Monument record 1295/3 - RAF Polebrook (Thor Missile Site)

A Cold-War Thor Missile Site, operational December 1959-August 1963, situated at the former World War Two Polebrook Airfield. Remains of the three reinforced concrete launch emplacements survive, but two are buried.

{1} A rapid archaeological field inspection of the Cold War Thor Missile site and part of the WWII airfield at Polebrook, was conducted on 2nd December 1997 with Graham Cadman and Martin Ellison on behalf of Northamptonshire Heritage, Bernard Lowry for the Defence of Britain Project, Wayne Cocroft for the Royal Commission on Historical Monuments for England and Austin Ruddy, a Defence of Britain Project volunteer recorder. Report submitted to SMR. Report also includes results of a previous visit by G Cadman in October 1996. 35mm colour transparency basic photographic record compiled and deposited in SMR. Following summary of structures includes refs to Record Site Plans for the airfield and dispersed sites dated September 1944 (D.G. of W. drawing numbers 34984/44 and 3498/44 published as airfield plans 183 and 184 by After the Battle Magazine).
The 1981 edition of the OS 1:10,000 map shows the dashed outline of the three launch sites and what may have been the location for associated features. The remains of the three launch sites survive. An ROC type monitoring post located approx. 1km to the west is of uncertain association.

{2} Thor missiles represent first operational Intermediate Ballistic Missile (IRBM) system deployed by the West, and mark move away from reliance on manned bombers to ballistic missiles as principal method of delivery for the nuclear deterrent. Their installation signalled beginning of the missile race between East and West, when western perceptions of Soviet missile technology, confirmed by Sputnik launch Oct 1957 , interp as forcing the rapid installation of Thor. Nevertheless they were a stopgap maesure, with urgency of their installation in late 1950s being reflected in their relatively insubstantial nature of the emplacements. This also an expression of their limited projected service life of no more than 4 years - predicted to end when more ICBMs were operational in N America - first of which activated in Oct 1959. Thor sites also illustrate global distribution of military technology during Cold War, with similar emplacements at two sites in the USA.
Historically Thor bases played a part in one of the tensest periods of The Cold War, the 1962 Cuban Missile Crisis when 59 of the 60 missiles "were raised to alert". The sites embody the special relationship which existed between USA and UK at this time.
There was a relatively short life span for the emplacements, from 1959 to withdrawal in 1963 illustrates close inter-relationship between an IRBM, its semi-portable support services and fixed infrastructure. Design of emplacements determined by missile size, fuel type and handling and strategic considerations. "The Thor missile sites are single-phase structures and were abandoned on the withdrawal of Thor." Its limited range (1500 miles or 2410km) necessitated launch sites in western Europe if Eastern European targets were to be reached. They were deployed on 20 airfields in eastern England. Airfields were chosen as the land was owned by the Government or could be easily requisitioned; also a need to be as close as possible to targets and to limit geog distribution of nuclear targets in UK. 4 sites acted as main bases, each servicing 4 satellite stations. Many of latter have a detached Commanding Officer’s house associated with them, as at Harrington.
Harrington and Polebrook are the two sites located in Northamptonshire. The former is better preserved being described in an MPP report as in good condition compared with fair for Polebrook. TL098866. Described in MPP report as in fair condition with "Pads buried".

{3} Chapter devoted to historical context utilising documentary assessment. Includes model description of sites and their layout. Confirms that both Harrington and Polebrook along with two other (out of county) sites were satellite bases to the main base at North Luffenham. This was one of four such ‘clutches ’(or complexes), others located elsewhere within the E Midlands, E Anglia and Yorkshire. Appendix III provides a gazetteer of all the clutches and their respective main bases and satellite Thor sites. Polebrook and Harrington identified as in place from Dec 1959 to August 1963. Plans of typical layout of a Thor site.

{4} TL 098 866. Construction of the Thor Missile Site, on the former Second World War Airfield at Polebrook, probably began in 1958 with the completion of the ageement with the US government
to deploy Thor missiles in the UK. It was one of twenty such bases built in eastern England. Responsibility for handling the missiles at Polebrook was given to 130 Squadron RAF, which became operational in December 1959; it was one of the last Thor squadrons to be stood down in August 1963.

The Thor Missile Site is of a standard form, comprising 3 reinforced concrete launch emplacements; each was designed to hold a single shot Thor missile. The easterly two emplacements at TL 0992 8665
and TL 0985 8645 are both buried by earthen mounds. L shaped blast walls protrude through the mound at TL 0992 8665, and part of a concrete tank is visible.

The best preserved emplacement is centred at TL 0965 8655, this survives intact but is partly covered by organic farm waste. At the centre of the pad is the smashed holdfast for the missile. To either side are lines of bolt fastenings which mark the line of the rails which carried a movable protective shelter. Set perpendicular to the rails are two concrete gullies. At one end was the kerosine fuel tank and at the other was a liquid oxygen tank. In operation the kerosine and liquid oxygen was piped along the gullies to the missile. Other features on the pad include conduits in which
control cables were situated and mounting for lamp standards.

A small building was shown by the OS to the north of the pads at TL 0972 8675. Its site was not visited, but may be the position of a guidance control hut. The OS also depicted two wartime bomb stores to the SW of the launch emplacements, centred at TL 0925 8610. This may suggest that they were retained for use by the Thor squadron {4b}. It is unclear whether or not the Thor squadron used the surviving wartime structures to the north. In the late 1950s these included two T2 hangars and a J Type hangar, only the J Type survives.

To the west of the Thor site is a Royal Observer Corps Underground Monitoring Post (HER no 1295/3/1) not thought to be directly associated with the Thor Missile Site. {4-4b}

<1> Cadman G., 2001, Defence of Britain Log Part 3, (unchecked) (Report). SNN101409.

<2> Cocroft W.D., 2001, Cold War Monuments: An Assessment by the Monuments Protection Programme, (unchecked) (Report). SNN101426.

<3> Dobinson C.S., 2000, Twentieth Century Fortifications In England Volume XI.1 The Cold War Text, Chapter 5 (unchecked) (Report). SNN100273.

<4> Cocroft, W D, Field Investigator's Comments, Wayne D Cocroft/08-JUN-1998/RCHME: Cold War Project (Notes). SNN113478.

<4b> Ordnance Survey Map (Scale/date), 1.2500, 1973 TL 0886-0986 (Map). SNN112944.

<4a> Wynn, H, 1994, The RAF Strategic Nuclear Deterrent Forces: their Origins, Roles and Deployment 1946-1969, p. 569 (Book). SNN113472.

Record last edited

May 20 2022 1:06PM