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60th Anti Aircraft Artillery (Automatic Weapons) Battalion at Lakenheath

Battalion shield of the 60th AAA
Motto: "We rule the heavens". The searchlight and battlements are self-explanatory; the star represents both the heavens and the State of Texas where the battalion was first designated.
(Image courtesy
United States Army Insignia Homepage)


The involvement of US Army radars in this case has to date scarcely been noticed. Yet it is quite an interesting aspect of the affair since BOI-485 not only states that the 60th AAA were alerted to be on the look out for radar targets, and lists what is almost certainly the Army radar among ground-electronic equipment involved, but also indicates that the 60th AAA were the point of coordination with the RAF for the decision to intercept.


Lakenheath GCA alerted 60th AAA (stationed at Lakenheath) and Sculthorpe GCA to watch for unusual targets.

And later:

Interception was undertaken by one British jet fighter on alert by 60th AAA Sector Control.

On reflection all this is only to be expected. The Air Force radars at Lakenheath were not air defence radars but traffic control and landing radars. A nuclear bomber base needs air defences, and if an object merits interception then it certainly merits the active response of AAA units on the ground. It is therefore of particular interest that witnesses in Ely to the west reported "panic" with "searchlights sweeping the sky in every direction" from both Lakenheath and nearby Mildenhall.

Common practice would be that the defence of the airfield would have been in the hands of a US Army anti-aircraft artillery battalion, in this case the 60th AAA, and the associated Army Air Defence Command Post would be equipped with long range defence acquisition radar, both for early warning and for tactical coordination of radar-directed anti-aircraft guns deployed around the airfield. Once the 60th AAA Command Post was alerted, the tactical defence responsibility for a potentially hostile intruder (as opposed to, say, strategic, or passive-intelligence or air safety responsibilities) would then automatically be born by the 60th AAA. This is why they would be the unit responsible for alerting the RAF, as noted in BOI-485, via Eastern Sector Operations Centre, RAF Bawburgh.

The extent of the involvement of the 60th AAA's defence radar can't be inferred from BOI-485. However the preparing Intelligence Officer, Capt. Stimson, famously states: "That three radar sets picked up the targets simultaneously is certainly conclusive that a target or object was in the air." Although this has been generally assumed to refer to the CPS-5, the CPN-4 and the AI radar on the interceptor, the involvement of the Army radar site suggests another interpretation..

Sightings by American personnel at the Army site would have been within the purview of Stimson's report since Project Blue Book was declared responsible (in principle) under AFR 200-2 for UFO reports made by all branches of the US armed services. Indeed the impetus for the upgrading of Project Grudge in early 1952 had been triggered in part by concern over UFOs reported on SCR-584 and MPG-1 tracking radars at the US Army Signals Corps radar centre at Fort Monmouth, New Jersey. AFR 200-2 did not and could not require action in respect of reports received from non-US personnel, however, and although the RAF interceptor's report of radar contact was described in BOI-485 no direct investigation of this would have been authorised. This might mean, therefore, that when Stimson says "three radar sets picked up the targets simultanously" she might have been referring only to events officially reported by US personnel and the "three radar sets" might have been "TS-ID [sic], CPS-5, and CPN-4" as listed.

That the 60th AAA were indeed using radar at Lakenheath at this time, and that its use was coordinated with RATCC and other Air Force radars, is confirmed in an article from a Lakenheath Air Force Newspaper of August 1956 (unfortunately the exact date is missing from the photocopy of this article in the author's file) coincidentally describing an incident just two days before the UFO event.

A B-45 declared an emergency and requested the assistance of the Lakenheath Fixer Net for precise position and a course to get to RAF Sculthorpe with limited fuel remaining. Radars at Lakenheath RATCC, Wethersfield GCA and Bentwaters began offering assistance. According to the article:

"Shortly after, using the Lakenheath Fixer Net and the assistance of the Army radar operated by PFC Tawl E. Rupert of the 60th AAA, the B-45 was advised he was 65 miles South-East of Sculthorpe and Sculthorpe was advised to have all crash equipment standing by. Several more fixes kept the B-45 on course to Sculthorpe. At 1837Z, the B-45 landed safely on a straight in approach, with less than 5 minutes of fuel remaining."

The Army radar referred to here was almost certainly a TPS-1D surveillance radar. Since there is scant original documentation on this point it is worth spending some time to explain how this conclusion was arrived at.

In answer to question #3 in the AFR 200-2 format, "Manner of Observation", BOI-485 says:

Ground electronic equipment was TS-ID, CPS-5, and CPN-4.
Air Electronic was A-1 equipment in British jet aircraft.

"Observation" with "ground electronic equipment" indicates that TS-ID refers to radar, but the precise designation is not familiar from study of USAF reports of the period or other findable USAF sources. In fact it doesn't make sense. It is not a generic code for the two surveillance radars, for example, since the "CPS" and "CPN" codes already fully define these equipments for all Air Force purposes, and there is no system or set of any kind designated "TS" in an exhaustive list of Army-Navy Joint Electronics Designation codes. The old wartime and pre-war Army nomenclature (disused by the Army since 1953 and by the Air Force since 1947, even though the AN system did not become officially formalised until 1957) did contain a "TS", but as this described a telephone handset it isn't helpful. Two-letter AN designations were only ever used for components (a test unit in this case) and could not describe a radar set or system. Single-letter Army designations could apply to radars, as in the T-38, which is a fire-control radar attached as a component to the 75mm Skysweeper anti-aircraft gun system ("T" meaning "ground transportable"). Such gunnery radars probably were present at Lakenheath (see below) but are not relevant to the designation "TS-ID".

