Harwich Redoubt was one of three redoubts built in the early 19th century to protect against the very real threat of invasion from Napoleon Bonaparte's forces that were massing along the French coast near Boulogne. The other two redoubts were at Dymchurch in Kent and Eastbourne in Sussex, and a 'string' of Martello Towers ran between the three fortifications.
A redoubt was usually circular in construction, sometimes temporary, occupying high ground, and was designed to be capable of sustaining a reasonably large garrison for a prolonged siege. Although forming part of the overall south east coast defences, Harwich Redoubt's primary function was to protect Harwich Harbour - strategically important between the River Humber and the River Thames.
Taking three years to complete, Harwich Redoubt was built by 1810 with the assistance of much labour provided by French prisoners of war. The site comprised a circular fort (200ft or 60.6m diameter) which could accommodate a garrison of up to 300 officers and men. This was surrounded by a 20ft (6m) deep dry moat, with access via a drawbridge that led through to a central parade area (some 80ft or 23.3m in diameter), containing a well at its centre. The main ring of buildings were constructed on two levels, with 18 casements (bomb proof rooms) on the lower level providing accommodation for the troops, as well as powder magazines and storage for provisions. The upper level contained 10 gun embrasures each housing a 24 pound cannon. These cannon were supplied by five hoists that drew ammunition up from four magazines on the level below.
Having slightly unusual names, the gun embrasures were believed to have been named by the gun crews themselves, using their own names or the places they came from. They are: Angel Gate, Nile Street, Hope Place, Cook Street, Box Street, King Street, Queen Street, Yeo Street, Tate Road and Bathside. The 18 casemates had purely functional names (kitchen, guardroom etc) but, since they no longer serve these purposes, they have been renamed by members of the Harwich Society and now represent notable people from the town.
In 1861-62 Harwich Redoubt was altered to facilitate 68 pound cannon and, in 1872, further changes were required to Cook, Box and King Street to take 12 ton rifle muzzle (RML) loading guns. Additional re-modelling work was carried out in 1903 to Box and King Street to accommodate 12 pound quick firing guns. However, a shot was never fired in anger from Harwich Redoubt and, in 1920, the now redundant site was sold to the Town Council for redevelopment with the surrounding land being used for housing. Harwich Redoubt itself was simply left to decay.
Subsequent military use occurred on a small scale during the Second World War, after which Harwich Redoubt passed to civil defence and was used for atomic exercises until no longer required. In 1968 the structure, now in a poor state of dereliction, was scheduled as an ancient monument.
With the formation of the Harwich Society in 1969 work soon started on clearing and consolidating the site, with the long term aim to fully restore and give access to the public. Major work ensued over the next 20 years, including the recovery of one of the 12 ton RML guns from the moat below Cook Street. Further research work from the University of East Anglia in 1972 established that the other two 12 ton RML guns were also very likely to be buried in moat. It appeared to be usual practice for these heavy guns to be tipped over the side of the embrasures when they became obsolete. This was found to be the case at Needles Old Battery on the Isle of Wight, where several of the original guns were recovered from the sea bed.
Harwich itself is lovely town and is blessed with some remarkable heritage. Access to all sites of interest is very easy, via the Harwich Maritime Heritage Trail and no visit to the town should exclude the Redoubt, which contains fine displays of guns and uniforms, as well as other military related exhibits.