Mid Kent College/Lower Lines, Brompton

August 2007 [GO TO November 2007]

The Trust is carrying out a programme of archaeological works prior to the construction of the new Mid Kent College Campus located off Medway Road, Brompton. The site is immediately adjacent to the Lower Lines, which are an extension to the Great Lines built to defend Chatham Dockyard. The Great Lines were constructed from 1755 onwards with the Lower Lines added from 1803 onwards largely in response to the threat of invasion during the Napoleonic wars. The lines consist of brick-lined ramparts and ditches and are currently very overgrown with vegetation.

Advances in gunnery made the lines obsolete by the mid 1800s and they ceased to have a defensive role. The Royal Engineers used them as a training area for siege warfare. Mock battles were staged and these became major spectator events for the public. Charles Dickens records such an event in the Pickwick Papers.

The area was used for training in trench warfare during the Great War (it is hoped that some evidence for this will come to light during the project) and the area formed part of anti-invasion defences during the Second World War. Elements of this Second World War activity are still evident on the site and the present work by the Trust has exposed a portion of trench, complete with corrugated iron revetment utilising portions of railway line to reinforce it. The Royal Engineers continued to use the area for training, though no longer the spectacular events of past years. Prior to commencement of the redevelopment of the site there were remains of practice constructions of brickwork, cast concrete buildings etc. on part of the site.

The Trust will be maintaining a watching brief during the groundworks for the new college building and on the renovation of the Lower Lines. Apart from the obvious military remains, there is also the possibility of earlier archaeology being revealed during the works. The programme is at an early stage with the clearance of the site underway.

Mick Diack, Project Manager

November 2007

A unique nineteenth-century listening post has recently been uncovered during on-going groundworks. This structure consists of a brick tunnel leading to a domed chamber and appears to be contemporary with the Lower Lines and therefore of Napoleonic date. A sapper would have been stationed in the countermine chamber to listen out for enemy tunnelling if the Lines had ever been besieged.

One tactic of siege warfare is for an attacking force to dig a series of trenches gradually getting closer to the defences. The first trench would run parallel to the defences (the 1st parallel). Further trenches cut from this towards the defences were called approaches. The attackers would repeat the process cutting a 2nd parallel, more approaches and then a 3rd parallel. The parallels would be increasingly protected from fire by reinforced earth banks and the approaches would also be crenulated to prevent the defender’s fire from sweeping down the length of the trench. After cutting the 3rd parallel the attackers would be close enough to attempt to breach the defences. In order to do this, they would cut a tunnel under the defences and pack it with explosives. This was called a mine. When exploded the mine would breach the defences and the attackers could attempt to storm the breach.

Whilst this was taking place the defenders would be listening for any tunnelling and would cut tunnels of their own towards the attacker’s mines and set off explosive charges to collapse the tunnels. These defensive tunnels were called countermines.

Though the recently discovered listening post was originally part of the defences of the Lower Lines, it also appears to have been used for training purposes, as backfilled tunnels were seen extending from the three arches in the dome. These tunnels represent practice countermines. Similar backfilled tunnels have been recorded elsewhere on site indicating that the Royal Engineers had spent a great deal of time practicing the science of mine and countermine.

The domed brick listening post found on the Mid Kent College site is the only known surviving example in the country. Due its unique nature it has been decided to retain it for the future. The damaged portion of the brickwork, which was damaged at some point in the past and not by the site works, will be repaired and the structure will be preserved.

Canterbury Archaeological Trust would like to thank Mid Kent College for funding the archaeological programme, their agents AYH, the principal contractor Kier Build, English Heritage, Kent County Council and particularly the earthmoving contractor Pryor for their skill and professionalism during these groundworks.

Mick Diack, Project Manager