14

In Conclusion

The Royal Navy’s Task

For half a century after the end of the Second World War there was a clear threat from the Soviet Union. At sea the perceived threat came first from the powerful cruisers of the Sverdlov class, which had an important effect on RN planning – for example, the 5in cruiser destroyer was seen as a Sverdlov killer (as was the battleship Vanguard). At the same time there was an enormous build-up of the Soviet submarine force. The Korean War was seen (perhaps wrongly) as demonstrating Soviet will for conquest.

The Admiralty dreamt of restoring something like prewar glory and only slowly realised that the economy would not support a large navy. The protection of the remains of the Commonwealth – ‘East of Suez’ – was important while there were a number of small but troublesome confrontations. The Korean War led to fairly large frigate programmes and a very large programme of minesweepers. Gradually, the primary task was seen as protection of convoys bringing US troops across the Atlantic to reinforce the central and northern fronts. The Soviet naval air force, based on the Kola Peninsula, was seen as an increasing threat and the carrier CVA-01 was designed to counter this threat by pre-emptive strikes.

With the demise of the fleet carrier force the RN’s role became even more concentrated on escort work. More recently the Falklands War, the 1991 Gulf War, and Afghanistan have all shown the value and flexibility of sea power, which is much less dependent on land bases and minimises problems of overflight of neutral or hostile territory. This has led (2002) to a new amphibious force and the promise of new carriers equipped with the Joint Strike Fighter.

Constraints

Shortage of money was and is the most obvious constraint, and funds for the navy have never been abundant. However, naval manpower has affected the size of the fleet and the design of ships, leading in particular to dramatic improvements in living conditions to help attract and retain personnel. There are other limiting factors, perhaps the capability of British industry being the main one. One may instance the introduction of the gas turbine, in which British aviation firms were world leaders, replacing steam turbines whose supporting industry was dwindling. Competition may have been effective in keeping prices down but, in 2002, almost all major warship building is in the hands of BAE Systems.

Missiles began to dominate – Norfolk firing an Exocet. (D K Brown collection)

Good seakeeping is vital to modern surface warships and the Leanders (this is Diomede) were the best for their size in NATO – at least prior to the ‘Dukes’.

(D K Brown collection)

Technology

In ship technology (hull and machinery) the UK has led in many areas, and been well up in others.¹ It is suggested that much of this success was due to the close links between the design team and research establishments working in hydrodynamics and structures. By far the greatest British achievements have been in the field of noise reduction, so that RN surface ships and submarines have been the quietest, a full generation ahead of their rivals. From about 1960, 10 years before other navies, AEW Haslar was able to design propellers with about double the quiet speed of earlier designs, and much quieter even above that speed when cavitation has begun. Air bubble screening was developed at AUWE, Portland, with ‘Agouti’ adding to the performance of quiet propellers, whilst ‘Masker’ screened machinery noise. Pumpjets from ARL Teddington further reduced submarine propulsor noise. AEL, West Drayton, and NCRE, Dunfermline and Rosyth, did wonders in reducing machinery noise.

Questionnaires on seakeeping among NATO navies consistently show British ships as leaders.² Submarine pressure hull design has been led by NCRE, whilst Ship Department with help from ARL developed the first full computer aided ship design system. The E-in-C led the way on gas turbine propulsion in NATO. New materials – GRP, steels, paints – have made ships stronger and reduced the maintenance load. It is notable that many of these advances may be attributed to a single individual and, where possible, these have been named in this book.³

One of the greatest post-war US naval architects, Dr Reuven Leopold, summarised his doctrinal thesis in a paper on innovation. His two examples of successful innovation were both British – gas turbines and fin stabilisers.⁴ He even gave a lecture in Ship Department, Bath, on this theme and was rather surprised that his British audience were not sure that the decisions taken were right and, even if they were right, that they had not been taken for the wrong reasons. NATO Committees formed a very competitive environment: to address one’s colleagues on the theme ‘First Again’ was very gratifying.

The Ships

These have been described and, at least in part, appraised in earlier chapters, and here one can only draw a few general conclusions. The first group of frigates were outstanding. The Whitbys and their derivatives were truly great, whilst the diesel-engined ships were inevitable given the state of the UK turbine industry – and some are still giving good service. The Blackwoods were uncomfortable but had almost the AS capability of a Whitby at half the cost. They would have been better and probably cheaper with simpler structure making them a little bigger. They were first-rate in ASW, second-rate only because they had little capability for any other role. Had war come, they would have been better appreciated.

