The Nelson class was a class of two battleships ( and ) of the British Royal Navy, built shortly after, and under the terms of, the Washington Naval Treaty of 1922. They were the only British battleships built between the , ordered in 1913, and the , ordered in 1936.
The ships were named after famous British admirals: George Brydges Rodney, 1st Baron Rodney, victor of the Battle of Cape St. Vincent and the Battle of the Saintes, and Horatio Nelson, 1st Viscount Nelson, who won the Battles of the Nile and Trafalgar.
To comply with the limitations of the Washington Treaty, these ships were of an unusual design with many novel features. They are often referred to as the first treaty battleships. The Nelsons were unique in British battleship construction, being the only ships to carry a main armament of nine guns. The most unusual feature however, and one that is immediately noticeable, is that these were all carried forward of the bridge.
Commissioned in 1927–29, the Nelsons served extensively in the Atlantic, Mediterranean, and Indian oceans during World War II. was made famous by her role in the sinking of the in May 1941. At the climax of the battle Rodney, in conjunction with King George V, closed on Bismarck to bombard her at short range. Rodneys main guns were credited with an estimated 100 to 130 hits, contributing greatly to Bismarcks final destruction.
Nelson and Rodney participated in the bombardment of targets in northern France during and after D-Day. In particular, during the Caen campaign Nelson was credited with destroying a group of five Tiger tanks which ventured into a red zone [within of the coast] deemed by the German command to be in range of Allied battleships.
Both ships of the class survived the war, but were scrapped in 1948–1949 along with all other British battleships except the four remaining King George V–class battleships and .
Background and design The Battle of Jutland had shown the value of firepower and protection over speed and maneuverability..
The next generation of British warships incorporated this lesson. After World War I, the Admiralty drew up plans for massive, heavily armoured battlecruisers and battleships, far larger and stronger than all previous vessels. The s would carry guns, and the proposed s would carry nine guns, and would be the most powerful vessels afloat. The Royal Navy was planning to hold its superiority in the burgeoning arms race, despite the large warships planned in Japan and the United States.Preston 1981
Development was abruptly curtailed by the Washington Naval Treaty of 1922, which brought the arms race to a halt. The four battlecruisers that had been ordered were cancelled. Some of the material acquired would later be used in Nelson and Rodney. The Treaty limited all nations' battleships to maximum limits of 35,000 tons and 16-inch guns. The British had successfully ensured that the definition of maximum displacement – the standard displacement – excluded both fuel and boiler feed water. They had argued that having to protect the widespread British Empire meant their ships had to carry more of both and they should not be penalised compared to nations, such as Japan, France and Italy, that operated normally much closer to their home bases. As a result, water-filled internal anti-torpedo bulges could be incorporated, which did not contribute to the "dry" (standard) weights and therefore did not exceed the treaty displacement limits.
The limits of the treaty inevitably led to compromises in the design of two new ships, and the resulting Nelson class sacrificed installed power (and hence speed) in order that the ships be well-armed and defended. They were often referred to as the "Cherry Tree" class, because they had been "cut down by Washington". The need to limit displacement resulted in a radical new warship design, drawn from the "G3" and "N3" designs of Eustace Tennyson-d'Eyncourt, Director of Naval Construction from 1912 to 1924. To reduce the weight of armour, the main gun turrets were all mounted forward to shorten the armoured citadel. The "G3" and "N3" had two turrets forward of the bridge with the third between the bridge and the funnels/aft superstructure. However, in the Nelsons, this was taken further and all three were in front of the bridge; "B" mount superfiring over "A", with "X" turret on the forecastle deck behind "B", and therefore unable to fire directly forward or aft. "X" turret is sometimes referred to as "C" turret and one alternative design, designated "O3", had it superfiring over both "A" and "B" turrets. The secondary guns were placed in totally enclosed director-controlled twin turrets at the upper deck level and were grouped aft – another innovative element taken from the G3 and N3 design.Brown 1999, p.
The machinery was of necessity limited in weight, size and installed power, and there were only two shafts with quite large screws. All previous British battleships after of 1906 had four screws as did all British battleship classes after Nelson. In order that fuel gasses be kept clear of the superstructure, the boiler rooms were moved behind the engine rooms, exhausting into a single funnel. This orientation also reduced the overall length of the armoured citadel. As a countermeasure to the limited power, the hull was of a very efficient hydrodynamic form, to attain the best possible speed.
