Alpine Logging has been supplying innovative solutions for steep terrain harvesting to the local market for the past ten years. Many first-time buyers of an Alpine Shovel Yarder have purchased a second yarder, proving the confidence that local loggers have in Alpine equipment.

by Peter Alpass

High power double drum shovel yarder with extended tower.	The excavator, fitted with a timber grab, was used to clear the chute in front of the high production shovel yarder.

Alpine Logging recently returned from Asia, where they successfully installed a variety of logging equipment onto three excavators, on site. They also provided a training crew to firstly run all the equipment, and then train the local crews over a three-month period.

A high-power double drum shovel yarder kit, with an extended tower that is capable of running a variety of yarding systems from a simple highlead to a semi-live shotgun skyline system, was fitted to the first excavator.

The machines were put to work in Acacia mangium plantations, with an average tree size of 0.25 to 0.4 cubic metres. The company that purchased the equipment is progressive thinking. In order to maximise cable yarding productivity, they went to the initial expense of supplying an excavator as a mobile tailhold, and pre-bunching timber on pre-planned extraction routes, with a second excavator kitted out by Alpine Logging.

The mobile tailhold meant that whatever yarding system was used, whether highlead or skyline, rack changes were done extremely quickly by simply slackening the lines, walking the mobile tailhold to the new rack, and then re-tightening the lines.

The pre-bunching excavator had an Alpine single drum winch unit, and a locally manufactured timber grab fitted, together with all the necessary hydraulic valves and controls. This conversion turned the excavator into a highly versatile unit that was capable of extracting timber from short, steep slopes and waterlogged gullies, and pre-bunching the tree lengths under the pre-planned racks, to be extracted by the high production double drum shovel yarder.

The single drum unit was also used as a very cost-effective extraction unit on its own, on shorter steep slopes of up to 100 metres, near roads, where the timber could be pulled directly to roadside, picked up and heeled onto the road. The same unit was also capable of sorting and stacking log lengths on roadside after merchandising, and loading out timber trucks.

A third excavator, kitted out with only a timber grab, was used to clear the chute from the Alpine Shovel Yarder, where very steep slopes made it impossible to 'cold deck timber'.

In South Africa, a three-wheeled loader would usually be used to do this, but conditions were just too wet to allow the use of conventional wheeled vehicles. The same excavator was also used for loading timber trucks, after the tree lengths were merchandised mechanically on landings or roadside, with an excavator fitted with a harvester head.

Pre-bunching the timber under the extraction lines meant that no lateral yarding or lateral slack pulling was done at all, which really speeded up overall cycle times. Where the 'semi-live' skyline system was applied, the skyline cable was lowered 'on the go', to land the chokers directly on top of the load to be choked. This completely eliminated all slack pulling, which was a big bonus for the chokermen in the extreme heat of the tropics.

The semi–live system also allowed the carriage and load to be lowered 'on the go' as it approached the landing by lowering the skyline cable. This made for very fast de-choke cycle times and eliminated the need for a top hook to hold the carriage while de-choking.

Alpine Logging also supplied a range of carriages and rigging to compliment the yarders. A 'highlead carriage' was supplied for the highlead areas, and a fallblock and radio-controlled clamping carriage were used in the skyline areas. The Alpine skyline carriages all pass over intermediate support jacks really smoothly, making multi-span skylining a dream.

Since the local market has been pretty much saturated with Alpine Shovel Yarders, and their first export deal has gone down well for all concerned, Alpine Logging is looking out for more export opportunities.

Published in October 2010