Plan Z

by David Wragg

  The remaining years of peace had not been wasted by the British government, which had reluctantly come to recognise the growing threat from Germany and Italy, while Japanese ambitions were also increasingly understood. Two First World War allies were now aligned against Britain and France. Neither Italy nor Japan had played a significant part in the First World War, although Italy had engaged Austro-Hungarian forces and Japan had sent destroyers to reinforce the British Mediterranean Fleet. Nevertheless, both countries deployed powerful forces and in their respective theatres of war, were far stronger than the British forces that could be deployed against them, even taking into account the French presence in the Mediterranean and those of Australia, New Zealand and India in the Far East and the Pacific.

  The Royal Navy in 1939 still had one of the world’s largest fleets of aircraft carriers, but the original ships were obsolete and in reserve. Furious and Argus were conversions, showing their age, but suitable for training, or as aircraft transports, and could also be used for escort work. The first aircraft carrier designed as such, Hermes, was too small and too slow, although again, she could have been a useful escort, but under wartime pressures, she was pushed into the frontline searching for German commerce raiders and was off Ceylon when the Japanese Navy Air Force found her in 1942. Courageous and Glorious, which had both started life as sister ships of Furious before conversion from battlecruisers, were limited and really due for withdrawal once the generation of new aircraft carriers entered service, but again were retained under wartime pressures. They didn’t last long, with Courageous being torpedoed and sunk just two weeks after the outbreak of war, and Glorious being sunk by the twin battlecruisers, Scharnhorst and Gneisenau, during the withdrawal from Norway.

  Nevertheless, six aircraft carriers that were larger, faster and heavily armoured were on order, as was a depot or support ship that was designed to operate as an aircraft carrier if necessary, HMS Unicorn. The first six ships, of the Illustrious and Implacable-classes, were described by many as the best aircraft carriers of the Second World War, but Unicorn was also useful and during the war mostly served as an aircraft carrier. These ships, with the last prewar carrier, Ark Royal, which had an impressive aircraft capacity but a weak flight deck, already more than matched the planned four large aircraft carriers and four smaller ships incorporated in the final years of Plan Z.

  No less impressively, the Admiralty before the war had already started to worry about not having enough flight decks and was looking at merchant ships for conversion, including the new fast Cunard liners, Queen Mary and Queen Elizabeth, but these were considered to be of greater use as troopships. By 1941, before Hitler’s promised date for the commencement of hostilities with the British Empire, the Admiralty was already ready to order aircraft carriers that could be produced quickly and easily in yards accustomed to merchant shipbuilding. In between, the merchant aircraft carriers or MAC-ships and the escort carriers, not all of which came from the United States, were ordered.

  Meanwhile, France would have been able to complete the Joffre and the Painleve, and possibly add two more ships of this design to the Marine Nationale had war been delayed.

  In fact, the two Allies, and the Royal Navy in particular, showed a greater ability to act and improvise, and make the best of what they had got, than was the case with the Germans. Obsolete ‘C’-class cruisers from the First World War were converted by the Royal Navy into anti-aircraft cruisers, ideal for convoy escort and recognising the fact that they would be hopelessly outclassed in a fleet action. Meanwhile, the impressive Town-class cruisers, classed as ‘heavy’ despite having 6-in main armament, doubtless because they had up to twelve guns in four turrets, were entering service. The new class of battleship, the King George V-class, were useful, although the main armament was reduced to 14-in due to a prewar decision to reduce the maximum calibre of guns aboard battleships, but more of a reminder that even in this field, the Germans would find that the Royal Navy had progressed, as would have had the French, completing the Jean Bart.

  Of course, the question arises, would the British and French electorates have objected to continuing high levels of defence expenditure without a war being fought? Undoubtedly, appeasement would have encouraged Hitler to continue to take risks and advance the boundaries of the Reich ever eastward and also southward. Poland was a relatively new ally of the British, but modern Greece was another area of British influence. There were also links with Yugoslavia through the royal houses of both countries. An attack by Hitler on the Soviet Union would have had Communists and fellow travellers in both the Allied countries pressing for war.

