Safer Tree Harvesting with ClimbMAX

August 2015

A tree harvesting machine developed and built in Nelson

An innovative idea for safely logging forests from steep slopes while going easy on the environment.

Nigel Kelly of Kelly Logging has worked with Richmond engineering company Trinder and other Nelson firms to develop the ClimbMAX,

The Brightwater based logging company has developed an innovative tree harvesting machine that is fast and safe. Already two units have been sold and marketed nationally and internationally.

Kelly Logging has spent the last five years developing an excavator-based system that can fell and bunch trees on hills with slopes up to 40 degrees. Kelly Logging’s owner, Nigel Kelly, says harvesting machinery was not usually permitted on slopes greater than 22 degrees for safety reasons.

This limits efficiency and productivity within logging operations on steep hill country where trees were traditionally felled by loggers on foot.

But that could be about to change now that Kelly Logging has developed a computer-controlled winch system that allows an excavator-based harvester to be safely assisted on steep slopes.

Nigel Kelly says it has been a big project for the last five years and over the last three years he has been investing money to start building a prototype machine. The company applied for a government research and development grant but were initially unsuccessful.

Nigel says the steep-slope harvester not only fells trees, but also puts them into bunches for their mechanised hauler operation, maximising the payload for their grapple hauler.

He says the innovation has increased production by around 20 per cent and has majorly reduced the need for loggers to fell trees and hook them on to the hauler ropes – both jobs are the highest areas for injury in the forest industry.

Nigel Kelly said the key to the system’s success is a computer-controlled winch which is attached with over 300m of cable anchoring the excavator at the top of the hill.

The integrated winch allows the machine to work on steep slopes, limiting the loss of operator or machine performance.

The project has been Nelson-based with Richmond engineering company Tinder Engineering helping with the design and construction. Nelson companies Rosa Electrical and Fluid Power Solutions also played key roles in the development of the winch system.

The ClimbMAX is an excavator equipped with a felling head and inbuilt winch, which the company claims is capable of felling and bunching trees on slopes of up to 45 degrees. It then ‘shovels’ them to downhill collection points using an action which has been compared to underarm bowling.

It removes the dangerous jobs of breaking out (attaching logs to cables) and felling, replacing workers on the hill face with one machine operator protected by a cab.

The machine is tethered to ‘deadmen’ such as tree stumps.  The winch is incorporated in the machine therefore operated by its driver, rather than a separate operator. The winch and rope do not take the full weight of the machine but aid traction and stability.

The machine minimises use of cable hauling where the angle of the slope meant it would not be possible to lift logs above the ground.

The system also eliminates the need for intermediate tracks which would be required without the tethering system. This reduces soil disturbance, visual scarring of the hillside and the potential for soil erosion.

The development and manufacture of this machine is a large undertaking for a couple of small New Zealand companies, in terms of capital investment, ingenuity and sheer effort.

The ClimbMAX is not just a digger adapted for purpose.  New excavators are disassembled and constructed from the ground up.

Each machine is worth over $1 million.