Third generation extraction winch gets the green light
The third generation timber extraction winch being developed by industry stakeholders in collaboration with the University of KwaZulu-Natal, was field tested at NCT’s Ingwe farm in Lions River recently.
This winch is being developed specifically to assist small-scale timber farmers to extract logs to roadside. The latest version has ticked all the boxes and is now ready to be commercialized and made available to timber farmers around the country.
Key attributes of the winch:
• Affordable: it will cost around R35 000 to buy.
• Fuel consumption is around 4-5 litres/shift.
• Easy maintenance: it is built with off-the-shelf components that are easy and cheap to source.
• Productive: it will extract around 1.6 - 2.5 tons/hour with a team of 5 on a 0-100 metre haul distance on 18% - 20% uphill slope.
• Light weight: it can be loaded and off-loaded (by hand) and transported on the back of a bakkie.
• Quick positioning: the winch can be wheeled into position by one person (like pushing a wheelbarrow) and is anchored to a tree. It takes max 15 minutes to re-position the winch for the next rack.
• Engine: it is powered by a 7 hp Kohler petrol engine.
• Simple operation: it is easily operated by one person, working in conjunction with 2 – 4 chokers/stackers.
• Health and safety: the winch will take the heavy work out of timber extraction for small-scale farmers who cannot afford expensive timber extraction equipment.
The project to develop the winch was launched in 2015, supervised by Simon Ackerman (ICFR) and Eric Msomi (NCT). The actual development work has been done by UKZN Bioresources Engineering students under the watchful eye of Prof Jeff Smithers. Funding for the project came from the Forest Sector Innovation Fund provided by the Department of Science and Technology and administered by Forestry South Africa, and Talidex (engine supplier).
The first generation winch was based on a chainsaw engine, but proved to be ineffective. The second generation winch worked well, but was found to be too heavy and unwieldy.
This latest version was developed by UKZN engineering masters student Clayton Prowse who was on hand to operate the machine at the field day. It was also put through its paces by Brad Shuttleworth of Forestry Solutions to gauge its productivity.
The study results show that the winch can extract around 10 tons of timber per shift (452 logs) with a 5-person team in a wattle compartment over a 0-100 metre haul distance on a 20% uphill slope.
Working in a gum compartment on an 18% uphill slope over a 0-90 metre haul distance with a 5-person team, the winch extracted 15 tons in a shift (974 logs).
Brad said that the winch was most productive with a five-person team: 1 winch operator, 2 chokers at the bottom of the rack, 2 de-chokers/stackers at the top of the rack. However the winch can be operated with four people, or even three (1 operator, 1 choker, 1 de-choker/stacker).
The winch is equipped with two drums, 100m haul-in cable and 200m haul-out cable. The haul-in distance could be extended to 175 m if necessary. It has a 2:1 reduction gearbox and has plenty of torque and there is very little strain on the engine during operation.
Clayton said maintenance on the winch will be minimal. Worn components can easily be replaced
According to Simon, plans are in the pipeline to find a suitable manufacturer who could make the winches available on the commercial market.
*First published in SA Forestry magazine, September 2018
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