Nelson Class Battleship - History and Design

History and Design

The Battle of Jutland had shown the value of firepower and protection over speed and manoeuvrability.

The next generation of British warships incorporated this lesson. After the First World War, the Admiralty drew up plans for massive, heavily armoured battlecruisers and battleships, far larger and stronger than all previous vessels. The G3 battlecruisers would carry 16-inch (406 mm) guns, and the proposed N3 battleships would carry nine 18-inch (457 mm) 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.

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 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, not contributing to the "dry" (standard) weights and therefore neither against the treaty 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 they 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, drawing from the G3 and N3 designs. In order to reduce the weight of armour, the main gun turrets were mounted all forward, shortening the necessary armoured citadel length. The G3 and N3s had put the two turrets forward of and one behind the bridge, but in the Nelsons, this was taken to extremes, and all three were in front of the bridge; 'B' was mounted superfiring over 'A', with 'X' turret at the main deck level behind 'B', and therefore unable to fire directly forward or aft. The secondary guns were placed in totally enclosed director-controlled turrets at the main deck level and were grouped aft - another innovative element borrowed from the G3 and N3 design.

Armour weight was also reduced by using an internal, inclined armour belt sloped at 72 degrees vertically, 14" thick over the main magazines and control positions to 13" over the machinery and 6" gun magazines . The slope increased the relative width of the belt to a plunging projectile. Water filled compartments surrounded by air filled Torpedo bulges were fitted internally between 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. 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" 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, 6.25" thick armoured deck to protect against plunging shells and aircraft-dropped bombs with 4.25" armour over the stern, both on top of the 0.5" deck plating.

The machinery was of necessity limited in weight, size and installed power, and there were only two shafts with large screws; all previous British battleships since HMS Dreadnought of 1906 had four. In order that flue gasses be kept clear of the superstructure, the boiler rooms were moved behind the engine rooms, exhausting into a single funnel - another feature unique in British battleships. As a countermeasure to the limited power, the hull was of a very efficient hydrodynamic form, to attain the best possible speed.

The large superstructure which was octagonal in plan, was known to its crew as the "Octopoidal"and was sometimes referred to as "Queen Anne's Mansions", due to its similarity to a 14-storey brick residential development of the same name, opposite St. James's Park underground railway station in London. The superstructure provided spacious, weatherproof working spaces for the navigating officers and any flag officers embarked. Other than an emergency conning tower at its base, and the trunking for the main gun directors mounted on top, it was lightly armoured against splinters only, to save weight. Weight-saving measures included the use of light materials such as aluminium for fittings, and fir instead of teak for deck planking, although in practice 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 compromise design, and unsurprisingly there were shortcomings. The rear location of the superstructure caused manoeuvrability problems in high winds, with the superstructure acting as something of a sail, causing the ships to "weathervane" when steaming at low speeds or at anchor. This was a potentially dangerous problem in crowded harbours, and the ships were sometimes difficult to dock and embark, though no record of any major incidents exist. Capt. T.H. Binney is quoted by R.A.Burt as saying "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" followed by "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 were also hard to steer when steaming astern. This may be attributed to having twin screws and a single centre rudder which was out of the propeller race. However at sea they were reported to handle well, with a comparatively small turning circle according to the Navigation Officer of Nelson and subsequently Rodney, Lt. Cmdr. Galfrey Gatacre RAN (later Rear Admiral). He reported no difficulty in navigating either ship through the boom gates at Scapa Flow and nor did his predecessor, both of whom served as Navigator in both ships. Nelson & Rodney were the only battleships to never have bumped the boom gate vessel as they passed through Hoxa Sound.

Their main armament of nine 16-inch (406 mm) guns were mounted in triple turrets, the only RN battleships with this feature. The guns themselves were a step away from standard British designs. Where previous RN weapons fired heavy shells at a moderate velocity, the Nelson's weapons followed the German practice of a lighter shell at a higher velocity. This change in policy was due to British post World War I testing of German equipment, although subsequent testing proved contradictory, nevertheless these weapons were never considered (by the RN) to be as successful as the previous BL 15 inch Mark I. The guns suffered considerable barrel wear and had a large dispersion pattern. As a result their muzzle velocities were lowered which reduced their penetrative power. A heavier shell was needed to offset this, but the cost of producing new shells, and modifying shell handling and storage equipment, had come at a time when RN funding had been heavily reduced. The need to reduce weight and the use of triple mount turrets led to problems with the ammunition handling and loading machinery. The incorporation of many safety features achieved with lighter materials meant that the complex but relatively fragile equipment had to be worked on constantly over the ships' lifetime. 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.

Finally, the blast of the guns disrupted officers on the bridge to such an extent that the guns of 'X' turret were usually prohibited from firing abaft of the beam at high elevations. Fitting tempered glass in the bridge windows was tried, but gun blast shattered them and filled the bridge with flying debris A great deal of effort was expended in correcting this problem, and fitting of protective ledges below the bridge windows proved successful. Blast was also a problem elsewhere; D.K. Brown tells of a firing test that was suspended when DNC observers beneath the foredeck reported a bright red flash after firing. This was later discovered to be caused by concussion of the observers' eyeballs.

Because of their unusual silhouette, HMS Nelson and her sister Rodney were sarcastically nicknamed Nelsol and Rodnol by the Royal Navy ratings who never served in these ships - their manoeuvrability issues and single-funnelled silhouettes reminded Navy men of oil tankers, and a series of fleet oilers had been built during the First World War that bore names ending in "ol". There was a long-standing rumour that the ships could not fire a full broadside without risk of structural damage. This was disproved in Rodney's action with the German battleship Bismarck, where upwards of 40 broadsides (380shells) were fired without major structural damage except to deck planking and upper deck fittings, although damage to sickbay fittings, partition bulkheads, toilet bowls and plumbing in the forecastle were extensive. Rodney also held the distinction of being the only battleship to have ever successfully torpedoed another battleship when one of its 12, 24" torpedoes hit Bismarck amidships. Despite the derisive criticism directed at this class of battleship by some of the media and 'old salts' of the navy upon their debut, well respected Naval Historian, Antony Preston declares that they were 'Soundly conceived ships reflecting all the hard-won experience of WW1' and 'they proved to be very well-protected and well-designed ships'. It is significant that in his 2002 book "The World's Worst Warships" he makes no criticism of the "Nelsons" whatsoever, yet lists both Bismarck class battleships and Deutschland class "Panzerschiff" (Pocket battleships) amongst the worst designs.