The ‘Tribals’ were an attempt at a second-rate, multi-role ship and failed to do anything very well and were unduly costly,⁵ though they introduced several technical developments. The Leanders were so good that it was difficult to design a better ship at a comparable price. Attempts at a cheap frigate failed because the only long range ASW sensor was a big hull mounted sonar making the ship and its services itself big and expensive. Towed array sonar made cheap and effective frigates possible, as for example the ‘Duke’ class.

Hardy, of the Type 14 Blackwood class. They were a reasonably successful attempt at a cheap frigate. (Crown Copyright)

Coniston, lead ship of the successful Ton’ class. (D K Brown collection)

Norfolk, lead ship of the numerous Type 23 ‘Duke’ class. (Mike Lennon)

The ‘County’ class had an excellent hull with novel and successful machinery but was let down by the failure of Sea Slug to live up to expectations.⁶ Bristol would have been more capable and cheaper but lost its role with the cancellation of the carriers. The Type 42 proved a valuable type of ship but was too small. The Type 22 was the true Leander replacement and a success.

Carriers exemplify the saying ‘Big is Beautiful’. Contractors for the new carriers under development have found that increasing the size actually reduces the cost, due to easier installation and maintenance. Many people both in the Admiralty and in industry had been saying this for years but no one listened.⁷ The Invincibles were another success.

At the other end of the scale, MCM vessels starting with the ‘Ton’ and ‘Ham’ classes have been very successful. GRP construction has been developed in partnership with Vosper-Thornycroft through Wilton, the ‘Hunt’ class to the Sandowns, and their capability has been proved in several operations.

The principal attributes of an attack submarine are speed, diving depth and silence. British submarines are constrained in cost, and many good designs have been dropped for that reason, but they are the quietest. Valiant started from scratch and hence is the author’s personal choice for all-time greatness, but Swiftsure and Trafalgar still improved on that good start. Comparisons of designs between different navies with differing roles and constraints are difficult but one such exercise is summarised in Appendix 5.

It is hoped that the reader will now be convinced that most of the decisions made by the Naval Staff and Ship Department were correct, or at least inevitable. Technically, there has been a willingness to innovate shown by novel designs such as the Whitby, Invincible, quiet submarines and the GRP minehunters. New ideas continue to flow, illustrated by the trimaran Triton and the WR-21 gas turbine, possibly combined with all-electric propulsion (see below).

The Royal Navy may not be the first-rate power seen at the end of the Second World War but the quality and flexibility of the fleet is being demonstrated in no uncertain terms. At the time of writing (mid-2002) the future appears bright, though the time taken to get new designs into service remains a matter for concern.

A Glimpse of the Future

At the time of writing, the future is very bright with two big aircraft carriers, a new class of nuclear submarines, six destroyers (six more to come) and numerous amphibious force ships planned, with steel work started on some. Let us hope these ships materialise. Brief notes follow.

The early studies for the two new carriers are outlined in Appendix 6. These are being developed by two competing consortia (led by BAE and Thales) and the final version may differ. Both team have increased size in order to reduce cost and it seems that the new ships will displace about 50,000 tons.

The Daring class Destroyer (Type 45)

The Type 45 destroyer programme is being led by BAE Systems and six have been ordered, with a promise of six more to come (2002).⁸ Much of the Horizon project work, including the weapon system, can be incorporated so that a fairly short timescale is hoped for – just as well considering the age of the Type 42.

An impression of the Type 45 destroyer to be built by BAE Systems and Vosper Thornycroft.

(BAE Systems)

Armament includes a Sylver vertical launch system with Aster 15/30 missiles (PAAMS), a Mk VIII Mod 1 gun and two smaller guns. Aster 15 is a close-range weapon and Aster 30 longer range; both are highly manoeuvrable. There will be a British Sampson multi-function radar and the S1850 search radar, hull and towed array sonars. Batch II ships will have enhanced land-attack capability.

Accommodation is provided for a crew of 235, of which 187 are the basic complement and the remainder a training margin. Space per man is up by an average of 39 per cent with single-berth cabins for officers, single or double for senior rates and six-berth for junior rates. The bow and much of the superstructure will be built in a new Vosper-Thornycroft yard in Portsmouth Dockyard, with the rest being divided between BAE yards on the Clyde (Yarrows) and at Barrow. 01 will be assembled on the Clyde, later ships at Barrow.

Basic details are:

7350 tonnes, deep. 162.4m × 21.2m. Endurance

7000 miles at 18kts.

