SHAW’S WIRE ROPES IRON TEST
As a brand, Kobelco has tended to operate under the radar in forestry, but the introduction of the generation 10 models could change that. The new Kobelco SK300LC-10, operated by Stubbs Contracting in its road lining crew in Gisborne, has much to commend it.
THIS NEW KOBELCO LOADER IS PROVING TO BE A REAL live wire, especially with its live heel. Working in one of Robert Stubbs Contracting crews out of Gisborne, it has been showcasing some typical Kiwi number 8 wire thinking with that handy attachment.
Who’d have thought that a live heel could be used to create a brand new track in the bush instead of digging it out with a bucket? Move a bit of dirt, yes, but not a whole damn track’s worth. That’s exactly what this machine achieved just prior to the arrival of the NZ Logger Iron Test team at the Stubbs work site in the Wharerata Forest to sample the newcomer.
Yet another example of how useful a live heel can be in the right circumstances. More on that shortly.
Let’s start with the machine it’s attached to, which is the first of the recently introduced generation 10 Kobelco SK-series excavators to go to work in the forest in New Zealand.
This particular model, a 34-tonne SK300LC, is set up for forestry at the factory with a standard high and wide base, which was another good reason for NZ Logger to drop in for a closer look – just add guarding and your implement of choice and it’s ready to go to work.
As a brand, Kobelco has tended to fly under the radar in the forest until recently, when Juken NZ decided to run with some of the bigger models for its previous company-owned crews on the East Coast. They certainly made independent contractors sit up and take notice.
And with the arrival of the newest generation Kobelco, interest continues to grow.
For Robert Stubbs, who runs a couple of harvesting crews and a road lining operation, it wasn’t so much a leap of faith, but more about having faith in the advice of the local MIMICO service agent who also works on many of the machines in his crews – MIMICO is the New Zealand agent for Kobelco.
Robert has been a Cat customer for much of his time in the forest. Still is. But he isn’t afraid to look over the fence and see what else is available that might be suitable for specific tasks, provided the price is right. That’s why you’ll find other interesting machines scattered across his operations.
When the road lining job came up in the Wharerata Forest, he knew there would be a lot of shovelling involved, which dictated the need for a live heel. Now, you’re either a live heel fan or you’re not – no halfway measures. Robert is in the former group. He thinks they are an extremely useful tool and has always had one fitted to a machine when undertaking road lining over the years.
“It makes a lot of sense, not just for shovelling stems on hillsides, but for doing the odd bit of blade work – you don’t want keep stopping to change over every time you need to move a bit of dirt,” he says.
For the Wharerata job, Robert wanted a new machine in the 30-tonne range set up specifically for shovelling and it had to be
equipped with a live heel.
That’s when his local service technician, Benny Fogarty, came into the picture. Being the MIMICO Service Agent for Gisborne, Benny mentioned the arrival of the new Kobelco generation 10 models to Robert as a possibility for the task.
“The fact they came out of the factory with a high and wide for the forest interested me, so we though we’d give it a go,” Robert adds.
“And I’ve got to say we’ve been impressed. It has plenty of power, good slew, good walk and the reach is just what we wanted with the live heel set-up. I’ve driven it and I like it. Some machines can feel a bit jerky because they are so light in the controls, this one isn’t jerky at all.”
To look at, you might be hard-pressed to spot the changes in Robert’s new Kobelco SK300LC-10 when compared to the earlier generation model – they look pretty much the same, with only a few minor exterior changes, apart from the obvious high and wide base (the SK260LC and SK350LC also come with the factory high and wide).
Much of the new stuff is on the inside.
It runs the latest version of the 7.7-litre Hino J08ETM-KSDQ 6-cylinder engine that now puts out 185kW (250hp) of power at 2,100rpm and 998Nm of torque peaking at 1,600 rpm, thanks to improved electronic software. Whilst the power and torque peak higher in the rev range than many of the SK300LC-10’s competitors, it doesn’t seem to affect the way the Kobelco performs its duties.
