HMS battleship Royal Oak   

The five Royal Sovereign class battleships were laid down just before the outbreak of World War I. As 15-inch gunned successors to the Iron Duke class they were a reversion to the standard type of Dreadnought battleship rather than an improved Queen Elizabeth type. With little more than half the designed horsepower of the Queen Elizabeths they would only have made 21 knots, and could therefore never have formed a special 'fast division'.

Events conspired to alter these requirements, for when War broke out in August 1914 the new First Sea Lord took exception to the Royal Sovereigns and redesigned them. First he altered them from coal-burning to oil-firing, which increased their speed by two knots by reducing the load displacement. Second, the ludicrous arrangement of two 6-inch gun positions aside at main deck level aft was suppressed during construction. Three more of the class were suspended, and two became battle-cruisers, Repulse and Renown (q.v.).

Although the Royal Sovereigns were always eclipsed by the faster and more glamorous Queen Elizabeths they should not be ~under-rated. In many respects they were better ships, with a more usable layout of 6-inch guns and better distribution of armour. They remained the backbone of the Fleet between the Wars, but on account of their slowness were never considered worth the sort of modernisation given to the Queen Elizabeths and the Renown.

The Royal Sovereigns introduced anew feature to British battleship design, the anti-torpedo bulge; in other words, an external water- or air-filled compartment capable of exploding a torpedo prematurely to minimise damage to the main hull. The Ramill;es was completed with the early type of shallow bulge, later replaced by a very deep type which reached almost to the upper deck battery.
This type of deep bulge was also fitted to the Royal Oak during her 1927 refit, but the other three were given the shallower type. Bulges had the effect of improving the behaviour of the class at sea, as they had been inClined to roll excessively.

The class were completed with an additional 6-inch gun to port and starboard on the shelter deck, to replace the main deck positions (much the same as had been done to the Queen Elizabeth class in 1915-16), but these were removed from all ships during the 1927-28 series of refits. Beginning with Resolution in 1924 most of the class adopted a clinker screen or funnel-cap to keep funnel gas away from the bridgework, but when war broke out in 1939 Royal Oak had not been altered.

RoyalOak and Revenge were the first of the class to complete, and so claimed the distinction of serving in the Grand Fleet at Jutland in the 1st Battle Squadron.
Royal Oak served in the 2nd Battle Squadron of the Atlantic Fleet from 1919 to 1926, and then following aTefit, in the 1st Battle Squadron of the Mediterranean Fleet to 1934. After a large refit in 1934-35 she joined the 2nd Battle Squadron of the Home Fleet.

With the remainder of the Home Fleet the Royal Oak was sent to Scapa Flow on the outbreak of war in September 1939. When the German battle-cruiser Gneisenau, the cruiser Koln and nine destroyers made a sortie early in October, she was sent with two destroyers to patrol the Fair Isle Channel, but like so many British sweeps at the time it proved abortive, as the intelligence and inter-service planning had been faulty.

After this operation RoyalOak returned to her anchorage off Kirkwall. In the early hours of 14 October she was found by the German U-boat U.47 under Leutnant Gunther Prien. U.47 fired one torpedo, which apparently hit, but It hardly attracted any attention aboard the battleship, for the explosion sounded too slight to be made by a torpedo. The reason for this will never be known, and the torpedo may have hit the anchor cable; on the other hand, German torpedoes at this time were proving unreliable, and the first may have  simply been a 'dud'. As the remaining two torpedoes missed Prien manoeuvred U.47 for a shot from his single stern tube, but this also missed.

The old battleship seemed to have a charmed life, but Prien was a determined submariner, and having achieved the great feat of penetrating the Flow was not prepared to leave without a victim. Having reloaded, and in spite of having one of his four bow tubes defective, he approached the anchorage again. This time his three torpedoes hit, or to be more correct, probably exploded under the battleship's keel, the worst possible place. Within thirteen minutes the Royal Oak rolled over and sank, taking with her over 800 men.

Although not a front-line unit, her loss was a blow to British prestige, and the knowledge that Scapa Flow could be penetrated by submarines was very disturbing. Ironically, the blockship intended to block the Kirk Sound passage used by U.47 arrived the day after the sinking of the Royal Oak. Although many a,mystery tale has been told about the sinking, it remains no more or less than a brilliant exploit by an ace submariner, who took great risks in entering the Flow, and was amply rewarded for his daring.

The drawing shows Royal Oak as she was in mid 1937, having changed little since her big refit in 1934-35. Note that she is the only one of the Royal Sovereign class still without a funnel cap, but in most other respects she has all the minor improvements made to her sisters between the two World Wars. It is in her detailed modifications that Royal Oak differs so much from her contemporaries, and the drawing shows all of them. Apart from the removal of the aircraft and catapult, Roval Oak had the same appearance in 1939.

The most important modification can be seen just forward to A turret, where two pairs of 18-i~ch torpedo-tubes have been added at upper deck level. These tubes are fixed, and angled about 35ш off the centre-Iine; in the mid-1930s the Admiralty fitted a number of ships with similar mountings, but in all other ships these were of the broadside type. Note also the conspicuous bulges already mentioned; she is unusual in having two sets of bilge keels, which may have been fitted to reduce her rolling.

The "Osprey" floatplane 1s carried on a catapult on IX' turret, and the turret has to be trained into wind to launch the aircraft. The catapult is offset on the port side of the turret-roof to allow it to extend sufficiently. Spare floats are carried on the level of the pom-pom platforms, abreast of the funnel.

The weakness of the.anti-aircraft armament is very evident. As far back as 1921 it had been stipulated that each of the "R" class capital ships was to have four multiple pom-poms, but none received more than two until war broke out.
Royal Oak's eight-barrelled pom-poms are fitted on large platforms, dating from her 1927 refit, but during her 1934-35 refit she had the new twin 4-inch mountings substituted for the older singles, and a 4-barrelled .5-inch machine-gun was added on either side of the armoured control position. The 4-inch high-angle mounting was a fine weapon, and it remains in service today, but the quadruple machine-gun was a lamentable close-range anti-aircraft weapon.

Note the solid appearance of the superstructure and tripod mainmast, all basically unchanged since 1916. A director has been added on a platform halfway up the mainmast, and the office for the direction-finding equipment is on the starfish platform, from which the aerials project. The boats are standard, with the exception of the unusual 35-foot power boat amidships, for which no details have come to light. Her largest boats are two 50-foot steam pinnaces and a 45-foot motor launch. Eight smaller pulling boats are also carried.

The "Osprey" floatplane is carried on a catapult on 'X' turret, and the turret has to be trained into wind to launch the aircraft. The catapult is offset on the port side of the turret-roof to allow it to extend sufficiently. Spare floats are carried on the level of the pom-pom platforms, abreast of the funnel.