Bell rings the changes
You could call it a ‘lightbulb’ moment.
The ability to transport 30-tonnes of logs over long distances in very short time makes the Bell a ‘super forwarder’.
THAT WAS WHEN NORTHLAND’S LARS ROSEWARNE AND his team realised they needed an alternative to traditional methods of forwarding logs or skidding stems from cramped yarder landings over longer distances to a load-out or processing site. Why not two-stage with an all-wheel-drive truck?
Using a truck as a super forwarder isn’t a new idea, of course – some contractors have been doing it for years, as two-staging became a requirement in certain areas due to the topography and/or ground conditions. But the solution selected by Rosewarne was certainly novel at the time.
They went with an ADT, otherwise known as an Articulated Dump Truck. You’ve probably seen them on big earthmoving sites where huge amounts of soil needs to be shifted.
The Rosewarne team got hold of some secondhand 6x6 ADTs, ripped off the dump bins and replaced them with their own engineered bunks and bolsters to cart logs. They worked pretty well, able to transport 20-plus tonnes at a time at higher speeds than a forwarder or a skidder.
Turns out that South African equipment manufacturer, Bell, was also thinking along the same lines and began making versions of its ADTs equipped with a variety of bunk and bolster options for forestry applications. Not surprising, as Bell does have a long history in forestry with its ubiquitous tri-loader.
So now Rosewarne Cable Loggers could purchase a brand new purpose-built log transporter with full factory warranty and back-up through local agent, CablePrice. The team got its first 6-wheel-drive Bell log truck seven years ago, which has been followed by another three and we’re here on the Pouto Peninsular, south of Dargaville, to assess the latest and most capable version, a TH403E model.
When the Rosewarne team first came up with the idea of using an ADT it was partly for efficiency and productivity reasons – heck, when you can cart in excess of 20 tonnes of wood at speeds of up to 50km/h over long distances, you’d have to be mad not to consider this option.
But there were also safety and environmental considerations, which have become increasingly important over time.
Lars Rosewarne has long been concerned about the amount of land disturbance from creating large landings for swing yarders and tower haulers, figuring they needed to become much more compact.
However, smaller landings mean there is little room for stacking logs or
stems, and it also reduces space for traditional log trucks to be loaded.
But there are compensations, because as well as being cheaper to build a compact landing, there is also an opportunity to make the roads in and out less obtrusive, because there’s no need to engineer them for 50-tonne log trucks and trailers.
Less potential for people to get hurt, too.
Lars Rosewarne explains: “We’ve been de-phasing that whole part of the harvesting operation for a while.
“It was done largely for health and safety reasons, because there was just too much happening on the landings and potential for things to go wrong. But we also realised that it wasn’t the right thing to do environmentally, creating such big landings – so reducing their size was another reason we went this way.”
The advantage of going with a purpose-built factory log transporter also meant it could be tailored specifically to meet the requirements of the Rosewarne operations. That included lengthening the chassis to fit multiple length of logs. Previous ADT-based log trucks working for Rosewarne could only carry one packet, which reduced their effectiveness – for instance, a single load of 3.9 metre logs amounts to just 12 tonnes.
“This is the first full-length machine we’ve had, which has made a real difference,” adds Lars. “It can take two bays of different-sized logs, which gives us flexibility and allows us to carry 30 tonnes of logs every load.
“Cost per tonne with a timber truck can be significantly less than other systems. This is all down to its productivity, given it can carry more timber than a forwarder and has faster ground speed. The timber truck certainly refines the concept of log forwarding in certain applications.”
When Lars and his team sat down to specify what they wanted in a log truck, they focused on the largest of the models built at the Bell factory in Alton, Richards Bay, on the Indian Ocean coast about 180 kilometres north of Durban.
They’re not strictly log trucks. Bell calls them Timber Haulers or Long Range Forwarders and the TH405E is the top of the range and comes in a number of options, from a compact 4x4 model up to a long-wheelbase 6x6, including the ability to tow a trailer. Some versions can also be fitted with self-loading cranes.