And with winter now upon us, Kobelco has also come up with a way to prevent condensation that can form within the fuel tank from getting into the engine, due to cold overnight temperatures. There’s a new pre-filter system with built-in water separator that has 1.6 times more filter area than previously, eliminating foreign particles and stopping water from entering the fuel system.
Good fuel consumption has always been a feature of the previous Kobelco machines working in the forest and the new one is reckoned to be better again thanks to a combination of various factors.
Compared to SK series-8 machines doing the same workload, fuel consumption is about 16% lower in H-mode, 14% in S-mode and 19% in ECO-mode. So there’s a good opportunity for an experienced operator to make some savings without affecting the work routine.
Another change sees a new travel motor used, which boosts traction force by 10%. The pump priority system allows it to move, lift and swing simultaneously without losing power, and the new Automatic Swing Priority system delivers full swing power during combined operations without switching modes – as highlighted by the swing speed, which is a very impressive 10.3rpm.
A key component to the SK300LC-10’s improved efficiency is primarily a result of the Arm Interflow System, which is an hydraulic regenerative system that uses the boom’s weight to force hydraulic fluid to the arm.
This eliminates the need for fluid to be artificially forced from the pump, lowering the workload of the engine and hydraulics.
All-in-all, some nice features that we can put to the test and see just how effective they are in this new model.
Arriving in the Wharerata Forest on a warm, dry day (rare for the time of year in this location), the Stubbs crew is just a short distance in from the main road that runs between Gisborne and Napier.
This is a purely ground base operation, no need for a swing yarder or Harvestline-style yoader to assist with recovering felled trees from any of the steeper sections, as they are all accessible from the new tracks created by the crew.
Our first glimpse of the SK300LC-10 in action is of the machine completing the finishing touches to a long track down from the skid site to provide better access to stems at the bottom of a gully. The skidder driver had been finding it difficult using the existing twisty track so Kobelco operator, Bob Mear, volunteered to create better access. All without having to resort to a half-hour break to swap from the grapple and live heel to a bucket.
Iron Tester, Sam Keefe, and I walk the old track down into the gully to witness Bob putting the finishing touches to his handywork with the blade of the heel.
Ensign built and installed this particular live heel in conjunction with one of its standard 1730-series grapples and, as always with the Rotorua company’s products, it’s a nice piece of engineering, dovetailing into the existing bucket linkages and making use of the Kobelco’s over/over piston layout to operate the heel.
When Bob just wants to use the grapple on its own, the piston on top of the stick draws the heel out of the way so that it doesn’t impede the operation. A flick of the control on his right joystick (where the bucket operation would normally be found) brings the heel into use for balancing those long stems when he’s in shovelling mode. And for blading work, Bob can push the heel up into the jaws of the grapple, close them up to hold it tight and, hey presto, he’s got a makeshift digging implement.
The bottom of the blade is straight, with a serrated edge that not only assists when grappling stems by holding the wood tighter during shovelling, but also works well for cutting into the surface of the ground for blading.
Bob is putting the heel to good use as he pushes and pulls dirt from the track to extend it down to where a number of stems are laying on the ground. Who needs a bucket?
It’s obvious he has done this many times in the past because he doesn’t muck around. In between bunching stems into piles and moving waste wood out of the way, he pushes more dirt off the track and creates a smooth surface for the skidder without any break in pace. Good blade operation is what you would expect of a welldesigned and engineered excavator and this one seems to deliver on that score.
After Bob completes this task, he closes the machine down and we join him next to the live heel to complement him on his dexterity.
Bob confirms that he’s had a lot of experience working with live heels since he arrived in Gisborne from Tokoroa a few years back.
“There is a lot of call for them up here,” he says. “I use the live heel all the time, shovelling and getting myself around places, creating tracks like this.
“The beauty of doing the track with the heel is that I don’t have to stop and change to a bucket – I might only use it for five minutes, but it means I’ve got a whole face of wood available to me immediately. I could lose half-an-hour or more going up to swap over to a bucket.”
Bob and Sam agree that live heels seem to be much more popular in Gisborne, compared to other regions, yet there is no special reason why that should be. Sometimes it just comes down to proper training for the operator in how to use a live heel for best advantage. For shovelling, a live heel allows the operator to speed up the process, so more stems can be handled per shift, and there is generally less damage caused – when used in the right way.
