Removing hold-over trees

Large harvester head an asset when removing hold-over trees

In a spruce forest in Vuodenkoski, hold-over birches are being cut down so that the remaining spruces will have more space to grow. Experienced forest machine operator Ilari Märkjärvi is weaving his way between the trees with a Logset 8H GT harvester from 2015. The harvester is equipped with a Logset TH75 harvester head. Märkjärvi picks up the cut off birches as if they were light weight candles and fells the birches carefully between the spruces.

- I’ve driven different forest machines for 20 years and I’ve operated harvesters for 13 years. This area is only two hectares, but the work will take me more than two days to finish. With this kind of job, there is no point in rushing. I usually work with clear fells, Märkjärvi says.

Forest owner Esko Vehmas stops by to see how things are proceeding. He says that 48 years ago the area consisted of fields on which he decided to plant birches. The spruces have grown there naturally.

- Ilari has a great responsibility. He makes the future forest. As today´s work is done with a big harvester, the remaining trees will not be damaged, Vehmas points out.

Being able to rely on the measuring accuracy

Märkjärvi is clearly a diligent operator who is conscientious about his work and takes good care of the harvester. He does the service on the machine himself, and according to him, it is easy to access the different parts. In August-September, Märkjärvi noticed that the measuring accuracy of the harvester head wasn´t on the usual level. The trees he cuts are sent to Koskitukki Oy, and the measuring accuracy must be over 90 %.

- The worst thing that can happen to a harvester operator is when he can’t rely on the measuring accuracy. I tried to adjust the measuring accuracy every day but couldn’t get it right. That’s when I called Juha Pukkala from technical support. We made some modifications and adjustments on the measuring wheel, and since then the harvester head has worked like a dream, with an accuracy of around 95 %, Märkjärvi says.

He has driven the Logset 8H GT harvester ever since his employer MKU Risto Kangassalo bought it new a few years ago. The TOC control system is so flexible that Märkjärvi could adjust it  to the habits and routines he had acquired while driving a harvester of another brand.