  Nevertheless, while it was the case that Germany could not afford the war economy in peacetime, and could only do so in wartime if the territory that she gained yielded prizes in the form of industrial capacity, raw materials, food and fuel, the British and French economies were in a condition that was not so different. It has long been said that in 1939, British politicians and their advisers knew that the country could only win a long war, but could only afford a short one. The level of rearmament in both countries in 1938 and 1939 was exceeding the capacity of both the British and the French economies to absorb the costs. When war came, it was funded not just by heavy taxation and borrowing from the British public, not just by Lend-Lease from the United States, but by heavy borrowing from the wealthier members of the British Empire and the use of their sterling balances.

  It is possible; therefore, that only those warships ordered in 1938 and 1939 would have entered service, and that, without going to war, defence expenditure would have begun to be cut back by 1940, or, would have had to be cut back. Certainly, the mobilisation of reservists would have had to be reversed under pressure from industry and, no doubt, their families, as well as the need to retain export markets. The last-mentioned has been a factor already mentioned in the case of Germany, but it was so important that even at the height of the Second World War, Britain continued to export a wide variety of goods, and especially consumer goods. Whisky still crossed the North Atlantic, and naval personnel going for a ‘run ashore’ in places such as Cape Town in South Africa, would find in the shops, freely on sale, items that were unobtainable at home. One member of the Fleet Air Arm rejoiced in being able to buy his mother and sisters knicker elastic.

  BATTLE OF THE RIVER PLATE REVISITED

  The first naval engagement of the Second World War was the Battle of the River Plate, which saw three cruisers, HMS Ajax, her Royal New Zealand Navy-manned sister Achilles, and the heavy cruiser Exeter, so damage the Panzerschiff Graf Spee that she was eventually scuttled by her commanding officer in the estuary of the River Plate. This was a brilliant action, and while minor in terms of the numbers of ships involved, was a much-needed fillip to British morale. The icing on the cake came the following year in Norwegian waters with the Altmark incident, when the Royal Navy rescued the Merchant Navy personnel who had been taken prisoners-of-war by the Graf Spee.

  Had the Graf Spee been operating with even a small carrier with an air group embarked, the outcome could have been different. First, she would have been even more successful in her commerce raiding, finding merchant shipping along the sea lanes linking the United Kingdom with the Argentine and Uruguay, both major sources of beef for British consumers. Second, had good well-planned reconnaissance missions been flown, it is unlikely that the three cruisers would have come within firing range. They could even have become victims themselves.

  On the other hand, would a Panzerschiff, after all only a ‘pocket battleship’, been allocated an aircraft carrier. Plan Z only specified four aircraft carriers in the early years, with four smaller ships following in the mid-1940s. The addition of an aircraft carrier would have required extra supply ships, which would in turn have had to be protected during their long passage between Germany and the South Atlantic. At first, some of these might have masqueraded as ordinary merchantmen, but their cover would have been blown sooner or later.

  In fact, it is unlikely
that the outcome of the Battle of the River Plate would have been any different. Aircraft carrier protection would have been most unlikely. Even if merchant ships had been converted to provide auxiliary carriers, these would have been unlikely to have kept up with the fast-moving Graf Spee, and might not have had her long range.

  On the other hand, had some of the ideas of the U-boat enthusiasts at the Marineleitung been fulfilled before war broke out, the presence of long-range submarines and supply submarines might well have changed the outcome. First, there might not have been the battle at all, and the three cruisers would have been vulnerable confronting a submarine. Operating submarines at such extreme range from a base would have been difficult, but it could have changed the pattern of the war completely. Indeed, what needed to be recognised was that the day of the surface vessel as a commerce raider had ended. As the war progressed, the German auxiliary cruisers, all of which intended to act as commerce raiders rather than as convoy escorts, in contrast to Royal Navy practice, were soon put out of action by British and American warships.

  HAMPERING THE WITHDRAWAL FROM NORWAY

  There can be no doubt that the German invasion of Norway showed considerable skill and planning with excellent use of the resources available, just as the armed forces were preparing for the launch of the offensive in the west. Amphibious warfare was in its infancy, with little progress over the means used at Gallipoli. While they lost the troop transport Bhicker, carrying the main headquarters staff, at Oslo, to Norwegian fire, the lack of an aircraft carrier was not a serious problem at first. It might have made the entire operation easier and completion faster, especially since good airfields ashore were few and far between. This was also a problem for the Allies, and had the Royal Navy had high performance fighters aboard its carriers deployed at short notice to Norway, the outcome might just have been different.

