William H Clements
Introduction.
The Martello towers built to defend the Kent coast against a French invasion between 1805 and 1808 are a familiar sight to visitors to the south coast around Folkestone, Shorncliffe and Dymchurch. That there are three other Martello towers in Kent, not so old but nevertheless Martello towers, is not so well known. These towers were built between 1850 and 1915 as part of the Medway defences at Sheerness and all three still stand today.
Spit of Grain Tower
The oldest of the three towers is the Spit of Grain tower constructed just off the shore opposite Garrison Point fort at Sheerness. In 1825, a committee of naval and army officers had considered the defences of the Thames and Medway arsenals and believing the entrance to the Medway to be poorly defended recommended the construction of a redoubt on the Isle of Grain to prevent an enemy force from occupying it and a tower at Yantlet Creek. Little was done to implement those recommendations until the 1840s when a newly emergent France began to make its mark as a major force in European politics. Together with the rise of France came technological advances in warship and gun design. Steam power and the use of cast iron armour revolutionised naval warfare together with the introduction of the new shell gun.
The British public was only too eager to believe the worst of the French and fears of a resurgent French army and navy equipped with the latest guns and ships were fanned by articles in the press, while senior military officers presented pessimistic papers on the subject to the government. The result was a panic in 1847-48 which, in turn, led to a review of the defences of the naval ports and a considerable increase in defence spending. All this was sufficient to ensure that in 1848 authority was given for work to start on the proposed Medway tower. The site originally chosen at Yantlet Creek was deemed unsuitable and the Board of Ordnance instructed the commanding engineer at Sheerness to proceed with piling work for the foundations of the tower in a new location opposite the dockyard. [1]
The Board of Ordnance works had been pre-empted in 1847 by work carried out by Captain Bullock RN. The Admiralty, also worried about the defences of Sheerness dockyard, had permitted initial work to go ahead following a proposal by Captain Bullock to construct a battery on stilts for five 32-pdr SB guns. Nine hollow cast-iron pipes each 12 inches (30 centimetres) in diameter were sunk to what was described in a Board of Ordnance letter as 'some indefinite depth' just off the Isle of Grain. The pipes were sunk by means of an 'air exhausting pump' and when completed the battery was to stand 8 feet (2.46 metres) above the high water level and 26 feet (8 metres) above low water. [2] The Admiralty having funded the initial work of putting in place the nine pipes then turned to the Board of Ordnance for their view of the practicality of such a battery. The Board gave the matter short shrift pointing out the inherent vulnerability of the pipes on which it stood to fire from enemy warships.
In 1848, the Board of Ordnance decided to go ahead with the construction of their own tower at Sheerness. The problem of how to provide a foundation for a standard pattern Martello tower in shallow water where the ground was actually shifting sand was solved in an ingenious manner. Two hundred and fifty timber piles each 13 inches (32.6 centimetres) square and 30 feet (9.2 metres) long spaced 3 feet 6 inches (1.06 metres) apart were sunk on the site. These supported a timber grillage of 12 foot (3.6 metres) by 6 foot (1.8 metres) scantling all set in a 3 foot (0.9 metre) layer of concrete and finished with a 6 inch (15 centimetres) stone paving on which the structure was to stand. [3] The work on the foundation of the tower cost £4,232 19s 10 3/4d, but the completion of this work coincided with the return of more normal relations between Britain and France when Louis Philippe was deposed in the revolution of 1848. The Board of Ordnance, despite having spent this considerable sum of money on the initial work on the tower, now believed there was little immediate urgency in completing it and the foundations were left to deteriorate. It required a further panic about a possible French invasion in 1851 -52 to restart the construction.
The tower took three years to complete and was finally finished in 1855, once again after the latest anti-French panic had subsided. The tower was oval in shape, constructed of masonry and was 71 feet (21.84 metres) by 63 feet (19.3 metres) in diameter with a height of 42 feet (12.92 metres). The average thickness of masonry was 12 feet (3.69 metres), and the interior wall of the basement and the first floor was lined with brick. [4] Unusually for an English Martello tower there were four embrasures at first floor level for the armament which eventually comprised one 56-pdr SB 97-cwt and two 32-pdr SB 56-cwt guns. When the tower was first built no armament was mounted and the final cost of construction came to £16,798.
