Grain Tower Battery is located on Grain Spit, a mud flat at the east end of the Isle of Grain, opposite Sheerness Port. The Tower is accessible by a causeway at low tide but at high water it can only be reached by boat; there was originally a jetty alongside the causeway.
Grain Tower was completed in 1855 and is similar to the earlier east coast Martello Towers being externally roughly circular but flattened on the east and north west sides; internally however it is completely circular. The tower has a slight taper towards the top. Externally it is built of granite blocks while inside the construction is of brick. As with the early Martello Towers, a central circular pillar rises from ground floor level to a vaulted ceiling above the first floor. The entrance is at first floor level with a doorway set into the north west side of the tower with a date stone of 1855 above the lintel.
The entrance opens into a small lobby from which brick vaulted stairs go up in two directions within the thickness of the wall. The north-east stairway leads into a small chamber with a semi-circular vaulted ceiling. The room contains a slate water tank supported on bricks.
The other stairway leads to a small landing. From here another flight of stairs decends sharply and enters the main body of the tower, near the foot of the stairs is a small vaulted room that was originally a latrine.
The first floor was the living quarters and is lit by three large windows. All original partition walls were removed during later alterations but there is evidence of a fire place and an original wooden cupboard remains. A trap door in the floor leads to the ground floor level which was accessed by a ladder. This is now partially flooded and not accessible. The roof is accessed via a granite staircase in the west side of the tower running between the brick inner walls and the granite outer walls. The original gun positions (one 56 pound cannon and two 32 pound cannon) would have been on the roof but later alterations have removed any original features.
The first remodelling of the tower took place between 1910 and 1912 when two 4.7" QF (Quick Fire) guns were moved to the tower from Grain Wing Battery to fire on high speed torpedo boats attacking ships moored at Sheerness or Chatham. Direction finding equipment and a crew room were added on the roof while the first floor became barracks and a magazine. The tower also formed an anchor point for the Medway Boom running across to Sheerness. A heavy chain still wrapped round the tower is the remains of the boom. Wooden posts sticking out of the tower around the chain on the east and west side are the remains of staging used in connection with rigging the boom.
On the first floor new brick partition walls divided the tower into three rooms, shell store, cartridge store and a barrack room. The barrack room was also used as part of the ammunition supply system with a hatch in the ceiling to the upper shelter. While the hatch was being used the barrack room acted as a shifting lobby.
To provide room for the 2 new 4.7" QF emplacements the tower’s parapets were removed and a 2 level crew accommodation block was built consisting of two blocks of rooms comprising an ablutions block, shelter, stores and a kitchen. The ablutions block is a single level brick building incorporating the top of the stair passage. The north west room of the block was an Officers' Shelter and adjacent to it the Men’s Shelter. The room on the south side of the Men' Shelter was an Artillery Store housing equipment for the operation, cleaning and maintenance of the guns. The room adjacent to the Artillery Store was the Kitchen which still retains a chimney.
From the kitchen a flight of steps leads up to the Gun Floor with a walkway and a further two sets of steps to the two gun emplacements. Only the south west set of steps and the south gun emplacement (No. 1 gun) survive. The concrete drum emplacement retains its holdfast of six bolts equally spaced around a depressed centre for mounting the gun pedestal. Around the base of the emplacement are three ready-use ammunition lockers, one for cartridges and two for shells. Both 4.7" guns were removed in February 1929.
Further modifications to the tower were made in July 1940 when a twin 6-pounder QF gun was installed. This was to fire on the high speed German ‘E’ and ‘S’ motor torpedo boats and Grain was one of the first sites to employ one of these recently developed guns. The gun had a very high rate of fire (60 - 120 rounds per minute) and was electrically powered with a search light mounting and director tower. The generator house was located on shore and connected to the tower by cables.
The searchlight emplacement was reached by a newly constructed route from the tower’s entrance and was located on a platform on the first floor. This still survives although the steel shutters and mountings for the light have gone.
The twin 6-pounder used smaller ammunition than the earlier 4.7" guns and the interior of the tower was once again changed to accommodate this.
There was no separate cartridge store so this room was put to other uses. The shell store became the new magazine and the barrack room became an ammunition handling area housing an electrically powered ammunition lift that was required for the rapid an uninterrupted supply of ammunition. This still survives in good condition. The ammunition was passed from the magazine through a steel door to the lift which ran in an open shaft delivering ammunition to the rear of the gun emplacement.
The new emplacement involved extensive alterations to the Gun Floor and Upper Shelter Level around the northern 4.7" emplacement which was demolished at this time. The gun was housed in a new reinforced concrete emplacement which still survives in good condition with its holdfast bolts set into the pit. A set of rails run round the edge of the emplacement to the rear of the gun for the ammunition trolleys. There are five ready-use ammunition lockers in the base of the gun pit and the top of the ammunition lift is located at the rear of the emplacement, five feet below the level of the pit.
The Battery Observation Post (BOP) is located in a 4 storey reinforced concrete tower. This would normally be a two storey structure with the gun-director and search-light director rising from the rear of the gun position. The ground floor room is reached by a set of steps from the upper shelter level. The other floors are reached by external steps with a handrail and a small landing at each level. Access to all the rooms is through an armoured door. The door to the searchlight-director room has been removed. The gun-direction position above retains its door and a concrete pillar in the centre where the rangefinder and director equipment was mounted. Both rooms still retain their armoured shutters.
A free standing, two storey barrack block was added to the north-west side of the tower to accommodate the increased compliment required to operate the battery. The new block incorporated a cookhouse, dining hall, sleeping quarters and latrines and had its own landing stage. There were three points of access from the tower, a reinforced concrete cat walk from the western end of the ablutions block to the top floor of the barracks, a set of steps up from the tower landing stage and a lower walkway from the tower landing stage to the barrack block landing stage.
The barrack block has been largely stripped but the cookhouse still retains its tiled walls and some pipes and supports indicating the position of the cooker and sink. There is a serving hatch through to the large dining hall which runs the width of the block. The latrines are at the north end of the dining hall with stairs down to the lower level. The lower floor consists of a shower room and the sleeping quarters, a single large room with a partitioned room in one corner for an NCO.
In 1954 the personnel required to operate Grain Tower Battery were 56 men and two officers. Of this number 16 had jobs on shore (engine room etc.) or jobs that didn’t require a permanent presence on the Tower (cooks etc) this left 42 men to be accommodated on the Tower. There were 4 beds available in the barrack room in the tower, 16 hammock spaces in the Men’s Shelter and 25 beds in the new barrack block.
Grain Tower can be visited at low tide when the causeway is exposed for two hours, access to the inside of the tower is difficult however as the steps have gone making access to the first floor entrance difficult.
- RCHME (Now English Heritage) Report on Grain Fortifications