A study that wrapped up late last year has examined the conditions in which winch-assisted skidding might shine.While there are many winch-assist units in the forestry industry, supporting felling and bunching on steep terrain, winch-assist skidding is a lot less common.
Under the right conditions, though, winch-assist skidding allows operation on what was traditionally cable logging terrain. Generally, however, our understanding of its full potential is still in its infancy.
Within the scope of the Forest Growers Research Harvesting programme, some initial productivity studies were done in 2019.
What we already knew
One of the successful studies was with Blake Speirs in Gisborne, operating a Tigercat 635G on 30° slopes, supported by a Falcon winch.
FEL’s Dan Fraser was the operations manager at the time. He noted that not only the safety, but productivity and cost efficiency were attractive. The method also allowed pulling away from waterways, achieving an improved environmental outcome.
Earlier excavator-based winch-assist units were designed to support the slower moving tracked felling machines.
Some teething problems were expected at the time, with issues such as the skidder being able to overrun the line speed, or adjustment of the tension setting for the skidder heading out empty.
Six years on, and the commercially available winch-assist systems have adapted to support skidder operations as well.
Good time for a re-study
So, now was a good opportunity to re-study winch-assist skidding.
FORCO’s Ian Wilton, who manages T-Winch sales in Australasia, knew one of the best crews making winch-assist skidding their preferred extraction method was NJP Logging and Tree Services, operating out of Colac, west of Melbourne.
Crew owners, Nathan and Carla Peters, are Kiwis who made their start logging in Northland and West Auckland before working for Treescape. They went over to Australia 17 years ago, gained experience in the Traralgon region, before setting up their own crew and securing a larger contract with HVP in the Otway Forest area.
Nathan runs a John Deere 959 self-levelling feller-buncher and a Tigercat 635D six-wheeled skidder, with the T-Winch 30.2 providing the winch assist. He has successfully recruited many of his operators from New Zealand.
The crew
At the time of the study, Sam Streeter, from Hawke’s Bay, was operating the skidder, with Jayden Marshall, from Taupō, operating a CAT568LL loader to clear the landed stems. Also in the crew was Processor Operator, Pauly Leota, operating the CAT568 with a Waratah 626. He is from Gisborne and gained his original experience with Kuru Logging. Loading out was Jaxon Burd, from Taranaki, on a CAT320DFM, whose initial experience was with V&S Yarding Solutions.
Two university summer students, Yotam Perchig and Noa Visser, came along to support the data collection.
The productivity study was over three days which started very wet, with rain and hail causing challenging conditions. The steeper part of the skid trail was particularly slick and there was deep mud on the flatter approach to the landing. However, by day three, the sun was out, the ground drying rapidly and the change in conditions made the operation easier.
The skid trail extended across and then downhill about 200m from...
