In the past few years a great deal of information has been published about battleships and their design; probably more than for any other type of warship. In the process the post-WW1 vessels of the Royal Navy have been criticised in comparison with contemporary foreign ships, a criticism all the more pointed because of the unquestioned superiority of the RN's battleships in the Great War. It is perhaps time to take a brief look at these arguments and their validity.
The two classes we are referring to are of course the l6in. gunned Rodney and Nelson and the five l4in. gunned vessels of the King George V class. The argument goes that the l6in. ships, with their 23 knot speed, were too slow to be effective in WW2 when battleships were required to operate with fast aircraft carriers. Furthermore, X turret, tucked away behind and below B turret, was of limited use as it could only fire on or close to the beam. It is therefore suggested that these ships would have been far more useful if X turret had been deleted and the weight and space saved used to provide more powerful machinery for higher speeds.
The KGVs, on the other hand, were (just about) adequately fast at around 28 knots but are criticised both for lack of gun power (as every other nation building battleships at the time went for at least l5in. calibre) and for the reliability of the main armament. The almost complete breakdown of the Prince of Wales' fire in the action against the Bismarck is notorious; perhaps less well known were the similar if less severe problems suffered by the King George V in the second action against the Bismarck, and the Duke of York when she sank the Scharnhorst; that is, in every action against enemy capital ships.
The Nelson and Rodney
The exercise of hindsight is of course all too easy. Military history is probably more vulnerable to wisdom after the event than most affairs of men, presumably because of the huge uncertainties involved in the planning and execution of warfare. It can therefore readily be conceded that the Nelsons would indeed have been more useful vessels with only six l6in. guns but the ability to reach 28 knots. However, the criticism of the designers can only be valid if they might reasonably have been expected to foresee that. (Incidentally, I use the term designers rather than naval architects because many others apart from architects were involved in determining the parameters of ship design; it became a very political matter.)
The fact is that the war which the big ships were called upon to fight in 1939-45 was radically different to that envisaged when they were designed in the 1920s. Contemporary paintings imagining their appearance in warfare show them steaming in line of battle together with other battleships, firing on the broadside at an enemy fleet as in the Battle of Jutland. It has frequently been observed that armed forces spend each period of peace equipping and training themselves to win the last war they fought in. While this may be true in this case, it is hard to see that the designers could have been expected to foresee at that time the way that battleships would actually be employed against enemy capital ships; singly or in pairs, together with aircraft carriers, in fast task forces forever pursuing an elusive enemy. Ironically, the Nelsons turned out to be very well suited to their most productive employment; that of shore bombardment.
To be fair to the designers, they wanted to combine the formidable gunpower and protection of the Nelsons with a much higher speed, but this would have required much larger vessels which were banned under the Washington Naval Treaty of 1922. Something had to be cut back, and the designers decided (wisely) that they could not reduce the armour protection and that nine guns were needed to establish a clear superiority over foreign equivalents (contemporary US and Japanese designs featured eight l6in. guns). Accordingly, the machinery was drastically reduced, although the resulting speed was still higher than the fleet average of 21 knots and was the same as the practical sea speed of the much admired Queen Elizabeth class fast battleships. There can be little doubt that the Nelsons were the most formidable vessels afloat at the time of their commissioning and for several years thereafter.
Perhaps the most curious aspect of these ships was the relatively light shells specified for the main armament. These weighed 2048 lb, hardly any more than the 1920 lb (later 1938 lb) of the l5in. gun. There would have been little difference in penetration or destructive power so it hardly seemed worth the bother and expense of developing a new gun. The only reason which comes to mind is one of national prestige; the USA and Japan were building 16in. ships so we had to have them too. This may seem silly but it is worth remembering that these capital ships were very much an expression of national pride; in modern terminology, their deterrent effect was more significant than their actual use.
The King George V Class
Having largely exonerated the Nelsons' designers let us turn our attention to the KGVs. In the mid 1930s the long "battleship holiday" was at an end and the British, Germans, French, Italians, Americans, Japanese and even the Russians were all planning new building programmes. The British were very concerned about the enormous cost involved and were very keen to keep the size of these new ships down to the minimum by international agreement. The result was the Second London Naval Conference, which agreed in 1936 to limits of 35,000 tons on displacement and l4in. on gun calibre. Unfortunately there were various escape clauses (and Japan and Germany weren't involved anyway) so in the end it was only the British, desperately keen to make a start and to set a good example, who adhered to the l4in. limit.
It is worth at this point reviewing briefly some of the main considerations of the designers. It was necessary first of all to balance the three main priorities; armament, protection and speed; all very demanding of weight and space. Within these choices lay others. How should the protection be arranged? How important was vertical armour against short range fire in comparison with horizontal protection against long range gunnery and aircraft bombs? Should the armament consist of a few large guns of great power or a larger number of lighter weapons with a greater chance of hitting the target?
