In the media
By John Cohen-Du Four & Sandrine Marrassé
Ingenuity and innovation can pop up in the most unexpected places. Like while you’re sitting in the cab of your Waratah harvester, swinging around its huge, dinosaur-like harvester head with such control and dexterity it’s like a bionic extension of your own arm, giving you the power, in one seemingly fluid movement, to lift a giant fallen tree, strip it of its branches and bark, and precisely cut it into pre-determined log sizes—all in the time it’s taken so far to read this article.
Welcome to Charlie Thomson’s domain, the place where he came up with his novel idea for eliminating chain shot, a very real, very lethal safety risk to any forestry worker in the vicinity of his mechanical harvester. Charlie, who along with Mike Fraser is part-owner of Nelson Management Ltd’s (NML)* contracting business Thomson and Fraser Processors, explains, “The two mechanised chainsaws working within the Waratah harvester head operate at tremendous speeds under enormous pressure. No matter how good an operator is, they can never stop a chain from breaking, and when it does any small debris that gets flung out is chain shot. Basically, in that moment, it’s flying shrapnel.”
Ten percent of all chain breaks will feature chain shot, and while the Waratah operator is protected by the cab they sit in, safe behind its 17mm bullet-proof glass, any other workers on the skid site, or other machinery or vehicles, are potential targets.
Charlie’s solution at first seems beguilingly simple: devise hanging guard flaps to block the chain shot from escaping beyond the harvester head.
But as he discovered, the guard flaps needed to be flexible enough to not constrict the ability of the unit to drop close to the ground for trees to be scooped up, yet not so flexible that they routinely got in the way of the chainsaws and damaged them, or became damaged by the saws themselves.
“And they had to be tough enough that if they do get struck by the saw blades, they wouldn’t be wrecked and of no further use. After all, it’s a lot easier and cheaper to sharpen chainsaw blades than replace a $500 flap.”
The final design has ended up being a mix of nine layers of laminated rubber and specially located reinforcing steel plating, precisely positioned to cover any angle of trajectory the chain shot might take.
“The rubber absorbs the impact and deflects the chain shot downwards to the ground. There are four guard flaps in all, two shielding either side of the main saw blade, and two shielding the topping saw blade. That’s the really critical one with the widest chain shot range—it can basically turn the entire skid site into a target.”
It’s taken Charlie a full 18 months of design variations and field trialling to devise a proven prototype that meets the high safety standards he’s been after. So convinced is NZ-based manufacturer Waratah of the value and future of Charlie’s breakthrough, it is building and is soon to open a specialised facility in Tokoroa devoted to developing his concept even further.
“Waratah want to keep me involved for ongoing design assistance and testing,” says Charlie. Given Charlie’s 30-years experience in forestry, the past 20 operating Waratah harvesters, that’s hardly surprising. In fact, it was thanks to Charlie, and in particular his business partner Mike Fraser, that the first Waratah was brought to work in NML’s forest estate back in 2002. “Mike was a huge believer in the technology—he was determined to mechanise the top of the South,” says Charlie.
NML are thrilled with Charlie’s latest innovation. “Safety is everything to them, but they also appreciate how the elimination of chain shot risk increases the ability for the company’s mechanical harvesters to be used in more constricted areas where skid sites are smaller.”
At a cost of around $800,000 per harvester, the log producing behemoths represent a huge investment—making the $2000 for a set of four chain shot guards a small price to pay to make the units much safer and even more capable in the field.
It’s a good news story all round—and all thanks to the sharp thinking of one clever man in a harvester cab.
New log truck safety innovation
As it turns out, innovative ideas are often also born while sitting in the cab of your logging truck, driving the long distances between forest and the log drop-off point. Meet Duncan Borlase, owner of Borlase Transport Limited, an NML contracted Brightwater- based logging transport company, and foundation member of the Log Transport Safety Council. Duncan is no stranger to innovation. In his 40 year career he has invented many of the features that are now stock-standard on every log truck in the country.
Duncan, and son Steve Borlase (also a partner in the business and its Health and Safety manager) have developed a simple and safer way to tighten and secure log loads, with the goal of eliminating the risk of injury to drivers. Log loads are secured
to logging trucks with chains and a load binder twitch – a simple, metal chain- tensioning device, with a hook at either
end to attach to the chains, and a lever to tighten. The twitches are traditionally attached vertically, and the action of tightening the chains by pulling down on the twitch handle was a very real safety risk.
“What’s happened over the years is that people have slipped and the handle comes back upwards at its most tensioned point (which has a lot of force behind it), and can hit the person in the face – we’ve had people lose their front teeth, someone working for another company lost their eye, and then in short succession two more people lost their eyes while working for other companies in the North Island. At this point Lees Seymour (NML’s Managing Director) turned around, got us contractors together and said “We can’t have this, we’ve got to come up with a solution to prevent this from happening,” says Duncan.
At first a winch system was used, but this method was both expensive and unreliable in less than perfect weather conditions. Thus the ‘Borlase Bellcrank’ was conceived. It’s a typical bellcrank system, but the way it’s being used is new, along with the repositioning of the twitch into a horizontal position. A 90-degree bellcrank usually consists of an “L” shaped crank pivoted in the centre where the two arms
of the L meet. In the Borlase system, chains and twitch hooks are attached to the ends of the L arms of the bellcrank – when one is pulled by the twitch lever, the L rotates around the pivot point, pulling on the other arm and tightening the chain around the log load on both sides, doing some of the work that was previously done by the brute force required to pull the twitch bar into its locked position.
By changing the placement of the twitch so that it operates horizontally rather than vertically, if the handle “kicks back” it travels away from the operator, hitting the side of the load and can not injure them. This positioning also eases long-term wear and tear on the upper body. “This is a very simple thing! The only thing that annoys me about it, is why the hang didn’t we think of it earlier!” says Duncan.
The bellcrank system is also cost- effective (roughly half the price of a winch system) and easy to maintain, but above all is improving safety in the workplace. “NML sets the bar very high when it comes to health and safety which pushes us to do the same. We’re already thinking about our next challenge – figuring out how to mechanise throwing the chains over the loads,” says Steve.
From Wild Tomato. Read the article here