Naarva - Model S23 - Stroke Harvesters
Naarva stroke harvesters are reliable and efficient harvester heads for first thinning. They have been designed especially for the cranes used in agricultural tractors and small excavators. S23 and S23C models are electricity free and very lightweight. S25 and S25R models have very high productivity with low operating costs.
- First thinning
- Making firewood
- Energy wood harvesting
- Integrated harvesting
Before now, getting a harvester head for agricultural tractor has been a tough decision. Lots of changes had to be done for the boom hydraulics, and an electric cable had to be drawn from harvester to the cabin. Not anymore.
To make it easy, Pentin Paja developed a stroke harvester that would be the as simple to use and install as possible. By cutting off everything extra, Naarva S23 weighs only 235 kg and uses only 4 hydraulic cylinders. The required lifting capacity of the boom is only 25 kNm. Switch between loading grapple and Naarva S23 is easy, connect two hoses and remove one pin.
Stroke harvester is operated with grapple open/close buttons. Close-button closes the grips and after a pressure limit is reached, the stroke feeding will start. After the stroke has reached its maximum position (50 cm), you can press grapple open-button and the stroke cylinder will reverse. This cycle will be repeated until the wanted length is reached. Then you can cut the tree by holding the close-button. When the stroke cylinder has reached its maximum position and a pressure limit is reached, the oil flow is guided to the cutting cylinder and tree is cut.
When delimbing head is not out and grips are open, S23 will stay upright because of center of gravity. When a tree is grabbed in upright position, S23 tries to start delimbing, but instead of delimbing the head is locked against the tilt body. When grip is released, delimbing head will unlock.This enables moving of small trees before delimbing.
S23 guillotine is designed with decades of experience. Guillotine is strong, reliable and easy to maintain. Cutting blade can be mounted with splitting wedges to make 25 -50 cm firewood directly after felling. Wedges are easy to mount and dismount with 3 bolts. Naarva firewood rack can be mounted to three-point linkage of a tractor to hold a firewood bag. Firewood can be made directly to firewood. This is the most straight forward firewood processor in the world.