The arrangement of armouring in the `G3’s and Nelson and Rodney embodied the `all or nothing’ principle, introduced for the first time in the Dreadnought era in the US ships Nevada and Oklahoma (laid down 1912).
Protection was concentrated over gun positions, magazines, machinery and boiler spaces, with the entire hull before and after this being completely unarmoured. To allow minimum length of the citadel, and maximum armour thickness, main armament was located forward, the after turret being located exactly amidships. The adoption of this method of application was a radical departure from British practice, but had been grudgingly accepted in order to secure the great freeboard required, good seakeeping qualities, extremely heavy armament and above-average speed on the 35,000-ton Washington Treaty displacement limit while at the same time meeting strict Admiralty requirements for a very thick belt (14in) to protect the main armament forward.
Extremely valuable information about armour protection was gleaned when the ex-German battleship Baden was used as a target for heavy shells on 29 September 1921. Rounds 3, 8 and 14 were of particular interest as they showed what modern AP shells could do, and the vulnerability of turrets protected by only medium armour thickness. The 7in side armour protecting the secondary armament, and that for the main belt lower edge (6_in) proved, in fact, almost valueless. These rounds also showed what AP shells could do against medium armour struck at large or oblique angles and proved how relatively ineffectual the armour was. It had long been recognized that armour plate was of the greatest value when worked in large thick masses. Distribution of medium thicknesses over large areas gave a general impression of protection, but this was, in fact, illusory. This was impressively illustrated by rounds 3, 8 and 14 when fired at the 7in plates of Baden, which were all pierced by 15in shells of armour-piercing quality, at a velocity of 1,380 fps. Not only was the 7in battery armour pierced, but the 7? in armour on the barbettes below the upper deck level was nearly perforated. This would have been accomplished had the range been greater and the shell diving at a steeper angle. The same shells attacking 14in armour under the same conditions would have broken up after considerable damage to the plate, but that thickness would have kept the blast outside.
The policy of the day was to protect any new ship with maximum concentration around vitals and at the maximum thickness that displacement would allow. Horizontal protection requirements were indicated by rounds 2, 4 and 10 which were fired at the unarmoured ends of Baden and resulted in explosions between the decks. In round 10 (CPC) the upper deck was lifted 4ft 6in and 43 feet of it was torn away from the side of the ship. The shell then pierced the main deck and produced a hole 16ft wide by 4ft 6in long and blew that deck 7ft downwards. It was considered that such severe damage in a strength deck would jeopardize the longitudinal strength of a vessel, especially if the vessel received more than one hit in the same area.
Round 6 was fired to test the tongue-type joints adopted by the Germans for their barbettes. The velocity and angle of attack was so arranged that the attacking shell would just fail to perforate and put maximum pressure on the joint. The result was that the strap behind the armoured joint gave way and the joint split; this was exacerbated by the number of bolt holes in the area.
To complete the tests against modern armour, further firing was conducted against the old battleship Superb (Bellerophon class, 1907) on 2 May 1922. Plates were taken from Baden and positioned in Superb to take the blast. A number of 15in shells were then fired at the decks (290lb plates) and side armour (560lb plates) from HMS Terror from a distance of 500 yards. The results were:
1. The armour quality of the plates from Baden stood up to the tests very well.
2. Any electric welding incorporated in the structure broke away.
3. Heavy deck thicknesses of this nature could be supported if necessary.
4. The angle of the 560lb armour was enough to cause the shell to break up on impact, but it was seen that the belt would have to be `keyed’ in properly so as to avoid any damage to the hull proper, or displacement of the armour strakes in question.
