Kent Underground Research Group
The Kent Underground Research group will have been in existence for 20 years this year. We are an affiliated society and were originally a group until the Charities Commission decided otherwise. We are interested in anything subterranean and this interest ranges from the distant past to the present day. If a hole appears in the county then we are prepared to go down it. We have the skills to get people and equipment up and down deep shafts and wells. This often includes air testing and sometimes this may involve pumping fresh air down to disperse high carbon dioxide levels. Although our members are well practiced in caving techniques for getting up and down we do have a powered winch, which has been tested and certified for carrying people. This does take the slog out of coming up a 300 foot well.
We have been working on an extensive iron mine exploration just over the border into Sussex. This has involved digging out two shafts. One of these is 40 feet deep and the other 35 feet deep. This excavation has enabled us to get into the old mine passages. Nearer home this winter and the high rainfall has resulted in a crop of deneholes, Victorian cesspits and soak-aways and several wells. We have even dug a tunnel into chalk. (It is surprisingly hard stuff). Over the years one of our members has designed security grills for many deneholes and icehouses so they can remain open as bat hibernation refuges and not become full of rubbish.
As mentioned, our members are experienced in the techniques of underground exploration and are covered by public liability insurance. A common problem is that subsidences occur in the most unexpected places and these are often the result of old mine workings which have collapsed. Perhaps the most frequent occurrences are:
a) The grubbing out of woods or field boundaries to make larger fields exposes old deneholes, which were commonly located in such features. Many of these deneholes were not infilled upon abandonment but merely capped with brick cones or blocked at the top with branches and a layer of soil. The vibration of agricultural machinery or irrigation can cause the shaft to open up.
b) Many old brickfields were converted into allotments or orchards on abandonment because they left a flat area of fertile soil. Any associated chalk workings are likely to subside eventually if they are not effectively capped. Many such holes were badly infilled with rubble and this settles over the years to leave a void, which will eventually collapse.
c) Old houses often had a well until the introduction of a mains water supply when the disused well was slabbed over. Where such a house is demolished and built upon, the presence of a well may be unsuspected and it may eventually open up.
d) New housing developments on the site of old brickfields or farming land may be built on top of old deneholes or chalk mines. Such features were not always shown on old maps and their existence unsuspected. The extra weight of high-density housing may eventually cause collapse of the mine workings under houses or in gardens.
We are mining historians - a unique blend of unlikely opposites. We are primarily archaeologists and carry out academic research into the history of the underground features and associated industries. To do this, however, we must be practical and thus have the expertise to carry out exploration and surveying of disused mines. Such places are often more dangerous than natural caverns but our members have many years experience of such exploration.
Unlike other mining areas, the South East has few readily available records of the mines. Such records as exist are often found in the most unlikely places and the tracing of archival sources is an ongoing operation. A record of mining sites is maintained and constantly updated as further sites are discovered. Members are encouraged to carry out research into the individual sites and this information is published in the Group's newsletters and publications.
Mining history is a relatively recent branch of archaeology and there is great scope for original research in the South East. We welcome new members who have an interest in mining history and are able to teach them the techniques of safe underground exploration. They are welcome to assist with ongoing projects and we can suggest many areas where they can carry out their own research. The unique feature of this interest is that there are many aspects and members can contribute just as much from surface recording and archival research as underground exploration. All are welcome, including those who merely have an interest in the subject and wish to receive the publications.
If you hear of any underground features please let us know of their whereabouts and we will investigate.
Mike Clinch, Secretary, Kent Underground Research Group.