ADT wanted more tubes because limited space in a submerged torpedo room made it nearly impossible to provide more than two or three quick reloads. After that no more could be fired for some time, yet the opportunity to fire effectively would not last long. This issue first came up with the 1910–11 ships, Queen Mary and the King George V class. All of these ships had limited internal space. Queen Mary would have to be lengthened by 10ft and displacement increased by 400 tons; in a King George V the extra tubes would cost 5ft and 250 tons. Controller (Rear Admiral Jellicoe) rejected the idea but was willing to reconsider it for the next year’s ships. Meanwhile tactical exercises were examined to see whether increased torpedo fire would be useful and experiments with gyro angling pursued. By September 1910 both the experiments and the exercises showed that two more broadside tubes were worthwhile. Exponents of more tubes also pointed to modern German battleships, which typically had four broadside tubes and a stern tube. DNO supported ADT’s argument and on 13 October Jellicoe agreed (but ADT’s request that slots be cut in side armour for torpedo directors was rejected, ships being given secondary conning towers with directors in armoured hoods instead). The first ships involved were the 1911–12 ships (Tiger and the Iron Duke class battleships). This battery was repeated in the Queen Elizabeth and Royal Sovereign class battleships.
In 1912 Home Fleet C-in-C Admiral Sir George Callaghan considered the long-range 21in torpedo so valuable that he wanted all dreadnoughts prior to HMS Hercules rearmed with 21in broadside tubes (with four such tubes in Dreadnought herself and in the Invincible class). That was impractical. By this time British gunnery was clearly effective at about 8000 yds and HMS Colossus had carried out a trial shoot (apparently against a fixed target) at 14,000 to 15,000 yds. Callaghan did not want torpedoes which could not reach an enemy battle line 10,000 yds away. Any great improvement in speed should be accompanied by greater range, the torpedo running time remaining constant at 10–11 minutes. Callaghan therefore wanted 10,000 yds at a speed of at least 22 knots. In his view anything slower would miss. In April 1912 there was interest in adjusting 18in Royal Gun Factory (RGF) heater torpedoes fired by battleships to run 10,000 or 12,000 yds at 22 knots instead of the current 6000 yds at 29 knots – to what was later called an ER setting. A July 1912 War College study concluded that long-range torpedoes fired from before the enemy’s beam could always hit from longer ranges than faster shorter-range torpedoes. Commander Second Battle Squadron (Admiral Jellicoe) seems to have been unusual in rejecting such slow torpedoes; in 1912 he considered 30 knots/10,000 yds and 44 knots/4500 yds the ideal.
The British were well aware that torpedoes produced tell-tale wakes: ships would evade if they were seen in time. The interaction of torpedoes and guns during a day action could be devastating. To keep hitting with their guns, ships needed to maintain a steady course and speed. If they saw massed ‘browning’ torpedo shots coming, they could either evade and stop hitting or they could accept underwater hits. The British made successful efforts to make torpedo wakes less visible, as attested to by Germans at Jutland. That the Germans did not (or failed when they tried) is evident in Admiral Jellicoe’s successful evasion of massed German torpedo fire at Jutland. Jellicoe clearly feared underwater damage, so he turned away.
Beginning in 1915, Grand Fleet C-in-C (Jellicoe) pressed for greater and greater torpedo ranges, which were typically called ER (extended or extreme range); he was willing to accept the low speed which had seemed unattractive in 1912. Late in 1915 trials were conducted with Mk II**** torpedoes which, it was hoped, would reach 18,000 yds at 19 to 20 knots. Each capital ship and each light cruiser with submerged tubes was to have had two torpedoes capable of reaching about 17,000 yds at 18 knots, but it is not clear how many such ER3 torpedoes had been provided by the time of Jutland. After Jutland, Jellicoe experimented with tactics emphasising the use of 15,000 yd torpedoes – torpedoes with gun range, as it was now understood. The 21in Mk IV* torpedo had settings of 15,000 yds at 25 knots and 18,000 yds at 21 knots, for submerged torpedo tubes. ER3 conversions were completed during 1917 and the longer-range Mk IV supplied, completing conversion of the fleet to longer-range torpedoes. As the fleet received longer-range torpedoes in 1917–18, ships were fitted with improved controls, supported by longer-base torpedo-control rangefinders.
UNDERWATER PROTECTION. BATTLECRUISERS.
“INVINCIBLE” CLASS
“INDEFATIGABLE”
“LION AND PRINCESS ROYAL”.
“QUEEN MARY”
“TIGER”.
Underwater protection of pre-1914 British battlecruisers.
Despite the pre-war decision to put four tubes in each capital ship, those built during the war reverted to two submerged tubes. By the beginning of 1916, Jellicoe wanted more tubes. Due to their speed, battlecruisers were most likely to gain a position of torpedo advantage. This was well before Jutland made Jellicoe wonder whether he might not have to rely on such shots until his armour-piercing shells were replaced. ADT proposed at least two and at most four fixed tubes per side arranged in pairs. DNO and Chief of Staff (Admiral Oliver) backed ADT. These had to be above-water tubes. There was no more internal space in the ships involved and trials were showing that submerged tubes might not be usable at high speed.27 To DNC, inherent limitations on the height from which torpedoes could be dropped into the water suggested that any new tubes should be on the main deck, which meant that in the new battlecruiser Hood armour had to be cut away to accommodate them (ADT thought they could be outside the main belt at the ends of the ship). In any case, above-water tubes introduced an element of vulnerability. Controller asked whether it was worth risking a £3 million ship ‘for the sake of problematical hits at very long range’. First Sea Lord was told that HE shells hitting a torpedo would destroy it and that fragments would detonate any unprotected warhead within 11 yds.
Hood was given eight above-water tubes with 3in armour mantlets around their warheads. In action this protection would be reduced dramatically, as armour doors would probably be kept open to allow quick shots. The tubes were just over the stringer plates on the upper deck which formed part of the ship’s hull girder. By the autumn of 1918, DNC was pointing out that if the torpedoes did explode, that would probably break the ship in half.28 This point was remembered when HMS Hood was sunk.
In July 1919 removal of four tubes was approved, the rest to be retained for experiments, but not as a war fitting due to the risk In 1923, however, approval was sought not only to make the tubes permanent, but also to add four more on each side. At this point the British were embroiled with the Americans in a dispute about whether increasing turret elevation was legal under the new Washington Treaty and it was decided to defer installation of further tubes until that had been resolved (adding tubes might have come under the same prohibition as changing the characteristics of the gun mountings).29
In 1927 the situation changed again, the Americans having announced that they planned to increase the elevation of the 14in guns in the Nevadas to 30°. In November 1927 Director of Tactical Division strongly supported adding above-water tubes to battlecruisers on much the grounds Jellicoe had cited in 1916 (Repulse already had eight tubes). DNC reported that replacing the four removed tubes and adding protection would cost 110 tons (which was no problem) and would require extra personnel and thus would crowd the ship’s mess decks. The Board decided not to add the tubes so as not to ‘give the USA further reason for abusing us’. However, the four existing tubes were to be considered a war fitting and the box protection originally planned was restored during her large 1929 refit.
After Jutland it was decided to fit all the new