Kempsey Shire Council went through a selection process by an Expression of Interest that lead to Arogen being invited to tender in late 2009. The$A3 million project was awarded to the company in January this year.

The project involves the installation of water mains in three stages, with the first stage already complete.

Stage one involved installing a water main, 1,300 m in length and 125 mm in diameter, that was designed and completed by Arogen. Commencing in mid-June, this stage involved an under bore at Fredrickton, and was completed in mid-July.

The second stage involves a 400mm OD water supply pipeline to South Kempsey that has been redesigned. The pipeline is approximately 780 m in length and is being under bored at Belgrave Falls, under the Macleay River. Work started in mid-July and is due to be completed in mid-October.

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The process of drilling the bore involved the gradual expansion of the pilot hole until it was able to accommodate the 400 mm diameter polyethylene pipe that will be drawn back through the completed hole. Arogen representative David Paul said “Because of the rock that we encountered and the length of the bore, Arogen opted to purchase and import a number of specialised cutting tools with tracking capability suitable to complete the bore.”

The third stage involves a 400 mm OD water main that is 550 m in length and will be under bored at the West Kempsey Rail Bridge, under the Macleay River. Work is set to commence at the end of September or early October.

Arogen chooses Vermeer’s D100x120rig to perform the under boring work with two engineers and several directional drill operators. The company has also sourced local suppliers for the project and is working closely with the council on an open book approach.

In regards to safety techniques used for the project, one of Arogen’s owners Tony O’Meley said that the Occupational Health and Safety Manager Richard Lipar took a detailed site-specific work management plan that was implemented for the project.

The project has been different to others in that the reputation of the Macleay River had previously seen several attempts by other contractors to under bore, and none had yet been successful.

Challenges

Some engineering challenges that Arogen has faced so far include the difficult subsurface conditions.

Mr O’Meley said “There was a lot of cobble, which is known in the industry as undrillable, and has been proven on many occasions on the Macleay River, and around the world, to be just that.”

The company used an upfront research method for looking into the conditions prior to commencing drilling to carry out its own detailed geotechnical information.

“This gave us the information required to design a methodology installation to overcome all of the challenges that we were going to encounter. Arogen’s owners on the ground, in operations and working closely with the client, using the latest in technology equipment and Arogen’s key operators was the key to success,” Mr O’Meley said.

Environmental challenges were also detailed in the methodology and the company had several risk assessment workshops where all environmental risks were highlighted and the correct processes were put in place.

Arogen was able to exit within 6 inches of the planned bore profile. The new infrastructure will help to protect the town from future floods.

Future projects

The future looks impressive for Arogen, as they are in discussion to use more Trenchless Technology for installing pipelines.

“We are in negotiations with some major pipelines and the future looks great in specialised installation of pipelines by the way of Trenchless Technology,” Mr O’Meley said.