The follow-on class, known as the Future Surface Combatant, is being studied – it may be an enhanced Daring but might be a trimaran.

The WR-21 Gas Turbine

The Northrop Grumman/Rolls Royce WR-21 gas turbine has been selected for the Type 45 destroyer and may be used in the new carriers. This 25MW engine has been developed by Rolls-Royce under a USN project, now joined by the UK and France; development costs up to the beginning of 2001 has been stated as £300 million. Northrop Grumman has a 50 per cent work share, Rolls-Royce 40 per cent and DCN 10 per cent. It has an exhaust recuperator, an intercooler and variable area inlet nozzles to the power turbine using units based on RB211 and Trent aircraft engines.⁹This gives it a flat fuel consumption curve and its fuel consumption averages 27–30 per cent less than conventional gas turbines. Because of the improvement at low power it is possible to do away with cruising engines, saving space and maintenance and simplifying gearboxes. It is designed to fit the same base as the widely used LM-2500 engine.

A prototype completed a 500-hour test at DERA, Pyestock, in 1997 and an engine to full production standards was due for a 3150-hour trial at Indret (France) late in 2001. The WR-21 will power an integrated electric propulsion system serving both ship propulsion and services. Podded propulsion has been used in several recent cruise liners but is probably seen as unproven at the power of a Type 45.

The first six ship sets were ordered early in 2001 at a cost of £84 million.¹⁰ They will each deliver 21.5MW and there will be two engines in the forward machinery space, together with two 2MW diesel generators. The after machinery space is separated by one compartment and will contain two advanced induction motors of 20MW with supporting services. The system has been developed over a decade by the USN at Philadelphia.

Astute class attack submarines

BAE Systems were awarded a £1.9 billion contract for the design and build of three Astute class in March 1997.¹¹ Originally described as ‘Improved Trafalgars’ they have the PWR 2 reactor from Vanguard, implying an increase in pressure hull diameter, and have six tubes instead of the five in Trafalgar. They have an updated tactical weapon system, a 50 per cent increase in weapon load, reduced complement and are even quieter. They will displace about 7200 tons, partly to reduce building costs. Fabrication of Astute began in September 1999 but the programme has been delayed and she is not expected to enter service until late 2006. Originally a second batch of two was planned but this may be increased to three at a cost of £1.7 billion as this would save the cost of a Trafalgar refuelling.

An impression of Astute.

(BAE Systems)

Future Attack Submarine (FASM)¹²

Studies have begun into attack submarines to follow the Astutes. It is almost certain to be nuclear powered but alternatives are considered – seven out of ten current options are nuclear powered. Targets include a 10 per cent reduction in first cost and 30 per cent reduction in through life costs compared with the Astute.

Amphibious Warfare Ships

Both the LPDs (Albion and Bulwark), and the Alternative Landing Ship Logistic are covered in detail in Chapter 11.

Electric Propulsion

There have been a number of developments in electric propulsion which are truly revolutionary. The weight of a generator or motor is expected to be about one-tenth of that of current machines, whilst reduction in the size of the bulky rectifier is likely to be even greater. The main generators will supply auxiliary power for all purposes and it should be possible to adopt a degree of separation and redundancy which will greatly reduce vulnerability to enemy attack.

The Trimaran Triton

Trimarans have been in use in the Pacific for all of recorded history and the idea was picked up by Nigel Irons in his record-breaking vessel Ilan Voyager.¹³ Professor D R Pattison RCNC and his assistant J W Zhang at University College London developed the idea in a series of design studies for much larger ships, including a range of warships from patrol vessels to aircraft carriers, as well as ferries.

The obvious advantage of this configuration is a reduction in the power required at high speed by about 20 per cent, but there are many others. Pitch and heave in head seas will be about the same as in a conventional ship of the same length but less than in such a ship with the same payload. The outriggers govern stability, allowing heavy weights to be carried high up, whilst the broad deck amidships allows a convenient landing deck for helicopters and for their hangars. The outriggers give some protection against torpedoes and sea-skimming missiles and can help to reduce the ship’s signatures.

The Ministry of Defence began to show official interest, as did Vosper-Thornycroft, and model tests were carried out in the Haslar ship tanks together with structural investigations at Rosyth. The loading and hence the stresses in the cross structure were the main area of uncertainty. It would be easy to overdo it and build a heavy (and costly) structure which would nullify the advantages, whilst an underestimate would be catastrophic. Damage stability calculations were more complex but presented no serious problems. These investigations confirmed the advantages and gave a very good guide to the structural design.