The Spit of Grain Tower in 1856 (The London Journal)
In 1859, four years after the tower was completed, yet another panic concerning French naval and military capabilities and intentions swept the country. The construction of the iron-clad battleship Gloire by the French temporarily gave them a technological lead over the Royal Navy. The hysterical reaction of the British newspapers and, through them, the British public forced the government to set up a Royal Commission. The commission was 'to report on the Defences of the United Kingdom and to examine the plans of the works now in progress at Portsmouth, Plymouth, Portland, Pembroke, Dover, Chatham and the Medway'. The commission concluded that the Royal Navy was no longer able to guarantee the security of the country against invasion, not even when supported by the Army. The commission recommended vast expenditure on the construction of permanent fortifications to defend the dockyards and strategic harbours.
Amongst the recommendations made by the commission was one that a casemated battery should be built to enclose the tower on the Spit of Grain. A similar recommendation was made for the Stack Rock tower in Milford Haven. However, the enormous cost of the commission's recommendations caused the government, at the urging of the Chancellor of the Exchequer, to reconsider some of the proposed works and the plan to change the Spit of Grain tower into a large casemated battery was dropped.
The tower was completed just as a revolution in artillery, brought about by the introduction of rifled guns, made all masonry forts and towers obsolete. The tower remained armed but gradually ceased to be an important part of the Medway defences. From 1892 until the abolition of submarine mining in 1904, the tower was used as a submarine mining station with a test room on the barrack floor and two observing stations on the roof. [5] In 1895, the RA and RE Works Committee completed a report on the substitution of breech-loading and quick-firing guns for heavy and medium RML guns on sea fronts. The proposed and approved armament for the tower was to be two 12-pdr QF guns and one machine gun. The role of these guns was to deal with hostile torpedo boats, submarines and what were described as 'boom-smashers and blockers'. The report showed that in 1895 the tower had been disarmed.[6]
No action was taken on this proposal although, in 1909, two of the 12-pdr QF guns on top of Garrison Point fort immediately opposite were earmarked for transfer to the Spit of Grain tower. This transfer was authorised by the newly established Home Ports Defence Committee, a sub-committee of the Committee of Imperial Defence, in response to a request from the Naval C-in-C Chatham. [7] However, advances in the speed and size of modern torpedo boats and torpedo boat destroyers caused doubts to be expressed as to the effectiveness of the 12-pdr QF gun in engaging such targets. The new 4.7-inch QF gun was considered to be a more effective weapon to engage such targets with a shell weighing 45-lbs (20-kgs) and a maximum range of 16,500 yards (15,250 metres) and, in 1910, the proposed armament for the tower was changed to two 4.7-inch QF guns.
The following year emplacements for the two new guns were built on top of the tower, with shelters for the gun crews and officers below. This involved building concrete gun platforms above the level of the old parapet and these were faced with granite blocks to match the original wall. The old barrack floor was remodelled to provide additional accommodation, a shell store and a cartridge store. The basement level, where the old magazine was located, was described in a plan of 1914 as being 'very wet' and appears to have been left unused.[8]. The conversion of the tower took fifteen months from 8 December 1910 and was completed on 6 March 1912. The total cost of the work was £1,795 and the new garrison was one officer and thirty ORs. [9]
Section showing the Spit of Grain Tower as converted in 1911-12 to mount two 4.7-inch QF guns. (PRO WO 78/5121 [4]).
In 1914, at the outbreak of war with Germany, the Admiralty decided to move the Medway boom defence from between Hook's Flat and Burntwick Island to the mouth of the Medway between Grain and Sheerness. The base of the Spit of Grain tower was used to secure the northern end of the floating boom and remnants of the chain securing the boom to the tower can still be seen around the tower today.
The guns installed in the tower in 1912 were two 4.7-inch QF Mks IV and IV* on Mk I central pivot mountings. A single 4 foot 6 inch (1.38 metre) Barr and Stroud range-finder was also fitted. Some time later a single .303-inch Lewis machine gun on an anti-aircraft mounting was also installed. Although the primary role of the 4.7-inch QF guns was anti-shipping, they had a secondary role as an integral part of the defence of the Chatham Land Front. The battery now became officially known as Martello Battery.
