It is not common to have ground-based machines performing regeneration activities on steep slopes. However, in harvesting the practice has been adopted and applied across the world. Silvicultural activities have traditionally been conducted manually on steep terrain; however new solutions are being introduced to improve the terrain handling abilities of existing silvilcultural equipment. (see article on steep-terrain-solutions-for-mechanised-ground-based-silviculture-equipment). One of the effective solutions for steep slope regeneration is the use of Ecoforst’s T-winch.
T-winch 10.2 basic configuration and application?
The T-winch is a traction assist solution which is integrated to conventional equipment to prevent wheel slippage and associated ground damage when operating on steep slope wheel. Furthermore, the system contributes to the safe use of equipment on steep slopes. The T-winch comprises of a diesel engine that transmits the maximum torque and has a double pump unit with adjustable delivery volume. These two pumps power both the closed hydraulic cycle of the winch transmission as well as the open cycle of the additional auxiliary functions. Thus the crawler movement drive and the movement of the plate can be controlled synchronously, which leads to a maximum ease of use.
The process to get the system working comprises of three main steps:
(1) Position - With the help of the compact radio system T-WINCH can be moved
to any position in the chosen terrain
(2) Anchoring - A stable anchoring of the winch takes place through both the crawler movement and the attached plate, as well as the use of additionally fixed strutting belts. These attachment points ensure that the T-WINCH is able to transmit the maximum tractive force on the timber harvesting machine.
(3) Operating - Tractive force assistance is presented by the operator on the radio transmitter. For detailed technical data refer to the attached specifications.
How it works in forest regeneration operations?
Machines used to perform regeneration tasks like stump pulling, residue windrowing, soil preparation and planting can work effectively on steep slopes. For example, 20-ton excavators can be used with attachments such as subsoilers for soil preparation. If the slope is not greater than 100%, the T-Winch 10.2 can be used, however the excavator must also be modified with track pads for better traction on steep soils. For equipment like excavators, the T-WINCH also offers helpful support if the driving power of the crawler movement is not sufficient. The operator must take into account the prevailing slope conditions and the direction or counter-slope to avoid unnecessary risks and optimize the work for the day.
Source of pictures and videos: Gonzalo Maureira
When the winch assist system is combined with comprehensive planning, regeneration activities can be productive. In places like Chile, where an excavator-based machine is used on steep slopes for sub soiling, the operator can prepare between 2 to 2.5 hectares per day (in average working conditions). Being able to prepare the soil correctly on slopes generates benefits such as avoiding excessive soil compaction, mitigating erosion and helping improve planting efficiency when the next growing season begins. Being able to use mechanised equipment across different slopes in regeneration activities is advantageous especially when companies have limited manpower and have to replant large tracks of land in a relatively short period of time (e.g. after a fire).
Forsilvitech acknowledges: Mr Gaël Calmet for information supplied