RON HORNER puts a 2012 Sakai SV512TF padfoot roller to work on our rock-strewn testing ground.
The need to push new access tracks across our rocky Queensland testing ground recently had us thinking we needed to get in a self-propelled vibratory padfoot roller — we could push the pesky small rocks back into the earth and get a decent used equipment test in at the same time.
We wanted to source one as close to the Boonah grounds as possible, so we turned to Compaction Australia (CA) down at Beenleigh, just south of Brisbane.
The boys put me in touch with another arm of their business based closer to home – Lockyer Hire in Ipswich. Between all of us, we reckoned the best machine for the job was a 12-tonne, self-propelled Sakai SV512TF vibratory padfoot roller with 1400 clock hours.
Sakai, a region in Japan not far from Osaka, is the home of Sakai Heavy Industries, which was responsible for manufacturing the first road roller in Japan over 90 years ago. Japan has over 1.1 million kilometres of road network and Sakai, now a specialised roller manufacturer, exports to all countries around the world.
What to look out for
When buying a used roller, there are many items which can cause you grief if you fail to do your checks and balances prior to purchase. Without going into all of the areas in too much depth, there are some basics you must attend to.
Visual inspection of any piece of used equipment is a must. Hydraulic hose leaks, looking at wear and tear, oscillation pins, joints and bushes, tyre wear and damage, hydraulic oil discolouring, clean engine oil, and dated filters are some areas that must be checked.
When buying a used roller, other items should be investigated, including wear on the steel drum and pads (if it is a padfoot roller), shock absorption rubbers for tearing, noisy or jerky hydrostatic transmission, and screaming hydraulic pumps when under load.
This particular machine covers all the bases to a tee. For a hire company roller, this is in very good condition and reflects the maintenance and servicing department at CA.
The SV512TF has 140 steel pads on the drum sitting 100mm high and shows minimal wear rate. When inspecting a machine of this type, check to see if the pads are significantly worn or rounded, which could mean it has been worked hard in a rock-based environment. Replacing these is a big expense if you are just starting out.
Once you get the manual/hydraulic assist rear-tilting engine cover sorted, you can see how the Perkins four-cylinder turbocharged diesel engine fits so neatly into that engine bay. Hydraulic pumps and filters are all easily accessible, as is the alternator, air filter, starter motor and radiator. They sit well up out of the dirt and mud, meaning no whinging from the fitters when called upon to instigate repairs.
The 250-litre fuel tank sits snugly under and is built into the counterweight at the rear of the roller, all under a lockable lid and well away from vandals. The 50-litre hydraulic tank is located under the side of the cabin with easy-view reading glass, and is well protected from damage.
This little girl weighs in at 13-tonne gross weight, therefore delivers approximately 40 tonnes of impact once the vibrator is engaged – not bad for a machine of this size and ease of operation. The Sakai fits inside the 2.4m width range, so floating it from job to job is non-confrontational with the law. And with both front-drum drive and rear-wheel drive from the hydrostatic transmission, climbing the ramps or the embankments on this job was not an issue.
In the cabin
The cabin is sparsely fitted out but has all the essentials required to make it work.
The dash layout is simple yet very effective, and not clogged with computerised icons requiring a university degree to decipher. All mechanical gauges, tacho, temperature and fuel gauges stare back at you, with a cable-operated throttle on the left-hand side of the dashboard in easy and comfortable reach of the operator. Just set and forget.
The air-conditioning (aftermarket) on/off dial, vibrator and water applicator are also located on the front dashboard. Forward and reverse are cable operated, and conveniently and comfortably located on the left beside the driver’s seat. Meanwhile, lifting your head upwards you have wipers, washers, and a two-way radio all at your fingertips.
Vision is great, with the tapered rear-engine cover just allowing you that bit of extra viewing from the driver’s seat. The mirrors are perfectly located left, right and centre, but all of them are a touch on the small side – personally I would like to see them domed and larger. Safety is paramount these days, and with rollers always working within the confines of pedestrian activity, I think they could be addressed.
The floor has a rubber mat/sheet applied for full coverage which doesn’t minimise the cabin noise too much, but that doesn’t detract from the performance of the machine in this particular application.
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The dash layout is simple yet very effective
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On the job
Performance on the job was well above expectations, as this is not a conventional application here. The rocks that seem to multiply on this mountain overnight (in a breeding campaign one could merely compare to the rabbit plague of the ‘40s) caused us a significant amount of grief when pushing access tracks into the areas deeper in the valley and on the next ridge.
Clearing of the vegetation is one thing, but the small rocks up to 300mm pop up everywhere in the topsoil, so we decided to get the padfoot in to thump the bejesus out of them and push them deeper to ‘whence they came’.
The two-speed transmission worked in our favour by just taking it easy over the rough terrain, and the finished product was surprisingly good.
There were no land speed records attempted here while working on the uneven and rock-littered ground. But after working the designated areas, we were happy with the outcome as it now enables us to bring in gravel material with a conventional tipper for capping, shaping, and sealing.
There was minimal vibration in the cabin, so the rubber shock absorption pads certainly have done their job here, although nothing will stop the jarring when you find a hidden boulder just millimetres under the surface … bone crushers were commonplace.
The padfoot is designed, of course, to compact soil and clay which is common in a roadworks job, and in its designed application will compact the underlying layer of material (thus the shape and pattern of the steel pads on the drum shell).
The rough, penetrated pattern left over the worked area is designed to act as binding for when the next layer of material is placed on top. This process is repeated until the designated fill height is reached and compaction densities achieved, before bringing in the flat drum roller and grader to trim and finish off to grade and level.
The bottom line
On the day, this machine performed admirably, albeit this was not a conventional job as we would normally see it. This mountain where we have our testing facility is strewn with porphyry rocks from a volcanic era millions of years ago, and the country is difficult to work in a conventional method.
The Sakai SV512TF padfoot roller is designed to perform under many conditions and in many types of materials, and this worksite stretched the boundaries in some aspects.
Overall, this machine performed extremely well and conquered almost all we could throw at it. I can honestly say that, with the exception of the hard uncomfortable seating, the Sakai SV512TF padfoot roller is well worth an inspection.