At the end of the First World War, the tower remained on a care and maintenance basis until 1929 when the 4.7-inch guns were removed and sold for scrap and the Martello tower was no longer included in the Sheerness defence plan. The tower remained unarmed for the next ten years and it was only the outbreak of the Second World War, in 1939, that caused it to be rearmed. Then two Hotchkiss 40-mm (2-pdr) QF guns were installed and these remained until September 1940 when a German invasion suddenly appeared imminent. [10]
The Spit of Grain Tower showing the gun pit and holdfast for Twin 6-pdr QF guns (Author's photograph)
An additional threat developed in 1940 when coastal convoys came under attack from German E-Boats. If these fast and very manoeuvrable MTBs were to be engaged effectively by shore batteries then a gun with a very high rate of fire was required. This requirement was met by the new 6-pdr QF gun which was usually installed as a twin mounting. The two guns were protected by a lightly armoured gun house and the pedestal stood in a pit. Behind the gun emplacement was a tall tower with two observations posts one above the other which directed the fire of the guns and the searchlights. The height of the tower was important because of the amount of smoke generated by the rate of fire of the two guns which, for the Mk I, was seventy-two rounds per minute. Ammunition was moved to the gun from the magazine by means of a shell hoist.
The old tower was radically altered to accommodate the new armament. The top third of the wall at the rear was removed to enable the four storey observation and control tower to be built together with the gun-pit and rear blast wall. By 1940, the old tower was no longer considered suitable for the accommodation of the battery personnel and so a two storey brick accommodation block on 20 foot (6.15 metres) high concrete piles was built alongside the tower.
The Spit of Grain Tower in 1966 showing the control tower and OP for the twin 6-pdr QF guns, the Second World War accommodation block and, around the base, the chin which secured the Medway boom defence. (Author's photograph)
In 1946, the tower ceased to be manned and was finally abandoned in 1956 when coast defence units were disbanded. It still stands today derelict and deteriorating.
Centre Bastion Battery
Centre Bastion Battery was originally constructed as part of De Gomme's fortification of Sheerness in the 1670s. Sited only a few hundred yards from Garrison Point Fort, the bastion was fronted by a wet ditch and faced across the Medway to the Isle of Grain. In 1828, the bastion was replanned for armament firing en-barbette and, by 1895, the old smooth-bore guns had been replaced by two 10-inch BL guns and two 7-inch RBL guns and these remained the armament until 1905. [11] In that year the Committee on Armament of the Home Ports recommended the removal of the existing armament and the substitution of two 12-pdr QF guns. [12] This was the armament in 1911.
The proposal to replace the two 12-pdr QF guns with two 4.7-inch QF guns is difficult to date. The decision was probably taken early in 1915 when England was in the midst of an invasion scare. The First World War had been in progress for over four months when German battlecruisers raided Scarborough and Hartlepool on 16 December 1914 and the official view was that if the Germans could raid the east coast with relative impunity then they could land troops as well. Before the war the Thames and Medway Defence Plan had been prepared to combat an enemy landing and, by early 1915, the Chatham Land Front had been set up combining field defences and a co-ordinated artillery fire plan.
Although it is only conjecture it seems probable that at this time the decision was taken to strengthen the armament of Centre Bastion by removing the 12-pdrs and replacing them with the heavier 4.7-inch guns. These two new guns firing in conjunction with the Martello Battery on the Spit of Grain tower effectively defended the boom defence between Grain and Sheerness and could deal with enemy torpedo boats which might manage to evade the fire of the heavier guns mounted on Garrison Point Fort, the Ravelin Battery and Grain Fort.
Plan of Centre Bastion Battery in 1919. (PRO WO 192/46)
To provide the most effective arc of fire it was decided to mount the 4.7-inch guns on towers thus raising them to the level of the two guns of the Martello Battery opposite. It would seem that the engineer in charge of construction could think of no better model for the new towers than that of the original Martello towers and the Spit of Grain tower. The result was two concrete towers built to the standard south coast pattern mounting one gun on each.
