Blue Streak Gantry

Introduction

Orford Ness was the location of a non-metallic gantry built to determine the best locations for the internal telemetry aerials located within a Blue Streak nose cone. This specifically designed wooden gantry, and its receiver block and aerial, 90m away, were located in the Orford Ness ‘airfield’ site: tests were conducted by AWRE* staff.

The strength of radio signals received during tests, each having differing orientation and frequency was used to create polar diagrams and these were then analysed by telemetry specialists to determine the optimum locations for the internal aerials within the nose cone.

The wooden gantry itself was removed soon after its worked ceased, but the remains of the brick receiving building and its associated aerial mast remain and are still visible to visitors from across the marshes. However, the circular concrete base itself, can only be seen using online satellite views with online mapping resources such as Google Earth, as visitor access to this marsh area is normally not allowed (in order to protect breeding birds).

Blue Streak’s background

Blue Streak was a British Intermediate-range ballistic missile (IRBM) with a designed range of 4400 km and was part of a joint program with the USA, who produced intercontinental missiles. The intention behind adding Blue Streak to Britain’s independent nuclear capability was to replace the V-bomber fleet which was due to become obsolete by 1965.

Blue Streak’s design was completed by 1957, built by a consortium of specialist suppliers. The main contactor was de Havilland Propellers, with many subcontractors being involved such as Rolls Royce and Raytheon, with AWRE designing and building the nuclear warhead. The missile was 18.75m tall, 3.05m in diameter and weighed 90,000 kg. Propulsion was via two Rolls Royce RZ.2 liquid oxygen/kerosene engines that had been tested at the Spadeadam Rocket Establishment in Cumbria.

It became clear during its development that Blue Streak, as a missile, was too expensive and too vulnerable to a pre-emptive strike, even though designed to be launched from underground silos. This project was thus cancelled in 1960, with US-led Skybolt the preferred replacement.

See also the Telemetry section for further information on Blue Streak telemetry.

https://en.wikipedia.org/wiki/Blue_Streak_(missile)

​Blue Streak’s repurposing

For political reasons, and to use Blues Streak’s capabilities and investment, it was proposed that it should become the first stage of the proposed ‘Europa’ satellite launch vehicle. This project was to be managed by the European Launcher Development Organisation (ELDO). Europa’s first launch was in June 1964 and its last, the 11th, was in 1971, and although the launches themselves were successful, ‘Europa’ as a whole was not, and the ELDO project was cancelled – without ever having launched a satellite.

https://en.wikipedia.org/wiki/Europa_(rocket)

Orford Ness Gantry

AWRE’s engineering drawings, specifically de-classified for the IRGON researchers in 2019, showed that this non-metallic gantry (or ‘Rotating Table’) could raise, rotate and tilt a nose cone located on a range of ‘tables’ or ‘clamps’. The gantry,19.2m high, was designed to rotate on the 10 m diameter concrete circular base.

The nose cone, 3.05m in diameter and 3.5m tall, was fixed to one of three platforms, each one clamping the nose cone, or different sections of it, in slightly differing ways. It was then elevated, rotated and tilted so that the strength of radio signals, transmitted in all directions by the aerials located within the nose cone, could be measured at the Aerial Measurement Building some 90m away. This was repeated with many frequencies, orientations and locations.

To minimise electrical interference with the radio signals the gantry was entirely made of wood. Thousands of small wooden blocks had been glued together with different grain alignments to prevent any warping or distortion of the wooden structure. This allowed the differing design ‘tables’ or ‘clamps’ holding the nose cone to move freely within the four vertical corner columns.

At the time the National Trust opened Orford Ness in 1995, the purpose of the ‘concrete base in the marsh’ was unknown. Its purpose as Blue Streak test gantry only became clear during a 2002 visit of an Orford Ness ‘Veteran’ who had been in fact a teenaged AWRE Scientific Assistant when part of the project team in 1960.

Period of Operation

It has not been possible to determine the precise start date and period of operation of these tests, but it is known that the testing took place sometime between 1960-1963. Equally it is not yet clear if this testing was for Blue Streak’s development as a missile or, with cancellation announced in 1960, as the first stage in the later ‘Europa’ project.

A Work In Progress

IRGON’s research continues to determine the purposes of the other two fixtures and to increase our wider knowledge of this largely unknown Orford Ness facility.

* Now AWE: https://www.awe.co.uk

Blue Streak test area: aerial photo courtesy Richard Flagg (2022)
Blue Streak Gantry
Drawing showing "nose clamp": Method of elevation within the four support columns
© Crown Copyright / AWE 2021. Contains public sector information licensed under the Open Government Licence V3.0.
« of 4 »
Blue Streak - photos
Blue Streak receiver building and mast (photo taken 2002. The front wall collapsed in 2018)
© IRGON (David Warren)
« of 2 »