The most frequent form of forest exploitation in the past was charcoal burning. Furnaces and forges, iron foundries and coke ovens needed for working abundant energy supply provided by charcoal. Only a few centuries ago on the Poljuka plateau beech wood was prevalent, but was modified heavily due to charcoal making. In the 'golden' age of iron foundry there were more than 1,500 pile places in the Zgornjesavska valley, on Mežaklja, Pokljuka and Jelovica plateaus. Nowadays, this kind of extraction is only a memory of once well developed trade.
WOODTYPES
Charcoal was made from deciduous as well as coniferous trees. Beech wood was used most frequently, but sometimes also maple, ash, pear, elm, lime or pine wood was used.
PREPARING THE WOOD
The wood was cut into logs from 1 m to 1.5 m in length. Beech wood was cut and chopped from autumn until spring and dried for 2 to 3 months.
PREPARING THE PILE
The area, in which the pile was to be constructed, was called the pile place. The pile was constructed in the woods where the delivery of firewood and the removal of charcoal was easy. The most suitable area was an open clearing with a water spring. The area was cleared and leveled with 50 cm of soil. The hearth was slightly raised in the middle to provide drainage.
BUILDING AND COVERING THE PILE
The size of piles varied according to the amount of firewood put into a pile, number of stacks and ground diameter of a pile. Thus, the smallest piles were built from only one stack, had 10 perimeters wood and 5 m ground diameter. The largest piles consisted of 80 perimeters wood, they were built from 3 stacks and the diameter was larger than 8 m.
STRUCTURE OF THE PILE
1. center pole
Charcoal burners started to set up the pile in the middle. With the help of four wooden stakes they formed a rectangular central stake.
2. floor
Radially from the central pole, logs were put on the floor, and a layer of firewood was placed across the logs to get more levelled and densely covered floor.
3. stacks
Around the central stake the charcoal burner set thin firewood upright and closely together. This inner part of the stack was called the nest and it measured around 2 m in diameter. Around the central part larger firewood was put. The material was thinner towards the periphery and the thinnest logs were arranged at the outer edge of the stack. From the central stake outwards the pile was constructed in such a way that logs were mutually supported. Usually, together with the first stack the second one was also being made. Most frequently the pile was constructed on two stacks, but never more than three here at our place. The surface between two stacks was called a joint.
4. head
The head was placed on the upper stack. Short and thin wood was used for it. The firewood was arranged in the direction of the center pole closely together and gave the pile an appropriate circular closing.
After the construction, the pile was usually measured. Depending on the size of the pile, two charcoal burners construsted the pile in about ten days.
COVERING THE PILE
First of all, the charcoal burner covered the pile with fir tree branches, ferns, juniper, grass or leaves. This layer prevented the 7-12 cm of soil that was put on top of the pile from penetrating into it. Air supply and leading away of smoke was regulated with small air vents in the layer of soil. The pile was loaded with heavy logs to hold back the soil.
LIGHTING AND HEATING THE PILE
The pile was lighted through the center pole. At the bottom of the center pole, called hearth, they lighted the pile with a burning torch thrown at the center pole, and then filled it with dry branches. From there, the fire spread towards the head of the pile Where the burning had begun. Collier bored 4 to 6 holes at the foot of the pile through which air was supplied. When the fire began to rise from the center pole the pile was closed also on top and so carbonization or burning of charcoal began.
Lighting the pile
BURNING
For carbonization the temperature of 240 to 280 degrees Celsius was needed. The burning was regulated with numerous air vents at the foot of the pile. The charcoal burner also walked on the pile. When walking around the center pole, the crackling indicated that charcoal in that area was already burned. He released the smoke through the smoke shaft at the head of the pile. The colour of the smoke served as an indicator of when the charcoal was burned. The quality of charcoal depended on the skill and experience of the charcoal burner as well as the speed of burning. The time of burning depended on the type and quality, dryness and the way of arranging the wood, weather conditions and attention of the charcoal burner. When smoke from the lower part of the pile disappeared and a blue flame appeared instead, the pile was burned and all air vents were closed.
CLEANING, COOLING AND LEVELLING
The cleaning was done in dry weather. The collier gathered the layer of soil from the pile, cleaned, cooled and then replaced it back to the pile. This was done line by line until entire pile was cleaned. The pile was levelled in two ways. They began at the side or at the top. Firstly, the soil was removed in straps, then the pile was opened and pieces of charcoal were raked out. These needed to be cleaned of soil. When a certain amount of charcoal was collected and ready to be taken away, the opening in the pile was re-covered with soil in order to prevent the rain from wetting the charcoal. Usually, it took three days for the pile to cool down, then the levelling followed and the loading of charcoal around the pile. The pile was levelled in lines. The charcoal was still red-hot while levelling and could easily be set on fire so there was water for extinguishing nearby. If there was no water, they used soil. The charcoal was spread out for a day or two to cool down completely. When levelling was finished, the charcoal burner cleared the place around the pile, mixed the soil and strewed it around for the next pile.
WELL CARBONIZED CHARCOAL
Well burned charcoal had a shiny, black colour, and sharp edges with clearly noticeable wood structure at the break. The weight of charcoal depended on type and quality of wood, way of burning, degree of humidity and air temperature. If the burning was successful, the colliers acquired around 100 kg of charcoal. The quality of charcoal was valued by a blacksmith. If it was well burned, he would remain his costumer.
DWELLING OF CHARCOAL BURNERS
By the pile place, there was also a dwelling cottage, a temporary residence of the charcoal burners. They could also dwell in triangular huts made of bark suitable only for sleeping. Usually, it was a makeshift dwelling, set up by a pile place that was removed from the charcoal burners' cottages. It was used when they kept watch on the pile.