The general scheme of armouring in Nelson and Rodney also embodied all the lessons learned during the Great War, especially at Jutland. New improved `D’ type steel with a tensile strength of 37 to 43psi was used for the first time, in place of normal high-tensile steel, on decks and anti-torpedo bulkheads. The main belt was fitted internally for the first time in a British battleship – to secure maximum support to the armour against being driven in bodily by a direct hit, as had occurred in Derfflinger and Lion at Jutland, and it was fitted at an angle of 72 degrees, running away from the waterline at its bottom edge to increase effectiveness against plunging shell fire. The belt was not deep enough, however, and caused great concern among the construction staff. The upper edge of the main strake was supported by a thick armoured deck, but the lower edge rested on an inclined shelf with individual plates `keyed in’ and heavy bars placed behind this. These chock castings which housed the lower edge would also help to direct fragments of a bursting shell upwards and take them away from the lower parts of the ship. The arrangement of internal armouring reduced the armoured water plane, but sufficient resources of buoyancy were available to ensure that the ship would be safe even if the outer hull were opened up by gunfire. The horizontal protection against plunging fire and bombing aircraft was developed to a very high degree, and was considered at the time to be adequate against anything that could be used against the new ships.
The sloping armoured deck behind the main belt, which had been a feature in all British battleships since the Majestic class (1893), was abandoned in Nelson in favour of a flat heavy deck across the top of the main strake and covering the magazines, boiler spaces and machinery. An extension aft, at a slightly lower level, ran across to protect the steering gear. The horizontal armouring was concentrated entirely in these two levels, and they were the thickest individual armoured decks ever fitted in a battleship to that date. Their design also received special attention in view of probable developments in aircraft attack.
All openings for ventilation were reduced to a minimum while special hatches, with operating gear under protection below, were fitted to provide a ready means of escape. Protection to the main armament and magazines was very thorough, special attention having been given to this in view of the high percentage of hits on and around turrets during the war, and the usually disastrous effects of these. Maximum armour thicknesses on barbettes and turrets were respectively 5in and 3in more than in the Queen Elizabeth and Royal Sovereign classes. The turrets were a new, low design with a flat crown to deflect projectiles falling at a steep angle, and reportedly they afforded a high degree of protection. Anti-flash protection to magazines was materially improved as a result of postwar experiments. They were the first British battleships to carry the anti-torpedo armament in closed turrets, these providing, in addition to other advantages, more complete protection to the gun crews than the battery system. They were the last British battleships to have a separate heavily armoured conning tower, this being abandoned in the succeeding King George IV class and Vanguard in which only a light splinter-proof navigating position high up in the face of the bridge tower was provided. Queen Elizabeth, Valiant and Warspite were similarly modified during their final reconstructions. Underwater protection was very complete particularly in the machinery and boiler spaces, where it reached a degree not previously attained in any other British capital ship. The usual external bulges were replaced by an alternative and very efficient system of internal sub-division developed after a long series of experiments and it is reported that this was designed to be capable of withstanding the simultaneous explosion of four torpedoes. A longitudinal bulkhead was fitted throughout the machinery and boiler spaces.
The DNC (Sir William Berry) had favoured inward sloping sides with external bulges as in Hood, but this was found to be impracticable because of: 1. Inability of existing docking accommodation to take the increased beam caused by the considerably wider bulges required to resist modern torpedoes. 2. Necessity for maximum armoured beam at waterline to ensure stability in event of heavy flooding.
Pumping and flooding arrangements were very extensive and were designed to deal rapidly with the correction of heel and/or trim resulting from damage. Eleven electrically driven pumps with individual outputs of 350 tons per hour were provided for compartments outside the machinery and boiler spaces.
The main armour protection was as follows:
Main Belt: was 14in thick amidships and ran for 384 feet. Angled at 72°, it was fitted internally and extended from the outer face of the forward 16in barbette (about 100 feet from the bow) to the inner face of the after 6in barbette (about 70 feet from the stern) and sloped inwards to the waterline. The 14in plates reduced to 13in abreast machinery and after magazines. Bulkheads were 12in and 8in forward closing forward extremities of belt armour between middle and lower decks, 10in and 4in aft closing after extremities of belt.
Decks: 6¼in armour plates plus 1½in plating laid over the top (6_in) laid flat over the length of the 14in belt armour on middle deck level. Lower deck 4¼in armour plates plus ½in plating laid over the top (4_in) flat, from after extremity of 14in belt to within about 25 feet of the stern.
