The Butterfly Effect: A British AAR

Chapter LXIV: Learning From The Past.​

The Navy Board's post war design review is generally regarded as an infuriating mix of intelligent analysis and missed opportunities, some experiences carefully dissected and thoughtfully applied while others languished ignored. In fairness to the Admiralty many of the lessons so obvious in hindsight were far from clear at the time, especially given the facts of the engagements that the conclusions were based on. Before looking at the review in detail it is worth briefly outlining the war experiences and the doctrine that informed the review.

From a purely naval perspective, and excluding the amphibious operations, the Abyssinian War consisted of four major set piece engagements (First Taranto, Coast of Tobruk, Second Taranto and the Taranto Raid), a determined convoy raiding campaign against the Italian supplies lines and a ongoing convoy protection operation for British shipping. Naturally the large battles had dominated both public and political opinion, being both better spectacles and the simplest for laymen to follow, though they were also the subject of much discussion throughout the fleet; a chance to serve on a battleship and fight a grand battle being the reason many officers had signed up. For the Naval Staff however the major battles were but one part of the picture, an important part no doubt but not something that could, or should, be considered in isolation from the other operations of the war. This wider view of the role of the fleet was a reflection of the essentially Corbettian attitude of the Admiralty, not that they would have expressed it in such terms. Given the vast size of the Royal Navy, even allowing for it's disparate and globe spanning commitments, the Admiralty felt it was more than possible to maintain both the correct 'Corbettian' control of the sea while a portion of the fleet engaged in seeking a 'Mahanian' decisive battle. Such had been the strategy of the Abyssinian War and events had, in the opinion of the Naval Staff, shown it to be correct. Future events however would show this position was not tenable in the face of more formidable opponents than the Regia Marina.


Having briefly touched on grand strategy we move onto the specific lessons of the war, ignoring low level tactical lessons on ship movement and positioning and the miniature of revised bridge layouts and so on. Reproduced below are the main lessons drawn from the conflict, presented in the same order and wording as found in the conclusion of the the Naval Review;

• Battleships remain the main 'battle winning' unit for at-sea engagements
• The role of aircraft, both shore and ship based, is to support and supplement battleships.
• The main aerial threat comes from air launched torpedoes not bombs.
• High speed, in both sustained long cruises and in combat, is of considerable, but not vital importance.
• Anti-Submarine operations were far less effective than expected and further investigation is recommended.

While hindsight tells us that the rapid advance of technology would render much of that list incorrect, save for the last two points, it is a most interesting insight into the thinking of the time. The list will be broken down below, but the general trends were the promotion of carriers and aircraft in general (though not as high as perhaps it should have been), the inclusion of shore based aircraft in the review (a nod towards Coastal Command and the MoDC's push for inter-service co-operation) and the focus on the submarine threat as pre-war confidence was proved somewhat misplaced.

Taking the first point, the primacy of the Battleship for 'at sea' engagements, it is tempting to believe the more conservative elements of the Staff determined that outcome first and then distorted the following lessons fit. In reality however the chain of reasoning in fact started with the third point; the perceived ineffectiveness of aerial bombing. While this would prove to be equally incorrect, it was at least a far more justifiable believe given the evidence to hand at the time. The history of aerial attack on surface vessels was, at best, patchy; the much touted 'decisive' Osterfiredland test conducted by United States in the 1920s had only proved that heavy bombers with 2000lb bombs could indeed sink stationary, uncrewed and obsolete vessels if given enough time. Conversely the test against HMS Agamemnon conducted in the late 1920s had shown that a slow, unarmed battleship manoeuvring on remote control could avoid being hit from the air. Outside these trials there was much evidence from actual attacks on smaller vessels; the Dutch De Zeven Provinciën and Greek Averoff had both been ineffectually but deliberately bombed by their own side, more pertinently there was the disappointing performance of the Fleet Air Arm Seals at the Battle of the Coast of Tobruk. Taken together these experiences had left the Navy convinced aerial bombing was not a threat, even arch FAA advocate Lord Keyes conceded that battleships had less to fear from bombers than from from plunging fire with armour piercing ammunition or, significantly, large torpedoes.

There were, of course, caveats to that view. The complete lack of a purpose designed dive bomber in either RAF or FAA service had prevented that type from being tested, an oversight the FAA was well aware of but had not been able to overcome due to RAF resistance to the concept. The FAA's drive to acquire a dive bomber, discussed later, is indicative of the high hopes they had of the concept, however at the time of the review it remained just that - hopes, not something on which you could base a radical change in strategy. The other major caveat was hinted at in Lord Keyes comment above, the air launched torpedo was quite explicitly excluded from the assessment of the aerial bombing threat. However the torpedo was considered a known quantity, ever since the first torpedo boats in the late 19th century people had been claiming the torpedo meant the end of the Battleship. That's not to say the Naval Staff ignored the problem, for instance there was a general re-assessment and uprating of torpedo protection on the new capital ship designs, however the threat was not considered grave enough to require re-thinking the very basis of British naval strategy. This perhaps shows the key problem of the review in microcosm, the failure to think ahead and make any allowance for improving aircraft performance and advancing technology. Fortunately they were far from alone in this mistake, air power advocates the world over encountered similar problems, however given the pioneering role of the Royal Navy in naval aviation the failure to capitalise on that lead must be marked as, at best, a missed opportunity.


