Charcoal Burning

CHARCOAL, sb. ME. (the second element, COAL, orig. meant "charcoal"; the first element is obscure; see CHAR v. CHARK sb) 1. The black porous residue, consisting (when pure) wholly of carbon, obtained from partly burnt wood, bones, etc. Hence specified as wood, vegetable, etc. "The Shorter Oxford English Dictionary"People visiting our 1992 event at Brockhole in Cumbria during the week would have noticed mysterious activities (doubtless sinister) being carried out by members of Middleseaxe assisted by Saint Cuthbert's Land and a cast of thousands. The Regia reading list seems not to extend as far as Swallows and Amazons, so for those of you who were too frightened to ask (in case you got sent down "t'pit" by Dai) or who only witnessed the aftermath (the huge smoking crater) I present here a brief account of the gentle and ancient art of charcoal burning, as carried out in Regia's period of interest.Firstly, why make charcoal? The simple answer is that no other combustible substance generates the heat necessary for the forging of metals (by the definition above, 20th century coke is "coal charcoal"). The process basically consists of Burning - or literally charring - wood at a very slow, controlled rate so that the combustion is never allowed to complete and thus turn the raw materials to ash. This is achieved by controlling the amount of air involved in the reaction - basically, covering the whole caboose in earth. The process takes about 24 - 30 hours for 3 - 4 tons of wood (the amount we had available in the lakes) and produces, in ideal conditions, about a ton of charcoal.First we had to prepare the ground, by removing the turf from a circle some 9 feet across, and thoroughly mattocking up and sifting through the top several inches of soil for stones. If a stone held any moisture it could be prone to explode at the temperatures of the clamp, putting a fast - burning hole in the clamp itself, possibly in little Johnny Public's head, or worse, in the Farrs' nearby tent. And so we made our first jargon - worthy product: a pitstead.The next problem we encountered was the construction of a pile of wood that was self - supporting and would remain so when converted. Fortunately, help was at hand in the form of Mike Davies-Shiel, a local industrial archaeologist who provided us with the fruits of his research and expert advice throughout the whole project, having done exactly the same charcoal-burning process himself several times before. I know that he has provided Regia with an enormous amount of help in the past, and will hopefully be available in the future for similar projects.Having built our (large) pile of wood around a central stake and Motty peg (fnarr, fnarr), Mike told us that a "real" one would be about 5 times the size. The total denudation of Windermere didn't seem to be an option, however, so we stayed content and sent the bracken teams out to collect, and set about digging a big (grave - shaped) hole in a corner of the site.A day and a half of digging and riddling had produced several piles of authentic clayish undersoil (known as sammel and by various other names in areas where Regia membership is high). Thanks at this point are due to everyone who was prepared to (or was browbeaten into) change into 20th century kit (yeeeuch) in order to use the inauthentic modern spade and riddle.The bracken piled over the wood as a support, we began to form an airtight layer of sammel over the lot down to within 6 - 8 inches of the ground level. This leaves a gap, called the flipe, which allows only a small amount of air to enter the clamp.So we had a five - foot high circular pile of wood covered in bracken and earth, with a motty peg in the top. The motty peg was withdrawn (fnarr fnarr again) with the aid of a spear loaned by the armoury, and blazing coals from the forge dropped into the resulting hole. After a considerable amount of tender loving care from everyone who had been involved so far, a roaring fire was going inside, and the hole was packed with charcoal and sealed with turves, or capped off as we say in the trade.Windbreaks were set up in appropriate and propitious places as determined by lengthy and hazardously un-christian divinatory procedures (ie. wetting a finger and sticking it in the air) so as to stop the wind forcing the combustion to one side of the structure.About at this point Mike pointed out that we might have a slight problem with putting it out when done. The correct method, he told us, is to rake the entire top half of the clamp off, douse it with several hundred gallons of water, and cover the whole lot with more sammel to stop the burning in about 24 hours. This is then repeated for the bottom half.This presented us with some logistical difficulties, as we had (a) no more sammel and (b) no water. He then went on to inform us that if we didn't manage to put it out, we would have a ton of highly combustible material at about 700° C (ie. combusting) within 10 yards of Su Farr's tent, and only we knew that it wouldn't be belching out cyanide gas! This made us sweat a bit, but, undaunted, we procured a big steel tub from the Rangers and stockpiled all the turves we could lay our hands on.The next unforeseen complication was that a burning clamp has to be watched continually until it has finished. This is because the roast is driving all the water out of the wood to turn it into charcoal, and therefore the five foot high pile of wood turns into a two foot high mound of charcoal. With this settling process the delicately crafted, airtight seal of sammel is prone to crumble, and any slight crack will admit too much air, meaning that half the clamp burns to a crisp.So we were crest-fallen to have to stay up and drink beer all night, occasionally stumbling round the thing to make the cracks worse before they got better, and having great fun breathing the steam, shining a multi - beam torch through it and taking photos to make ourselves look like we were in Excalibur. Well, suffice it to say it really, really rained and the Middleseaxe lightweights couldn't hack it and having seen it safe to 5.30 am, we tried to catch forty winks. We came back to find our beloved steaming heap much the worse for wear. The rain had delivered a mortal blow, and its last wisps of steam were seen around eleven.Phase two: cooling the 700° C charcoal to a point where it wouldn't just burst into flames the minute it saw the light of day. We filled the Rangers' steel bin with water and played with the leaks for a couple of hours till they slowed down a bit. Cooling it down involved two people, one raking off a section of the baked sammel, and the other saying (or tipping) loads of water in before it was all sealed up again. This all proved not to be that crucial, since the rain had done much of our work for us, and we didn't need to seal it up for the next 24 hours as we had expected.The roast had been far from complete, and instead of the possible charcoal yield of one - third of the amount of wood put in, we had a lot of nicely dried out staves of wood, some of them called browns, having been charred at the ends, and a whole basketful of the first authentically produced charcoal Regia had made.Later that day we were actually visited by a fellow who currently burns charcoal for barbecues but in a dustbin - type thing. He said we had done very well, but what could we expect with our materials: a very small clamp, of mostly damp wood, and about half as much sammel as we should have had. And the rain of course.So we each grabbed a piece as a souvenir of our time as Brother charcoal burners, and then it was gone - spirited off to the forge. The smiths said it was quality stuff, and they liked the idea of working with authentically produced materials too. Nothing went to waste though, the wood was all dried out at a time when dry wood was getting to be like gold dust, and the part - charred browns were very well - received over on the cooking fires. Even the pitstead, which was now more like a mud-wrestling sumo arena, and therefore called in Cumbrian a scrow, was turned over to baking pottery, but that's another article.This charcoal clamp had taken shape over 5 days of the Windermere show. It had involved a lot of people who hadn't done anything on the living history exhibit before - and generated a great deal of public interest, even if they did start off by asking if it was the bread oven! So, are we allowed to denude northern England next year and build a proper one.......?Footnote: Anglo - Saxon word "col" often taken to mean "coal" (ie. mineral coal) actually meant charcoal - cf. "The Wen charm" - "scring pu alswa col on hearde" - "may you be consumed as charcoal on the fire". Mineral coal was called sea - coal, because it was found on beaches (washed up from exposed seams). Only the monks at Margam actually dug for it, from about 1054.