Click thumbnails for the original sized photograph.

 

HMS Penelope	HMS Broadsword - January 1980
967/968 Surveillance on HMS Boxer 1983
Old British Aerospace promotional video for Sea Wolf	Thermal Imager
Tracker and "A Man from the Ministry" - Norman Willcox	Alan Ware, Phil Hunt & Norman Willcox
Penelope statuette	Statuette Presentation

 

 

In Homer’s Odyssey Penelope is the wife of Odysseus renowned for her fidelity to him, despite having many suitors, while he was was called to fight in the Trojan War. On Odysseus's return, disguised as an old beggar, he finds that Penelope has remained faithful having devised tricks to delay her suitors. She announces in her long interview with the disguised hero that whoever can string Odysseus's rigid bow and shoot an arrow through twelve axe heads may have her hand. When the contest of the bow begins, none of the suitors are able to even string the bow, but Odysseus does, performs the shoot and wins the contest so proving himself her husband.  

So firing missiles with extreme accuracy and being faithful to duty is an appropriate theme to relate to HMS Penelope and Seawolf/GWS25.

 

We have tried without success to locate the present whereabouts of the statuette - if anyone can help please use the link to owner at the bottom of this page

 

We have recently learned that the Trials team comprised Trevor Hayden, Alastair Thomas, Dave Breen, Brian Keeble, Jimmy Wheeler-James, Roger Patrick, John Wardle, Brian Marjoram, Roger John May and Phil Hunt.

 

Falklands

See here,  here,  here, here, here and here for items on the successful use in this conflict

 

Sea Wolf - HMS Brilliant against Argentine Skyhawks, three shot down or crashed off Stanley, 12th May

The ART of DANIEL BECHENNE

 

 

The following description is an extract from the late Harry Cole's unpublished work "The History of the Marconi Radar Company" 1997.

 

Sea Wolf, the rapid-reaction, anti-missile defence system for the Royal Navy, was to become the Company's breadwinner in later years and so deserves more than passing mention.

 

Development work was conducted at a rapid pace from 1970, resulting in achieving production versions in 1973.

 

It consists of a masthead-mounted surveillance radar - Type 967/968* - and a deck-mounted tracking radar - Type 910 - which allow targets to be acquired by entirely automatic means. Missiles launched at the mother ship are automatically tracked and their position and track data passed to the anti-missile launching system. Upon launch, the defending missile has steering data passed to it by a J-band data link. The whole system is fully automatic, requiring no manual operations in target acquisition or evaluation. There is, however, a television sub-system which monitors the defending missile's flight; this sub-system can also be used for back-up in the event of a radar system failure. (Editorial note: The 968 surveillance was an E Band antenna for short range target detection).

 

The design philosophy was one wherein the missile was kept as simple and cheap as possible, all complications resulting from this were in the ship­-borne equipment and thus much easier to manage.

 

The defending missile was made by BAC under contract to a Ministry different to that funding the ship­-borne system; these two Ministries seldom talked to each other, which created unwanted and frustrating delays. These were further exacerbated by the imposition of a Ferranti computer in the system. BAC began their work well in advance of the Radar Company and, as Marconi Radar were breaking new ground in tracking techniques, delays were generated by software problems. Despite this, the trial firings on HMS Penelope in early 1975 were repeatedly successful. For these, an 'attacking' vessel would lay off about 20km from the GWS25­ defended ship and fire a 4.5-inch shell at it at a randomly-chosen time unknown to the defender. Within seconds, the GWS25 system would detect and destroy it in flight. This impressive 'party trick' was used as a standard demonstration to prospective customers — it was very persuasive.

The first system was delivered to the Royal Navy in 1977. Its success led to the development of lightweight versions which sold in significant numbers to the export market.(Editors note - it was on these installations that Locus16 was fitted, never on Royal Navy vessels - see paragraph below)

The system's performance was outstanding, not only because of its completely automatic operation, but also for its intrinsic radar performance. The surveillance radar had a 99.9% PD on a 0.1m² target, using pulse Doppler clutter suppression (90db) when the ship was making 10 knots. The Tracking radar, also using pulse Doppler, had similar clutter suppression performance. It used differential tracking on both attacking and defending missiles (the latter being distinguished by gaining the name 'Hittile'. The track difference became the command signals for guidance of the 'hittile' ). The system was also able to command two 'hittiles' at once.

GWS 25 was another 'world first' for Marconi. It is the Royal Navy's standard fit today. To me, it represents yet another example of the - somehow innate - genius that the Company fostered. (Editors note - this is exemplified by the following entry.)

 

Input from Bernard de Neumann

My team of mathematicians at Baddow also worked on GWS25, as we, on behalf of MRSL, had a contract from ASWE to simulate the system in action.  Initially we produced a dynamic model of the entire system including the ship and attacking threat, but as there were often tweaks to the control system, which weren't always easy to incorporate into our software model, in the end we developed a general dynamic system simulator, in which we could describe the system in fairly high level terms, and our software turned that into an accurate mathematical model of the processes.  The purpose of our work on GWS25 was to reduce the number of trials necessary to (im)prove the system. MRSL was the main contractor with BAC, Ferranti and Vickers as subcontractors.  We also used the software on various GWS25 variants, such as VM40, and SANDOWN, and built so-called statistical models of GWS25.  

