SHAW’S WIRE ROPES IRON TEST
I’ve seen some strange sights in the forest but few of them compare to an outsized Tigercat forwarder behaving like a spritely mountain goat on a steep slope.
Watching the full-size Tigercat 1085C – the first to go into operation here – behave like a mountain goat on a steep forest slope in Southland with 22 tonnes on board is a rare and interesting sight. But DM Logging manages to make the task look simple, hauling more than 220 tonnes of blue gum out to the skid site each day.
IWAS FINDING IT HARD ENOUGH STAYING ON MY FEET AS I struggled on what must have been a 45-degree angle at one point, so how Craig Braven in the operator’s seat didn’t pitch-pole his 30-tonne machine and 22 tonnes of wood down the hill beats me.
There was no tether to provide the Tigercat with any sort of assistance.
They sure do breed people with nerves of steel down here in deepest Southland.
And yet, what makes this act so unusual is that it isn’t really out of the ordinary for Craig and his boss, Dean Dahlenburg.
You see, DM Logging has become expert in harvesting and removing logs from the sort of country that others shy away from. And steep slopes come right at the top of that list.
“We’ve tended to specialise in steep forests more recently because not a lot of people are into it, and that’s why I’m buying gear to suit,” says Dean very matter-of-factly after we’d witnessed Craig nose off a lip that defied belief.
As we watch the underside of the forwarder’s bunk disappear from view, he adds: “Yeah that is a bit steep, but if you know what you are doing and approach it the right way – and you’ve got the right gear – it shouldn’t be a problem.”
We’ll talk about the “right approach” in a minute, but first I want to know why the new Tigercat 1085C is the “right gear” for this deathdefying work.
A bit of background. This is a blue gum operation, which you might have guessed from the location – Southland has the largest concentration of Eucalyptus forests in the country and most are within a stone’s throw of Invercargill, like here in Drumfern Forest, 20 minutes north-west of Winton. They are planted on undulating and occasionally steep sites, so forwarders are the key to transporting logs to a place where road-going trucks take over.
After serving his apprenticeship in pines, Dean went on to cut his teeth in gums, being one of the early loggers to work in these southern ‘euc’ forests some 17 years ago, along with Waka West and Blanchy. That was right at the start of SouthWood Export’s venture to supply the Japanese pulp mills with chip.
But the ebb and flow of Eucalyptus supply saw Dean return to Radiata forests until five years ago, when he was asked to tackle a steep block of windblown gum in Drumfern that others had walked away from. Once in, he never left.
To make that job work, Dean figured it would require a BIG forwarder that would do regular runs from the cut-over to the skid site with a good-but-not-too-large load on board. There are two reasons behind such thinking; not pushing the limit with the load keeps the height down and lowers the centre of gravity, thus making it more stable, and it also reduces weight, so less strain on the machine.
Keeping the forwarder to a steady flow of wood, rather than pushing the envelope is part of the recipe for success in these challenging blue gums.
Dean has seen a few forwarder operators go hard-out to carry as much as possible, as fast as possible, and reckons they won’t beat a smooth and steady person at the controls.
“I’ll back my man any day against someone who goes like the clappers,” says Dean. “He’ll bring in just as many loads.”
Around the time the windblow job came up, one of the biggest forwarders working in Southland forests also became available; the Caterpillar 584HD that Scott Bradley was running in Eucalyptus forests near Tuatapere. Tipping the scales at 20 tonnes and able to carry a similar size load, it was among the largest of any purpose-built log forwarder when introduced and Scott was the first to employ one in New Zealand, which NZ Logger Iron Tested in September 2011.
When he got his hands on it, Dean worked the Cat to his formula of carrying reasonable loads at a steady pace and made it pay in the windblow. But running secondhand gear is never ideal, especially in such unforgiving country so when the 584HD began getting up in hours he cast around for a replacement.
By now, Caterpillar had decided to get out of the forwarder market, which narrowed the choice slightly, although there was nothing available locally that precisely matched Dean’s requirements.
That is, until AB Equipment suggested he look at Tigercat’s flagship forwarder, the 8-wheel-drive 1085C.
Even though the 1085 had been added at the top of the range more than three years ago, none have been sold in New Zealand. Both AB Equipment and Tigercat were keen to see it introduced to our market, especially as several are already hard at work in gums across the Tasman. Some have been reported to regularly transport 35-tonne loads – against an official maximum capacity of 25 tonnes – so it can obviously handle big weights (over the short term, at least).
