The Butterfly Effect: A British AAR

Chapter LXV: The New Pride of the Fleet.​

Having considered the long term plans and the doctrinal considerations we can at last turn our attention to the actual design of the Royal Navy's new warships, a field that was the purview of the Royal Corps of Naval Constructors (RCNC) and it's head, the Director of Naval Construction (DNC) Sir Stanley Goodall. The post of DNC had been in decline since the days of the great Sir Tennyson d'Eyncourt, designer of everything from the pre Great-War R-class destroyers through to the Nelsons. The relatively brisk rate of naval expansion therefore was a test of a branch that had not fully designed anything larger than a slightly modified County class cruiser for almost a decade. Even the many smaller vessels that had been designed had been essentially evolutions of existing vessels, the progression of the 'Post-war standard' class of destroyers being the classic example. On the positive side the many modernisation programmes had allowed some experience of large vessels to be retained and the Naval Staff attached several officers, both staff and fleet, with experience from the Abyssinian War to ensure the hard learned lessons were communicated to the more detached designers.

Following the Navy's priorities let us begin with the battleship, specifically the new King George V class. The class had begun life as a series of design studies, a method for the Admiralty and Government to establish the British position for the abortive Second London Naval Conference. By producing a string of outline designs with varying tonnage, speed, armament and armour it was hoped to establish what limits Britain could accept and which restrictions would produce unacceptably compromised designs like the Nelsons. By late 1935 the design had been progressed to a 35,000 ton, ~28knot, well armoured vessels armed with 10 x 14" main guns, far from what the Admiralty had originally wanted but all that could be extracted from the tonnage given the diplomatic, political and treaty considerations. With the failure of the conference the Naval Staff were free to push up the specification and while the Abyssinian War raged the RCNC worked away to 'optimise' the design. Of course the ideal solution would have been a blank sheet of paper design to completely break free of the treaty limits, however the Admiralty was very keen to get hulls on the slipway as soon as possible, before the government, or the Treasury, had a chance to change their mind. This compressed schedule forced the designers to reuse much of their earlier design work and would mean the Royal Navy having to wait for it's first proper post-treaty battleship.


The final design was essentially a fusion of two earlier designs, coded 14A and 15C, the former was used for the basic hull and armour, while the latter was the basis for the armament and machinery. Turning our attention to the 15C design elements first, as their heart were 9 x 15" main guns in three triple turrets, two forward and one aft. Notably these guns were not to be the venerable 15"/42s MkIs used by the rest of the battlefleet but the brand new 15"/45s MkIIs in equally new mountings. Though using identical ammunition to the older guns the new 15"/45s incorporated many new features, most importantly switching from wire-wound to all steel construction and a revised "all cast" recoil mechanism. The effect was lighter, stronger and more accurate guns, testament to the value of Ordnance Board's belated re-discovery of thorough testing and experimentation. The mountings were based on the triple turrets of the Nelson class but incorporating all the many changes and revisions that had been implemented on the originally far from successful design. As excellent as this work was, and both guns and mounts proved reliable and accurate in service despite slight initial teething problems, it did take up much of the RCNCs time and thus other areas of the design received less attention. This was most apparent in those elements drawn from the the 14A, many of which were essentially adopted wholesale with little time for revision or alteration. While the impact was slight in most cases, this enforced prioritisation would see the final design fall just short in one significant area.

The 14A design had been for 12 x 14" guns in three quad turrets, a decidedly optimistic target given the substantial amounts of armour and 28 knot speed the design also specified. To accommodate this the original design was longer and beamier than the 15C, making it a more stable gunnery platform but pushing up the tonnage further. While the 14A had been discarded precisely due to such concerns, hence the 10 x 14" of the final 1935 design, it was those very 'problems' that made it perfect for the RCNC who, no longer constrained by tonnage limits, could afford to breach the now arbitrary 35,000 ton barrier. The main work was in switching the three quad turrets for the three triples and simplifying the below deck gun workings accordingly; for instance dropping from 12 to 9 guns allowed a theoretical 25% decrease in magazine size and ammunition handling facilities. Gains such as these, even after the switch from 14" to 15" guns and shells reduced the theoretical gain, provided significant extra internal tonnage, space that the RCNC used to fit extra machinery in order to reach the 30 knot target speed recently set by the Naval Staff. Despite these efforts something had to give and, even though the new ships came in at a hefty 38,000 tons standard load, it was the target speed that suffered; HMS King George V herself just breaking 29 knots when in trials. It was somewhat unfortunate for the Sea Lords that so soon after setting the battleline speed at 30 knots they had to approve a design that didn't meet it, however the priorities of the Admiralty remained "Armour, Arms then Knots" and, given the tonnage, the new battleship certainly fulfilled the first two categories with aplomb.

