The 1–inch gun fires a1–pound shot.
The 2–inch gun fires a6–pound shot.
The 3–inch gun fires a12– or 15–pound shot.
The 4–inch gun fires a28 to 32–pound shot.
The 5–inch gun fires a50–pound shot.
The 6–inch[[17]] gun fires a100–pound shot.
The 7·5–inch gun fires a200–pound shot.
The 9·2–inch gun fires a380–pound shot.
The 10–inch gun fires a500–pound shot.
The British 12–inch gun fires a 850–pound shot.
The German 12–inch gun fires approximately a 1,000–pound shot, but this is asking a lot of the gun.
The 13·5–inch gun fired a 1,250–pound shot; and its later marks fired a 1,400–pound shot.

The increase of 1½ inch in the calibre of the gun was enough to raise the British shell from 850 pounds to 1,400 pounds. No fewer than twelve ships were actually building on the slips for the Royal Navy armed with these splendid weapons, quite unsurpassed at that time in the world, and firing a projectile nearly half as heavy again as the biggest fired by the German Fleet.

I immediately sought to go one size better. I mentioned this to Lord Fisher at Reigate, and he hurled himself into its advocacy with tremendous passion. ‘Nothing less than the 15–inch gun could be looked at for all the battleships and battle-cruisers of the new programme. To achieve the supply of this gun was the equivalent of a great victory at sea; to shrink from the endeavour was treason to the Empire. What was it that enabled Jack Johnson to knock out his opponents? It was the big punch. And where were those miserable men with bevies of futile pop-guns crowding up their ships?’ No one who has not experienced it has any idea of the passion and eloquence of this old lion when thoroughly roused on a technical question. I resolved to make a great effort to secure the prize, but the difficulties and the risks were very great, and looking back upon it one feels that they were only justified by success. Enlarging the gun meant enlarging the ships, and enlarging the ships meant increasing the cost. Moreover, the redesign must cause no delay and the guns must be ready as soon as the turrets were ready. No such thing as a modern 15–inch gun existed. None had ever been made. The advance to the 13·5–inch had in itself been a great stride. Its power was greater; its accuracy was greater; its life was much longer. Could the British designers repeat this triumph on a still larger scale and in a still more intense form? The Ordnance Board were set to work and they rapidly produced a design. Armstrongs were consulted in deadly secrecy, and they undertook to execute it. I had anxious conferences with these experts, with whose science I was of course wholly unacquainted, to see what sort of men they were and how they really felt about it. They were all for it. One did not need to be an expert in ballistics to discern that. The Director of Naval Ordnance Rear-Admiral Moore was ready to stake his professional existence upon it. But after all there could not be absolute certainty. We knew the 13·5–inch well. All sorts of new stresses might develop in the 15–inch model. If only we could make a trial gun and test it thoroughly before giving the orders for the whole of the guns of all the five ships, there would be no risk; but then we should lose an entire year, and five great vessels would go into the line of battle carrying an inferior weapon to that which we had it in our power to give them. Several there were of the responsible authorities consulted who thought it would be more prudent to lose the year. For, after all, if the guns had failed, the ships would have been fearfully marred. I hardly remember ever to have had more anxiety about any administrative decision than this.

I went back to Lord Fisher. He was steadfast and even violent. So I hardened my heart and took the plunge. The whole outfit of guns was ordered forthwith. We arranged that one gun should be hurried on four months in front of the others by exceptional efforts so as to be able to test it for range and accuracy and to get out the range tables and other complex devices which depended upon actual firing results. From this moment we were irrevocably committed to the whole armament, and every detail in these vessels, extending to thousands of parts, was redesigned to fit them. Fancy if they failed. What a disaster. What an exposure. No excuse would be accepted. It would all be brought home to me—‘rash, inexperienced,’ ‘before he had been there a month,’ ‘altering all the plans of his predecessors’ and producing ‘this ghastly fiasco,’ ‘the mutilation of all the ships of the year.’ What could I have said? Moreover, although the decision, once taken, was irrevocable, a long period of suspense—fourteen or fifteen months at least—was unavoidable. However, I dissembled my misgivings. I wrote to the First Sea Lord that ‘Risks have to be run in peace as well as in war, and courage in design now may win a battle later on.’

But everything turned out all right. British gunnery science proved exact and true, and British workmanship as sound as a bell and punctual to the day. The first gun was known in the Elswick shops as ‘the hush and push gun,’ and was invariably described in all official documents as ‘the 14–inch experimental.’ It proved a brilliant success. It hurled a 1,920–pound projectile 35,000 yards; it achieved remarkable accuracy at all ranges without shortening its existence by straining itself in any way. No doubt I was unduly anxious; but when I saw the gun fired for the first time a year later and knew that all was well, I felt as if I had been delivered from a great peril.

In one of those nightmare novels that used to appear from time to time before the war, I read in 1913 of a great battle in which, to the amazement of the defeated British Fleet, the German new vessels opened fire with a terrible, unheard-of 15–inch gun. There was a real satisfaction in feeling that anyhow this boot was on the other leg.

The gun dominated the ship, and was the decisive cause of all the changes we then made in design. The following was in those days the recipe in very unexpert language for making a battleship:—

You take the largest possible number of the best possible guns that can be fired in combination from one vessel as a single battery. You group them conveniently by pairs in turrets. You put the turrets so that there is the widest possible arc of fire for every gun and the least possible blast interference. This regulates the position of the turrets and the spacing between them. You draw a line around the arrangement of turrets thus arrived at, which gives you the deck of the ship. You then build a hull to carry this deck or great gun platform. It must be very big and very long. Next you see what room you have got inside this hull for engines to drive it, and from this and from the length you get the speed. Last of all you decide on the armour.

All these calculations and considerations act and react upon one another at every stage, and the manner in which the Royal Corps of Constructors can juggle with these factors, and the facility with which the great chiefs and masters of battleship design like Sir Philip Watts and Sir Eustace Tennyson-D’Eyncourt and their faithful confederate Sir Henry Oram, the Chief Engineer, were able to speak on these matters were marvellous beyond belief. In a few hours, or at most in a few days, one could be told the effect of an alteration in any one set of conditions upon every other set of conditions. On this vast process of juggling and higgling we now embarked.

From the beginning there appeared a ship carrying ten 15–inch guns, and therefore at least 600 feet long with room inside her for engines which would drive her 21 knots and capacity to carry armour which on the armoured belt, the turrets and the conning tower would reach the thickness unprecedented in the British Service of 13 inches. For less armour you could have more speed: for less speed you could have more armour, and so on within very considerable limits. But now a new idea began to dawn. Eight 15–inch guns would fire a simultaneous broadside of approximately 16,000 lb. Ten of the latest 13·5–inch would only fire 14,000 lb. Therefore, we could get for eight 15–inch guns a punch substantially greater than that of ten 13·5–inch. Nor did the superiority end there. With the increased size of the shell came a far greater increase in the capacity of the bursting charge. It was not quite a geometric progression, because other considerations intervened; but it was in that order of ideas. There was no doubt about the punch. On the other hand, look at the speed. Twenty-one knots was all very well in its way, but suppose we could get a much greater speed. Suppose we could cram into the hull a horse-power sufficient to drive these terrific vessels, already possessing guns and armour superior to that of the heaviest battleship, at speeds hitherto only obtained by the lightly armoured 12–inch gun battle-cruisers, should we not have introduced a new element into naval war?