The «Ren­dez-vous» meet­ing point is the name of the place where the 5 ways lead­ing to Sen­ninger­berg, Find­el, Kirch­berg, Wald­haff and Boeschhaus come togeth­er in the mid­dle of the Grünewald. At times when cross­ing the Grünewald still was a dan­ger­ous adven­ture, loca­tions like this had always been meet­ing points or impor­tant marks.

Not far from this meet­ing point the for­est rangers did con­struct a char­coal wood­pile for exhi­bi­tion purposes.

The trade of the col­lier is a very old craft, going back to the Iron Age (1000 ‑500 a.Chr.) and con­sist­ed in trans­form­ing the wood into char­coal. Already at these times the iron ore or oth­er pre­cious met­als were melt­ed with the help of charcoal.

In fact the char­coal has the prop­er­ty to burn with a much high­er tem­per­a­ture than the wood and also its weight and vol­ume is less impor­tant, facil­i­tat­ing the trans­port and storing.

Until the 19th cen­tu­ry char­coal had a very high indus­tri­al val­ue in the sec­tor of the iron ore pro­cess­ing, ask­ing for huge needs of wood vol­umes. Entire forests had been lum­bered for this pur­pose. In the Grünewald numer­ous char­coal wood­piles were active, in order to feed the blast fur­naces in Dom­meldage and Eich for exam­ple. It is only with the dis­cov­ery of the min­er­al coal that the use of char­coal slow­ly dimin­ished and had been replaced by the coke.

The collier’s charcoal wood pile

Rep­re­sen­ta­tion of the dif­fer­ent steps of the char­coal process.

The collier’s char­coal wood pile was erect­ed imme­di­ate­ly on the ground and with pref­er­ence near to the waters (in case a fire had to be extin­guished. First of all the col­lier had to dig a pit in which sev­er­al wood poles were plant­ed. Then 1m long logs were piled around this shaft in sev­er­al lay­ers in form of a cone. The wood pile had than been cov­ered a roof of dry leaf, hay or straw and than her­met­i­cal­ly closed by a thick lay­er of soil, grass and moss. Then the col­lier threw some hot embers into the shaft in order to light a fire going up to a tem­per­a­ture of around 300°C to 350°C, engen­der­ing the char­coal­ing process. The job of the col­lier con­sist­ed then in watch­ing this fire for the next 6 to 8 days (or weeks if it was a very large wood pile) all by reg­u­lat­ing the incom­ing winds to avoid that the fire went out or became to impor­tant. This could be done by per­fo­rat­ing the pile with small holes that could be closed or opened accord­ing to require­ments. The char­coal­ing process hap­pened only under oxy­gen defi­cien­cy and with this method of open­ing and clos­ing the lit­tle wind holes in the pile near­ly 90% of the car­bon could be pre­served. Final­ly by clos­ing all holes in the pile’s roof, the fire went out and the pile had to coo down. Then the char­coal could be tak­en out. 100 kg of wood gave approx­i­mate­ly 25 kg of charcoal.

From the Mid­dle Ages until mod­ern times peo­ple were very afraid to find ghosts, brig­ands or thieves or eremites behind every tree in a dark for­est. For this rea­son cross­ing the Grünewald to go to Lux­em­bourg City at these times had always been a very fright­ful and dan­ger­ous jour­ney for the locals. Nowa­days the for­est has mutat­ed to a site of leisure and plea­sure, to a pre­cious habi­tat for fau­na and flora.