And here we leave the region of material. I have built the process up stage by stage as it was argued out, but of course all the processes proceeded in simultaneous relation, and the result was to show a great possibility. Something like the ship described above could be made if it were wanted. Was it wanted? Was it the right thing to make? Was its tactical value sufficient to justify the increase in cost and all the changes in design? We must turn for the answer to the tactical sphere.
Here I felt able to see a little more clearly. As cannot be too often repeated, war is all one; and the same principles of thought which are true in any form are true mutatis mutandis in every other form. Obviously in creating an Army or an Air Force or a squadron of battleships you must first of all have regard to their highest tactical employment, namely, decisive battle. Let us, therefore, first of all visualise the battle. Let us try to imagine what its conditions will be; what we shall have to meet and what would help us most to win. The first naval idea of our supreme battle at this time was that it would be fought about something: somebody would want to be going somewhere and somebody else would try to stop him. One of the Fleets would be proceeding in a certain direction and the other Fleet would come along and try to prevent it. However they might approach, the battle would soon resolve itself into two lines of ships steaming along parallel and bringing all their broadsides to bear upon each other. Of course if one Fleet is much stronger than the other, has heavier guns and shoots better, the opposite line begins to get the worst of it. Ships begin to burn and blow up and fall out of the line, and every one that falls out increases the burden of fire upon the remainder. The Fleet which has more ships in it also has a tail which overlaps the enemy, and a good many ships in this tail can concentrate their fire upon the rear ships of the enemy, so that these unlucky vessels have not only to fight the ships opposite to them, but have to bear the fire of a number of others firing obliquely at them from behind. But smashing up the tail of an enemy’s Fleet is a poor way of preventing him from achieving his objective, i.e. going where he wants to go. It is not comparable to smashing up his head. Injuries at the head of the line tend to throw the whole line into confusion, whereas injuries at the tail only result in the ships dropping astern without causing other complications. Therefore the Admiralissimo will always try to draw a little ahead if he possibly can and bring his van nearer and nearer to the enemy and gradually, if he can, force that enemy to turn off, so that he can then curl round him. This well-known manœuvre is called ‘Crossing the T,’ and Admiral Togo had used it in the battle of the Sea of Japan.
If the speeds of the Fleets are equal, how can this be done? The heads of both lines will be abreast and the fire will only be given and returned ship for ship.
But suppose you have a division of ships in your Fleet which go much faster than any of your other ships or of your enemy’s ships. These ships will be certainly able to draw ahead and curl round the head of the enemy’s line. More than that, as they draw ahead they will repeat in a much more effective fashion the advantage of an overlapping tail, because the ships at the head of the enemy’s line will have to bear the fire of the overlapping ships as well as the fire of those which are lying opposite to them, and therefore two or three ships might be firing on every one of the leading ships of the enemy, thus smashing to pieces the head of the enemy’s line and throwing his whole formation into confusion.
Here then in simple outline is the famous argument for the Fast Division. A squadron of ships possessing a definite superiority of speed could be so disposed in the approaching formation of your own Fleet as to enable you, whichever way the enemy might deploy, to double the fire after certain interval upon the head of his line, and also to envelop it and cross it and so force him into a circular movement and bring him to bay once and for all without hope of escape.
Hitherto in all our battle plans this rôle had been assigned to the battle-cruisers. Their speed would certainly enable them to get there. But we must imagine that they would also be met by the enemy’s battle-cruisers, whereupon, as they say in the reports of the House of Commons ‘debate arising,’ they might easily fight a separate action of their own without relation to the supreme conflict. Further, the battle-cruisers, our beautiful ‘Cats,’ as their squadron was irreverently called,[[18]] had thin skins compared to the enemy’s strongest battleships, which presumably would head his line. It is a rough game to pit battle-cruisers against battleships with only seven or nine inches of armour against twelve or thirteen, and probably with a weaker gun-power as well.[[19]]
Suppose, however, we could make a division of ships fast enough to seize the advantageous position and yet as strong in gun-power and armour as any battleship afloat. Should we not have scored almost with certainty an inestimable and a decisive advantage? The First Sea Lord, Sir Francis Bridgeman, fresh from the command of the Home Fleet, and most of his principal officers, certainly thought so. The Fast Division was the dream of their battle plans. But could we get such ships? Could they be designed and constructed? And here we came back again to Sir Philip Watts and Sir Henry Oram and the Ordnance Board and the Royal Corps of Naval Constructors.
At this stage the War College were asked to work out on the tactical board the number of knots superiority in speed required in a Fast Division in order to ensure this Division being able to manœuvre around the German Fleet as it would be in the years 1914 and 1915.
The answer was that if the Fast Division could steam in company 25 knots or better, they could do all that was necessary. We therefore wanted 4 or 5 knots additional speed. How were we to get it? With every knot the amount of horse-power required is progressively greater. Our new ship would steam 21 knots, but to steam 25 to 26 she wanted 50,000 horse-power. Fifty thousand horse-power meant more boilers, and where could they be put? Why, obviously they could be put where the fifth turret would go, and having regard to the increased punch of the 15–inch gun we could spare the fifth turret.
But even this would not suffice. We could not get the power required to drive these ships at 25 knots except by the use of oil fuel.