In a challenging HDD project in the Darling Ranges, WA, operators installed HDPE pipe using Chase Corporation’s Trace-Safe® tracer wire through a tight bore hole in solid granite to resist breakage.
The Darling Ranges, north of Perth in Western Australia consists of a rocky and difficult terrain to conduct horizontal directional drilling (HDD) activities, with special rock drill bits required to penetrate the solid granite.
Manufactured to be robust
Chase Corporation’s Trace-Safe is unique due to its tough construction. Where ordinary wires have a tensile strength of approximately 100 kg, this tracer wire has a tensile strength more than 8 times that at 818 kg.
Encased in a robust jacket made of high density polyethylene (HDPE), Trace-Safe uses polyester yarns – the same type of yarn used in radial tyre cord – and it is these high tenacity yarns that absorb the stress of the pull, rather than the tin coated copper wire. It is imperative that a tough tracer wire is used in difficult HDD operations, to ensure the protection of underground assets.
The manufacturing process of Trace-Safe takes things a step further by treating the products with an absorbent powder. The procedure means that if the HDPE jacket is breached the yarn swells to prevent any water from getting to the conductor.
The HDD operations in the Darling Ranges required a tracer wire to be installed along with a 110 mm diameter HDPE pipe and be pulled back 80 m, which can be a challenging task. To complicate matters even further, the size of the bore hole was only 130 mm wide.
The HDPE pipe occupied 85 per cent of the bore hole, meaning the tracer wire had to be squeezed in with the pipe. Ideally, a bore to duct ratio would allow for at least 50 per cent head room, but Trace-Safe is designed for situations where this is not possible.
For this project, a Trace-Safe RT1800 tracer wire was used. Its 30 mm jacket and high tensile strength means it has the required strength to survive a tension pull back.
The project was able to be completed successfully and efficiently. A locating clip was attached so that the wire could be easily accessed and energised by the locator before the wire was pulled back, with the process only taking less than 20 minutes to complete.
This article was featured in the March edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet, or mobile device, click here.
For more information visit the Trace-Safe website.
If you have a project you would like featured in Trenchless Australasia contact Journalist Chloe Jenkins at firstname.lastname@example.org