Exploring Kent's Past

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Monument details

Summary

The Royal Naval Air Service established two bases on the Isle of Grain, one at Cockleshell Hard and one at Port Victoria (at neighbouring points on the coast). Known as Grain Air Station, they were used between 1912 and 1924. Few extant remains survive. Credited with the invention of the aircraft carrier.

Monument Types

• MILITARY AIRFIELD (Modern - 1912 AD to 1924 AD?)
• MILITARY BUILDING (Modern - 1912 AD to 1924 AD?)

Full description

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The Royal Naval Air Service (RNAS), established two bases on the Isle of Grain, one at Cockleshell Hard and one at Port Victoria (at neighbouring points on the se corner of Grain). These bases were used between 1912 and 1918 as a repair depot and Experimental Armament Depot as well as a seaplane station. Grain Air Station, as it was also known, was used as a Marine and Armament Experimental Establishment (MAEE) between 1918 and 1924, when the facility closed. The Air station’s buildings were ranged over three sites centred on grid refs 588570,174220; 588295,174245 and 588930,174610 (estimated from the photos in the report below). The Port Victoria side of the base undertook the flying of new aircraft for naval use and also developed their own aircraft and aircraft equipment. At Horseshoe Point a new slipway was built for the Port Victoria Depot in 1917, the remains of which were removed and disposed of in 2003 (see TQ 87 SE 1056). These timbers represented one of the few extant remains of the former Air Station, which was an important contributor to the early history of maritime aviation [1].

In a letter from the Admiralty to the Admiral commanding Coastguard and Reserves, classified SECRET, approval was given for the establishment of a 'regular chain of stations for naval aircraft along the coast of the United Kingdom within easy flight of each other.' 16 sites for hydro-aeroplanes were suggested and three for airships. The first of these, RNAS Grain, on the Isle of Grain, Medway was an experimental seaplane station which opened 3.12.12. On 1.1.1913 it became the first RN Air Station to be commissioned.

On 1 January, 1913, the first British seaplane station was commissioned at the Isle of Grain (in the region TQ889745) under the command of Lieutenant J. W. Seddon, R.N. An extensive area of foreshore was purchased and a slipway cut through the sea wall, giving access to land on which sheds were built, while a number of coastguard cottages (close to the village) were taken over for the personnel?on the understanding that the navy performed the coastguard duties.

The Isle of Grain was an obvious choice for such a station as planes based here would be in a position to give aerial protection to the eastern approaches to London, both Chatham and Sheerness docks, and the Admiralty oil tanks on the Island itself. At the outbreak of war the seaplane station was given the task of patrolling the Thames estuary and part of the Channel out to the North Hinder and Galloper lightships. The first patrol was on August 9 but most flying was expended giving cover to ships transporting the BEF to France.

By August, 1914, the air station at Grain had become one of the largest seaplane stations in the country. It employed about eight hundred workers, many of whom came from the ranks of local civilians. Used as a holding unit for reserve Short and Sopwith seaplanes for the forward bases at Westgate and Clacton, the emphasis at Grain shifted away from front-line operations, and a number of very rough grazing fields were joined up to form an aerodrome by boarding over numerous dykes. Bessoneaux hangars joined the seaplane sheds inside the sea wall.

Early in 1915 the R.N. Aeroplane Repair Depot was commissioned under Squadron Commander G. W. S. Aldwell. This unit was housed in what had once been a Salvation Army Congress Hall; the building having been transported to the Isle of Grain and re-erected a few hundred metres away from the original Air Station. The new unit was named Port Victoria and was located to the immediate SW of Grain in the region TQ886743. Later in 1915, the Experimental Armament Section was set up beside the Repair Depot, and early in the following year the Seaplane Test Flight came into being.

As the war progressed, Port Victoria grew in size using three large sheds, while the Test Flight became a separate organisation with hangars on the main Air Station and the Isle of Grain air station declined to little more than an Acceptance Depot, though it did continue to administer both stations.
Ultimately the place became known as the Marine Experimental Aircraft Depot, and was divided into the Experimental Construction Depot, Seaplane Test Depot, and Experimental Armament Section. The Experimental Construction Depot was originally the R.N. Aeroplane Repair Depot. It began its construction work early in 1916.

