N E W S R E L E A S E from FURMANITE AUSTRALIA
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Cutting edge finish for diamond mine
High level in-situ machining expertise from Furmanite, the speciality services company geared to maximising asset uptime, has enabled shovel car body and slew bearing 
mounting surfaces on three hydraulic mining excavator machines to be machined on-site, to restore manufacturer-specified flatness and surface finish with minimum disruption and downtime.
The work was undertaken for Argyle Diamonds, part of the Rio Tinto group, at its diamond mine site at Kunanara, East Kimberley in Western Australia, which operates an open pit mine, alluvial mine and processing plant 24 hours a day, 365 days a year.
When the excavator machine car body and slew bearings were due for renewal due to wear and tear in use, the mounting surface faces had to be checked for deterioration and, if necessary, machined to restore the required flatness and finish to avoid premature wear of the replacement bearings. The work needed to be undertaken as quickly as possible to minimise the time with the shovel off-line.
Furmanite, known for its experience and expertise in on-site machining to workshop tolerances, was called in to survey the surfaces and undertake the required machining in-situ, avoiding the need to transport the excavator machines off-site with the associated cost and logistical issues and additional time involved.
Furmanite mobilised eight tons of equipment and a team to the site to undertake the work in 24 hour shifts so as to complete it quickly and within the tight time windows allocated. Furmanite technicians surveyed the surfaces using laser technology and, where they were found to be out of true, then used specialist low profile circular self-levelling machine (CSLM) technology. This is capable of machining circular structures up to 24 metres diameter to extremely high levels of accuracy, within onerous tolerances and exceptional overall flatness, on-site.
In this instance, the 3.5 metre outside diameter (3 metre inside diameter) shovel slew bearing face required a radial flatness across inner to outer diameter of 0.05mm. With its advanced technology and expertise Furmanite rose to the challenge, achieving 0.04mm radial flatness.
The CSLM machine (measuring some 3m x 3m x 1.5m) consists of a wheel-mounted milling box/cutter that rolls on the face being machined as it rotates round a central pivoting system. A datum ring mounted around the central pivot point is used as a reference and is set parallel to the desired plant. Electronic probes sense the position of the beams relative to the reference datum ring and continuously adjust the height of the wheels, and therefore the milling head, accordingly to ensure high level accuracy.
The work was successfully completed on-time and in-budget, with the post-machining graphs showing the final flatness (at 0.04mm) to be even better than the allowable tolerance of 0.05mm. Moreover, these results were achieved within minimum timescales – around just 4-5 days per excavator, depending on the level of work required.
With the car body and slew bearing faces conforming to specification, the new bearings could then be fitted with any premature wear and associated cost concerns removed.
“Our technology coupled with our experience in undertaking such projects enables us to produce repeatable results with high level accuracy and minimal re-work, allowing the necessary high standards to be achieved with maximum efficiency,” Furmanite WA business manager Martin Hurst said. “This is just one example of the service we offer, applying our extensive engineering skills and technologies to help our customer minimise downtime, representing substantial savings.”
For further press information contact:
Sarah Manwaring-White
Keep in Touch Ltd
Tel: +44 (0)1451 844 488
Email: sarah_mw@keepintouch.co.uk