In the past, swing boom excavators haven’t been able to enjoy the benefits that GPS guidance brings to more conventional excavators, due to the fact that it’s difficult to make a GPS system work accurately on a swing boom excavator. Previously, the continuously changing geometry of the machine has been the problem – until now.
In the Goulburn Valley, Jarvis Delahey Contractors (JDC) works mostly for local governments and subdivision developers. They know the productivity gains available from GPS guidance on conventional excavators – the company’s excavator fleet ranges from a 5t Kobelco to a 14t Sumitomo.
However they find swing boom excavators best in tight spaces, so late last year they were looking to buy a new 8t Kobelco SK85 swing boom machine.
Hoping that someone in the world had developed GPS guidance for these machines, the company’s Managing Director Richard Jarvis approached C.R. Kennedy, the national distributor for Leica Geosystems products in Australia.
Independently, C.R. Kennedy had been working on the swing boom problem and had already developed a concept solution that utilised GPS and a series of machine-mounted sensors. The system just needed installing somewhere and testing.
JDC quickly offered up their SK85 for some trials. And Melbourne Tractors, who were supplying the machine, provided a workshop and staff to support C.R. Kennedy with the installation. Testing proved that even with the machine at its worst working geometry, and sitting 25 per cent to the horizontal, the 3D positioning provided by the new system was well within the required tolerances.
Since JDC took delivery of the newly rigged machine they have been working it hard, and Richard Jarvis can now pass judgement.
“It’s the accuracy of the system that makes the biggest difference,” Mr Jarvis said. “On most jobs we’d usually over-excavate by about 20 per cent, just to make sure we’d got the minimum specified thickness of base or concrete. Now we excavate to the design level, so there’s less excavation and less materials required, and no rework either. The savings there are massive.
“At the same time there’s greater productivity,” said Mr Jarvis. “Adding GPS guidance to the 8t swing boom machine has lifted the machine’s productivity to something close to that of a 12t machine, without the capital outlay for a big machine. And the operator can take the 8t machine to the job in a tipper, instead of calling up a float,” he said.
Part of the increase in productivity is due to the system giving the operator absolute confidence that he or she is working to the design levels and alignment.
“If the client has an issue with your work, you can demonstrate quite easily with the software that you’ve done the work to the design,” Mr Jarvis said. “If something’s wrong, it’s the design that’s wrong.”
The SK85 is currently installing underground power for a subdivision. The work has to be audited to ensure the cable is at least 900mm deep and that minimum separations (horizontal and vertical) are maintained to other services. As work proceeds, C.R.Kennedy’s system records the trench invert level and alignment. And a report or log downloaded from the software satisfies the client’s auditing requirements.
Mr Jarvis said that the professionalism of C.R. Kennedy and Leica is the key to everyone’s acceptance of the downloaded reports and the job’s accuracy.
“They don’t get this stuff wrong,” Mr Jarvis said. “Everyone has absolute confidence in their products, so we get that same confidence in our work. I love it for that,” he said.
For JDC, C.R. Kennedy’s GPS system has introduced other benefits too. Before the system was installed, the swing boom machine needed an operator, a supervisor and level checker for most jobs, but now the operator does 90 per cent of the job on his own – freeing up staff for other roles.
“A job that used to take three blokes three days, now takes one bloke just one day,” Mr Jarvis said. “That lets an operator take more ownership in his work, so he can take more pride in it too.”
Contact C.R. Kennedy Survey Solutions for more information on GPS Guidance for Swing Boom Excavators and for any other information on Machine Guidance and Attachment solutions at www.survey.crkennedy.com.au.