“We’d never think of putting 35 tonnes on it in here,” gestures Dean, “but it can easily cope with 22 tonnes on some of our steeper blocks. That’s good enough for me.”
At 22 tonnes, it gives Dean a weight buffer of 3 tonnes under the 1085’s maximum, so it’s not likely to be flogged. It’s also more than the 20-tonne capacity offered by the Tigercat 1075, the previous top-of-the-range model that already works with a number of New Zealand operators.
“I didn’t consider a 1075 – I really couldn’t see the point, except for the price,” adds Dean.
While it cost more than a 1075, the larger Tigercat hit the sweet spot for Dean and when the Cat 584HD was finally traded in at 14,000 hours a couple of months ago, he became the owner of the first 1085C in New Zealand.
It wasn’t just the load factor that swayed Dean. He likes other features, adding “This thing is exceptionally strong in lifting and that was the other reason I went with this because it had the big crane. Plus, it has a stronger slew, the bigger bogies and the power to make it climb really well, even on slopes this steep. I like the single speed transmission, too.”
Dean didn’t go with the unique low-wide bunk introduced as an option on the 1085C as part of the C-series upgrade over the previous B-series, preferring to stay with the more conservative regular configuration bunk to keep the load within the confines of
the wheel tracks……..and even then he’s not using the entire width.
“It’s only sitting in the second hole on the bolsters so we haven’t opened it up yet, there’s another two to go,” he says.
“If we were in green gums and opened it right up as wide as it would go, we’d end up with 35-to-40 tonnes in there, which would be way over weight. It wouldn’t get up the hills anyway, but even on the flat I still wouldn’t run it at that weight because you are inviting problems down the line. Anyone can load a machine young and get away with it, but at 8-to-10,000 hours, that’s when you start to do bogies or diffs and drop boxes. So we base our business on the 20-to-25 tonne range and as long as we keep ticking over with that, it’s doing what it’s supposed to.”
The 1085C has been built with large loads in mind, according to Tigercat, which describes it as an “severe duty” machine. While it’s based around the 1075, the newer machine has been upgraded in key areas, including larger, heavy-duty bogies and axles, a heavy-duty centre pivot and more steelwork around the frame.
In place of the 1075’s two-stage hydrostatic transmission, Tigercat has developed a unit it calls the WideRange transmission in the 1085C, similar to the one equipped to the 632E skidder we sampled last year, but without the EHS technology. Essentially, this is a CVT-type variable-speed hydrostatic box incorporating a pair of piston motors to offer an infinitely variable drive with no set gear changes. Tigercat says it delivers “extremely high tractive effort” to boost performance, especially when transporting full loads up steep slopes and Dean concurs with that description, adding: “It just powers up.”
Another advantage of this type of transmission, compared to a conventional two-speeder, is the quicker working travel speeds. Dean says the 1085C gets along at 6-to-7km/h, whereas another forwarder might be doing 5-to-6km/h on the same challenging terrain. The only drawback with this transmission is the top speed on easy tracks is limited to 8km/h, compared to 17.5km/h for the 2-speeder in the 1075,
But the WideRange does deliver better fuel economy. We already know from experience with the new FPT engines adopted by Tigercat that they sip less diesel, but that advantage is increased when coupled to the new WideRange tranny.
“It’s certainly more economical than the old 584,” says Dean. “Before it went onto tracks it was only using 120 litres for the day and we got almost three days out of the (370-litre) tank. But with the tracks fitted, and in this mud on the hills, it’s gone up to 170-to-180, or around 17 litres per hour. The 584 would use up to 300 litres a day.”
The 6.7-litre, 6-cylinder FPT N67 engine is exactly the same as used in the latest 1075C model, and also the bigger Tigercat skidders, built to Tier 2 specifications and delivering a rated power output of 230 kW (308hp) @ 2,000 rpm, which is up there with the best.
“The power in it is phenomenal,” confirms Dean. “And it’s so quiet, it can creep up on you without you knowing.”
To ensure all that power is transferred reliably and more effectively to the ground, especially in slippery conditions, Tigercat has equipped the bogie axles with a friction clutch differential lock or MDDL (multi disc differential lock). This allows the operator to engage and disengage the differential locks while the machine is moving, instead of having to stop.
The 1085C also has some other tricks up its sleeve to aid progress, or should I say, slow progress on particularly steep hills.
“Forwarders don’t like going down hills fast,” explains Dean, “so you can wind the engine revs back with one dial, and also wind the transmission back with the other dial, like a retarder. You definitely need that because it will try and get away on you, especially when the fully-loaded weight is 50-to-60 tonnes, although since the tracks went on they’ve helped.”
