The steamer Salamander appeared in 1832, and thereafter several similarly propelled wooden-hulled steamers were added to the Navy. Between 1840 and 1850 tubular boilers were generally adopted, the boilers being lighter and more compact than those previously in use, enabling the working pressure of the steam to be increased to ten or fifteen pounds above that of the atmosphere. All these vessels had paddle-wheels. Warships similarly propelled were adopted by other nations also, but with the exception of skirmishes with the natives of uncivilised or semi-civilised countries, vessels of this type were not tested in serious warfare until the war in the Crimea. Even then many of the British and French warships were stately wooden three-deckers. Such vessels of the attacking fleets as were paddle-driven usually suffered badly about the wheels when they ventured within range of the Russian guns; while those, chiefly despatch vessels and gunboats, which had screws, were comparatively safe so far as their propellers were concerned, but were too weak to engage the Russian batteries. Floating armoured batteries were therefore decided upon, some of which had screw propellers, single or twin, but from the marine, apart from the military, point of view, they achieved no great success.
Long before this, however, the screw propeller had proved so reliable and the advantage of its position below the water-line was so obvious that the Admiralty could no longer maintain its prejudice, and the warsloop Rattler was built at Sheerness in 1843 and fitted with a screw propeller. Her displacement was 1078 tons. Her engines, of 437 indicated horse-power, had a spur gearing by which the revolutions of the screw were increased to four times those of the crank. The steamer Alecto had paddle-engines of the direct-acting type, and of about the same power as those of the Rattler. The two vessels were made fast stern to stern with only a short distance between them to test the powers of their respective methods of propulsion, and although each did her best the screw boat towed the other at a speed of nearly 2¹⁄₂ knots. Of course a test of this sort could not demonstrate the superiority of one method over the other; all that it proved was that the Alecto was less powerful than the Rattler. A similar contest took place in the English Channel in June 1849, between the screw corvette Niger and the paddle-sloop Basilisk. The tug-of-war lasted an hour, and the Niger towed the Basilisk stern foremost 1·46 knots. These two vessels were very evenly matched in every respect, and the test in this case left no room for doubt as to which was the better method.
The first screw-propelled vessel in the British Navy was the Dwarf, built as the Mermaid by Messrs. Ditchburn and Mare at Blackwall in 1842, and as she attained at her trial the guaranteed speed of twelve miles an hour, the Admiralty fulfilled its promise and took her over and then renamed her. She was engined by Messrs. J. and G. Rennie. Her cylinders were vertical, of 40 inches diameter with 32 inches stroke, and the propeller was on their conoidal principle in which three blades are used, the surface of which, according to the specification, is “obtained by the descent of a tracer down the surface of a cone or conoid,” this giving an increasing pitch. The vessel was 130 feet long and of 164 tons measurement. Three years later she was used for a series of experiments with a variety of screw propellers.
Of the many inventions brought under the notice of the Admiralty and of private shipowners, one which attained a considerable measure of success was the contrivance patented by Taylor and Davies in 1836, and known as a modified and improved form of Bishop’s disc engine. It was tried in a pinnace, the Geyser, built in 1842 by Rennie.
In this form of engine the steam chamber is partly spherical, and the end-covers are cone-shaped, while the chamber contains a piston or circular disc fitted with a central boss that fits into spherical seats made in the covers, and a projecting arm placed at right angles to the disc engages with a crank arm on the screw shaft. A fixed radial partition intersecting the disc divides the chamber into four cells, to which steam is admitted by a slide valve. In 1849 H.M.S. Minx was equipped with one of these engines having a disc of 27 inches diameter, in addition to the high-pressure engine, and coupled to the propeller shaft in such a manner that it was not necessary to disconnect the horizontal engines. With the disc engine the vessel attained a speed 11 per cent. higher than without. Improvements in other engines, however, rendered inevitable the relegation of the disc engine to the list of superseded contrivances.
In 1838 Mr. John Penn’s oscillating engines with tubular boilers were fitted in some of the boats running above London Bridge, and attracted the attention of the Admiralty. The Admiralty yacht Black Eagle was turned over to him and he installed, instead of her former engines, oscillating engines of double their power, with tubular flue boilers, the change entailing no addition to the weight or engine space. The advantages of this installation were so great that many other vessels were similarly treated, among them being the royal yacht Victoria and Albert. His trunk engine, designed for the propulsion of warships carrying a screw, and capable of being placed below the water-line so far as to be out of reach of hostile shot, achieved an even greater success, and in 1847 Mr. Penn was instructed to place engines of this type in H.M.S. Arrogant and H.M.S. Encounter. These were so satisfactory that orders for engines were received for vessels ranging from a small gunboat, to be fitted with engines of 20 horse-power, to vessels like the Sultan, with engines of 8629 horse-power, and Neptune (ex Independencia), with 8800 indicated horse-power. Up to the time of his death his firm fitted 735 vessels with engines having an aggregate actual power of more than 500,000 horses. Among them were the Orlando, Howe, Bellerophon, Inconstant, Northampton, Ajax, Agamemnon, Hercules, Sultan, Warrior, Black Prince, Achilles, Minotaur, and Northumberland.