The only possible conclusion is that this is the result of lax reading or typing on the part of whoever made up the Lakenheath teletype. This is not merely an ad hoc hypothesis. Apart from known mistakes elsewhere in the teletype, a clear typographical error occurs in the very same paragraph that we are considering (shown below), where a capital "I" is mis-typed as a numeral "1" and air-electronic equipment is given as "A-1" instead of the correct acronym "AI" (for Airborne Interception).

Fragment of Lakenheath teletype listing "TS-ID, CPS 5, and CPN4" ground radars and "A-1" airborne interception radar.

Going back to the fact that "TS-ID" is described as ground-electronic observing equipment, which means a "radar system", and given that all US military AN-series system codes have a common structure of 3 letters, not 2, indicating installation, type and purpose respectively, then we can infer that it should include a "P" for "type: radar" in position 2, by analogy with CPS-5 and CPN-4. Thus the correct code should be TPS-ID. But the fourth character in an AN designation is always a model number, and cannot be a letter, so "I" must be wrong also. It is natural to suppose a transcriptive error from the number "1" to a capital "I", the reverse of the error provably committed elsewhere in the same paragraph. So this leads to the final correct version: TPS-1D.

This inference would be fruitless speculation if there was no such equipment code in the US inventory, but there is. And not only is there a widely used radar called the TPS-1 it turns out that the TPS-1D is a version of this set developed as a defence acquisition radar for Army anti-aircraft battalions.

A detailed history of air defence artillery control systems by Ed Thelen of the Nike Preservation Group has this to say about 'The evolution of defense acquisition radars':

The present defense acquisition radars (DAR) have evolved from the early warning radar AN/TPS-1. This radar included only the essentials required to provide early warning information. Similar but not identical equipment, the SCR-602A, appeared in the military radar inventory during World War II. Later the AN/TPS-1B radar was designed. The addition of moving target indicator circuits to the AN/TPS-1 produced the AN/TPS-1D, a medium-power search radar designed to detect targets in excess of 290 kilometers. It was first employed bythe Air Force and the Navy. Subsequent issue of the AN/TPS-1D satisfied the requirement for long-range radars at battalion level in air defense artillery units. (emphasis added)

For this air defence artillery role the TPS-1D antenna was mounted onto a metal shelter containing the radar equipment, IFF transponder, radio, telephone and plotting board. This created a self-contained Army Air Defence Command Post which could be mounted onto a 2 ton truck, an arrangement known as 'electronic search central' and designated AN/GSS-1.

AN/TPS-1D radar in 'electronic search central' installation, AN/GSS-1 mobile Army Air Defence Command Post (courtesy Ed Thelen)

Addition of a larger 11' x 40' free-standing antenna turned the AN/GSS-1 into AN/GSS-7 (courtesy Ed Thelen)

According to Col. William J. Lawrence, who commanded a Nike Hercules missile unit in Gary, Indiana under the newly formed Army Air Defence Command 60th Artillery Regiment in 1958, the old 60th AAA probably would have used TPS-1D radar:

I have some knowledge of automatic weapons battalions, as I served in the 91st AAA AW Bn (Mbl) in Germany from 1954 through 56.  This very likely was the type of equipment the unit of interest to you had in England. . . . The Skysweeper [AA gun] had its own fire direction radar, the T-38, whose parabolic dish could be set to rotate to provide surveillance and acquisition in the area around the gun. The battalion also had an AN/TPS-1D radar for longer range surveillance.  We did have such a radar while we were still an automatic weapons battalion, and I suspect that the units in England were also converted from automatic weapons battalions, or at least some of them.  The AN/TPS-1D was always an Army radar.

75 mm Skysweeper radar-directed AA gun, dish of T-38 fire control radar visible top center (courtesy Col. William J. Lawrence)

Col. Lawrence confirmed the usual command structure in Germany as follows:

The battalion ran an Air Defense Command Post, and was also connected to a higher level command and control facility run by the brigade and ultimately to an Air Force-run command and control facility. . . The Army radars were supplemented by a separate, Air Force-operated network of surveillance radars. The overall mission of air defense of a major area always belonged to the Air Force. 

In a UK setting the overall US Air Force air defence mission would generally be subordinate to the territorial defence arrangements of the host nation. Hence the plugging in of the 60th AAA Air Defence Command Post at Lakenheath, via the '60th AAA Sector Control' organisation described in BOI-485, to RAF Eastern Sector HQ at Bawburgh.

I have so far not been able to confirm the above from contemporary records since the relatively brief life of the 60th AAA as an Automatic Weapons Battalion falls into a grey zone just before the radical reorganisation of the entire Army Air Defence Command with the large scale introduction of the new Nike Ajax missile battalions. Memories are sketchy and the Army Military Historical Institute's online document library contains no unit histories or other records relative to this era. Research kindly carried out at the author's request by SSgt. Stephen J. Blair of the Air Force Historical Research Agency, Maxwell AFB Alabama, also failed to locate information relative to the 60th AAA in this period (letter from AFHRA, 29 April 2003).

According to a brief history in the Nike Preservation Group Newsletter:

On 1 August 1946, Battery B, 60th AAA Automatic Weapons Battalion was activated at Ft. Bliss, Texas. From that time until its deactivation in England on 17 June 1957, the unit conducted the usual peacetime operations and underwent minor TO&E and name changes.

The modern 60th Artillery was activated as the 1st Missile Battalion (NIKE-AJAX), 60th Artillery, with four firing batteries, at Gary, Indiana on 1 September 1958. The Battalion took over the NIKE Sites of the deactivated 79th AAA Missile Battalion and came under the operational control of the 45th Artillery Brigade

TPS-1D radars deployed with US forces in Germany, 1950s (courtesy Radomes, Inc. - The Air Defense Radar Veterans' Association)

Martin Shough 2003

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