Alphabet Soup 4 – Small but Sensible
In the autumn of 1920, the ‘H-series’ battlecruisers were an attempt to take the best features of the ‘I-series’ and use them in a smaller ship. H-3a, b and c were all 860’ long with a 106’ beam, and so would fit in existing docks. They carried two triple 18" Mk.2 45-calibre turrets and would achieve speeds in excess of 33 knots.
The initial version, H-3a, mounted all guns forward of the bridge in super-firing turrets, while a powerful secondary armament of 16-6" guns in twin turrets would be mounted aft. Decks would be up to 9" thick, and the 18-degree inclined belt armour was 14" thick over the magazines and 12” elsewhere. Speed was 33½ knots, and all this was achieved on a displacement of 45,000 tons.
However, while all these new designs had very heavily armoured turrets, there was still an argument that a single lucky hit could knock out 50% of H-3a’s firepower, and a very unlucky hit might disable one turret and jam the other. H-3b and H-3c rectified this by mounting the turrets fore and aft of the bridge. Without the need for any long, heavy barbettes, H-3c came in at just 43,750 tons, with a speed of close to 34 knots.
An attempt was made to produce an H-4, with eight 18” guns in two quadruple turrets, but it resulted in a ship more than 880' in length. It still suffered from being a two-turret concept, and as it would not fit any existing docks, the outline design was never completed.
To some in the service, the H-3 designs represented a great deal of displacement and cost for a ship with only six main guns, while many more were not keen on any design with fewer than eight guns. However, if viewed as a ‘fully-armoured Furious’, the H-series showed that firepower, speed and armour could be achieved on reasonable displacements, if six guns were considered adequate.
Few details survive of the ‘G-series’, and indeed there may only have been a G-3, which was an attempt to cut the size of the ‘I-series’ by reducing the calibre of the guns rather than their number.
Outline details show her to be a ship of 46,000 tons with nine 16" Mk.2 guns, capable of 32½ knots. Deck armour was thinned over the machinery spaces to just 2”, although magazines were still heavily protected by a 14” belt and 8” deck.
Tantalisingly however, the design probably triggered the re-examination of the D-series and the sketching of D-33 as a way to compare the guns-forward design with a traditional one. The absence of plans may also be because G-3 was part of the inspiration for what was subsequently built, and drawings may have been re-used or kept secret when new ships were finally laid down in 1922.
The final pair of these smaller designs were neglected by most seagoing officers at the time, as they were seen as too small and limited. They did, however, have considerable appeal to a debt-laden government.
E-2 was an attempt to take the battlecruiser back to its roots, while saving money and weight in the process. It was a much smaller ‘I-series’, with six 16” Mk.2 guns in three turrets, while secondary armament was reduced to ten 4.7” guns in twin shielded mounts. The main turrets were heavily protected, but during the design process there were suggestions that a ship with four lightly armoured turrets might be preferable to one with three heavily armoured ones.
Torpedo protection was up to the latest standards, but the ship’s main armour was an 11” internal belt, inclined at 18-degrees, with 10” over the machinery, intended to keep 14” shells out of the machinery and 16” out of the magazines at longer ranges. Deck was 5” and 4”. Machinery was described as ‘modernised Hood’ which meant new boilers and 140,000shp, which would give 32 knots at a load displacement of 35,200 tons.
R-3 did much the same for battleships, with two triple 18” Mk.2 turrets, one at each end of a relatively stubby 590’ hull. Armour consisted of a full length 14” external belt and a 6-7” deck. Displacement fell to just 33,000 tons, and 60,000shp was expected to deliver 23¾ knots.
By the New Year of 1921, the Constructors and the Admirals were closer to agreeing what was needed. By that time it was clear that the existing 15” ships would form a major part of the fleet for many years to come, and so new ships would have to reinforce them. Other navies were known to be building 30 or 32-knot battlecruisers, and so very large 27 or 28-knot battleships seemed to be simultaneously too slow and too fast for the Navy’s needs.
A mix of powerful battleships and fast, but less heavily armed battlecruisers therefore seemed to be the way forward.
In the spring, the government announced a new construction programme of two battleships and two battlecruisers would be included in the 1921 Programme, and it was expected that a further ship of each type would follow in both 1922 and ’23. The exact designs were not specified at that time, but by the early summer, the RN had placed orders for two ‘fast battleships’, each very similar to N-3. Battlecruisers were still the subject of debate, with arguments raging between the merits of H-3c, or the more conventional D-33.