These considerations often influenced each other. This particularly applied to the arrangement of the armament; to concentrate the guns in a few large turrets saved not just on the armour need to protect the turrets and barbettes but also reduced the length of the armoured citadel around the armament and machinery and therefore reduced the weight of armour needed still further. On the other hand, the loss in action of one large turret would have a serious effect on the fighting ability of the ship. Even with the machinery there were choices to be made; to select high pressure equipment with its much improved efficiency and reduced size and weight, or to stick with older but more reliable methods?
It is interesting to examine the effects of the choices made by the various nations involved. The French went for high speed and high levels of protection, achieved by a very economical armament layout of eight 15in. guns in two quad turrets mounted forward. This layout, featured in the Jean Bart and Richelieu, gave a formidable forward fire well suited to the ships' intended role as Scharnhorst/Gneisenau hunters.
At the other extreme, only the Germans retained the traditional eight guns in four turrets in the l5in. Bismarck and Tirpitz. This layout was wasteful of weight although offering advantages in minimising the effect of the loss of a turret. Given the vessels' high speed this should in theory have meant they were very poorly armoured, which they would have been had they not exceeded the 35,000 ton standard by some 20%. In fact, they were not as well armoured as the KGVs.
The Americans and the Italians both took the middle ground of nine guns in three turrets as being the best overall compromise, but differed thereafter in priorities. The Italians chose speed at the expense of protection in their Romas, the Americans the reverse in the Washington and South Dakota classes; until the Iowa class when they had both (at the cost of another 10,000 tons). The Japanese Yamatos featured enormous (l8in.) gunpower and massive (although flawed) protection, but they were in a different size class altogether.
This brings us back to the KGVs. The original design featured twelve l4in. guns in three quadruple turrets but increasing worries over keeping to the weight limits led to the reduction of B turret to a twin. These ships were therefore unique in their layout as well as their calibre. Speed was at the low end of the range but protection at least as good as anything of comparable size. The loss of the Prince of Wales demonstrated the vulnerability of the "underpinnings" to underwater damage, but then so did that of the Bismarck and it is unlikely that any other ship would have fared better if hit in the same place.
In practice, the l4in. calibre proved adequate to meet the demands made upon it, but it cannot be denied that the armament was surprisingly troublesome. Surprisingly for two reasons; the British had a long tradition of producing reliable armament, culminating in the classic twin 15in., and secondly there had been great teething problems with the complex l6in. leading to a much simplified design being adopted for the l4in.
Apart from this serious fault, the ships were satisfactory enough in practice. The armament layout was not ideal and the selection of nine guns in triple turrets would have preserved the weight of forward fire while saving some tonnage for extra machinery and speed. More radically, the adoption of the Richelieu's layout would have permitted a significantly greater speed, which would have been useful. One can understand why the designers did not wish to take the risk of concentrating the armament in only two turrets, although no KGV ever had a turret knocked out by enemy action (self-inflicted failure was another matter). Given the political and time constraints within which they were working, the KGVs' designers did about as well as they could, apart from the serious unreliability of the quadruple turret.
Battleships were designed almost exclusively to fight each other. The fact that at their peak of development in WW2 they hardly ever met in combat is just another of the ironies of warfare. It is now clear that many of the issues over which designers agonised were simply unimportant in practice. Gun calibre hardly mattered provided it was at least l4in. Even the number of guns carried did not prove particularly significant in action; six were enough, though eight were preferable. Those immense thicknesses of side armour were scarcely tested. It is interesting that the modernised Renown proved exceptionally useful despite being one of the notorious battlecruisers, previously despised for their vulnerability.
On the other hand, speed proved of vital importance, as did horizontal protection against aircraft bombs and (to a much lesser extent) long-range shell fire. By far the most important aspect of protection turned out to be that against torpedoes, mines and other underwater contrivances. Older ships fared badly in this respect, but the Nelsons and KGVs benefited from the RN's unmatched experience and were very well protected, apart from the aforementioned "underpinnings" of propellers and rudders.
If one could ever be in the intriguing position of being able to cross the barriers of time and advise those concerned with ship design in the mid-1930s, the temptation would be to tell them to settle for a 15in. gun limit, scrap the obsolete R class battleships and reuse their armament (suitably modernised) at a huge saving in cost and time, make sure the new ships were well protected underwater, could do at least 30 knots and had excellent AA armament, and not to worry too much about the thickness of the main belt. And, oh yes, modernise the Hood and Repulse instead of spending so much time and money on the Queen Elizabeths. The resources saved by such a programme could be spent on additional aircraft carriers. However, it has to be admitted that while the wartime Vanguard design did of course make use of surplus 15in. turrets, prewar national pride might well have precluded the use of 20 year old main armament for the Navy's new class of battleships.