Being able to do some track work in a road lining operation is just a bonus.
“They are very good once you get used to them,” says Bob.
“I find I use it for reach and lifting those 50 tonne trailers, because you can just bring it out a little bit and grab the trailer and lift them no sweat. If you have it hanging right down you run out of lift.”
The conversation turns to the machine itself and Bob tells us it’s the first Kobelco he has operated, having come out of a Cat 325DFM loader (no live heel attached), which has gone into another of the Stubbs crews.
He goes on to say: “I quite like it now – I was a bit spoiled with the Cat, but this one is really good eh. They’re very good on fuel – I can do a 12-hour day and there is still a quarter of a tank in there. That’s not bad. I only work that long when I need to, when weather interrupts and jobs need doing.”
When asked which operating modes Bob uses, he adds: “It depends on what I’m doing. I’ll go to low mode if I’m on steep country but if I’m on the flat I’ll use the high setting with the revs turned down and that gives you more power.”
And, like his boss, Bob is also impressed with the slew and drive power, especially when heading up a steep hill and also where ground conditions are particularly heavy, thanks to the 260kN of drawbar pull.
“You get more drive going up steep places when it’s in low,” Bob
While we’re down here by the big stems it’s a good opportunity for Sam to test out the slew power and live heel by shovelling some of the wood still lying out of reach of the skidder to a more accessible spot. After a quick briefing on the controls, Sam climbs into the cab and gets busy moving and then bunching the stems next to the newly created track, taking full advantage of the Automatic Swing Priority system when manoeuvring some of the really big wood.
Although it has been dry today, this area was hit with a lot of rain recently and the ground cuts up easily, but the Kobelco’s double grousers on longer and wider tracks, compared to the standard model, provides plenty of traction and there is good stability when Sam gets hold of a heavier stem.
He doesn’t have to worry about the stumps, rocks and mounds of dirt that litter the ground here because the SK300LC-10 has a generous ground clearance of 785mm. That’s as good as any purpose-built machine we’ve sampled recently.
And if the base does come into contact with anything bigger, the belly is reinforced, as part
of a programme to make the generation 10 machines withstand the rigours of harsh treatment in the bush.
The beefed-up crawlers feature full track guides to eliminate de-tracking concerns, a reinforced guide frame built to withstand heavy impact and large, double-support, outer-flanged upper rollers unfazed by powerful vibrations.
Kobelco also says that the boom and arm have been further strengthened, with an increased and improved boom foot crosssection, along with new heavy-duty joints, for longer life.
We want to get a closer look at some of these, and other improvements, so when Sam has finished shovelling, it’s time to take the SK300LC-10 back up Bob’s newly created track to the skid site.
Once on the skid site, Bob takes a smoko break while Sam and I crawl over the SK300LC-10, using the redesigned and roomy walkway
up to access the engine through the top hatch. There’s more space moving through the steps and walkway because Kobelco has shifted the fuel tank on the SK300LC-10 and it now sits further down.
Furthermore, this has also allowed Kobelco to improve the upper deck layout, providing a large flat space for the technician to place a toolbox without it encroaching on work space. The hinged hatch to the engine isn’t very large, so to improve access the surrounding panels can be unbolted to allow the techie to get to all parts of the engine and transmission. Regular maintenance items, such as filters, are accessed through the side panels from the ground. There’s a new compact and easily replaceable canister-type hydraulic oil return filter and a new reinforced air-cleaner element.
Kobelco has designed an indirect flow cooling system, dubbed the iNDR, for use in excessively dusty locations, but it was decided that the standard system could easily cope with conditions in the Gisborne forests, so long as the operator keeps an eye on the radiator fins and the air-cleaner element.
Finally, to the standard ROPS/FOPS cab, which still needed to receive more protection before it headed out into the forest. So Robert commissioned Rotorua’s Active VMA to fabricate the cage around the working area, consisting of front screen and side guarding rails, roof protection, and the beefy steel rails around the top perimeter of the engine compartment.
