Monument MPM1982 - Torpedo Testing Range, Horsea Island

Former torpedo testing range opened in 1889. Due to advances in technology the majority of torpedo testing was moved to Stokes Bay Torpedo Experimental Station in 1921 and torpedo experimentation and firing at the range ceased entirely by the end of the Second World War. The site is now the headquarters of the Defence Diving School.

The torpedo testing range on Horsea Island was constructed between 1885 and 1889. When it opened in March 1889 it was described as the 'finest torpedo experimental range in Europe'. Constructing the range involved joining together the two islands of Little Horsea (west) and Great Horsea (east) to form one island. Chalk excavated from the torpedo range and Paulsgrove chalk-pit was used in the land reclamation. Some of the labour was provided by convicts from Kingston Prison who were housed in temporary wooden huts on the south side of Little Horsea Island. The huts were distmantled in 1889. Little Horsea Island was effectively cut in two by the firing range and the island levelled to a more or less uniform surface. The georgraphy of Great Horsea Island remained relatively unaltered until the 20th century. Horsea Island was joined to the mainland in the 1970s.

The buildings and structures associated with the range were constructed at the extreme western end of the island. These included workshops, a boiler-house, stores, mess-rooms, a boat house and the firing-point for the torpedo range. The old farmhouse on Little Horsea was enlarged and used as the caretaker's house. Most of the late 19th century buildings were badly damaged by Second World War bombing and subsequently demolished. A Wireless Telegraphy Station was housed on the island from 1909 until the 1960s (see MPM1983 & MPM1984).

A small quay, known as 'Stores Pier', equipped with a five-ton Ransome and Rapier hand-operated crane, was constructed at the north-west corner of the island in 1886. This quay was originally used to land building materials and heavy machinery during the construction of the range and later for unloading heavy stores and coal. A two-foot gauge railway track was laid from the quay to transport building materials and later to transport heavy torpedoes and general stores. The railway connected a number of buildings including the torpedo workshops, stores, firing-point, boiler-house and a pier built in 1898. It remained in use for sixty years. A wooden pier around 230m long with a a standard island two-foot gauge railway track was constructed on the western side of Horsea Island in 1898 (see MPM1979). This was known as the Long Pier, and was used as a mooring point for all vessels except those unloading heavy goods at the Stores Pier.

The firing range was originally 850 yards long by 20-30ft deep. It was lengthened to 1,100 yards in 1904/5. However, rapid advances in technology between 1890 and 1918 meant that a longer range was required and some of the testing began to be carried out at a site at Stokes Bay. Horsea was still in use during the First World War and a new torpedo experimental tank to stimulate improvements in torpedo submerged firing was built in 1915. In 1921 the majority of torpedo work was transferred to Stokes Bay Torpedo Experimental Station. Most of the old machinery and plant on Horsea Island was dismantled and transferred to Stokes Bay or sold.

After 1921 various improvements were made to the range at Horsea, including the installation of a new compression unit and reservoirs with modern tubes in the firing point, new workshop facilities and the modernisation of the torpedo experimental tank. Experiments in submarine design and control using scale models were carried out between 1923 and 1932. Although routine torpedo-firing in the range had virtually ceased by 1939, some trials were carried out in 1941 and 1942. The site has subsequently been used by the Royal Navy for training in firefighting and diving, and also for experiments and trials in under water weapons and amphibious tank trials by the army. It is now the headquartres of the Defence Diving School.

The former mess-rooms built in 1888 and the 1915 torpedo tank-house were recorded as still surviving in 1982, but they do not appear to be shown on the modern ordnance survey map. The five-ton Ransome and Rapier crane is still situated near the former quay. The remains of the Long Pier and the foundations of a boat house built in 1898 were recorded during a walk over survey in 2016 (see MPM1978 and MPM1979).

Ripley, Basil, 1982, Horsea Island and The Royal Naval (Bibliographic reference). SPM410.

Maritime Archaeology Trust, 2018, Forgotten Wrecks of the First World War: First World War Wireless Stations of the South Coast of England (Bibliographic reference). SPM582.