Turning from the battleship we consider it's great rival the aircraft carrier, in this case represented by the new Ark Royal class. While the design work on the King George Vs had been rushed the speed was as nothing compared to that put into the carriers for the simple reason that the lead ship, the Ark herself, was on the slipway when the order for the re-design went out. The re-design had two parts; increased protection and improving air operations. Taking the former first the work is as notable for what was not done as what was carried out, had it not been for the post-war review it is likely the work on the Ark Royal would have been to implement the 'armoured box' design concept, essentially armouring the flight deck and sides of the ship. This concept was very much in line with the thinking of the RAF, and hence the FAA of the time, that 'The bomber will always get through', hence the necessary protection from the inevitable bombing. The concept had been dropped from the original design as the weight increase would have taken the new ship beyond treaty limits and, more worryingly, risked compromising stability and manoeuvrability of a design that already had an alarming large turning circle. With the official policy set to counter the torpedo, not the bomb, it is unsurprising that that 'armoured box' concept was not revived and that instead torpedo protection improved. In the case of the second Ark Royal class, HMS Bulwark, this entailed a re-design of her 'sandwich' protection and interior division, increasing her beam and bringing her torpedo protection up to the standards of the KGVs. For the Ark herself this was not an option, too much work had been done on the keel and the dockyard would have had to virtually start from scratch to implement it. Thus the decision was made to retrofit the slightly out-dated 'torpedo bulge' form of protection onto the part built hull, a most inelegant fix that required significant internal cross bracing and disrupted the lower deck layout. The upshot for the Ark was a marginal increase in torpedo protection, a 0.5knot slower top speed than her half-sister HMS Bulwark and an un-necessarily complex machine room arrangement that complicated maintenance and upgrades her entire life. With the benefit of hindsight it would have been better to either start again or not do the work at all and, given the later changes to the hangar and flight deck depended on a beamier hull, it would have been wisest to do the former.

The second set of changes came from operational experience but also allow an insight into the naval bureaucracy of the time, a system that was both a great strength and a terrible liability for the Royal Navy. Admiralty records were amongst the most comprehensive in Britain, almost everything was recorded officially whether success or failure giving the Navy an outstanding 'institutional memory' of what it had tried, tested or examined stretching back centuries. The flip side was the tendency of temporary decisions to be made permanent by bureaucratic inertia, in the case of the FAA a late 1920s target strength of 360 machines had been transformed into a mid 1930s limit of 360 machines, certainly in the eyes of the treasury and the RAF neither of whom wanted to increase FAA spending. This decision prompted the navy to artificially limit carrier air groups, for the simple reason that putting too many on one hull would 'use up' too much of the limit and severely reduce their chances of getting additional ships authorised. Hence the original 72 machine target for the Ark Royals had been allowed to wither away down to 48, though in fairness some of this shrinkage was also needed to help meet the target tonnage; less aircraft meant less support equipment (fuel/ammunition storage, crew quarters, repair equipment, etc) and hence less tonnage. With the tonnage limitations removed, and the FAA quick to abolish the 360 machine limit, the designs were pushed back up to the 72 machine target, indeed as the FAA began to establish itself and break away from it's former parent's thinking that target would be pushed still higher.

The FAA was still very much a service in transition in late 1936, despite the re-establishment of the post of Fifth Sea Lord and the Naval Air Service, complete with as much staff and support as the Navy could muster, the FAA still relied upon everything from RAF training programmes through to shore based repair and maintenance depots. As we shall see later it would take the judgement of the independent Ministry for Defence Co-ordination to oversee the sharing and splitting of those facilities, however in terms of strategic and operational thinking the FAA managed to break away far faster, doubtlessly helped by the Abyssinian War which enable a great deal of junior, and not so junior, officers to try new ideas out in combat. Amongst dozens of tactical lessons and design 'tweaks' that came from that experience several key ideas came out, not least the confirmation that the pre-war air groups were too small for extended fleet operations. Having been denied funding for large scale exercises it took the experience of the war to confirm that the RAF figures on availability, turn around times and so on did not translate well from land based aerodromes to carriers. To solve this problem the FAA wanted to further increase the machine target, however it was apparent that most of the extra beam was needed for support equipment and aircrew/mechanic quarters for the 72 machine target. The solution was to turn to the previously mentioned 'institutional memory' of the Navy, digging out an old investigation into 'on deck' aircraft stowage an option that had been previously rejected, however it soon became apparent this was a political, not practical, rejection. 'On deck' parking was not an operational problem, particularly not for the Ark Royal class as they were equipped with twin hydraulic catapults and purpose designed arrestor gears, but would have meant the 360 machine limit being reached far earlier, thus potentially robbing the fleet of additional carrier tonnage. Thus the final design of the Ark Royal was to included provision and, crucially, supporting equipment and crew quarters for aircraft stowed on deck using the last of the extra tonnage and volume made available by 'bulging' the hull.

In summary the final designs were far from perfect; the aircraft lifts and hangars would prove to be too small for the rapidly advancing aircraft size, the much vaunted hydraulic catapults would require a string of upgrades to deal with the increasing weight of aircraft and HMS Ark Royal herself continued the tradition of early British carriers by being something of a compromised design. However HMS Bulwark would prove a fine ship and the starting point for the larger, follow on designs of carrier and both ships were the first in the Royal Navy that could carry and support large air groups, a pattern that would be followed in latter designs. For those reasons alone the designs have to be considered a success, regardless of their other qualities.


