The Nepean Highway is one of Melbourne’s major arterial roads carrying large volumes of traffic from St Kilda Road in the heart of the city all the way out past Frankston to the Mornington Peninsula. A recent routine CCTV inspection conducted for South East Water by ‘us’ – Utility Services on some sewer mains in the suburb of Cheltenham exposed a substantial hole in a concrete sewer main running under the highway.

The problem – hole in sewer main

The pipe in question was a 375 mm diameter vitrified clay pipe running at a depth of 6.5 metres under seven lanes of heavy traffic, three median strips and two service lanes. As is often the case when ‘Murphy is on the job’, the discovered hole was 30 metres into the pipe from the manhole on the southbound side of the road. This placed it under the outside lane curb and channel of the outbound lanes of the highway – pretty much right in the middle.

Given the sensitivity of traffic related issues and the need to repair the hole quickly, ‘us’ – Utility Services chose to use a new technology called Quick Lock to repair the fault at a conservative cost saving of over $A20,000 to South East Water. The solution – Quick Lock

Quick Lock is a pipe relining technology that enables trenchless pipeline repair using stainless steel pipe lengths that expand under air pressure with a one-way, locking ratchet system. The result is an almost seamless pipe repair for holes, cracks, fissures and leaks.

Using remote controlled CCTV to identify the exact location of a hole or leak, the operator can then guide the stainless steel sleeve into place on a carrier unit pushed along by the CCTV trolley. From the comfort of an air conditioned CCTV van, the operator then uses air pressure to inflate the carrier unit inside the sleeve. Under pressure, the sleeve expands via a one-way ratchet system until it locks to form a structural and seamless seal inside the existing pipe.

Quick Lock has been used to great effect within South East Water’s network for:

• Blocking root intrusions;
• Stopping leaking joins and couplings;
• Locking blind inflow closures;
• Sealing water/sewer leaks; and
• Repairing cracks and fissures
.

Quick Lock is a German engineered product that has a guaranteed lifetime of in excess of 50 years as a structural pipe. Quick Lock is also suitable for council drainage applications and multiple sleeves can be used in a line to repair longitudinal cracks and fissures.

Saves time, money and community frustration

The Nepean Highway repair activity, if conducted using traditional methods, would have required;

• A minimum of 48 hours of work time with multiple crews;
• Closure of a minimum of two lanes of traffic (one in each direction);
• An excavator to dig down 6.5 metres, shielding for the trench;
• Pipe cutting and replacement;
• Management of a considerable number of risk and OH&S issues;
• Reinstatement of the road, kerb and channel; and
• Traffic management for the period of the works.

In comparison, Quick Lock only required an ‘us’ – Utility Services CCTV crew of three operators, less than three hours and the cost of the Quick Lock materials.

A conservative estimate of the savings to South East Water in dollar terms would be in excess of $A20,000 just for this repair. The savings in terms of community frustration through road closures and inconvenience on a major arterial… that is without doubt ‘priceless’!

‘us’ – Utility Services estimates that this technology could be used effectively in a large number of pipeline repairs for 150 mm to 700 mm pipes. For South East Water’s network alone, Quick Lock has the potential to provide substantial cost and resource savings, particularly against traditional methods of digging and replacing sections of pipe.

Lastly, what may take three or four days of work by a pipeline repair crew, can now be identified and repaired within a couple of hours, with very minimal OH&S risk, regardless of the depth of the pipe.