The barque-rigged steam frigate Penelope attracted as much attention in the Admiralties of the world as did the advent of the first Dreadnought a few years ago. She was an ordinary 46-gun frigate, and might have attained neither more nor less publicity than fell to the lot of other ships of her class. Her conversion in 1843, however, into a steam frigate made her famous. She was described as “a war steamer of a magnitude unequalled in our own or any foreign service, with an armament that will enable her to bid defiance to any two line-of-battle ships, especially as her steam will give her the means of taking a commanding position.”[95] She was one of the old French Hebe class of frigates, of which there were between thirty and forty lying in the various British ports in good condition, but considered useless, as larger frigates had been introduced by other powers. She was cut in half amidships and lengthened by 63 feet, the new middle space being devoted to her engines and boilers and to bunkers capable of holding 600 tons of coal. In addition to her crew of 300 officers and men, she could accommodate 1000 soldiers, with provisions and water for a voyage to the Cape of Good Hope. Her armament as a steamer consisted of two 10-inch pivot guns, each weighing 4 tons 4 cwt.; eight 68-pounders capable of firing both shot and shell, and fourteen 32-pounders. Her two steam-engines were believed to be of greater power than any yet made, having a combined horse-power of 625 horses. The cylinders had a diameter of 92 inches with a piston stroke of nearly 7 feet. The engines were direct-acting, and similar to those of the Cyclops, Gorgon, and other steam frigates in the Navy. A recess between the two foremost boilers contained the step for the main-mast, which therefore stood almost in the centre of the engine- and boiler-room. The funnel was placed abaft the main-mast, but the paddles were before it.
[95] Illustrated London News, July 1843.
In 1845, Admiral Fishbourne adopted Scott Russell’s wave-line principle and made certain recommendations as to the lines on which a ship of war should be built. These were: “the buttock-lines are continuous curves, to minimise pitching; with the same object a fine bow and full afterbody are provided. To promote steady steering there is a long run of perpendicular side, a long keel, a lean forefoot, and a fine heel, while to insure powerful action of the rudder the draught of water is greatest aft; the floor rises aft from the midship section.”
But although shipbuilding of the modern type was initiated nearly three-quarters of a century ago, and iron vessels as warships had proved their utility more than once in the “affairs” of other nations, the British Admiralty remained faithful to wooden three-deckers long after a radical change in their allegiance would have been justified. It took a long time to convert the Admiralty. As early as 1842 an iron frigate was built by Laird at Birkenhead, called the Guadeloupe, for the Mexican Government. It was 187 feet long by 30 feet beam and 16 feet depth. An iron vessel, the Nemesis, was used in the Crimean War and was struck fourteen times by the enemy’s shot, the holes in every instance being clean and free from splinters. The Admiralty was not convinced, however, and as late as 1861 ordered nearly a million pounds’ worth of wood for warship construction. Other iron vessels carrying heavy guns, the Nimrod, Nitocris, Assyrian, Phlegethon, Ariadne, and Medusa, were built for the East India Company at Laird’s. The Admiralty had their first iron vessel, the Dover, built there, followed by the Birkenhead troopship, both paddle-steamers. The brigantine-rigged steam frigate Birkenhead was 210 feet in length between her perpendiculars, 60 feet 6 inches breadth outside the paddle-wheels, and 37 feet 6 inches inside the paddle-wheels, and had a depth of 23 feet. Her engines of 556 horse-power were by George Forrester and Co. A peculiar feature she had in common with several of her contemporaries was that she was clincker-built below water and carvel-built above. The unhappy ending of this ship is one of the most tragic events in the annals of the British Navy. She sailed from Queenstown, January 1852, for the Cape, having on board a portion of the 12th Lancers and of nine infantry regiments. She struck a pointed rock off Simon’s Bay, South Africa, and of the 638 persons on board no fewer than 454 of the crew and soldiers perished. The remainder, many of whom were women and children, were saved by the boats.