PARANOID????
I can fuly understand (some) members reluctance to venture into unfamiliar territory, so here are "dumps" from the original forum articles.....
"Posted: Sun Dec 28, 2008 2:39 pm Post subject: The Type 984 radar.
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The Type 984 is the radar that was famously only fitted to Hermes, Eagle and Victorious. The system is credited with being one of the most advanced systems of its day as a true 3D radar with a range of 180 miles. It was associated with the Comprehensive Display System used on the Batch 1 County class destroyers and the 3 carriers that took the Type 984. There was some discussion out installing the Type 984 on the County class destroyers (Batch 1) however this would have required the sacrifice of at least one of the gun mounts and would have pushed up the cost of the county class programme. Instead the destroyers were data linked to the carriers they were escorting, whilst this was not ideal world solution one must regard the Type 984 equipped carrier in comany with county class destroyers as one of the most effective AAW capabilities to have ever put to sea at that time.
This is supported by an exercise undertaken between the USN and HMS Victorious during which the American side was astonished when the radarless Scimitars were credited with shooting down 22 of 23 attackers and driving off the 23rd. The aircraft were directed by the then relatively inexperienced fighter directors aboard Victorious.
Other vessels planned to be fitted with the Type 984 include the cancelled 6 inch cruisers that were to ultimately have been fitted with two Sea Slug Launchers when the Blue Slug nuclear tipped AShM was fielded, the Majestic class missile cruiser conversions and likely also the 1952 carrier. The latter two offer the most interesting examples as they are the only vessels that I know of that would have been equipped with a 'full' Type 984/CDS set. The system was intended to use two antennae's and only the Majestic class conversion was for certain planned to be thus fitted and I suspect the 1952 carrier of also being planned for this. HMS Eagle came closest to getting a 'full' fit with the use of a Type 965 radar in addition to her Type 984. Eagle also used another innovation, in place of her CDS she took the Action Data Automation (ADA) system.
ADA was evolved into ADAWS1 (Action Data Automation Weapon System 1) for the Batch 2 County Class, mostly through the addition of weapons calculation capability. At least one source states that this system was to have been associated with the Type 985 radar that was to have been an electronically as opposed to mechanically scanned array follow on to the Type 984 however this seems to have been abandoned and the Type 988 Broomstick of Dutch origin selected for the next generation of warships. Interestingly the carrier studies undertaken prior to the CVA-01 design process included the Type-985. This time it was planned from the start to shoehorn the massive primary radar onto both the carrier and the escort. Both the Type 82 and CVA-01 were intended to get this radar, however the British withdrew from the project and the Dutch cancelled it. However the associated ADAWS 2 survived and made it into HMS Bristol whilst the ADAWS-3 died with the carrier meant to carry it. ADAWS 4 became the system used for the Type 42 destroyer.
A brief summary of radars, systems and weapons associations:
1st Generation: Type 984 - CDS/ADA - Sea Slug Mk1
2nd Generation: Type 985 - ADAWS 1 - Sea Slug Mk2
3rd Generation: Type 988 - ADAWS 2/3 Sea Dart
Sources used have been:
Vanguard to Trident
Cold War Hot Science
Rebuilding the Royal Navy
British Destroyers and Frigates
An excellent online source for the Type 984 is http://www.rnmuseumradarandcommunications2006.org.uk/984.htm
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"Posted: Fri Jan 02, 2009 10:17 pm Post subject: Type 984
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As promised, here is extrct from "Naval Radar":-
Type 984:
A very complex and ambitious three-dimensional radar, contemporary with the U.S. SPS-2. It was designed from the first to support fighter control, and therefore emphasized data rate and accurate continuous height-finding.
Design requirements included effective tracking of a fighter out to 75nm, and warning at twice that range. Type 960 had better range (e.g. 175nm on a DeHavilland Mosquito at 35,000-40,000ft) but was considered easily jammable; moreover, it gave no precision tracking or height-finding. The original limits imposed on the design were a turning circle of less than 25ft, and a weight not too much more than existing sets (i.e. about 15 tons, which was considerably exceeded in practice).
Many projects of the early post-war period, such as carrier reconstruction and the Fleet Air Defence Escort (FADE), showed pairs of 984, although in fact only single sets were fitted to the three carriers (Victorious, Hermes, and Eagle) which installed it. S-band was chosen as a compromise between X-band, (compact, but power would be insufficient) and L-band (which would make range easier to obtain, but which would provide insufficient precision given practicable lens sizes). Multiple, simultaneously scanning beams were chosen in favour of a stacked-beam system to give higher precision and slightly better range, with greater simplicity. As the beams swept up simultaneously they could cover a full 25* of elevation (five 1.7* beams, each scanning a 5* sector at 16 cycles per second) quite rapidly; the use of five separate scanners was justified on the grounds that the antenna could then rotate five times as fast for the same number of pulses on target (6rpm). The top feed was a fixed horn (1.7* beam) which scanned the horizon for long-range search. The entire system was roll-stabilized, using trunnions at either side. In order to avoid high-power rotary joints, the transmitter was mounted on the carriage proper, connected directly to the scanners. Net peak power was comparable to that of the SPS-2, but three separate water-cooled magnetrons, each generating about 3MW, were used.
Given the complexity of the scanning system, it was natural to use a lens antenna; sources differ as to whether it was 14ft or 14ft 6in in diameter. Lens design was a major problem, as conventional dielectric lenses could not be used given their immense weight and thickness. Instead a waveguide lens (i.e. with a refractive index dependent on frequency) was used, and the restriction in bandwidth (2-3 percent) accepted.
Development began in the late 1940’s at the Admiralty Surface Weapons Establishment, and was transferred to Marconi about 1950. The first installation was made in HMS Victorious in 1958, and Type 984 made a great impression as a fighter control radar in HMS Eagle the following year during a visit to the United States. It was specially designed for integration with the Comprehensive Display System (CDS) developed by the Royal Navy and, in effect, replaced the combination of Types 960, 982 and 983 characteristic of British carrier practice.
The following are also mentioned:-
The later Type 985 was a fixed-array radar system for carriers, in the design stage about 1959, and thus a rough equivalent of the contemporary US SPS-32/33 system. Development of this system was later cancelled. The new carrier CVA-01 was intended to be equipped with Type 988, which was the planned Anglo-Dutch three-dimensional radar, also intended for the Type 82 “frigate” HMS Bristol. Although this was also cancelled, its design probably survived in the Dutch MTTR radar which was fitted to the Dutch destroyers De Ruyter and Tromp.
- Sorry it goes on a bit, but thought I should reproduce the complete item."
Hopefully this answers your questions and helps with those members who don't like searching "unknown" sites.
Pete