HMS cruiser Ajax

When the Admiralty paused to reflect on the effects of the Washington Treaty on auiser-design it was clear that the big 8-inch gunned cruiser had not proved to be the type best suited to the needs of the Empire. For both financial and strategic reasons the Royal Navy would be better served by a large number of smaller auisers. As experience had shown in 1914, numbers were always more important than quality, and building cruisers to match individual foreign ships had been proved futile in the 19th Century.

Under the disarmament treaties, 'B' Type cruisers, that is cruisers armed with guns of 6.1-inch calibre or less were not subject to a limitation of numbers, provided always that they did not exceed the upper limit of 10,000 tons. Hence the decision to keep the new 6-inch cruiser design down to the lowest possible displacement. The new 7 ,000 ton design owad something to the 'County' class, for the same layout of guns was 'adopted, with the same far-sighted emphasis on good elevation for the twin turret to enable it to engage distant aircraft.

As weight limitation played an important part, far more than it had in the 'Counties', the boilers were concentrated in a unit of four, in two adjacent compartments. This made sense on the drawing-board but it was obvious to any practical per-son that an unlucky torpedo-hit abreast of the interconnecting bulkhead must result in flooding of both boiler-rooms, total loss of power, and almost inevitably the loss of the ship. In practice this never happened, and the solitary war loss out of five Leander class cruisers, the Neptune, withstood a great deal of damage from mines before she sank.

Cruisers are difficult vessels to armour adequately, for their moderate freeboard militates against longitudinal bulkheads." All that could be achieved in the Leander class was to localise damage by means of 2-3" armour plating and athwa1ships bulkheads as closely spaced as was practicable. To offset the danger of the double boiler-room already mentioned the machinery layout was designed to give the maximum assistance in limiting battle damage. The forward turbines drove the outer shafts, while the after set drove the inner shafts, and either unit was capable of driving the ship at 23 knots. Any measure of longitudinal bulkheading was ruled out in view of the danger of increasing a list and thus reducing stability.

The 6-inch turrets were an improved version of the twin semi-automatic mounting first tried in the Enterprise and then fitted in the Nelson and Rodney. In World War II they proved to be an excellent backup to the 4-inch anti-aircraft a-mament, being able to fire controlled barrages at 60° elevation. Although the original armament of single 4-inch was puny it was very much improved when the twin 4-inch mounting was substituted after 1937.

Ajax differed slightly from her four sisters in having a fuller hull and reduced draught. In addition she was completed with a crossed catapult and two aircraft, as in the Exeter . With her sister Achilles (on loan to the Royal New Zealand Navy) she was part of Commodore Henry Harwood's South American Squadron at the outbreak of war, a hunting group intended to hunt down German commerce-raiders. With the 8-inch cruiser Exeter the two small cruisers found the German pocket-battleship (more correctly an armoured cruiser) Graf Spee off the River Plate on the morning of 13th December, 1939.

The signal from Ajax at 08.16, 'I think it Is a pocket-battleship' was the beginning of one of the great sea-fights of the War. The three cruisers, all outranged by the Graf Spee's 11-inch guns, hung on like terriers and used their high speed to break off action whenever the German ship tried to finish them off. Opening fire at 19,000 yards, the Ajax and Achilles were disregarded at first, as they were mistaken for destroyers with their unusual silhouettes.                                                      

 As an indication of the  precision of their tactics both ships were firing concentrated salvoes, but with Ajax directing fire. When the Graf Spee tried to finish the crippled Exeter both small cruisers dashed to her aid and fired so effectively that they deflected the Germans from their purpose. Ajax was hit twice, the first hit knocking out 'X' and 'Y' turrets, and the second carrying away a topmast.

What followed is well known; the Graf Spee although not seriously damaged was so badly rattled that she put into Montevideo, thereby giving Commodore Harwood time to bring the Cumberland up from the Falkland Islands to replace the Exeter. By a skilful diplomatic bluff the British persuaded Captain Langsdorff that he had to face not only three cruisers but also the Ark Royal and the Renown. Faced with the certain knowledge of defeat if this were true, Hitler authorised the scuttling of the Graf Spee as preferable to internment in Uruguay. Naturally the victory was a great tonic to British morale so early in the war, and a corresponding blow to Nazi prestige.

The drawing shows Ajax as altered during the refits which she underwent after the Battle of the River Plate and subsequently to November 1942. Note that the tripod masts were added during the 1940 refit, which makes them the first tripods added as a wartime modification which was later extended to virtually all the older cruisers. On the other hand Ajax was one of the few cruisers to retain her full main armament to the end of her career, whereas the others had 'X' turret replaced by light anti-aircraft guns and additional radar .

By March 1941 the aircraft and catapult had been removed. The crane, however, was retained as it enabled boats to be handled with ease, and a 36-foot motor boat was carried in the space left by the catapult. The radar sets installed up to November 1942 included the usual Type 279 for air-warning, the transmitting frame on the foremast and the receiving frame on the main topmast. Note that the transmitting office for this set has been added to the rear of the bridge, and has been given splinter mattresses for added protection.

Gunnery radar follows the normal pattern for cruisers at this time. Type 284 has been added to the front of the main director, and a Type 282 barrage director for the 6" guns has been sited on a platform at the front of the bridge. However , there is no barrage director for the multiple 2-pounder pom-poms.

The high-angle directors controlling the twin 4-inch guns have had Type 285 aerials added, but the ship appears to be sadly deficient in close-range A.A.
weapons on forward bearings. Although eleven Oerlikon guns have been added, including one in place of the quadruple machine-gun on the roof of the secondary steering position, there are none on 'B' or 'X' turrets.

The boats include, apart from the 36-foot motor boat already mentioned, two 32-foot sailing cutters and a 35-foot motor boat. Note also an inclined platform on the port side for stowing rafts. The former searchlight platform on the after superstructure has been cut down, but the 44-inch searchlights are still in place on either side of the funnel. Note also the crews' shelters between the 4-inch guns amidships, with carley rafts stowed on the roof .

After her refit in 1940 Ajax went to the Mediterranean, and was damaged in action with Italian destroyers in January 1941. During this period she served with Force 'H', and went to the United States for a refit in 1943 before returning to the Mediterranean, where she served until the end of hostilities.
She was laid up in reserve until sold to J. Cashmore in November 1949, and was broken up at Newport, Monmouthshire. Her name has been revived for a Leander class frigate.