Gyroscopic Mapping
Proving the location of a horizontal directional drill (HDD) is critical when there are concerns about the alignment of underground utilities. Traditional methods like electromagnetic locating can be unreliable, especially in challenging environments. In this context, the Reduct gyroscopic mapping tool provides a highly accurate and interference-free solution. Its ability to map pipelines without the need for continuous surface access makes it ideal for complex situations, such as verifying the position of gas mains that may have drifted outside their easements.
Key project details
Scope: Mapping two gas mains, 230m and 270m in length, with multiple direction changes.
Challenge: Navigable river nearby, making surface access and traditional locating methods ineffective.
Goal: Confirm if the gas mains had deviated outside their negotiated easements.
Technology used: Reduct DR-HDD-4.2 Survey System, ideal for:
- Independence from surface access (only start and end points required).
- Immunity to electromagnetic interference.
- High accuracy and safety with no need for confined space entry.
Execution:
- Conducted over two days with the client’s site team.
- Control points and topographical survey carried out.
- Gyroscopic tool pulled through the pipes multiple times using electric winches.
- On-site data quality checks to ensure accuracy.
Results
The survey successfully produced an accurate as-built map of both gas mains, showing that they had indeed deviated outside their intended easements. The client was able to use this evidence to confirm the disputed position of the pipelines, which would require further corrective action. The final data, visualised in a single CAD file with long sections, allowed for easy comparison between the original design and the as-built routes, ensuring the client had the necessary information for decision-making.
Conclusions
Trusted Partner: M J Rees has built a strong reputation for delivering precise, cost-effective surveys using the latest technology.
Risk Management: With proven gyro technology, M J Rees is currently helping clients quantify HDD issues quickly to help avoid design, safety risks, and project delays.