From the operator’s seat the guarding does remind you that you’re not in a purpose-built cab, which would normally feature Marguard glass, but Bob says the vision is still quite good through the bars and he doesn’t think about them now.
The factory-designed and built cab is modern, well trimmed, comfortable and still very light and airy even with the steel cage around it, due to the expansive use of glass on all sides. And ACTIVE VMA also incorporated a line of four lights into the top of the guarding frame above the front screen, so there’s much more forward light than on a standard machine. A couple more lights halfway up the boom and another built into the guarding next to the steps on the right of the machine supplement the night vision.
A by-product of the redesign of the walkway up to the bonnet on the right-hand side is that it also improves the operator’s view in this area.
A further visual aid for the operator is the installation of a rearfacing camera on top of the counterweight that provides a nice view of the area behind the machine on the new LCD display monitor fitted to the front-right pillar in the cab. The operator can also dial up a range of information, from fuel burn to when the next service is due on the monitor. This information is also available to Robert Stubbs and his team in their office in Gisborne city via the Geoscan Excavator Remote Monitoring System so they can see how the Kobelco is working when they choose.
One interesting aspect of this system is that it can be set up with a geo fence around the machine to alert the operator if he goes outside a certain boundary, which would be ideal for keeping Bob and the SK300LC-10 away from any known danger zones when he’s out shovelling or making one of those impromptu tracks.
Among changes that have taken place in the cab is a new airconditioning system, with improved venting behind the operator that provides a more powerful airflow around the interior to compensate for the hot summers in the Gisborne region.
The seat is now air-suspended and also has a heat function so that Bob can get warm through the seat of his pants on cold winter morning starts.
Kobelco has also designed new light-touch control levers, which it says are smoother and less tiring to use, requiring 38% less effort – probably more noticeable if used in a digging operation in construction and road-building work, than for loading and shovelling, but still very welcome for any operator.
I’ll leave Sam to describe the controls and cab environment in greater detail in his Iron Test column on page 36.
With the main inspection completed Sam is now given the opportunity to test the fleeting and stacking abilities of the new SK300LC-10 towards the back of the skid site.
To the right of this area is where the skidder drops the stems that are dragged up the new track Bob created. Sam uses the live heel and grapple to manoeuvre these away from the main thoroughfare until they can be processed. Some are quite large, in excess of four tonnes, but they don’t seem to bother the Kobelco, thanks to the combination of good hydraulic set-up. No rocking on its tracks, either.
Should heavier stems arrive on the skid, the operator can select a special heavy lift mode, a first on this machine. This works by decreasing the flow and raising the pressure, to make lifting heavier objects easier whilst providing finer control of the procedure – handy for lifting big 5-axles trailers off the back of a truck.
In between moving the stems to one side, Sam sorts the processed logs into their various stacks, occasionally staying fixed to the spot and trying out the reach, which is around the 11-metre mark with the live heel. At maximum reach, he can still pick up a grapple-full of logs weighing in excess of 4 tonnes.
With day’s end rapidly approaching, we hand the Kobelco back to Bob to finish the rest of the fleeting duties, satisfied that his boss has purchased a machine that can handle all the work asked of it – and some tasks that might not be fully apparent when you see it fitted with a live heel. We certainly dig this Kobelco.
Facing page: Upgraded hydraulics deliver a very speedy slew on the new Kobelco SK300LC-10.
Above left: With the blade of the heel tucked into the grapple, Bob Mear, has a handy tool for moving dirt.
Above right: This track was constructed completely with the live heel blade.
The Kobelco comes straight from the factory with a high and wide base – the rear-facing camera sat up on the counterweight is standard.
For picking up extra-heavy stems and also lifting trailers off log trucks, the Kobelco SK300LC-10 has a special heavy lift mode that increases pressure in the boom and arm pistons.
The live heel comes in just has handy for moving large stems to one side on the skid site.
Above left: Good access to the top of the engine through the hatch. The surrounding panels can easily be unbolted if required.
Above right: Access to the cooling system and filter is through the left-hand side panel.
Left: The redesigned walkway provides more room for getting up onto the top deck.
Right: This is the first Kobelco for regular operator, Bob Mear.