  At the outset of the campaign, however, there was one naval engagement that might have had a different outcome had the Germans had an aircraft carrier operating with the two battlecruisers Scharnhorst and Gneisenau. On 9 April 1940, the battlecruiser HMS Renown was off northern Norway accompanied by nine destroyers when the two German ships were sighted. At 04.05, at nine miles, Renown opened fire, and shortly afterwards she hit Gneisenau and put the German ship’s main armament out of action. The Germans withdrew, but Renown gave chase at 29 knots despite a rising sea and snow squalls. Her destroyer escort, unable to maintain high speed in the prevailing conditions, were diverted to cover the entrance to the Vestfjord. Renown scored further hits on Gneisenau before contact was lost at 06.30 in appalling conditions.

  This action was inconclusive as no losses were incurred, but the much older and lightly protected Renown, originally commissioned in 1916, faced an enemy force that was in many ways superior, for while she had 15-in guns against the 11-in of the German ships, there were two of them and 11-in shells could have penetrated her light armour. On the other hand, had an aircraft carrier been with the German ships, before the weather closed in, they could have detected Renown, denied her the chance of surprise, and even mounted a successful attack.

  The need to withdraw from Norway to reinforce British and French troops fighting in France came so late and took so long that the Dunkirk evacuation was completed as the last troops withdrew from Norway. The withdrawal was marred by the loss of the British aircraft carrier Glorious on 8 June to gunfire from Scharnhorst and Gneisenau. Glorious was completely unprepared for the engagement, having her aircraft struck down into the hangar deck, no reconnaissance sorties being flown and not even the crow’s nest manned by a lookout, while she had no radar. She was sunk despite a courageous and sacrificial attack on the German battlecruisers by the carrier’s destroyer escorts, Acasta and Ardent.

  Again, a carrier hunting with the two German battlecruisers could have struck at Glorious before she could have mounted a defence. Even more important, the other aircraft carrier engaged in the evacuation from Norway was the new Ark Royal, fast but with a fatal weakness, a thin and weak flight deck through which bombs would have penetrated without difficulty. Both ships could have been sunk by naval air power.

  THE BISMARCK ENGAGEMENT

  If any German warship justified being paired with an aircraft carrier, it was the battleship Bismarck, the pride of the Kriegsmarine when she entered service. Bismarck had an official net displacement of 46,000 tonnes and a full load displacement of 50,955 tonnes, although a post-war USN assessment put the latter figure at closer to 53,000 tonnes. Her reconnaissance aircraft were four single-engined Arado Ar196 monoplane floatplanes, capable of flying at almost 200mph. Bismarck had a complement of 2,200 men. Her value to the Germans can be judged by the fact that she was escorted by the heavy cruiser, Prinz Eugen.

  On 18 May 1941, the two ships left the German port of Gotenhafen for a commerce raiding operation under the command of Captain Lindemann with Admiral Gunther Lutjens in overall charge, for a commerce-raiding mission, code-named ‘Operation Rhine Exercise’. Bismarck’s fuel tanks were not completely full since a hose had given way and interrupted fuelling and even when she called at Korsfjord in Norway, no more fuel was taken on, possibly because it was not available. After leaving Norway, the German ships were shadowed by two heavy cruisers, Suffolk and Norfolk, and using radar these managed to track the Germans in heavy seas. Vice-Admiral Holland took the battlecruiser Hood, and the new battleship Prince of Wales, planning to bring the Germans to battle. On 24 May, the four ships met in the Denmark Strait for a classic naval engagement. Only minutes into the battle, Hood blew up, generally believed to have been caused by a shell from Prinz Eugen penetrating one of her magazines, with the loss of 1,500 men, leaving just three survivors. Prince of Wales, still not fully worked up, was forced to retire after taking several hits from the German ships. The engagement was not completely one-sided as Bismarck was hit three times, breaking the connections to the engine rooms from the forward fuel tanks. Lutjens was forced to break company with the Prinz Eugen and head for St Nazaire, in occupied France.

  Norfolk and Suffolk had continued to track Bismarck. At 21.30 GMT, 22.30 British Summer Time, nine Fairey Swordfish from HMS Victorious found the Bismarck and launched a torpedo attack. A torpedo dropped at close range hit the armour belt at the waterline amidships, doing little damage but killing a warrant officer and injuring six engineers. The attack was followed by a brief gunnery exchange with the Prince of Wales before nightfall.

