Fort Luton Fort Luton was built between 1876 and 1892 south of Chatham , Medway , South East England . It is one of the five late Victorian land front forts built to defend the overland approaches to Chatham . It is the smallest of the Chatham forts and was built near to the village of Luton . Construction and Purpose . The fort was ordered under the auspices of the 1859 / 60 Royal Commission on the Defences of the United Kingdom , but it was deleted by Parliament in an attempt to save money and divert funds to the construction of the sea forts , and the Land Front Forts of Milford Haven , Plymouth , Cork and Portsmouth / Isle of Wight Fortresses . The 1869 ' Report on the Construction Condition and Costs of Fortification ' criticised the lack of landward protection for Chatham , yet it was not until 1872 that the Treasury relented and the land was purchased . Even so , it was not until 1876 that the order was given by the War Office , after approval by Parliament for construction to commence . The original design was by W . F . Jervois , but as by 1876 he had been promoted to major general he had no further part in its planning . The work was surveyed and " pegged out " on the ground that same year . In 1877 work on the building started , using convict labour and the light railway to bring up the materials from Borstal Creek jetty . The method adopted was to build all structures directly on to the land surface , and no form of preparation tunnelling was attempted . The work was slow due to lack of funds and the insistence of using convict labour , which meant that the labour force was constantly changing due to release or transfers to other prisons . In 1882 the work stopped for a re - think and once again restarted in 1886 when the decision was taken to delete from the plan one quarter of the design . This meant the loss of the Main Magazine ( which was to have been in the western corner ) and one quarter of this structure survived , much modified to become the above ground water tank . The well was also removed from the plan so the 4 inch water main had to be laid from Fort Horsted and the proposed under - bridge caponier was never even started . From 1886 to 1892 , when the fort was finally completed , the ditch was dug and the spoil was used to cover the exposed buildings , some of which had been standing for over ten years , and to form the ramparts , the six very basic gun emplacements , two to each flank and a pair overlooking Luton Valley . Even so no armament is on record as ever having been issued to Fort Luton other than that brought in by units participating in the Annual Militia and Volunteer camps . The final act of engineering was the installation of the drawbridge in 1892 which is a rare type of rolling bridge and possibly the only one still left in the UK Siege Trials . For the next thirteen years the fort was used for summer camps and , on alternate years , the Chatham Siege Trials . The final one in 1907 was the largest in both scope and number of men employed , and was in effect a rehearsal for a major war . Three breaches were made in the counterscarp wall and three " camoflets " were exploded in the moat bottom . The " defenders " dug a large counter - mine shaft outwards from the base of the moat . The breaches were repaired in 1908 by infilling with flint rubble , but the main counter - mine shaft was left . As a result of all this , in 1914 , the north scarp wall shifted slightly and had to be braced by a steel joist from off the top of the counterscarp wall . The damage to the moat and the subsequent repair are still visible . Layout of the Fort . The Fort consists of a D shaped rampart with prepared earthen gun positions for movable armament , two to each flank . The front parapet was prepared for infantry defence . Beneath the rampart are four ammunition stores with vertical lifts to handling rooms on the rampart above . To the rear of the main rampart at the gorge of the fort is a series of eight casemated barrack rooms serving as accommodation for the garrison , ammunition stores and general stores . All are constructed of concrete with an earth covering . At each end of the casemates is a tunnel to the ammunition stores . The casemates formed a longitudinal parados protecting the ramparts from reverse fire . The main entrance to the fort was over the rolling bridge at the centre of the casmemates . The ditch surrounding the fort was intended to be dry . The ditch . The ditch is lined with concrete on both the scarp and counterscarp faces . It has on both faces a slight batter of three degrees from the vertical . The depth varies from 25 ft . to 30 ft . maximum and the width at the base also varies , being wider on the rear ( long north east to south west ) face and at its narrowest on the southern and northern flanks . It is 15 ft . wide . There are no caponiers or counterscarp galleries in the ditch , the only known major British Defence work to adopt a purely passive defence posture . There is much evidence of the 1907 siege works in this ditch , three of the counter - mine shafts still survive , now mostly covered up with debris and rubbish ( post 1962 ) . Near the RSJ which spans the moat are seen five massive cracks and more repair work , again from the siege trials of 1907 , but this time , the hole in the base of the ditch was not dug by the defenders but was the result of a failed " camoflet " or " petard " . Accounts vary as to the title of the device used , but it was a type of tunnel driven from the attacker ' s side along the length of the moat to here and exploded . The first left the now mostly back - filled crater but at the second attempt blew a section of the wall outwards causing the damage still to be seen . After the sale of Fort Luton to Kent County Council the ditch fell into rapid disuse and became an illegal dump for all manner of refuse . A great pile of debris has been allowed to build up beneath and to either side of the drawbridge and beneath the RSJ . The disuse of the ditch has also caused much growth of vegetation . The Fort in Use . From 1914 to 1919 the fort was used as a Transit Barracks for troops en route to Europe . From 1920 till 1933 it was used as a store . In 1938 conversion of the fort to a Gun Operations Room ( GOR ) began . In August 1939 it opened as GOR for the 27th . AA Brigade ( Thames and Medway South ) Gun Defended Area . Brigadier C . W . Bayne - Jardin D . S . C . M . C . was in command until relieved circa 1942 , after which other officers of the same rank continued in command until December 1945 . From 1945 / 6 to 1961 the fort was used by Army Cadet Force and T . A . Summer camps . In 1961 or 1962 it was sold to Kent County Council ( D100 procedure ) for educational uses , but the KCC just wanted the land to build the nearby Fort Luton Boys Secondary School , and the fort was abandoned . In 1990 it was bought by a private individual who ran the site as a model museum and visitor attraction with tea shop . In 2001 the fort closed and has since been left to decay . The fort has statutory Scheduled Monument status .