Barbettes: 15in carried down to middle deck (see plan for various thicknesses).
Turrets: 16in faces, 7¼in crowns and rear.
Secondary barbettes: 1in. Conning tower: 14in sides, 12in front, 10in back and 6½in roof.
Conning tower hood: 5in-3in. Funnel uptakes: 8in-7in.
Anti-torpedo bulkheads: 1½in, longitudinal port and starboard, set well inboard, extending completely between forward and after magazines from keel to middle deck and sloping inwards from top to bottom.
On completion they were probably the best armoured battleships afloat although the shallow 14in belt led to much criticism after completion. During firing experiments in 1931 on Marlborough and Emperor of India one shell (hit no. 4) burst under the armoured belt, apparently just where it was in contact with skin plating, and caused considerable damage. This hit emphasized the desirability of a deep belt and it was proposed that Nelson and Rodney be improved in this respect when they came in hand for refitting, but the extension of side armour was never effected and their armour protection remained the same throughout their lives. The only addition was to Nelson, which was fitted with 100lb and 120lb NC armour on the lower deck forward between 80 and 84 stations, `160lb armour bulkhead at 80 station from hold to platform deck. Rodney was not completely fitted with additional armour forward, but it is understood that she did receive something along these lines although the official records are not clear. Later proposals to modernize the armour protection (1938) were finally abandoned.
Both ships proved to be excellent steamers in service and it is said that while chasing Bismarck in May 1941 Rodney attained a speed in excess of what had been thought possible in view of previous machinery and boiler breakdowns and the long time that had elapsed since her last refit. In relation to displacement Nelson and Rodney were, on completion, probably the most economical steamers in the Royal Navy.
A complete breakaway from the normal bridgework and heavy tripod foremast, which was replaced by a high tower structure, was considered to be the only satisfactory means of obtaining adequate support and clear vision for the extensive modern fire control equipment, as well as providing the necessary accommodation for the navigating and signalling positions and extra cabins, etc. The controls for the main and secondary armament were located at the top of the tower, and the Admiral’s bridge, navigating and lookout platforms were arranged around the upper sides and face of the tower, with signalling searchlights in ports inside and lower down. The sea cabins, plotting offices, etc., were positioned at the base of the tower. All flag signalling was carried out from the foremast.
The massive tower bridgework, introduced in this class, was retained in the succeeding King George V and Vanguard classes, and (in modified form) in the reconstructed Warspite, Valiant, Queen Elizabeth and Renown.
The heavy boats were all stowed abaft the funnel, and handled by the main derrick which was worked from the mainmast base.
Accommodation greatly embodied the recommendations of the Accommodation Committee, which had been appointed by the Admiralty in 1923, and in these two ships it was especially good both for officers and ratings – the space available being much greater than usual as a consequence of the high freeboard over the whole length of the ship, which also offered ample headroom between the decks. Natural light was provided in most living spaces, and ventilation was greatly improved over preceding classes. The ships were also provided with such items as reading and recreation rooms, drying rooms for wet clothing, bakery, oil-fired galley, laundry and electric ovens for the first time.
Ventilation received special attention and proved to be generally satisfactory in service. In the crew’s galley, however, exhaust fumes were stated to be intolerable during the war when the skylights were often closed to darken ship.
The pair were known affectionately as `The Queen’s Mansions’ (because of the massive tower) and by 1930 had become part of the British constitution – the general public loved them and they were always crowded out on `Navy Days’, but a more relevant opinion came from Captain T. H. Binney of Nelson when finishing his term of service in her:
Before relinquishing command of HMS Nelson, I have the honour to submit the following remarks or points of interest relating to this class of ship. I have been fortunate in that I have joined the ship at that moment when she may be said to have got over her initial troubles, and my period of command has included the last twelve months of the first command with a well-trained ship’s company, and the first five months of the second command with a new ship’s company.
