Abstract An apparatus is described which will produce spontaneous heating in a 2 m length of as-mined subbituminous coal, with a moisture content of 18 wt%, without the introduction of any external heat. Preliminary successful results are described, and it is believed that this is the first time that such success has been achieved. Some details of the construction and operation of the apparatus are described. The experiment closely duplicates the full process of one-dimensional spontaneous heating of coal containing its as-mined moisture content. The preliminary results are in good agreement with the one-dimensional model described by Quan.