The Evolution of Naval Armament

by Frederick Leslie Robertson

So far, then, new methods of propulsion had not been greeted with enthusiasm. Yet to the First Lord himself was due the utilization of steam for minor purposes in the navy. In spite of the non-success of Lord Stanhope’s experimental “ambi-navigator” ship in 1795, Lord Melville in 1815 caused the three-masted schooner Congo, designed for a surveying expedition to the river of that name, to be fitted with paddlewheels and machinery by Boulton and Watt, expressly to try it in a ship-of-war. This machinery was so large and ponderous that, not only did it usurp one-third of the space aboard the ship, but brought her down so deep as only to give four knots through the water. It was all removed again before she sailed, and sent to Chatham for use in the dockyard. In the following year we find Mr. Brunel in correspondence with his lordship on the question of steam navigation. Brunel wrote quoting evidence to the effect that paddlewheels could be made of sufficient strength and stiffness to withstand the violence of seas and gales; to which Lord Melville replied that the Board deemed it unnecessary to enter, at that time, into the question of steam navigation generally, but desired his views on the application of steam to the towing of ships-of-war out of harbour against contrary winds and tides: which would be a matter of great advantage to his Majesty’s service. Brunel answered recommending that the steamer Regent, plying between Margate and London, be chartered during the winter and employed on this work, as a particular experiment.

“From this period may be dated the introduction of steam navigation into the English navy. Lord Melville was now so fully convinced of the great utility which the naval service would derive from it, that he ordered a small vessel to be built at Deptford, by Mr. Oliver Lang, to be called the Comet, of the burthen of 238 tons, and to have engines of 80 horse-power. She was built accordingly and ready for sea in 1822.”[146] As a matter of fact, the first steamer actually brought into H.M. service was the Monkey, built at Rotherhithe in 1821; and she was followed by the more powerful Sprightly, built at Blackwall by Messrs. Wigram and Green in ’23. Gradually the use of these paddlewheel tugs extended, their tonnage and horse-power increased, and the Surveyor of the Navy and his master shipwrights began to divert their talents to a consideration of the small steamers.

For the reason stated by Lord Melville, steamers were at this time tolerated only for towing and other subsidiary duties; authority poured cold water on the idea of utilizing them as ships-of-war; and if steam could have been dispensed with altogether, everyone would have been the better pleased.

Even at this period the idea of using manual labour, applied in an effective manner, for towing and bringing into position sailing warships had not been altogether abandoned. In 1802 the transport Doncaster had been propelled at a slow speed in Malta harbour by the invention of a Mr. Shorter: a screw propeller rigged over the stern. In 1820 experiments were made at Portsmouth with paddlewheels manually worked, and in ’29 Captain C. Napier took his ship Galatea out of Portsmouth Harbour by use of paddlewheels geared to winches which were worked by the crew. One hundred and thirty men were able to give her a speed of 2½ knots, while the full crew of a hundred and ninety produced a speed of three. After this doubtful success another trial was held—a race between the Galatea, propelled by paddles, and the Briton, towed by boats—which Galatea won. Captain Napier’s paddlewheels afterwards did good work for his ship in other quarters of the world.[147] Nothing resulted, however, from his initiative in this connection; only was emphasized the enormous superiority of steam-propelled vessels as tugs, in which capacity they had already made their appearance, and from which they were destined to evolve, in the next decade, into fighting vessels of considerable force.

By 1830 steam navigation had made significant strides along the lines of commercial development. In that year a service of steam mail boats started to run at regular intervals between Falmouth and Corfu, covering the distance in about one-fourth of the time which had been taken by the sailing packets; a Dutch government steamer, the Curaçoa, built in England, had since ’27 been running between Holland and the East Indies; and already the Indian Government had built an armed steamer, designed as the forerunner of others which were to connect Bombay with Suez and thus to place India in more direct communication with England.

The navy was still represented only by paddle-tugs. With a change of administration, however, came a change in Admiralty policy. The new Board took a distinctly progressive view. It was agreed that, if foreign powers initiated the building of steam war-vessels, this country must build as well, and not only as well but better: a policy tersely summed up by Admiral Sir T. M. Hardy in his saying, “Happen what will, England must take the lead.” Certain objections to steam vessels as naval units which had hitherto held a vogue were now seen to be ill-founded or baseless. In particular it was discovered, not without surprise to many, that steamers could be manœuvred without difficulty. A paddlewheel steamer, the Medea, gained her commander considerable credit from the skill with which she was navigated from the Thames into the basin at Woolwich dockyard, which proved that steamers could be steered and manœuvred better than sailing ships. In ’33 the construction of steamers was placed in the hands of the Surveyor.[148]

But small progress was made. One reason alleged was that the shape of hull which the Surveyor had made peculiarly his own was ill-adapted for steam machinery. “Nothing more unpropitious,” observed a later writer, “for Sir William Symond’s mode of construction than the introduction of steam can be conceived. His sharp bottoms were the very worst possible for the reception of engines; his broad beam and short length the most unfavourable qualities that could be devised for steam propulsion. As much as he could, he adhered to his principles.... Rather than yield to the demands of the new power, he sacrificed the armaments of his vessels, kept down the size of their engines, and recklessly exposed the machinery to shot should they go into action.”[149] There doubtless was something in this criticism. And yet, as we have seen, experience in America led to a form of hull for paddle steamers in many respects approaching that condemned as being favoured by the Surveyor!