 

The simulation software was called SPADE, which ran on the KDF9 at Baddow, then on the EELM/ICL470 and its successors, an IBM370 and an AMDAHL.  SPADE was also extensively used throughout the GEC company, on such things as the auto-landing system on Concorde, orbiting satellites, the dynamics of electron beams in TWTs, logistics of uranium mining, heli-tele, STIR, industrial process control, dynamic vehicle allocation (like taxi despatchers), for simulating proposed railway systems for GEC TPL, and for the NATO 6S project, also for astronomical calculations for the Royal Observatory, tethered satellite experiments for the European Space Technology Centre (ESTEC), and countless other systems.  The idea it implemented was to make what is a highly mathematical process into a descriptive computer language complete with translating software accessible to engineers, for both MRSL and GEC, and was a major success as an internal product that stayed in use for about 20 years. 

 

During the Falklands campaign we used SPADE, often in the middle of the night, to evaluate various proposed tweaks to the system, as well as for more general Operational Analysis of various military options.  Such techniques continued to be used by ACCSCO (partly owned by MRSL) for their proposal to NATO (or, SHAPE Technical Centre), for the NATO ACCS system.

 

Related comments by Norman Willcox

There was also a Thermal Imaging addition which was a change to the Television system that was made by GEC Avionics at Basildon to overcome radar multipath problems at low level

and Bernard

Whilst I didn't know about the MAv TV camera mod, I remember that at one time we were particularly concerned about multipath effects, but in the end we concluded that, as SEAWOLF's control system directed it along the apparent azimuth and elevation of the target,  and very accurately at that, then, whatever path/beam it actually followed, it was virtually certain to hit its target, the source of any multipath.  Of course, there was the rider that the multipath would reduce the effective range of SEAWOLF, by wasting energy/fuel on unnecessary high-speed flight deviations from the direct path.  This all came about because of the Israeli successes with "Gabriel" sea-skimming missiles against a variety of Egyptian vessels in the early 1970s, and the need to defend against them.

 

Input from Malcolm Mack

The Mod0 Tracker did suffer multi-path problems particularly over land, as I know myself when I was at Stoughton tracking American A10 fighter bombers as targets of opportunity. They used to appear in the east on the horizon whilst on their circuit and bumps routine on the Wash bombing range. It was interesting to see the reaction, as obviously the cockpit alarms must have started ringing, as they dived for cover. The tracker then became unstable as lock was lost with reflections off infrastructure of the horizon. Mind you it didn't help that some software engineer hadn't loaded the track tables  into that issue of software properly.

 

The original camera also suffered from problems of glint from the white horses on the sea, especially when the sun shone. I was at Aberporth at the time working on the TV, when Marconi Avionics engineers were there experimenting with solutions. Alan Ware and Brian Urry, I think Brian Strudwick their Quality Manager also paid a visit (Father of Ray Strudwick MRSL Production Dept and later Mechanical Engineering.) We had had a couple of 'soggy doggies' during previous trials. (Sea Wolf had crashed into the sea to the un-initiated).

 

Input from Barry Pettican - 1

Several pieces of recent correspondence triggered my memories of the late 1970’s at Gt. Baddow. I shared an office in H Block with Tony Edwards. We both reported to Eric Gildersleve, but were pretty much dedicated to the GWS 25 Project under Fred Gibney.

One of my tasks at the time was to define the tracker vertical search procedure and associated software requirement to Ferranti. They would then implement this using Fortran 4 code into their FM 1600 machine which was incorporated into the below decks tracker office. On a ship-based system the tracker and resulting true verticality of the tracker’s elevation search is obviously affected by the amount of ships roll and pitch. This data is continuously available from the ships gyro compass so it is essential to use it to continuously modify the drive commands to the elevation and training servos to correct for these influences and ensure as far as possible that the elevation sweep is true vertical.

In those days we used slide rules, and graph paper and I had a lot of fairly complex trigonometry and associated equations to derive and evaluate. One morning Bruce Neale came into the office with a Hewlett Packard HP25 calculator. He suggested we try it out. I believe they cost over £200 each. I found it ideal for my task. These early HP calculators used Reverse Polish Notation. ( e.g. to do 5+4 =9; You press 5, Enter, press 4 then + and the answer 9 comes in the display). It also had most of the functions found on modern scientific calculators.

Once Ferranti had completed the software implementation we were keen to try it out. Initially this was done on dry land on a development model at Bushy and later on one of the trials ships (HMS Penelope) The two responsible Ferranti Bracknell engineers were Roger Butland and Terry Quested. Monitoring was done via a data logger and line printer, supplemented by a UV Recorder. I received a call that my equations did not work. I drove out to Bushy and after a look at the records, I concluded that there was something wrong with the polarity of the drive commands. There was a requirement for a continuously variable position signal and a matching velocity command coming from the software to the tracker. With Roger Butland’s help we proved that while one command was driving the tracker upwards the other was trying to drive the tracker down and vice versa. Roger did a quick correction by changing a sign from minus to plus in the software and the system performed as expected. To try it on board ship we had to get permission to run the ships stabilisation system in reverse to induce a forced roll. Not very popular with many on board!

