5030-G-SHIP DESIGN

WARSHIP DESIGN IN THE SECOND HALF OF THE 19TH CENTURY

The second half of the 19th Century was a period of unprecedented change in warship design. In the 1840s the ships of the fleet would have been almost identical to those that had fought at Trafalgar and indeed their design would not have changed significantly in the past two hundred years. By the 1890s the new capital ships being built would not have been dissimilar to those that fought in the First World War and in broad outline have many of the characteristics of a modern warship.

The principal features which govern a warship's design are its propulsion, hull construction, including the use of armour, and armament. The first of these to change was propulsion.

PROPULSION

During the 1830s a number of steam paddle ships joined the fleet, but for various reasons this form of propulsion was not suitable for larger warships and it wasn't until the screw was adopted in the late 1840s that the major units of the fleet were provided with steam propulsion. At first existing ships were adapted to take the new form of propulsion, but by the 1850s all major warships were being designed to take the steam engine and screw.

The complete transition from sail to steam in capital ships took nearly 30 years. Sailing ships of the line were first fitted with steam engines in the early 1850s and Indus, the last ship of the line to be totally dependent on sail, was not paid off until 1860. Devastation, the first capital ship that was completely dependent on steam propulsion did not enter service until 1873 and Inflexible, the last capital ship to carry a sailing rig, was not completed until 1881.

No doubt this long transition period may have been partly due to a feeling of nostalgia for the days of sail, but the main reason was that early steam engines were not very reliable and their performance did not give a ship sufficient range unless it could also make use of wind power. As will be seen this was particularly the case with cruising ships which were employed in policing the more distant parts of the Empire.

HULL CONSTRUCTION

The next major design feature to change was the material used to construct the hull, and the use of armour. Although merchant ships had begun to have iron hulls in 1830s, warships continued to use wood for the next twenty years. Trials had shown that iron hulls, when struck by a projectile, splintered in a way that had devastating results for the crew of the vessel concerned.

In 1858 the French, after experimenting with armoured floating batteries during the Crimean War, converted a wooden hulled ship La Gloire and covered its central part in armour of 5 in ironplate backed by 26 in of wood. This combination was able to resist the firepower of contemporary guns. In response the Royal Navy built the Warrior. Like La Gloire her hull was protected with armour, in this case 4½ in ironplate and 18 in of teak, but there was also one other important difference. Her hull was made of iron. These two ships introduced the era of the Ironclad and in 1860 in reply to French plans to expand their Ironclad fleet the British cancelled, with the exception of three ships, one of which was the Lord Warden, all construction work on wooden capital ships.

ARMAMENT

The final major design feature we need to look at is the armament of warships. At the battle of Trafalgar the main armament of Victory consisted of 100 32 pdrs arranged broadside on three gun decks and the Quarter Deck. The guns were smooth bored, muzzle loaded and at their maximum range of about 1 mile, their shot could penetrate 2 feet of oak. By the 1850s few important changes had been made and Victory's main armament, except for the introduction of a 64 pdr, would have been very similar to that carried by the major units of the fleet at that date.

The first major changes to the design of guns coincided with the introduction of armour. In the early 1860s the fleet was reequipped with rifled guns, and after a false start with a breech-loading (BL) version, the standard design for nearly twenty years became the muzzle-loaded rifled (MLR) gun. During this period the size of guns increased rapidly. In 1865 the weight of the largest MLR gun was 6½ tons which fired a projectile of 110 lbs; in 1878 the largest gun weighed 80 tons and fired a projectile of 1684 lbs.

Initially these larger guns were fitted in reduced numbers in broadside ships. For instance Warrior carried twenty eight 6½ ton and four 9 ton MLR on one gun deck and fifteen years later, Alexandra, the last broadside ship to be built, carried twelve MLR guns weighing between 25 and 35 tons, placed in a central battery.

However in the 1860s the increased size and reduced number of guns made it possible, and indeed necessary, to mount these weapons in power operated turrets placed on the centreline of the upper deck. This arrangement allowed the main armament to be brought quickly into action on either side and had the further advantage that it removed the guns from the living quarters of the ship's company.