Moving on down the list, we come to the somewhat vaguely worded statement on speed. This point reflects the difficulty in compressing a somewhat wide ranging idea down to a brief sentence, for the review had reflected long and hard on the 'ideal' speed for future warships. This was no easy task for speed, unlike the other elements of the warship triad armour and armament, was a very subjective attribute; while the value of an extra inch of belt armour or an additional turret were obvious and would be useful in any engagement, an extra half knot of speed (which could easily take more tonnage and cost more than either of the previous) could be vital in catching a fleeing enemy but equally could never be used outside of trials. There was also the matter of cruising speed to be considered, traditionally this had only been thought important for convoy escort and protection vessels so 'fleet' units had maximised top speed at the cost of economic cruising. The war experience had shown not only did roles swap and merge as operational requirements shifted, several destroyer flotillas had spent the war switching between escort work, submarine hunting and serving in traditional fleet roles, but that even 'pure' fleet units needed a fast economic cruise speed, in order to move between theatres quickly without needing regular refuelling stops. The final consideration was the Italian navy's experience with high speed vessels, with several prized former units of the Regia Marina in dry dock in Rosyth, the Naval Staff took the chance to study them for lessons the Royal Navy could learn. The investigation revealed that, as suspected, Italy had been breaching the various naval treaty limits and all the vessels were indeed over prescribed tonnage. However despite their extra tonnage all of them had been compromised to varying degrees in order to reach their high speeds, indeed the most balanced were also the slowest; the formidable Zaras barely making over 30knots when fully laden. These findings confirmed the Royal Navy's own experiences of high speed vessels;that any ship could be made faster or slower for relatively little change in tonnage up to a certain point, beyond which any speed change required exponentially more power and tonnage for the same increase.

Taking all of the above into consideration the review attempted to produce a series of recommendations that were not too prescriptive but equally avoiding being vague to the point of uselessness. The first problem was that to be useful the recommendations needed firm numbers, yet one of the key findings was that designs should not be compromised by aiming for arbitrary speeds. Secondly there was the issue of the legacy fleet; in practice none of the battleships in commission could exceed 25knots when fully laden, a speed that was believed too slow, and had equally poor sustained cruising speeds. Yet under the recently agreed re-armament plans the Nelsons and the Queen Elizabeths were to remain in service for a minimum of six years, likely longer, and thus would have to operate along side the newer, potentially faster, design. Such was the importance of the decision, effectively it would set the battle line speed for the future fleet, the Naval Staff passed the buck, referring the decision up to the top for consideration by the Navy Board. The eventual decision of the Sea Lords was to break with the past and set the speed at 'not less than 30knots when fully stored and equipped for war', commenting that if the Navy only concerned itself with older vessels then it would never build anything faster and thus the speed would never rise. The remainder of the specific recommendations ruled out any speed focused designs such as the E-Class cruisers and confirmed that, subject to the minimum speed set by the Navy Board and any specific requirement, speed should be treated as the least important leg of the warship triad.

Finally we come to the consideration of the anti-submarine campaign of the navy, operations that had been strategically successful but tactically very worrying. While the main aim had been successful, the supply and troops convoys had reached the theatre un-molested, the worrying fact was that no Italian submarines had been sunk. This was of particular concern as the entire campaign had been conducted under almost perfect conditions; The Royal Navy had been able to concentrate the bulk of the fleet in theatre allowing for heavy convoy escorts and numerous 'striking groups', the convoy routes had been limited with the vast majority running between only three points (Gibralta <-> Malta <-> Alexandria) and the campaign had been conducted in the spring/summer giving the British maximum daylight 'hunting time' and the submarines the fewest hours of 'safe' darkness. The optimistic interpretation was that the Regia Marina had appreciated all the British advantages and not risked their submarines out of fear of losing them. While this is perhaps partially true, certainly there were no engagements or detections near convoys, the destroyers of Rear-Admiral Horton's 'Striking Groups' based out of Malta were involved in several engagements with enemy submarines, however they singularly failed to sink any of them. The conclusions drawn were that ASDIC detection and tracking was far less reliable in actual engagements than hoped and that a major re-think on anti-submarine weaponry was required. The former had been suspected as ASDIC was known to have significant limitations, particularly when close to target, while the latter was an unpleasant surprise as rear-dropped depth charges had been thought sufficient. On the positive side the Naval Staff were able to confirm that the convoy system was effective, though the 'loss of efficiency' (the time spent waiting while convoys formed up and the time lost by travelling at the speed of the slowest merchant) remained a concern. Overall, however, the campaign had been disconcerting to an Admiralty that had believed the submarine menace had been dealt with, on the evidence of the war they were forced to accept that both tactically and technologically they were still some way from that goal.