The Evolution of Naval Armament

by Frederick Leslie Robertson

The reply to these was the Inflexible, laid down in ’74.

We have already seen how, in the last of the Devastation class, the central armoured breastwork was widened to the full beam of the ship. It had been proposed by Mr. Barnaby to take advantage of this arrangement to off-set the two turrets of the Dreadnought at a distance each side of the centre line of the ship, so as to allow a powerful ahead fire. Although not then approved, this suggestion was embodied in the Inflexible as her most distinctive feature. In this, however, she was forestalled by the Italians. Her two turrets, each weighing 750 tons, were carried diagonally on a central armoured citadel plated with compound armour of a maximum thickness of 24 inches. Forward and aft of this citadel the unarmoured ends were built flush with it, and along the centre line was built, the whole length of the ship, a narrow superstructure. This superstructure did not contribute anything to her stability; nor was such contribution needed in view of the comparatively high freeboard. But it rendered unnecessary a flying deck such as had been fitted in the Devastation class, and provided accommodation for the crew, without restricting to any appreciable degree the arcs of fire of the big guns.

The Inflexible was of over 11,000 tons displacement, the heaviest and most powerful warship that had ever been built. She was 320 feet in length and 75 feet broad at the water-line; this unprecedented beam being required, in spite of the high freeboard, on account of the height at which the turrets were carried. Nevertheless, so improved was her propulsive efficiency as compared with that of former ships, so great the gain resulting from Mr. Froude’s historic researches on ship form and the action of propellers, that a speed of 15 knots was obtained at a relatively small expense in horse-power.

The idea of sails was not yet altogether dead. In deference to a strong naval opinion she was originally designed to carry two pole masts, with sails for steadying her motion in a seaway and as a standby in the event of her propelling machinery being disabled. But this scheme was modified owing to the possibility of falling masts and rigging interfering with the working of guns and screw in action. It was decided that she should be brig-rigged for peace service; and that, on an anticipation of war, she should be docked to allow the cruising masts to be removed and replaced by two short iron masts without yards for signalling and for carrying crows’ nests.

But it was in the bold abandonment of armour for the ends of the ship and its concentration on the sides of the citadel that the Inflexible design was most freely criticized. Armour, except in the form of an under-water protective deck, was not used at all forward and aft of the citadel. The ends of the ship were left unprotected, but subdivided; the compartments near the water-line formed watertight tanks filled with coals, stores, or—next to the side of the ship—cork. This criticism was directed from two directions.

To many naval men the attempt to beat the gun by adding to the thickness of the armour was a game no longer worth the candle. The point of view, moreover, that the defensive power of a ship was accurately represented by the defensive power of an armour patch upon its side was condemned as altogether too partial and theoretical. The same fallacy was abroad in respect of guns. “Men were apt to think and speak as if the mounting of a single excessively heavy gun in a ship would make her exceptionally powerful, no matter what number of powerful, but still less powerful, guns were displaced to make room for it. The targets and guns at Shoeburyness were held to be real measures of the defensive and offensive powers of ships.”[170]

On the other hand, experience was at this time bringing to light the inefficiency of heavy naval artillery. In ’71 a paper by Captain Colomb attracted attention, in which he analysed the effective gun power of the Monarch, and showed, by the light of experiments carried out by her against a rock off Vigo in company with Captain and Hercules, that “in six minutes from the opening of her fire on the sister ship at 1000 yards, she will have fired twelve shot, of which one will have hit and another may have glanced, and it remains an even chance whether the single hit will have penetrated the enemy’s armour.” In the following summer Mr. Barnaby was himself impressed with the difficulty which the Hotspur experienced in hitting the turret of the Glatton at a range of 200 yards in the smooth water of Portland Harbour: an experiment which, while confirming confidence in the reliability of a turret and its power to withstand shock, led him to question whether we were wise to put so much weight into the protection of turrets, and whether it might not be a better plan to stint armour on guns in order to add to their number and power.

From another direction the criticism was more directly effective. In ’75 Sir Edward Reed, now a private member of parliament, made a pronouncement on his return from a visit to Italy in the following words: “The Italian ships Duilio and Dandolo are exposed, in my opinion, beyond all doubt or question, to speedy destruction. I fear I can only express my apprehension that the Italians are pursuing a totally wrong course, and one which is likely to result in disaster.” The Italian Minister of Marine indignantly refuted the assertion, based as it must have been (he said) on incomplete information; and the construction of the Duilio and the Dandolo proceeded. But the remarks of the ex-Chief Constructor applied with equal force to the Inflexible; and in the following session he stated as much in the House of Commons. It was possible, he insisted, that in an action the cork and stores which filled the unarmoured ends of the Inflexible might be shot away, and the ends riddled and water-logged; and that in such an event the citadel, though intact, would not have sufficient stability to save the ship from capsizing.

The reply of the Admiralty was to the effect that Sir Edward Reed had assumed an extreme case, and that such a complete destruction as he had envisaged was, even if possible, never likely to occur in a naval action.

The effect of both statements was to cause widespread anxiety in the public mind, and a lamentable loss of confidence in the projected warship. A decision was therefore made to appoint another Committee, of unquestioned eminence and freedom from bias, to investigate and report on the Inflexible design. In due course the Committee reported. They confirmed in a long statement the Admiralty point of view that the complete penetration and water-logging of the unarmoured ends of the ship, and the blowing out of the whole of the stores and the cork by the action of shell fire, was a very highly improbable contingency; they found that the ship, if reduced to the extremest limit of instability likely to occur, viz. with her ends completely riddled and water-logged, but with the stores and cork remaining and adding buoyancy, would still possess a sufficient reserve both of buoyancy and of stability; and, balancing the vulnerability of the citadel with its 24-inch armour and the destructibility of the unarmoured ends, they came to the conclusion that the unarmoured ends were as well able as the armoured citadel to bear the part assigned to them in encountering the risks of naval warfare, and that therefore a just balance had been maintained in the design, so that out of a given set of conditions a good result had been obtained. Except that a recommendation was made that the system of cork chambers should be extended, no structural alteration from the existing design was proposed.