In the late 1860s two turret ships, Monarch and Captain, were built. Their main armament consisted of 4 12 inch guns, each of which weighed 25 tons. It was also considered necessary for them to carry a full set of sails, a decision that restricted the arc of fire of the main armament, and in the case of the Captain, had a serious effect on the stability of the ship. Both ships were built as a result of Parliamentary and Press agitation, led by The Times and inspired by a Captain Cowper Cowles who was an enthusiastic advocate of the turret.

The first of these two ships, Monarch, was built to Admiralty specifications and was in fact a great success; however certain aspects of her design failed to satisfy Captain Cowles, who with considerable political and press support, was allowed to supervise the building of the Captain to his own design, an important feature of which was an exceptionally low freeboard. This design and the unusual arrangements under which it was fulfilled led to one of the Royal Navy's worst peacetime disasters. During the early hours of 7th September 1870 the Captain capsized in a gale off Cape Finisterre with the loss of 472 lives. Only 18 members of the ship's company survived. One of those who lost his life was Captain Cowles. However the loss of the Captain proved to be only a temporary setback to the concept of the turret, which had been indirectly responsible for the disaster.

In 1873 Devastation was brought into service. This revolutionary ship had a main armament of 4 12in guns, each weighing 35 tons, which were mounted in two turrets; a higher freeboard; and most important of all, did not carry a single sail, and therefore was totally dependent on steam power. As the drawing shows, here was the ship that provided the basic design for all future battleships. Subsequent changes were evolutionary rather than revolutionary with the guns becoming larger, the armour thicker and the speed of the ships faster. The design changes were stabilised in the 1890s by the introduction of the Royal Sovereign Class, which subsequently became known as pre-dreadnoughts.

The development of cruising ships, which in the 1850s were classified under the names of frigate, corvette and sloop, falls broadly into two stages during the second half of the 19th Century. In the days of sail the essential feature of the cruising ship was its speed. This gave it the ability to act as a scout and dispatch vessel, but perhaps most important, was its main source of protection against the more powerful ships of the line. With the introduction of steam the role of the cruising ship changed. Their speed was no longer greater than that of the capital ship, which was able to destroy them at will, and they ceased to be 'the eyes of the Fleet' or indeed to have any important value in a major war. Instead these ships became the main vehicle for policing Britain's rapidly expanding world trade and empire.

This new role slowed down changes in their development. The greater distances over which they had to operate and the lack of adequate coal supplies in the more distant parts of the empire resulted in a continued need for sail power, and lack of suitable docking and repair facilities made the wooden hull preferable for service in some parts of the world. Because of these factors a number of sloops continued to be fitted with sails until the end of the century although by that date the need for sail power as a complement to steam had virtually ceased to exist. Hulls continued to be constructed with wood until the mid 1870s when the all wooden hull was first replaced by the composite hull, where the keel and ribs were made of iron, and then in the late 1870s by the steel hull. Until the end of the 1870s the main armament in most cruising ships continued to be mounted broadside. However in the early 1880s the new breech loading guns were introduced. These were often mounted, protected by a shield, on the upper deck.

During the 1880s the classification of cruising ships was changed. The names of frigate and corvette ceased to be used and the new classifications of Cruiser, 1st, 2nd and 3rd class, were introduced. The important features of these ships were that they were capable of speeds of 18 knts and more, had good endurance and were made of steel and in many cases had side and deck armour. Their main armament consisted of breech loading turret guns and was augmented by smaller calibre guns, including the new quick firing versions that were introduced after 1888. Unlike earlier steam cruising ships the new cruiser had a valuable war role and was the direct ancestor of the 20th Century cruiser that played such prominent part in the 1st and 2nd World Wars.

Before leaving this subject there is one further development that needs to be briefly considered. In the 1870s the Admiralty began to equip ships with the newly invented torpedo. This weapon had enormous future significance, because for the first time it gave the small vessel the capability of sinking a larger and more powerful ship. This weapon led to the construction, in the 1890s, of new types of vessel, generally known as torpedo craft, which were small and fast. The first of these, torpedo boats, which were only armed with torpedoes, were only suitable for coastal waters. They were soon replaced by the torpedo gunboat and torpedo gunboat destroyer, larger vessels with better sea keeping qualities, which had the dual role of protecting the main fleet from torpedo attack and attacking the enemy fleet with torpedoes. The last named soon became known as destroyers and were the forefathers of the modern destroyer which, like the cruiser, played a vital part in World Wars I and II.