The 1–inch gun fires a 1–pound shot. The 2–inch gun fires a 6–pound shot. The 3–inch gun fires a 12– or 15–pound shot. The 4–inch gun fires a 28 to 32–pound shot. The 5–inch gun fires a 50–pound shot. The 6–inch[17] gun fires a 100–pound shot. The 7·5–inch gun fires a 200–pound shot. The 9·2–inch gun fires a 380–pound shot. The 10–inch gun fires a 500–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.