A 6x6 was deemed necessary for the Northland forestry environment – all the previous ADT-based log transporters have successfully used this layout. There are plenty of tracked loaders working with Rosewarne crews, so the crane wasn’t needed and neither was a trailer because it would make manoeuvring in tight spots more difficult. But the ability to carry more logs became a serious point of discussion with CablePrice and Bell.
The longest of the standard bunks offered by the factory is around 7 metres in length, and at a smidgeon under 3 metres in width, plus 1.34-metre bolsters, the load capacity equates to 39.6 cubic metres. That translates to a maximum load in the low 20 tonnes, depending on the logs.
A lengthened and beefed-up chassis allowed the bunk to be stretched by almost 3 metres in length, with the pair of rear axles re-positioned to accommodate the additional weight.
Additionally, Rosewarne specified big balloon tyres to make sure all that weight is evenly spread over the ground, without cutting up the surface, which can be an issue with skidders, especially in wet winters.
Result: a tailor-made log transporter than can carry two packets of 3.9m log lengths, which boosts the carrying capacity to around 50 cubic metres and as much as 30 tonnes in weight. And, best of all, the work was engineered at the factory and covered by warranties.
The Bell was pretty much ready to go on arrival in New Zealand. All it required was bolsters and base plates for the logs to sit on, which the Rosewarne team decided to make at the company’s Whangarei workshop to save shipping weight and costs.
Once it was suitably bolstered, the new TH403E was sent down to the Pouto Peninsula to join the Rosewarne 78 crew harvesting a Maori trustowned forest for Rayonier / Matariki.
Pouto is an interesting area; a long slither of land jutting south of Dargaville separating the northern part of the Kaipara Harbour from the
Tasman Sea. While some dairy and sheep farms remain from the pioneering days, its mix of sand and poor soil is not very productive, so much of the land was planted in Radiata in the 1990s and those forests are ready for harvest.
It’s rolling country, with some steep sections that necessitate the use of a swing yarder to access certain blocks. But on the day NZ Logger visited Rosewarne 78, the crew’s Madill was parked up while they attacked an easier ground base area just 200 metres from the main skid site, serviced by a twisting track that gets boggy when wet.
The setting is not quite what the Rosewarne team envisaged for the Bell log transporter, but the fact that the truck has still managed to deliver 30-tonne loads consistently and in quick time, even when rain turned parts of the track to mush, does showcase the TH403E’s versatility.
“It’s not ideal,” concedes Lars Rosewarne’s eldest son, Luke, who is foreman of this crew, adding: “You should have been here when we were running it last winter, carting logs over one kilometre, two-staging off the swinger.
“Here it’s only a couple of hundred metres and can be quite tricky in the wet with a steep section that can cut up easily.”
The flotation tyres help, but these soils are very fragile and it doesn’t take much to disturb them. That’s another reason the Bell was introduced to the Pouto, as the skidder the crew previously relied
on was causing too much damage to the ground. However, the skidder hasn’t been pensioned off completely, it has been retained to use on steeper and rough terrain or where they don’t wish to build a track.
Those stems still need to be processed out in the cut-over, at a place near a well-formed track for the Bell to collect because the skid site is set up just to receive cut-to-length wood for stacking and loading out, not full-length stems for processing.
“We don’t want to be skidding into this site, because you’d have a bigger volume of wood here, plus a processor, then you’d be walking the diggers more up and down the skid and making much more mess,” says Luke.
“Doing it this way, the mess is left out at the landing or in the cut-over and the Bell comes to unload and it’s all sorted. It eliminates a lot of congestion on the skid.”
Couldn’t the company have gone with a traditional forwarder, some of which can now carry loads well into the 20-tonne capacity and have the ability to traverse areas without formed tracks, which would have allowed Rosewarne to cash in the skidder? Yes, it could, and Rosewarne has used forwarders extensively over the years, but that argument ignores how much the Bell has allowed the company to improve efficiencies across the board.
Since adopting this system, both the size of the yarder landings and the skid sites have shrunk in size, reducing infrastructure costs and time in setting them up.
Luke has been impressed with how the Bell has performed when given its head, adding: “It’s pretty quick, provided you run it over a nice piece of road.
“You won’t get it into the same places you’ll get a forwarder into – it’s a completely different sort of vehicle – but it is doing a good job for us.