Description The Nelsons had a length between perpendiculars of and an overall length of (Nelson) or (Rodney), a beam of , and a draught of at mean standard load. They displaced at standard load and at deep load. Their crew numbered 1,361 officers and ratings when serving as flagships and 1,314 as private ships. At deep load, they had a metacentric height of ,Burt, pp. 348–349 which gave them a quick roll between 11.2 and 13.6 seconds.Raven & Roberts, pp. 126–127 In calm weather, the Nelson-class ships were very manoeuvrable, but the large surface area of the superstructure gave them a large amount of weather helm and they could be a handful in confined spaces with a strong wind as was demonstrated when ran aground off Southsea beach in 1934.Burt, pp. 350, 357–359
The ships were powered by two sets of Brown-Curtis geared steam turbines, each driving one shaft, using steam from eight Admiralty 3-drum boilers fitted with superheaters that operated at a pressure of . The turbines were rated at and intended to give the ship a maximum speed of . The sister ships exceeded their designed speed during their sea trials in 1927, reaching speeds of from . They carried of fuel oil to give them a designed range of at a cruising speed of .Raven & Roberts, pp. 114, 124–125
Armour Armour weight was also reduced by using an internal, inclined armour belt sloped outward at 18 degrees from the vertical. The armour belt was thick over the main magazines and control positions to over the machinery and 6-inch gun magazines. The slope increased the relative thickness of the belt to a plunging projectile. Water-filled compartments, surrounded by air-filled ones, formed internal torpedo bulges which were fitted between the armour and the external hull of the ship, which was not armoured. The outer hull plating was meant to initiate detonation of shells which would then explode outside the armour. This innovation dispensed with external torpedo bulges which would otherwise have reduced the speed of the ships due to drag. Underwater protection for the Nelsons was provided by a double bottom 5 feet (1.5 m) deep and a layered defence of an empty outer watertight compartment and an inner water-filled compartment. The torpedo defence system had a total depth of 12 feet (3.7 m) and was backed by a torpedo bulkhead 1.5 inches thick. The system was similar in design and effectiveness to that of Hood, and was rated to withstand an explosion of 750 lbs (340 kg) TNT. The armour scheme was of the "all or nothing" principle; areas were either well protected, from the front of "A" barbette rearwards to the after 6-inch turrets, or were not protected at all, disposing of the multiple intermediate thickness of armour seen in older designs. For the first time a British battleship had a single, thick armoured deck to protect against plunging shells and aircraft-launched bombs, with armour over the machinery spaces and armour on the lower deck over the stern, both on top of the 0.5 in (12.7 mm) deck plating. The main turrets had armour on the faces, on the sides, on the roof and on the rear with around the barbettes. The secondary turrets, however, had only NC all round over 0.5 in (12.7 mm) structural steel plates.
Superstructure The large superstructure, which was octagonal in plan, was known to its crew as the "Octopoidal"HMS Rodney, Iain Ballantyne, Pen & Sword Books, and was sometimes referred to as "Queen Anne's Mansions"Burt, p. due to its similarity to a 14-storey brick residential development opposite St James's Park tube station in London. The superstructure provided spacious, weatherproof working spaces for the navigating officers and any flag officers embarked. Except for the emergency conning tower at its base, and the trunking for the main gun directors mounted on top, the superstructure was lightly armoured against splinters only, to save weight. Additional weight-saving design measures included the use of light materials such as aluminium for fittings, and fir instead of teak for deck planking, although subsequently, teak decks were fitted in the late 1920s, following concerns that the ships could not fire a full broadside without causing structural damage to the decks.
The Nelson class was a revolutionary but compromised design, and unsurprisingly, there were shortcomings. The location of the superstructure towards the stern caused manoeuvrability problems in high winds, especially when steaming at low speeds, where the superstructure acted somewhat like a mizzen sail permanently set, causing the ships to "weathervane" but according to Captain Hugh Binney, who commanded Nelson in the late twenties, "if this is kept in mind, no real difficulties should be encountered in any circumstances". This was potentially a problem in crowded harbours, and made the ships somewhat difficult to dock and embark although this issue never led to a major incident. Binney also stated "In the early stages of the ship's first commission, there was a general misconception that the Nelson class were unhandy and difficult to manoeuvre. Both my predecessor and myself, however, very soon discovered that this opinion was entirely fallacious! In calm weather, the ship's manoeuvring capabilities are in no way inferior, and in many ways superior to those of Queen Elizabeth or Revenge." They could also be awkward to manoeuvre when moving astern. This was attributed to the ships having a single, central rudder which was out of the propeller race of the twin screws. At sea, however, they were reported to handle well, with a comparatively small tactical diameter (turning circle) particularly when turning into the wind, according to Lt. Commander (later Rear Admiral) Galfry Gatacre RAN, who served in 1941–1942 as the navigator for both Nelson and subsequently Rodney. He reported no difficulty in navigating either ship through the boom gates at Scapa Flow. Nelson and Rodney were the only battleships never to have bumped the boom gate vessel as they passed through Hoxa Sound.Reports of Proceedings 1921–1964, G.G.O. Gatacre,
Armament
These ships were fitted with the HACS AA fire control system and the Admiralty Fire Control Table Mk I for surface fire control of the main armament.