Tyres for forestry equipment is something of an unknown area. Earthmover vehicles in forest location presents some of the same challenges that using earthmover vehicles in quarrying, dock side and in agriculture have, but it also presents its own challenges.
Putting aside safety and efficiency respect for the environment and the need to minimise damage is a big issue, especially on soft ground. And this is not just when timber is being felled, timber wagons make repeated journeys into the forests for a variety of reasons, including maintenance, planting and transportation of logs.
Factors include how heavy the vehicles used are and this is influenced by number of wheels, tyre pressure, tyre dimensions, tyre tread and traction aids that increase the area through which the weight of the machine is transferred to the ground. A large contact area with the ground area produces less surface pressure and means vehicles have less chance of sinking even in soft soil and as important has less effect of the forest floor.
This also gives stability and improved manoeuvrability on soft ground, steep slopes and rough rocky tracks. Vehicles also needs stability in order to climb in rough terrain. Using the correct tyres increases machine stability, improves flotation and protects tyres, extending their usage. As with all earthmover tyres, tyres for forestry equipment must be used at the appropriate pressure, as stated by the manufacturer.
Interestingly demand for forestry tyres is increasing around the world and in the UK, including Scotland and large areas of the north. Vehicles need to safely access difficult sites, slopes and in the winter through snow and ice producing more challenges.
Manufacturers produce track types in a range of models to suit different tyre specifications and operating conditions. Wider-spaced tracks with narrower plates are better suited to harder ground conditions and steeper slopes, offering greater climbing ability. Closely spaced tracks with wide plates are better suited to soft ground conditions. Tracks with closely spaced plates are not suited for use in heavy snow or some types of heavy mud.