tracking
  5.9      Settlement/Heaving Monitoring
  5.10    Ground Water Control
  5.11    Boring Failure
  5.12    Contamination
  5.13    Bulkhead
  5.14    Work Site Restoration