The Clausen Rolling Platform was a missile launching platform, built at the coastal missile test range of RAE Aberporth, West Wales, in the 1950s. It used a floating platform in a pool of water to simulate the rolling of a ship at sea, without the drawbacks and costs of going to sea. The Platform was first used for development trials of the

Seaslug missile Seaslug was a first-generation surface-to-air missile designed by Armstrong Whitworth (later part of the Hawker Siddeley group) for use by the Royal Navy. Tracing its history as far back as 1943's LOPGAP design, it came into operational service ...

. Most of the Aberporth site is on a plateau above 450 foot cliffs. The platform was a 750 ton circular steel caisson floating in a diamond-shaped pool, on a concrete platform just above sea level. The pool was across and deep. Access down the cliffs was made by a cable

funicular A funicular (, , ) is a type of cable railway system that connects points along a railway track laid on a steep slope. The system is characterized by two counterbalanced carriages (also called cars or trains) permanently attached to opposite e ...

, taking 11 minutes to descend with a loaded 20 ft long, two-ton missile. The action of the platform was controlled by actuators fixed to the land. They could move the caisson in both 20° roll and 10° pitch axes independently. Variable water ballast within the caisson allowed its dynamic behaviour and period of oscillation to be adjusted. Its movement could be so violent as to induce seasickness in even experienced sailors, leading to its informal name of 'HMS ''Rock'n'Roll. The platform was fitted with a triple launcher for the missiles and a mounting for the Type 901 fire-control radar. Both of these mounts were stabilised and held a constant direction as the platform rolled beneath them. The radar mount tracked the position constantly, the missile launcher moved in discrete steps. The Type 901 radar provided the beam-riding guidance for the missile. This tracked the missile and broadcast control signals to it. Separate radars were used to search for targets, track them and estimate their height. At Aberporth these were provided by existing radar equipment, not dedicated to the platform, mounted on top of the cliff. Additional radio equipment was used to control the target drones used, and to receive

telemetry Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', "remote", an ...

from test missiles. The first Seaslug launch was made from the platform in April 1954. Further tests of the complete system were made from the dedicated missile trials ship , off the coast of Aberporth and in the Mediterranean around

Malta Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...

, beginning from the summer of 1957. Testing at Aberporth continued for the improved Seaslug GWS.2 until 1968. The solid-fuel ''Gosling'' rocket boosters for Seaslug GWS.1 were produced at RNPF Caerwent in South East Wales. Caerwent also carried out motor trials on these. The last ''Gosling'' was produced there on 14 June 1966. Like that on , the launcher was a triple launcher. The intention was that Seaslug would be launched in salvoes, to guarantee a successful interception. After successful trials, the size of these salvoes was reduced and the production launchers installed on the

County-class destroyer The County class was a class of British guided missile destroyers, the first such warships built by the Royal Navy. Designed specifically around the Seaslug anti-aircraft missile system, the primary role of these ships was area air defence aro ...

s were simplified to a dual launcher. The platform's launcher was reloaded from the static ground alongside the platform and there was no capacity to test reloading ability under rolling conditions. The platform was named for Hugh Clausen (1888–1972), who had worked on Royal Navy

fire control Fire control is the practice of reducing the heat output of a fire, reducing the area over which the fire exists, or suppressing or extinguishing the fire by depriving it of fuel, oxygen, or heat (see fire triangle). Fire prevention and control i ...

since

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

and was the driving force for the construction of the platform. It was shown off to the public press on occasion, being visited by the '' Daily Express's'' science correspondent

Chapman Pincher Henry Chapman Pincher (29 March 1914 – 5 August 2014) was an English journalist, historian and novelist whose writing mainly focused on espionage and related matters, after some early books on scientific subjects. Early life Pincher was born ...

and the Duke of Edinburgh in 1959. The platform remained in service for testing naval radar and satcom terminal stabilisation. It was also used for testing other sea-launched missile launchers, including Seaslug's successor

Sea Dart Sea Dart, or GWS.30 was a Royal Navy surface-to-air missile system designed in the 1960s and entering service in 1973. It was fitted to the Type 42 destroyers (United Kingdom and Argentina), Type 82 destroyer and s of the Royal Navy. Originally ...

. Developments in missiles made them smaller and lighter, and no longer requiring to be pointed in such an accurate alignment before launch. Much of this was due to the shift from beam-riding guidance (LOSBR) to

automatic command to line of sight Command guidance is a type of missile guidance in which a ground station or aircraft relay signals to a guided missile via radio control or through wire-guided missile, a wire connecting the missile to the launcher and tell the missile where to ste ...

(ACLOS) or similar systems. These no longer required the missile to be launched on a precise alignment from a trainable launcher, so that they could be gathered into the command beam. Later missiles such as Sea Wolf would be launched from simpler vertical launchers, which require no stabilisation, but the sextuple launcher for the original Sea Wolf GWS-25 conventional launch block was also tested at Aberporth. The platform was decommissioned in 2004 and most surface buildings removed, although the underground bunkers remain. The caisson has now been removed but the pool remains and can be seen on public mapping services.

References

{{coord, 52.142591, -4.557742, display=title Cold War military equipment of the United Kingdom Funicular railways in Wales Missile launchers

See also

References