Leaving behind capital ships we turn to the new cruisers and destroyers where, in stark contrast to the designs considered above, things were considerably simpler. With most of the RCNCs time devoted to the capital ships there were quite simply not the resources to engage in wholesale redesign elsewhere as well. However given the generally high standard of the existing designs this was not a significant omission, though it is interesting to speculate what would have emerged if the Sea Lords had felt able to delay the designs while they re-thought their requirements for a post-treaty world.

Taking the Southampton or 'Town' class cruisers first, they were treaty ships through and through; conforming to the letter but perhaps not the spirit of the agreements. With heavy 8" armed cruiser restricted the obvious loophole was equally large ships but armed with a preponderance of 6" guns, a common solution that produced the USN's Brooklyn class and the IJN's Mogami class. While the class was partly a response to those vessels it was also designed to fill a gap in the fleet, that of 'fleet' cruiser as opposed to the 'trade protection' classes that had dominated construction in the 1920s and 30s. Taking one quite harsh assessment no new 'fleet' cruiser had entered service since the Great War era 'C' and 'D' classes, while perhaps an exaggeration it is certainly true post war cruisers had tended to emphasise the 'trade protection' requirement of endurance, high free board and efficient cruising speed at the expense of the bristling guns and large ammunition stocks looked for in a fleet cruiser. While a true fleet escort cruiser would have to wait for the follow up Dido class the Southamptons were certainly better designed for fleet work than their predecessors. The design process of the class was something of a challenge for the RCNC, aiming to equal or exceed the IJN's design it was found impossible to match the Mogami's 37 knot speed and 15 x 6" guns within the tonnage, indeed even getting respectable armour and 15 guns on a 32 knot vessel proved impossible, Sir Goodall summed up the RCNC view of the Japanese design by stating "They must be building their ships out of cardboard or lying". The reality was the IJN were doing both; the Mogamis were both over weight and incredibly lightly built, making extensive use of thin aluminium and light duty welding (leading to serious hull cracking during trials) and seriously skimping on protection.

All this however would not be known by the Royal Navy until the Secret Intelligence Service operations in Japan kicked into high gear later in the decade, thus while the Admiralty suspected such tricks being used they could not prove it and get a cautious government to allow them a similarly relaxed attitude to tonnage. Hence the design emerged at 32 knots with 12 x 6" guns in triple turrets, the 6"/50 BL Mark XXIII gun from the Leander class that had given solid, in unspectacular, performance in the Abyssinian War. With the treaty lifted the way was clear for a total rethink, everything from uprating the guns to the 8"/50 Mark VIIIs from the County class through to skipping the design entirely and jumping to the Dido class was proposed. However the Admiralty was, as with so much of the 1936 Naval Programme, keen to get tonnage laid down, or at least approved, while the Navy's stock was high and the Treasury was prepared to pay for it. While not the best reason for pursuing a design bitter experience had taught the Sea Lords that opportunities for new tonnage should be taken whenever they became available, their belief was better a less than perfect ship than no ship at all.

Finally we come to the Tribal class of destroyers, by far the simplest to cover for the simple reason it was a design that the Navy had no desire to change. As a destroyer the class had been, mostly, free from treaty constraints and so the design had evolved naturally, if somewhat slowly, via many permutations (including an abortive attempt at being a very light fleet cruiser) to a point the Admiralty was happy with. As with the Southampton class the Tribals were more a fleet unit than an escort unit, though it is worth noting that destroyers were considered 'maids of all tasks' by the Admiralty; a destroyer could be expected to lay mines, hunt submarines, act as a scout, form the screen for a fleet, defend against enemy aircraft or engage capital ships in torpedo attacks. Indeed it was this flexibility, and the relatively low cost (including weaponry the 'I's had come in at around £250,000 a unit, a bargain compared to a £2,000,000 County class cruiser) that gave rise to the Admiralty's regular request for more destroyer tonnage. Such attitudes not withstanding there was a distinct lack of fleet destroyers, again it is arguable the last fleet destroyers had been the Great War era V and W classes, the post-war standards lacking the fire-power, particularly gunnery, necessary for the role. Moreover it was realised that a ~1,400 ton destroyer was fast becoming somewhat small in comparison to the designs of rival navies and that a major jump in tonnage would be required to retain parity. Taken together this produced a 37 knot, 1,850 ton design with eight 4.7"/45 QF Mark XII in four twin mounts and only four torpedo tubes (as opposed to the four single 4.7"/45s and ten tubes of the 'I's). While the design suffered the Achilles heel of most of the 1936 Naval Programme, a worrying lightness in terms of anti-aircraft weaponry, they were overall a great success in service, being both popular with crews and admired by the public.

With our analysis of the Royal Navy complete we can move on to the Royal Air Force, a service having to cope with major organisational changes while absorbing the lessons of the Abyssinian War. As we shall see in these tasks the Air Staff were alternately helped and hindered by the new Secretary of State for Air, a certain Winston Churchill.