Trenchless cable exchange
Energy and utilities providers are increasingly confronted with the problem of exchanging defective underground cables with new ones. With the over-bore method TT has found a viable and economical solution for trenchless cable exchange employing the fluid-assisted GRUNDODRILL HDD rig. The drill rods with the patented over-bore head are screwed together and driven over the old cable, parallel to its position. The old cable acts as a guiding track, and the. Wash-over head evenly cuts a small annulus around the old cable, separating it from the soil and any root growth which may have become attached. On arrival at the target pit, the old cable is then very easily pulled out with a pulling device like a GRUNDOWINCH. Tracking of the over bore wash head is highly recommended, just in case of any deviation from the intended bore path.
When pulling back the drill rods, the new cable can be pulled in simultaneously. After completing many practical tests, the wash-over head is now available to TT customers who are interested.
Advantages for the provider:
- Wash-over lengths between 100 and 150 metres
- Applications to date: exchange of 10 kV and 20 kV power cables and telecom trunk cables, 40 mm in diameter and larger
- High speed installation - great savings on time (open-trench installation takes five times as long) - eco-friendly new installation
- With only one bore: the old cable is bored clear - the new cable is pulled in whilst pulling out the old cable which is done with a towing device which is usually available on site
- Complete removal of the old cable - no cable remains in the soil
- Easy separation of the old cable from soil or clinging roots
- No need to locate a new bore path: you can bore straight in to an existing cable line.
- Little or no third party utility service verification, as the old bore path is used for the new cable
- No time delay due to the application for a new right of way
- Soft cable bedding due to Bentonite coating - better heat conducting properties than sand
- Economical installation, particularly in greater depths, due to the elimination of civil engineering works
- Installation of (punched) protection pipes for subsequent cable pulling as an option
Advantages for the client/contractor:
- Economical acquisition of new fields of application
- Utilisation of existing equipment with special patented wash-over heads (only available from TRACTO-TECHNIK)
- Suitable for boring free any drill rods which are trapped in the bore hole
- Old cable’s route acts as compulsory track – so no detection is required
- Trenchless replacement secures a competitive advantage
- No laborious jobsite preparations, fast completion, minimal disruption, easy access to the work places
- Trenchless exchange –advantageous for complying to tree root preservation by-laws