 

Input from Barry Pettican - 2

I was interested in the excellent notes on the developing relationship between B.A.E. Systems and Marconi over the years. There have also been several exchanges between MOGs on their personal involvements in some of these projects. It has prompted me to write the following which primarily covers the period 1969 to 2000. I have also tried to show how many of these projects evolved into some of the systems in service today.

 

GWS 25, which was in development from the early 1970’s, was a good example of BAC Guided Weapons Division, as it was then called, working very cooperatively with Marconi Radar Systems. Marconi Radar Systems was the Design Authority for the radars (Type 967 surveillance and Type 910 tracker); BAC(GW) was the design authority for the Seawolf missile and its guidance system.

 

Missile development work continued with an international team and involved some further evolution of the French Aster missile. It eventually resulted in development of Sea Ceptor, which is the latest missile system to be introduced into RN service (2018). The new multi-function radar in use with it provides a wide-area multi-target defence system.

 

Yet another thread of the evolution into today’s operating Naval systems was taking place at Plessey Radar (Cowes). They were developing a multi-function radar with back-to-back arrays intended for an RN requirement. This system was called SAMSON. Plessey Radar eventually also became part of GEC, and were already supplying the Type 996 surveillance radar on the Type 23 frigates. MOD(RN) needed a multi-function radar for the new-build Type 26 frigates, the Type 45 destroyers and the aircraft carriers HMS Queen Elizabeth and HMS Prince of Wales. The chosen multi-function radar referred to above in conjunction with Sea Ceptor was basically developed from formative work on SAMSON.  The EMPAR radar was adopted by the Italian navy and is in service. 

 

The above is a summary of how B.A.E Systems and Marconi Radar complemented and supported each other over many decades in the recent past where they had common interests in providing world-class systems to the Royal Navy and successfully opening up export markets. This has involved Marconi Radar at both Chelmsford and Leicester (909/Sea Dart), also in land-based systems with Marconi Command and Control Systems at Frimley (Rapier/DN181).

 

Input from Ian Brighton

I remember that time very well being part of the late Chris Arnold’s development on the 967 Signal Processor and related equipments through from initial development through to its initial sea trials on HMS Penelope. Peter Marlow led the Surveillance team project office that dealt with all equipment in the Surveillance cabin that was being produced by different engineering sections. By far the most complex was the Signal Processor whose set up was crucial in capturing the required target. We also designed the Master Synch Unit, installed within the cabin, that took into account the synchronisation with other ships radars and traffic. This was crucial to ensure that signals considered as clutter did not appear in the active range gates of the processor. Prior to the installation on ship there was exhaustive testing in the factory at Writtle road including climatic checks in the environmental chamber. Some of these tests involved 24 hour testing and those of us in the development team were required worked shifts. By the time we started testing at Bushey Hill we were certain that the ruggedised version of the equipment was fit for deployment. Prior to the sea trials we performed clutter mapping fine tuning the equipment while in the dock at Devonport.

 

During the sea trials, shells were fired from a local battery and successfully acquired and tracked by processing system. This was a significant achievement in the development process and any recommended changes were incorporated into the processor models later deployed on active service

 

 

Seawolf simulation video

 

GWS 26

Extract from Haverhill Museum article - see Editors note above

This system [Locus16] was used in conjunction with the Sea Wolf a naval guided missile system designed and built by BAC, later to become British Aerospace (BAe) Dynamics (now MBDA). It is an automated point-defence weapon system designed as a final line of defence against both sea-skimming and high angle anti-ship missiles and aircraft. It has been fielded by the Royal Navy in two versions: the GWS-25 Conventionally Launched Sea Wolf (CLSW) and the GWS-26 Vertically Launched Sea Wolf (VLSW) forms.

Shipborne trials of the Seawolf were carried out on a modified Leander class frigate, HMS Penelope, from 1976 onwards. Sea Wolf was tested with a vertical launch system early in the missile's development on a modified Loch class frigate, Loch Fada, but for unclear reasons work did not continue in this direction: the GWS-26 "VL Seawolf (VLS)" being a much later (1980s) development. During trials the missile performed impressively, successfully intercepting a 114 mm shell on one occasion.

The first deployment, in the GWS-25 form, was on the Type 22 frigate (2 systems) and later on modified Leander class frigates (1 system) in six-round, manually loaded, trainable launchers.

It has been used by the Royal Navy since 1979 and was fired in anger during the Falklands War. Current deployment is the GWS-25 Mod 3 system on the Type 22 Batch 3 and the GWS-26 Mod 1 system on Type 23 frigates. The latter fields 32 vertical launch missiles (VL Sea Wolf) in its missile silo. It is expected to remain in service until 2020.

 

Articles - 1. 2. 3. 4. 5.

Wikipedia entry

 

 

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