In the early stages of the ship’s first commission, there was a general misconception in the service that the Nelson class were unhandy and difficult to manoeuvre. This was probably due to the unaccustomed position of the bridge and the initial inexperience of the personnel of what the ship might do under various conditions. 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. The astern power is much better than that of Queen Elizabeth, they steer much better with the engines stopped, and at rest they turn very easily by working the engines. Owing to the high superstructure aft, however, they carry a good deal of weather helm, and for the same reason, their turning circle when turning away from the wind is greatly increased, while when turning into the wind, it is correspondingly decreased.
As an example of the effect of the wind, on one occasion when getting under way with a wind of about 5-6kts on the starboard beam, the ship swung 4 points to starboard against full starboard helm, and it was not until the ship was moving through the water at 9kts that she started to answer her helm.
On another occasion, when anchored with the fleet, with a wind of about 5 knots on the port beam, the ship’s head could not be kept steady with full port helm, and swung to port in spite of starboard screws being reversed. On entering a harbour through a long narrow channel such as Gibraltar a strong head wind is the cause of some anxiety; but the effect seems to be greatly reduced if the wind is a few points abaft the beam or on the bow.
When pointing the ship using the engines, the wind has little effect, except to stop the swing at once.
Generally, the superstructure has the effect of a mizzen sail continuously set, and if this is kept in mind, no real difficulties should be encountered in any circumstances.
I hold the opinion that the low-angle gun equipment as a whole, and particularly the 16in main armament, is a very marked advance on any previous capital ship, and should result in improved rate of hitting at all ranges.
On account of various improvements (rangefinders, control apparatus, etc.) as well as the increased size of splashes, long-range firing from Nelson should be more effective in the 25/28,000 yds long-range firing than in Queen Elizabeth at 21/25,000 yds.
In the case of secondary armament, although the rate of fire is rather low, the increased range at which fire can be opened, and the absence of loss of output due to fatigue, combined with excellent ammunition supply arrangements, will be a very prominent factor in war.
In view of the modem tendency of construction for `all or nothing’ armour protection leaving controls and secondary batteries unprotected, the possibility for using the secondary battery for `harassing fire’ at the main armoured target when the range has been found assumes greater importance, and in Nelson the secondary armament can do this efficiently without loss of anti-torpedo boat efficiency.
The 16in triple mounting has been subjected to considerable criticism from time to time, and there is little doubt, that in some quarters the view is held that a triple mounting for heavy guns is not a good investment. The great advantage of the triple mounting system from construction point of view (which is that the armament can be concentrated in a much smaller space, and will require less area of armoured protection) has not, perhaps been sufficiently emphasized. The main disadvantage of Nelson’s triple mounting is loss of output on account of the fact that the three guns cannot be fired together owing to ballistic difficulties, whereas they must be loaded together. This, however, is not in itself a reason for condemning the triple mounting in general. The mounting may be said to have proved itself, when in October 1929, one turret crew with two years’ experience, loaded and fired 33 rounds without mishap. The main defects appear to be the roller paths and the rollers.
The main armament fire control is very satisfactory, and a marked advance on that of earlier battleships. The efficiency of the rangefinder installation and the Admiralty fire control table are of a high order, and it has been found a comparatively simple matter to train the personnel in their use. In secondary armament apparatus no great advance can be recorded as the installation is essentially the same as in older ships though more automatic in action. The installation, however, fulfils the required condition of simplicity.
Summary: Nelson and Rodney were the only two battleships designed and completed in the 1920s.
Construction: Nelson: Armstrong (1922-1927); Rodney: Cammel Laird (1922-1927)
Displacement: 33,950 tons
Dimensions: 660′ x 106′ x 30′
Armament: 9 x 16″ in main battery guns in 3 x 3-gun turrets
Armor: 14″ belt; 9″-16″ turrets
Machinery: 2 x shaft Brown-Curtis geared turbines = 45,000 hp = 23 knots
Fate: Nelson: used as bombing target before being broken up, 1948. Rodney: sold out of service, 1948