But the tracks, or bands, currently fitted to the DM Logging machine are not the ones that Dean ordered and they have a tendency to become clogged with mud – Dean says that while it will climb, “when it gets to a certain angle on this ground it starts to skid because it runs out of traction, and that’s down to the tracks (bands)”.
A new set with more aggressive grousers are on order and should have arrived by the time you read this.
Another important part of the operating equation for any forwarder is the loading crane; it needs to have good reach, be capable of lifting weighty logs and do the job quickly. The Tigercat 1085C ticks all three boxes with the heavy-duty F195T85 telescoping crane and medium capacity FG43 grapple.
The crane and grapple are well matched, having both been designed with the aim of assisting the operator to grab good loads without compromising speed, making for quick cycle times.
The crane is built to last, with thick walled bushings, a heavy-duty link, and rotator/swing dampener to reduce shock loads. Nice to see the hoses are routed through the box section to provide good protection from wayward logs.
Selecting the right grapple is an art-form, but the design of the FG43 seems to blend good bunching with the ability for the operator to easily pick up single logs when needed. It has a capacity of 0.43m, which is large enough for up to six or seven narrow logs or one big 3.5-to-4-tonner!
That’s right, some of these southern Eucalyptus 6-metre logs can weigh the same as a large Radiata log, which really tests the lifting ability of the crane, even with 195kN-m (143,825 lb-ft) at its disposal.
“It can handle most logs, but heavy ones can be difficult to load, especially on a steep hill,” says Dean.
“Technically it’s supposed to be able to lift a 3-axle trailer off a truck. But you can’t get close enough.”
Effective maximum lift is around 3.5 tonnes if the log is close to the machine, but when the boom is stretched out to its full 8.5 metres reach, the theory of quantum mechanics kicks in.
Both Dean and Craig have developed a neat flip-over manoeuvre to coax heavy logs into the bunk by lifting them end-over-end.
They’ve also developed a smart way of loading the wide variety of logs on the steep stuff that most effectively utilises the Tigercat’s prolific carrying capacity. And it answers the question about why Dean decided against the low/wide bunk.
“If we were only on the flat, the low/wide would be great, especially being able to fill it up and have a lower grille, but it doesn’t work on slopes – you’re spreading the weight further out,” says Dean, who then goes on to explain his approach to forwarding.
“Forwarders are designed to go up and down, not to be on sidings. So we have to do a lot of planning to make sure we get it right. And that starts with me making sure I put the logs down when harvesting (with the Komatsu PC300 and Woodsman PRO800) and do my bit right, otherwise he could be four or five loads down.
“Then he has to figure out how to load it. There’s no point doing all
the easy stuff and then struggling later with the hard bits – the idea is to be consistent right through and pick the right logs and progress down the hill. No point doing 20/20/20 (tonnes) and then finding you’re out of room and ending up doing 6/6/6.”
Consistency is the name of the game, says Dean, adding that we won’t see Craig spending ages trying to place the last few logs on the top so that they are well contained within the bunk and behind the frame. That time is better spent travelling, not juggling.
Like the 1075B we tested a while back, there is a conventional rising headframe to protect the cab from logs trying to shift forward when the Tigercat is bumping its way down a hill. Dean points out that the frame is not what it seems.
“We took it off and we made the space between all the slats in the headboard about 35-to-45mms wide, compared to the original 70mm,” he says.
“Some of the smaller stems can force their way through the larger gaps. It’s not just the cab and your man you need to protect, because your hoses, fire extinguishers, everything is in front of that grille.”
It was an extra expense, but necessary, and Dean thinks the factory may well adopt it as an option for future buyers.
Also unusual is the blade fitted to the front of the 1085C, which Dean specified because it enables the operator to clear the track of slash and debris without calling on assistance from a separate machine. It was designed to be used in snow in much colder climate and is a bit skinny for the job envisaged by Dean.
“They don’t usually put blades on because forwarders aren’t designed to push, so it’s not as deep as we wanted,” adds Dean. “It needs more of a scoop, so the dirt goes where it’s supposed to and at the moment it’s piling over the top.”
A few weeks later Dean had re-fashioned the blade with an extension that rolls the dirt over and works much better.
Such attention to detail underlines the success of the DM Logging approach to the difficult task of making money from harvesting Eucalyptus, which is notorious for tight margins.
