Skidding (forestry)

Skidding in forestry is the first operation after logging: it consists of transporting felled trees from the felling site to a temporary dumping site, known technically as a "loader", near a road or track suitable for further transport. This name is still applied to the first emptying of stones in quarries or stone heaps and possibly heavy equipment in mines, to heavy transport operations and cumbersome handling.

Ancient skidding method
In mining, quarrying, and forestry, skidding mainly concerned the usual transport of felled or cut material (wood, logs, stone) or extracted material (ores), sometimes cut to size (squared ashlar), to the road, track, river or top of the slope which, from the loader or loading point, enabled it to be transported onwards. The skidder is then either a worker or a contractor who, in a quarry or on a cut, carries out the skidding, often on behalf of the owner or purchasing merchant. In the rural and forestry world, the skidder is often an independent farmer who adapts his wagon and carriage to this type of activity in winter, on behalf of a timber merchant. The itinerant galvachers or bouviers-charretiers of the Morvan region, who rented the pulling power of their ox teams, practiced this trade among other rural services, migrating north and west.

Forest skidding
Forest skidding is based on a multitude of techniques, which are sometimes combined or added to in succession:


 * portage, by laying the trunk on rows of sticks held perpendicular (as in the ritual case of the mat de cocagne) or by the triqueballe;
 * throwing fir trees or limbed trees from the heights, formerly a very rare wild operation across the slopes on specific corridors, and more common on steeply-sloped sunken paths or partly-engineered downhill corridors, to reach the valley or river. The specific localities of this sometimes dangerous activity were called the lançoir(s), jet(s) or get(s). Most of the trunks or logs thrown or tossed were not destined for the sawmill, where they were sawn into boards. In the past, the squaring of timber was done with an axe;
 * dragging on the ground, possibly using draft animals (oxen, horses, buffalo, elephants) or motorized equipment;
 * dragging using adapted bards or sledges, such as schlittes, with use of the slope, installation of paths, and possible animal or motorized traction on the flat;
 * trailering using animal or motorized traction;
 * floating on the river or sea, with possible towing;
 * flotation or floating by means of a pipe (flumes);
 * cable logging;
 * aerial skidding using dirigible balloons (tested and studied several times, but not tested on a large scale), as the spans are small and the evolution results are catastrophic in changing winds;
 * aerial skidding by helicopter in the mountains (in France since 1975).

Skidding by dragging and hauling, then by water, was the most common method until the development of railroads. In the 20th century, this method was often replaced by mechanized skidding in forestry operations, which was sometimes considered to be responsible for considerable soil degradation (compaction affecting roots and the circulation of water and nutrients) and environmental damage (noise, pollution from engines, oils, etc., the need for a dense network of roads and tracks, destruction of country lanes and footpaths, etc.).

Today skidding by animals (horse, buffalo, elephant) is in line with ecological concerns in that it is more respectful of the soil and uses less fuel. Cable logging limit the impact on the soil, but at a slightly higher cost, except in difficult environments (mountain ranges not easily accessible to machines).

The specific case of horse skidding
The use of horses in forestry offers numerous advantages, such as soil protection, absence of pollution, and virtually silent operation. Horses can also be used to welcome the local population. The latter creates a social bond with the sponsors and the public, who are more fascinated by the strength of the horse than by the turbulence of forestry machinery. However, this working technique requires much more preparation and maintenance time (feeding, cleaning, trimming, etc.). What's more, a horse may also need medical care, which requires considerable outlay. Finally, the use of a horse results in a much more expensive hourly service (around €60/hour).

To work safely the horse must have undergone rigorous training to enable it to work in good conditions. Many service providers prefer to lead their horses with a rope called a "Cordeau", as opposed to long reins called "Guides", which require the use of both hands.

To pull logs the horse is fitted with a harness for forestry/agricultural work (made up of lines), a bridle, a pair of guides (or a rope), a collar on the chest and neck, and a spreader bar to hang the wood with a chain consisting of a choke hook at each end.

The use of draft horses is much sought-after by owners of wooded parkland, as without the presence of roads allowing access to forests for forestry machinery, the horse can also work in protected areas or areas with fragile soils and plant species (nature parks, Natura 2000 areas, peat bogs, marshy areas, etc.).

Horses, faster and more maneuverable, more nervous although sometimes more fragile than the placid and resistant oxen, were very soon appreciated for forest skidding. A powerful, well-trained horse could sometimes accomplish in half a day the task of a pair of oxen harnessed together in a day.

It reduces soil compaction and does not require the creation of new tracks or access roads. Contenting itself with passages less than a metre wide, the horse respects fragile soils and works without engine noise or pollution. The horse's performance varies according to the team, the size and shape of the trees to be pulled and the terrain, and it can pull an average maximum cube (in direct drag) of 1m3, 1.5 for two horses, with maximum efficiency at 0.5m3 for a single horse and 0.7m3 for three horses. Performance rises to 2.5m3 if a triqueballe or foretrain is used. This means an average daily dragged volume over 100 m of 18m3 (for an average cubic distance (DCM) of 0.25m3), 25 m³/day for a DCM of 0.5m3, and 18 m³/day for a DCM of 1m3. For a distance of 200 m, these figures fall to 12, 18 and 12 respectively. On easier terrain, the fardier (or trinqueballe; a horse-drawn machine with 2 braked wheels, a drawbar and a winch) enables 2 or 3 horses to lift and pull logs weighing up to 5,000 kg (3 to 4m3). The horse is slower on average, but more efficient for skidding on difficult soils, and less costly (24 euros per hour of service versus 32 euros for the farm tractor (taking into account the cost of purchase and use, wage costs and maintenance and travel costs (identical or close). The tractor remains more profitable for skidding outside the forest itself (on tracks). The horse is more expensive per m³ exported, but it is easier to exploit steep slopes (in the downhill direction), and this extra cost is sometimes entirely offset by the lack of need for infrastructure and by the benefits (wood sold at a much higher price) ofeco-labels such as FSC, which are more easily acquired with this type of skidding.

In the Belgian Ardennes (province of Luxembourg), around 90% of the first three clearings in coniferous woodlands are now harvested using horses, which can easily and profitably remove these light woods.

With motorized machines equipped with auxiliary motorized cranes, carts or sleds, daily production varies from simple to double (15 to 30 steres/day) depending on the difficulty of the site. The tractor also imposes compartmentalization, which results in a considerable loss of usable surface area and soil degradation, as well as a marked artificialization of forests.

Unlike the tractor, the horse is just as much at home in regular forests as in planted forests or protected areas (e.g. for grouse), where it is particularly appreciated. It is also appreciated in cases where the owner applies for an "ecological" forest management label or certification (FSC, for example). It is also effective in assisting the work of river wardens in removing log jams and macro-waste, and in restoring riparian forest.

Winter skidding
For a long time, harvesting in winter was the preferred option for a variety of reasons. Skidding to rivers was often done in winter on frozen ground. Floating was established in spring, when rivers were swollen withmeltwater, and in summer. This was true in Quebec in the early 20th century: around 1930, the first trucks appeared on building sites, and by 1950, lumber was being trucked on expanding road networks; floating was gradually abandoned; finally, all-season timber harvesting and transportation operations appeared in the decades that followed; winter harvesting and transportation activities remained, almost exclusively concentrated in areas such as thin, hydromorphic soils with low bearing capacity, etc. Timber harvesting in Quebec is now often carried out in summer, with autumn spent building winter roads, and transportation taking place when the structure is sufficiently frozen, at the end of November. Frost can multiply soil bearing capacity by a factor of 8 or 10.