Work on the airfield concentrated on landing trials by Sopwith Pups and 1?-Strutters, using a 200 ft diameter dummy deck, trying various arrangements of arrester wires. Meanwhile, the Experimental Construction Depot started modifying a Sopwith Baby with high-lift wings. This aircraft was designated the PV1 (for Port Victoria). It was the start of a number of Port Victoria designs. The PV2 was an anti-Zeppelin fighter which flew in June 1916 but suffered from poor lateral control. The PV3 was a two-seat pusher fighter landplane project, and the PV4 a seaplane version which was not a success. The PV5 was a single-seat fighter seaplane. The depot was asked to build a small aeroplane capable of being carried aboard torpedo-boat destroyers and similar small craft. The resulting PV7 Grain Kitten had a span of 18 ft (5.5 m) but, powered by the inadequate 35 hp ABC Gnat, was not a success. A rival design produced at Eastchurch fared better when tested in September 1917 as the PV8. The Port Victoria design team now tackled another single-seat fighter in the same category as the PV2. It first flew in December 1917 as the PV9, but its 150 hp Bentley BR1 engine caused continual problems. During 1917, a Sopwith B1 single-seat bomber was delivered to Port Victoria for conversion into a two-seat fleet reconnaissance aircraft for carrier operations. In addition to the conversion, a number of redesigned aircraft were produced under the name Grain Griffin. The Experimental Armament Section evaluated British and German equipment, including such devices as the Davis recoilless gun and the Rankin anti-Zeppelin explosive dart. Flight testing of both land and seaplanes involved such diverse items as flotation bags, hydrovanes, catapult trials, W/T sets and hydrophones?the latter to detect submarines under the water.

By the autumn of 1918 the number of sheds had reached 15, most of them just behind the sea wall which was now cut by three slipways. A large accommodation camp had been built just south of Grain village, around the coastguard quarters, for the staff which numbered about 1,480.
In 1918, Grain seaplane station was integrated into the newly formed R.A.F., and given the title 'Marine Aircraft Experimental Establishment' (M.A.E.E.). It was given the task of test flying all new seaplanes. During these years, the nearby Shorts aircraft company at Rochester also used the facilities at Grain. After the war, work proceeded at a relaxed pace but when Orfordness closed in 1921 the Armament Experimental Squadron moved in. The testing of flying boats, in particular the Saunders Valentia, the Short Cromarty and the Fairey Atalanta went ahead slowly, the latter probably the last new type at the depot. But with the amalgamation of the Army's Royal Flying Corp and the Navy's Royal Naval Air Service, there was an obvious duplication of facilities.

On March 17, 1924 Grain was closed; the wireless experiments were moved to the, then, new air field of Biggin Hill whilst the maritime work was transferred to Felixstowe. By early 1924 sufficient accommodation was ready at Martlesham, and a small group of personnel, stores and aeroplanes moved from Grain to form the first flight of No.15 Squadron for armament testing. Orfordness, 20km east of Martlesham was reopened in May 1924, although, at first, unsuitable for much of the firing and bomb dropping and as a result the smaller bombs and explosive devices for testing continued to be dropped onto the aerodrome at Martlesham. (2)

Mentioned in Isle of Grain Historic Area Assessment conducted by English Heritage in 2014. "A slipway from Grain Air Station was still in existence in 2000 but dismantled soon after" (3).

<1> RSK ENSR Environmental Ltd, Port Victoria Seaplane Slipway, Isle of Grain, Kent (Unpublished document). SKE12509.

<2> Fleet Air Arm, 2016, Fleet Air Arm Officers Association. (Website). SKE31491.

<3> English Heritage, 2014, Isle of Grain, Hoo Peninsula, Kent: Historic area assessment (Monograph). SKE29397.

Sources and further reading

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