Through planning, employing the “right gear” and careful execution, Dean and Craig are able to pack off eight truck loads to the SouthWood Export chip plant outside Invercargill each day – around 220 tonnes. And they’ve been able to achieve that in spite of the steepness of some slopes and the difficulty posed by windblow, which has dogged DM Logging since arriving in Drumfern.
Having watched the Tigercat 1085C from afar, Craig has now brought the beast to the skid site adjoining the steep, twisting road into the forest. It looks much bigger up close, every bit the 27.5 tonnes plus an additional 4.5 tonnes of tracks on the bogies, even though the dimensions are no different to the 1075.
The only external difference I can make out is there are now four lights per side on the top of the cab instead of the seven on the 1075B we last tested five years ago, working with Phil Russell in a Canterbury thinning operation. They are all LEDs and turn “dark mornings into daylight” according to Craig.
Inside the cab, it’s pretty much how I remembered the 1075B, roomy, modern, with the joystick controls nicely placed at the end of each arm on the swivelling seat and a small instrument display fitted at the end of the right arm. A pair of separate screens mounted on top of the front and rear dashboards offer views from the two cameras; one fitted between the lights above the front screen to give the operator a good close-in view ahead of the machine and the second enclosed in a small housing at the end of the chassis for an expansive rear view.
Craig says he uses the cameras all the time, adding: “I had it on this morning when I dropped over that other hill. The camera points down so it shows more than you can see from the seat. Quite handy. Then I had the forward camera playing on the rear screen when I was facing backwards so I could still see what was ahead of the machine.”
He’s a fan of the cab layout and says there’s plenty of storage spaces to keep things tidy, however he would like to have a pie warmer, just like the Komatsu forwarders.
Iron Tester Stephen ‘Pud’ Unahi will flesh out more details on the cab and controls in his column on page 35.
Back outside, tipping the bonnet forward, the view is similar to the Russell 1075B, even with a new engine now sitting under the air cleaner, with all daily checks in the same easy-to-reach positions.
With dark clouds massing above us, the predicted showers look like they are on the way, so Craig gets back into the cab for a demonstration run on one of the steeper sections to allow ‘Pud’ to
observe his technique and for me to grab photos.
Following the 1085C over the brow, I’m more-than impressed with Craig’s prowess and bravery in tackling such a steep incline, along with the ability of the machine to operate so well on this angle.
Dean has made life easier for Craig by bunching logs so they are within easy reach either side of the Tigercat. There’s not a proper track down here and there are still stumps to negotiate, which adds to the complexity of the task. But at least Craig has more ground clearance (716mm) than in his previous machine.
Whilst large tracts of the forest were hit by windblow five years ago and were still being cleared until very recently, the trees on this section were standing until a few days ago and Dean says that makes it easier to lay out the logs.
As Craig begins to load the bunk, Dean also points out that when he was processing some of the larger stems he had to be careful not to cut them too long, in order to keep the weight within the crane’s lifting capabilities.
Craig grabs the lengths he wants, judging what to leave for the next trip and moves further down the slope.
“He normally starts at the top and if he’s done the job right, he’ll still have logs when he gets down to the bottom to finish it off,” says Dean.
“And if he is going uphill he will only take a third, then halfway up he might take a wee bit then get the rest at the top because forwarders don’t like being pushed up a hill with 25 tonnes on the back.”
Fortunately, the clouds blow over and the demonstration doesn’t need to be hurried. After offloading onto a small skid site at the foot of the hill, ‘Pud’ replaces Craig in the hot seat (no harness, strangely) and receives his operating instructions. Having driven plenty of forwarders in his time, the briefing doesn’t take long.
For his test, ‘Pud’ decides to start at the bottom of the hill because he’s experiencing this machine for the first time and wants to ease himself into the task without the added pressure of negotiating a long drop from the top. It’s a good move because he is facing up the hill and is able to concentrate on loading the mostly skinny logs.
Craig is happy to take a break and says: “Working in blue gums can be challenging at times. It’s pretty steep in places and when it’s wet it gets a bit hairy. We’ll need those tracks with the bigger grousers because we do this sort of steep stuff every summer.
“That’s why we went for that machine. It’s pretty much tailormade for what we do. It’s ticking all the boxes so far – I’m probably doing one extra load a day than before, and we are noticing a lot more wood going out the gate.”
When this hill is completed, Dean and Craig are due to move to another Eucalyptus forest nearby with easier terrain to work on over winter before they hit the steep stuff again.
And when they do, they’ll have the “right gear” to make a good fist of it.
NZL