“Fuel consumption is great, it hardly works, if you know what I mean and then only on the drive in when it’s fully laden. On a flat track it’s not really working that hard at all. We probably only fill it up once a week or twice if it’s really working hard. Compared to a skidder that you fill up every day with 300 litres.”
The tank in the Bell takes 379 litres of diesel, so that makes it around four times as fuel efficient as the skidder in straight dollar terms, but when you consider that the TH403E is bringing 50% more wood to the skid site per trip and it’s making three trips for every two made by the skidder, the sums just keep adding up in the high-speed log transporter’s favour.
A large, traditional forwarder capable of carrying in excess of 20 tonnes of logs will use around 40% more fuel than the Bell and would probably make half the number of delivery trips in a typical day. So it’s safe to say that the Bell is a key to making this operation meet its 500 tonnes per day target.
Time to sample the Bell TH403E in real life.
When you first catch sight of the machine it looks more like a six-wheel forwarder than a log truck, highlighted by the articulated joint between the bunk and the cab/engine. But hop into the ROPS/ROPS protected cab and it’s the reverse, this definitely feels more like a truck.
There’s a traditional steering wheel in front of the centrally-positioned seat and the dash layout and controls are more truck-like, too.
Iron Tester, Stan Barlow, agrees and he should know because he was a truck driver in a previous working life. I’ll leave him to run through the cab interior and driving details in his column on page 32, whilst I hop out and take in the rest of the package.
The TH403E does look like it’s been engineered for the challenges of life in the bush, with large belly plates protecting vital parts like the transmission and plenty of steel encasing the prop shaft running back to the pair of rear axles under the sturdy box chassis. Even still, there’s only 427mm ground clearance at its lowest point, so drivers need to steer clear of any stumps or humps in the tracks.
The heavy-duty articulating joint that enables the Bell to pivot and turn in the same way a forwarder or a skidder does is very handy for manoeuvring around sharp corners and through pinch-points at each of the loading zones.
As any log truck driver or forwarder operator will attest, the most challenging manoeuvre is reversing when there’s a full load of logs sitting behind the big safety grille. The three mirrors hanging off each door do help, but Bell has thoughtfully fitted a rear-view camera at the end of the chassis and a huge screen on the dashboard to give the driver an unimpeded view behind the bunk.
Speaking of the bunk, it’s a simple piece of engineering, consisting of four all-in-one base plate and bolster units bolted onto the truck’s central spine. The base plates are straight, much like on a log truck, though unlike modern forwarders that have a v-shaped drop in the middle to place up to four or five logs lower in the chassis. This means the load is carried quite high on the Bell and I’ll be interested to hear Stan’s views on stability when he drives a full load back to the skid.
The final step in our static inspection is to see what makes the TH403H so frugal with fuel and tipping that front hinged bonnet forward reveals the 6.37-litre, 6-cylinder Mercedes-Benz OM906LA engine that delivers gross power output of 205kW (275hp) at 2,200 rpm and peak torque of 1,100Nm available between 1,200 and 1,600 revs.
There’s plenty of room in the engine bay to work on the engine if required, and in the year since the TH403E began working in Pouto it has been completely reliable, so it may not see a repair technician very often, if at all. Good to see all the regular maintenance items are easily reached from the ground.
Drive from the engine is transmitted through an Allison automatic transmission that features an integral retarder – more on this feature shortly. The transmission provides six forward gears and one reverse, with lock-up applied to all gears to reduce slippage that is usually associated with a torque converter. Top speed in sixth gear is rated at a heady 50km/h, but even in the readily accessible third gear the Bell can still reach 23km/h, equivalent to the top speed of the fastest forwarders. In practice, it’s the track that will dictate the speed it can travel.
Bell makes its own transfer case to provide a lower range when conditions demand more traction for the six big tyres, in order to maintain momentum.
On easy runs, only the two axles at the rear are used, but on challenging surfaces the driver can bring in the front axle by operating the centre diff, along with diff locks for the rear axles.
