The introduction of the Hawle NoDig System – the first entirely trenchless solution for establishing water house connections – has been recognised with the ISTT New Machine Award for 2018.
The new system stemmed from the ‘No-Dig Challenge’ issued by a Norwegian municipality in 2014, encouraging market players to develop techniques to connect houses with water main networks using trenchless technology.
Striving to meet the ambitious No-Dig Challenge issued by the Oslo Municipal Agency for Water and Sewerage Works (VAV), Hawle Water Technology Norge AS was determined to use its drive for innovation to meet the need for a system to form trenchless house connections.
By 2017, the company was announced as the winner of the challenge for development of the Hawle NoDig System, which gained further recognition as a top five finalist for the Norwegian Tech Awards in 2017.
For the development of the system – which comprises a number of components – a majority of the research and development were outsourced to Norwegian product development company Techni, while Hawle remains the sole owner of the technology and the IP.
After 45,000 hours of research and development, the capabilities of the system were successfully demonstrated on site in 2017 and a number of patent families were filed.
The system is able to locate the main water pipe, drill to it from a building’s basement and establish the connection, using remote-controlled robot technology without any digging required.
A gyro-based pipe logger is used to precisely determine the position and location of the water main pipe.
A drill string features a retractable drill head, an integrated flushing system, a propulsion and directional steering unit and pull back module. The drill head is driven by a compact purpose-built hydraulic motor and an integrated sensor system allows precision drilling, while a braided sleeve minimises friction.
The system also comprises a multitool that, among other things, can remove obstacles and aid in drilling a pilot hole to the main water pipe. This facilitates the positioning of the pipe robot from within the main water pipe.
A pipe robot is used to locate and enlarge the pilot hole before it mounts a special fitting into the main pipe in one operation. A connection tool is used to join the house connection pipe from inside the sleeve pipe onto the fitting established by the pipe robot. It also has the ability to compensate any alignment deviations.
In addition to the above components, the system also uses other related equipment, including a small jacking frame, pneumatic system, suction unit, control software modules and more.
The trenchless techniques that are currently available for installing or replacing water mains – including sliplining, pipe bursting and horizontal directional drilling – still require a keyhole or pit to be constructed for connecting the service pipe, at which point the works become semi-trenchless rather than trenchless.
Though pits and keyholes are small, they still cause significant disruption to traffic, utilities, road surfaces and the environment. Further to this, the fact that a hole must still be installed for semi-trenchless projects encourages water suppliers to stick with open trenching methods.
The Hawle NoDig System is entirely trenchless, which limits these issues. It has also been tested and approved by a large public water supplier, offering efficient installation at a competitive price.
The system is also able to limit water loss during the transition of the main water pipe and service pipe, saving water and lessening environmental impacts.
According to Hawle, roughly 25 million water house connections exist in urban areas across its initial target markets in Norway, Sweden, Denmark, the UK, Germany and Austria. Of these, when considering a renewal rate of 0.7 per cent – or 175,000 connections – are in need of renewal annually.
The company’s testing has shown the new system can match current costs for traditional or semi-trenchless methods, event without accounting for indirect costs like CO2 emissions caused by digging or traffic diversions.
Possibilities for the future
Currently, the applications of the Hawle NoDig System includes drilling lengths of up to 30 m with a minimum radius of 20 m; installing PE100 main water pipe with and inside diameter (ID) 150–400 mm; installing polyvinyl chloride sleeve pipes ID 103 mm; polyethylene service pipe ID 25–40 mm; and working in granular soils like sand, clay, silt or gravel. With some modifications, the system shall also be capable to connect to CIPP linings in the water main.
While the current system, like other trenchless operations, requires that the water main supply line be taken out of service, future plans for the technology are considering the potential advance of connection taking place with the main still in service.
This article was featured in the Winter edition of Trenchless International. To view the magazine on your PC, Mac, tablet, or mobile device, click here.
For more information contact Christian Dobretsberger at firstname.lastname@example.org
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