Another and more valid reason for the slow progress made lay in the inherent unsuitability of the paddlewheel steamer as a substitute for the large sailing warship. Not only did the paddlewheels offer a large and vulnerable surface to destruction by enemy shot, but the wheels and their machinery could not be embodied in a ship design without interference with its sails and sailing qualities and, still more, without serious sacrifice of broadside armament. The machinery monopolized a large section of the midship space, the huge wheels covered the sides and interfered with the training of those guns for which room remained. The problem of arming steam-vessels was novel and difficult of solution. The guns must be few and therefore powerful. Hence it appeared that paddlewheel steamers, notwithstanding the advantages they possessed of speed and certainty of motion, could only sustain a small concentrated armament, consisting of the heaviest and most powerful ordnance: guns of large calibre, which possessed large power of offence at ranges where the broadside cannon would be deprived of much of their efficiency. Hence in ’31 a 10-inch shell gun of 84 hundredweight was expressly designed and cast for this purpose; and all the classes of steamers in early use in the navy were armed with it until, in ’41, it was displaced by the 68-pounder pivot gun, which then became the principal pivot gun of the service. Thus the development of paddlewheel machinery reacted on the development of artillery. The steamer was a stimulus to the development of large ordnance worked on the pivot system. And this form of armament in turn influenced the form of the ship. The main weights—those of the propelling machinery—were already concentrated in the waist of the vessel, and it was now possible so to place the few pivot guns that the ends of the vessel were left very lightly loaded. Thus it was possible to give unprecedentedly fine lines to the new steamers, a sharp and lengthened bow and a well-tapered run: an improved form of body by the use of which high speeds were obtained. In the case of commercial steamships the advantages of fine lines had already been recognized, and their designers had been free to give them a form which would allow of a high speed being attained; but in the case of war vessels designed to carry a broadside armament the limitations imposed by the heavily weighted ends had hitherto prevented other than bluff bows and sterns being given them. But now the subject of ship form came under general consideration, and the new conditions led to a more serious study of the laws governing the motion of bodies through water.

Year after year the size of steamers grew.[150] And as with size the cost of construction and maintenance increased, the question pressed itself more and more clearly—what was the naval utility of such expensive and lightly armed vessels? Numerous attempts were made to produce a form of paddlewheel steamer which would carry a broadside armament comparable with that which a sailing vessel of the same burthen would bear. In 1843 the Penelope, 46 guns, was cut in halves at Chatham and lengthened by the addition of about 65 feet, in which space engines of 650 horse-power were installed. But the extra displacement failed to compensate for the weight of the machinery; the altered vessel drew more water than had been anticipated and, though various alterations were made to minimize the effects of this, the experiment was not a success and was not repeated. In ’45 a steam frigate called the Odin was built by order of the Board. “The results aimed at in constructing this ship were—capability of carrying broadside armament; diminished rolling, in comparison with any war steamers then built; and less draught of water in relation to the size. These objects were accomplished; but as the position of the machinery and boilers is partially above the water-line, and the propellers are exposed to danger in broadside fighting, the ship is necessarily imperfect in these two conditions, as well as in the position of the sails; for in this case the proper place of the mainmast was occupied by the boilers, and consequently the centre of effort of the wind on the sails is in a wrong place.”[151] In the same year the Sidon was laid down, the design being on the lines of the Odin but modified in accordance with the ideas of Sir Charles Napier: with greater depth of hold and with machinery below the water-line. Iron tanks were placed in the hold for carrying the coals; by filling these with water when empty the steamer was kept at a more or less constant draught, a matter of considerable importance to the efficient working of the paddlewheels. In other respects, however, the Sidon was unsatisfactory. She was so crank that the addition of ballast and a modification of her armament were necessary. Her engines were cramped, her boilers of insufficient power and of unsuitable design, and her coal capacity too small to give her a useful radius of action. For the attainment of all the properties specified it was subsequently calculated and shown that a much larger displacement was necessary. Just as Fitch had discovered and Fulton had discerned, increase in scale reduced many of the difficulties encountered in designing heavily weighted steam vessels. Hence the success of the Terrible. In the case of the Terrible, a large paddlewheel frigate of 1,850 tons and 800 horse-power built in 1845, it was clear that an increase of size had given a partial solution to the problem of designing a war-vessel with heavy and spacious propelling machinery, with adequate armament, and with full sail-power and all the properties of a sailing ship.

Still the steam war-vessel was not satisfactory. Her machinery usurped the weight and space required for armament, her cumbrous paddlewheels were far too exposed to damage by shot or shell. And how to surmount these difficulties and reconcile the conflicting requirements of artillery and motive power, was a problem which cost the country years of unsuccessful experiments and millions of money. “It was,” said Dahlgren, “the riddle of the day.”