Bell has ensured the TH403E is provided with good suspension to cushion the ride for both the driver and the load, installing a semiindependent set-up at the front, utilising a leading A-frame supported by hydro-pneumatic suspension struts, with the heavy-duty rear layout consisting of pivoting walking beams distributing equal load through laminated rubber suspension blocks.
In place of the standard 23.5 R25 tyres, the Rosewarne team specified larger Michelin 750 / 65 R25 flotation tyres that make it easier to work on the softer, sandier surfaces without causing damage, particularly in wetter winter weather.
The large footprint created by those tyres requires plenty of steering effort and the hydrostatically-actuated system has two-double acting
cylinders and needs very little input from the driver to manoeuvre the truck. Just 4.1 turns are all that’s needed from lock-to-lock, which is impressive, given the amount of turn provided by the pivot – 45 degrees either side of centre.
Luke’s uncle, Tony Rosewarne, who is filling in with the driving duties while regular operator 76-year-old Dale Right is on medical leave, says it’s an easy piece of equipment to pilot and very sedate when compared to the falling machine he normally controls.
“Pretty cruisy, by comparison – all I’ve got to do is drive from point A to point B and back,” he chuckles and then adds in a more serious vein: “It’s still an important job, as I’ve got to get 30 tonnes to the skid regularly or they’ll run out of wood pretty quickly.”
That means anywhere up to 18 trips to the skid each day, which is not so hard when there’s only 200 metres to cover either way but can be a challenge on a 2-kilometre round trip. Or when rain intervenes, as it did the previous week, making the track much more difficult to traverse.
“People think Pouto is easy to get around because it’s on sand, but it’s not all like that,” says Tony. “On this side there’s no sand on the surface and it gets very puggy.”
Tony likes the Bell and puts it among the best machines he’s operated in more than 40 years in the bush, saying: “This is a dream compared to some of the equipment I’ve experienced in the past.
“It’s lovely inside, pretty comfortable. You’ve got a fridge in there for keeping drinks cool. Very easy to drive, even when you’ve got 30 tonnes on the back, it handles that pretty well.”
One of the items he’s most impressed with is the rear-view display that he uses when reversing up to the loading site, saying: “It’s a huge screen and really helpful for reversing, I use it more than the mirrors.”
Over the past year, the Bell has transported a variety of log lengths, from two packets of 3.9s, to one packet of 3.9s plus a few longer lengths
hanging out behind (see the photo on page 25), to single loads of 5.9s. Today, it’s mostly 5.9s being transported, some of them going to local mills, much to the relief of Northland wood processors.
A John Deere 3754 with a big Waratah is processing stems that have been shovelled down the hill from where they were felled, while a John Deere 2154 loader stacks and fills up the bunk on the Bell – much quicker than using a small loading crane.
The track back to skid starts with a long downhill stretch, but it’s not steep enough for Tony to require use of the retarder to hold back the fully-laden truck. With lesser inclines, such as this, Tony can elect to hold it in a lower gear, which is also handy when driving up the steeper section leading onto the skid site. When the retarder is called into play on very steep sections no one outside the Bell would be any wiser because it runs through the gearbox, so there’s no exhaust bark, like you’d hear on a road-going truck.
After Stan has ridden for a couple of trips on the small dickie seat that folds down next to the driver, he and Tony swap places for the next part of our Iron Test. Test? It’s more of a busman’s holiday for Stan, after he spent several years driving road going logging trucks before switching to working inside the forest. He settles in very quickly and even gives Tony a break to grab lunch while continuing to shuttle logs to the skid, noting the exact tonnage on each trip via a readout on the screen so that he can maximise every load. You can read his impressions on page 32.
The Bell seems to make light work of the log transporting task, to the point where it flatters to deceive. Would a suitably tricked-out 8x8 version of a road-oriented log truck handle this work just as well? Unlikely, that steep incline heading up to the skid would almost certainly defeat it – thus underlining the versatility of the TH403E.
While it was purchased with long, straight hauls in mind, it can adapt to most situations and still deliver the goods.
Sure, it cannot go out into the cutover – it’s not supposed to. The trick to making it work to its full potential is to tailor the operation to suit the strengths of the Bell, which is what Rosewarne Cable Loggers has done. They’ve rung the changes and it’s paying dividends.
NZL