Armour
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.
Tube: 6in.
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.
General Notes
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.
Manoeuvring powers.
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.
Armament
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.
16in mountings
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.
Fire control
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
Complement: 1,314
Fate: Nelson: used as bombing target before being broken up,
1948. Rodney: sold out of service, 1948