The trimaran demonstrator Triton. (Vosper Thornycroft)

The characteristics of the trimaran made it seem very suitable for the future frigate programme to follow the Type 45, but it was thought unwise to commit a major part of the navy to a concept which had not gone to sea. It was decided to build a demonstrator to prove the basic approach. There followed a lengthy period of negotiations and studies leading to a design which was big enough and fast enough to prove the concept yet simple enough to be affordable. The contract was awarded to Vosper-Thorny-croft at the end of July 1998 at a cost of £13 million. Cutting of steel began in January 1999 with construction in four 250-ton blocks. Triton was launched 97 per cent complete – on time – on 6 May 2000. Preliminary trials were in July 2000 and she was accepted at the end of August.

The main hull is of round bilge form with gently rising buttocks to a small transom stern. The side hulls are multi-chine outboard with a plane inboard face for ease of construction. The structure may be seen as simplified warship style with fairly thin steel plating and longitudinal framing, though it is not designed to warship shock standards. It complies with Det Norske Veritas’s High Speed and Light Craft rules. There are nine watertight bulkheads to satisfy damage stability requirements and contribute to transverse strength in way of the cross deck. Since the wetted surface area of a trimaran is greater than that of a mono-hull, it is important to reduce fouling as much as possible. She has been coated with Hempel’s SP-EED biocide free, silicone-based anti-fouling paint with a very low friction, non-stick surface. It is hoped that this paint will have a life of 15–20 years.

There is a flight deck that can accept a Lynx helicopter, and up to eight containers can be carried with trials equipment. There is a work boat with crane to starboard of the superstructure. Triton is a diesel-electric ship with two Paxman generators giving 2085kW. The main shaft is driven by a 3.5MW motor with a single fixed pitch propeller and the fixed side hull thrusters are of 350kW, each which give a speed of 12kts. The cabins are single or twin pre-fitted modules complete with a ‘wet’ (toilet) space. Variations in geometry, such as with two side hulls, one behind the other, on either side, have been tested.

It is understood that Phase I trials have been completed very satisfactorily. These have confirmed her performance, handling and general operation. In particular, seakeeping will be studied in increasingly severe sea states, which will include monitoring of the stresses in the hull. These trials are being run in partnership with the US Navy Sea Systems command, who provided the Trials Instrumentation System (TIS) – it has been said that this cost more than the ship! She will also carry out trials with an unmanned air vehicle.

Early in 2002 the main electric motor will be changed to a permanent magnet machine leading into Phase 2 trials up to March 2004. Details are not finalised but will probably include integrated technology masts, 8MW and 1.25MW gas turbines, composite shafts and electric rudders. In later years she will be used for trials by MoD and may be chartered by others concerned. In 2003 she was fitted with a propeller made of carbon-reinforced plastic.

In the author’s personal view, all design is a compromise and if one aspect is enhanced, there is usually a price to pay elsewhere. However, in the development of the trimaran it seemed that virtually everything improved at the cost of a small increase in structural weight and complexity.

¹ The author has been associated with several of these advances but only as part of a team.

² Canada’s St Laurent is another favourite, but she was designed by Rowland Baker, a British constructor.

³ Apologies for any omissions or errors.

⁴ Dr R Leopold, ‘Innovation Adoption in Naval Ship Design’, Naval Engineers Journal (December 1977).

⁵ I cannot understand why the ‘Tribals’ were more expensive than the Leanders.

⁶ It is claimed that Sea Slug was no worse than the early models of Terrier and that it should have been developed rather than replaced.

⁷ P J Usher and A L Dorey, ‘A Family of Warships’, Trans RINA (1982). This paper by two senior directors of Vosper-Thornycroft was taken very seriously. Their claim that a larger ship would be cheaper to build was examined by DNC cost estimators, who concluded that there would be little difference in cost. I argued, unsuccessfully, that if there was no difference in cost the larger ship should be chosen for improved seakeeping and easier maintenance.

⁸ Names announced are Daring, Dauntless, Diamond, Dragon, Defender and Duncan.

⁹ The technology is very much that tried in the RM60 engines for Grey Goose.

¹⁰ ‘IEP for Daring Class’, Warship Technology (May 2001).

¹¹ Names announced are Astute, Ambush, Artful.

¹² ‘Affordability is the future for FASM’, Warship Technology (May 1999).

¹³ Ilan stands for ‘Incredibly Long And Narrow’.