  On 25 May, Force H left Gibraltar under the command of Vice-Admiral Sir James Somerville, with the aircraft carrier Ark Royal, the battlecruiser Renown and two cruisers. Contact with the Bismarck was lost early on 26 May, until an RAF Consolidated Catalina flying-boat rediscovered the ship. Early in the afternoon, in rough weather, fifteen Swordfish took off from the Ark Royal, but attacked Sheffield by mistake. Meanwhile, closing in on the Bismarck was Admiral Tovey, commander-in-chief of the Royal Navy’s Home Fleet, with the battleships King George V and Rodney accompanied by a destroyer escort. At 19.15, again in low cloud and poor visibility, a further strike by fifteen Swordfish was launched from Ark Royal. This time two torpedoes struck the ship, one immediately after the other, jamming the rudder and sending the ship into a continuous turn.

  A night torpedo attack on the Bismarck by destroyers caused little further damage. On the morning of 27 May, King George V and Rodney engaged the Bismarck in a final gunnery duel, hitting the Bismarck several times and after ninety minutes she was burning fiercely. Two cruisers then torpedoed the stricken ship, after which Captain Lindemann gave the order to abandon her.

  Once again, the presence of naval aircraft could have changed the outcome as decisively for the Germans as they did for the British. The two heavy cruisers, Norfolk and Suffolk, could have found that they were being tracked and even attacked. This would have made it more difficult for Prince of Wales and Hood to find the Bismarck, but not necessarily made it impossible. Would a classic naval engagement have developed, or would the German carrier-borne aircraft ha
ve attempted a torpedo attack on the two British ships? One possible scenario would have been that the engagement that did develop could have been a forerunner of the Battle of the Coral Sea, with strikes flown by carrier-borne aircraft from, say, the Graf Zeppelin and the Ark Royal. In such conditions, the Junkers Ju87 Stuka would have been superior to the Fairey Swordfish. Whether or not the Messerschmitt Bf109 would have proved a good carrier fighter is open to doubt, as the aircraft had a weak tail section and would have found the arduous conditions of carrier landings difficult to sustain. On the other hand, Ark Royal had a thin flight deck, which on one occasion was breached when a 20-lb practice bomb fell off the wing of an aircraft, killing personnel in the hangar below. The Admiralty was fully aware that this ship was vulnerable to air attack. Certainly, she could not have survived an attack such as that endured by Illustrious off Malta in January 1941.

  THE INVASION OF CRETE

  The German airborne invasion of Crete started on 20 May 1941, led for the first time in history by the Luftwaffe rather than by seaborne troops. The initial assault was by paratroops and air-landed troops, many of whom arrived by glider but, as airfields were taken, the ubiquitous Junkers Ju52/3 trimotor transports also ferried in men and supplies. The rationale behind awarding the operation to the Luftwaffe was sound. Discovering that most of the British and Greek forces defending the island were deployed on the coast, expecting a seaborne invasion, Goering had persuaded Hitler that the Luftwaffe, which included Germany’s paratroops, could mount the invasion, leaving the German army and navy to support it. In the event, despite the defenders losing their heavy weaponry and communications equipment in Greece, the invasion proved so costly for Germany that for a time Hitler forbade any further airborne assaults. The loss of paratroops and glider-landed troops was bad enough, but the Royal Navy seriously disrupted the convoys bringing troops and heavy equipment by sea, wiping out one major convoy and sinking the heavily laden but unwieldy caiques. Typical of the fate suffered by the seaborne force was the action on the night of 21/22 May, when the cruisers Ajax, Dido and Orion with four destroyers completely destroyed one convoy carrying troops and munitions. The Luftwaffe responded on 22 May with another crippling attack on the Mediterranean Fleet, sinking the cruisers Fiji and Gloucester and a destroyer, and badly damaging Warspite and the cruisers Carlisle and Naiad. Cunningham sent the battleships Queen Elizabeth and Barham with nine destroyers to attack Axis airfields in the Dodecanese, with attacks by aircraft from Formidable, but by this time the carrier’s air power was seriously limited due to a shortage of aircraft, and she could do little to defend herself when the Luftwaffe turned its attentions to her, causing serious damage.