Each tower was 32 feet (9.8 metres) in diameter at the top and slightly larger at the bottom giving the traditional batter to the wall. The wall itself was only 18 inches (45 centimetres) thick and there was no accommodation or magazine provided in the lower levels of the towers. The towers were of unequal height because of their location. One tower, furthest from Garrison Point Fort, was built on the terreplein of the bastion itself while the other was sited slightly to the rear of the bastion on ground about 12 feet (3.6 metres) below the level of the terreplein. The left hand tower, nearest the fort, was approximately 35 feet (10.76 metres) high, while the right hand tower was only 20 feet (6.15 metres) high.
Centre Bastion Battery in 1915. (RE Library, Chatham)
The 4.7-inch QF gun was mounted on top of each tower and built into the raised rear parapet were three cartridge recesses and one shell recess all 3 feet 6 inches (1.07 metres) by 4 feet (1.2 metres) by 3 feet (0.92 metres) high. Each cartridge recess held thirty six cartridges, while the shell recess was slightly larger and held forty eight shells. There was a sitting shelter under the gun platform for the gun crew. The main magazines, shell store and troop rest area were all located under the terreplein of Centre Bastion between the two towers. These were the old magazines for the earlier smooth-bore and rifled muzzle-loading guns which had formerly comprised the main armament of the bastion. [13]
No 1 Gun Tower, Centre Bastion Battery in 1999 showing Second World War OP on top (author's photograph)
No 2 Gun Tower, Centre Bastion Battery in 1999 with the Second World War Observation Minefield Control Tower Type 'E' on top (author's photograph)
Section of Observation Minefield Control Tower - Type 'E'. (PRO Adm 189/127)
Between the two towers and sited at the same level as the left hand gun tower was a third tower. This was the battery command post which was square in shape with a domestic-style hipped roof and chimney stack with three chimney pots, all helping to disguise its military role. The command post was approximately 45 feet (13.8 metres) high with two doors and two windows at the first floor level at the front of the building.
Access was by means of a raised walkway linking all three towers at a level with the third floor of the command post and parapet level of the two gun towers and an iron staircase led up from ground level to the walkway in front of the command post. An 8-cwt davit was mounted on the walkway close to the command post and there were two further davits mounted, one on each tower. Additional access was provided by iron ladders secured to the wall of each gun tower rising to a door just below the level of the gun platform while the command post had an internal spiral staircase. All three towers were painted with a disruptive camouflage pattern and on the bastion terreplein there was a concrete pillbox in front of the command post tower.
In 1919, the Artillery Chain of Command showed that two 4.7-inch QF Mk IV* were mounted on Mk III mountings. There was a Depression Range Finder Mk II* and the guns were to be fought by night only. [14] In 1927, it was recommended that both guns should be withdrawn but, seven years later, they were still mounted and manned by three officers and fifty ORs of 167 Heavy Battery RA (TA). [15]. Two .303-inch Lewis machine guns were mounted for AA defence.
In 1937, it was proposed to mount two 6-inch Mk VII guns from Garrison Point Fort on the towers in place of the 4.7-inch guns, but this proposal was never implemented. Instead the two towers were disarmed and, in the Second World War, they were taken over by the Royal Navy. Both towers had additional concrete structures built on the old gun platforms, one of which was a standard pattern square shaped OP probably for control of nearby searchlights. The other structure on the tower nearest Garrison Point Fort was considerably more interesting. This was an hexagonal OP with a raised dome-shaped top and was built for use by the Extended Defences Officer (XDO) who supervised the firing of the controlled minefield laid at the entrance to the Medway. This type of OP was known as 'Observation Minefield Control Tower-Type E' and on the lower floor of the OP were the mine firing panel and electric batteries together with a 4 feet 6 inch (1.38 metre) rangefinder. The upper observation dome contained an open sight bearing indicator. [16].
By 1946, the towers had finally been abandoned and today they cling precariously to the bastion which is now flanked by a new promenade on the seaside while at the rear Sheerness commercial docks encroach more and more. Little has been done to protect these structures and it can only be a matter of conjecture as to how long it will be before further expansion of the docks brings about their demolition.
