Heavy Cruisers of World War II (Part 1)
By Chuck Hawks
In this essay I intend to examine the heavy cruisers of the major naval powers of World War II. This will include the class of ships I regard as the pinnacle of design from each nation, as well as the rational for their design, their mission as it were, and a few words about their wartime record. It will not be a direct "comparison test", but some conclusions will be drawn.
One might assume that the focus of every new design would be to surpass the likely enemy's recent ships in fighting power, and that is a common thread, but not the only one, in the fabric of warship design. Often international, or national, political concerns played the dominant role in the philosophy behind the design of warships. And, of course, there was the London Naval Treaty of 1930, which limited all cruisers to a maximum weight of 10,000 tons standard displacement.
Some nations took these treaty limits seriously, particularly the British and the Americans, others simply cheated by as much as they thought they could get away with. This resulted in ships nominally rated at 10,000t standard displacement which actually displaced upward of 13,300t, a 33% overrun. A ship 1/3 larger than her potential adversary is bound to have some advantages!
Of course, once the war had started, all treaty limits were off, and cruisers could grow to any size. Evidence of this is the American Alaska class of "large cruisers" (CB rather than CA) which, at almost 30,000t and mounting 12in guns, were battlecruisers in all but name. An interesting point is that many authorities, and the U.S. Navy itself, really thought of these as cruisers rather than as capital ships. Of course, Jackie Fisher, appointed First Sea Lord of the Royal Navy in 1904, and prime moving force behind both the revolutionary battleship Dreadnought and the first battlecruiser Invincible, also drew a clear distinction between the two types. Fisher conceived the battlecruiser as a type with cruiser speed, and armored to defeat cruiser shell fire, but with battleship size and guns. Unfortunately, commanders at sea found it nearly impossible to resist including such large ships, armed with battleship guns, in the battle line (this led to disaster in both World Wars, as we shall see).
Fisher saw the battlecruiser as making the armored cruiser obsolete, a ship fast enough to scout enemy forces, brush enemy cruisers aside, and run down enemy commerce raiders on the high seas (all of which battlecruisers actually did in W.W. I). My point is merely that these are also among the purposes for which the Alaskas were built. Also, the Alaskas perfectly fit the above definition of a battlecruiser, which makes them battlecruisers to me. Which means that the Alaskas, and other "large cruisers", "super cruisers", and "pocket battleships" will have to be dealt with in another article. This essay is for real, traditional 8in gun, heavy cruisers (CA) only.
Among the major powers which completed heavy cruisers prior to or during the Second World War are Great Britain, Italy, France, Germany, Japan, and the United States. Let's take a look at the ships, starting with Great Britain.
The last British heavy cruiser to be built was the famous Exeter, which battled the German "pocket battleship" Graf Spee in the South Atlantic, and was later sunk by Japanese cruisers and destroyers in the Java Sea. Exeter was completed in 1931. She is a good illustration of the British cruiser design philosophy in practice. The particulars of Exeter in 1941 follow (from Conway's All The Worlds Fighting Ships, 1922-1946 and The Encyclopedia of the Worlds Warships, by Hugh Lyon):
Exeter was smaller than most of her contemporaries at 8,390t standard displacement, and carried only 6-8in guns. She was a compact and workmanlike design, maybe a little cluttered looking. She had a stepped hull, with her forecastle extending back to mid-ship. Her two vertical funnels were of different size, the larger one in front.
The British 8in/50 Mk. VIII gun fired a 256lb projectile at 2805fps MV to 30,650yds at 45 degrees of elevation. British surface fire control was good, but AA fire control was inferior to that of the United States and Germany (which were the best in the world). Exeter was sunk before she could benefit from the advanced radar fire control technology of the later war years. The Mk IX 21in torpedo (carried by British cruisers) was excellent. Only the Japanese 24in oxygen fueled torpedo had better performance. The Mk IX carried 810lb of explosive, and could travel 5,000yds at 44.5kts, or 7,000yds at 40kts.
Exeter played a major part in the Battle of the River Plate, the chase of the "pocket battleship" Admiral Graf Spee. Against the Graf Spee, she was the only British cruiser with 8in guns in Commodore Harwood's squadron of three cruisers (the other two were the small 6in gun cruisers Ajax and Achilles). Together, they were sufficient to defeat the larger German ship and send her running to the neutral port of Montevideo, Uruguay, where she was scuttled. In this battle, Exeter was hit by 7-11in shells, and sprayed by splinters from several near misses. Sixty one of her crew were killed, and twenty three more wounded. Her entire main battery was put out of action and her speed was reduced to 18 knots, but she was able, after temporary repairs, to steam all the way home without assistance. It took 14 months in a shipyard to put right all the damage.
This engagement is a clear vindication of British cruiser policy. The answer to the German "pocket battleships" was not a few large battlecruisers, but many smaller cruisers which could effectively patrol great areas of ocean and bring them to bay.
February of 1942 found Exeter, along with four other Allied cruisers (total: two heavy, three light) and nine destroyers of the ABDA (American, British, Dutch, Australian) striking force, in the Java Sea. They were attempting to interdict the Eastern Japanese amphibious landing force heading for Java, and were engaged by the covering force of four Japanese cruisers (two heavy and two light) and thirteen destroyers.
The battle on February 27th was a long and complicated series of gun and torpedo duels that lasted from 4:16 PM in the afternoon to almost midnight. At 5:08 PM Exeter was hit in the boiler room by an 8in shell, which caused her to sheer out of line in a 90 degree turn to port. Her speed was reduced to 16 knots. Admiral Doorman (ABDA force commander) ordered Exeter to Surabaya, escorted by one destroyer. She took no further part in the battle, which ended hours later with the loss of two Allied light cruisers, and three destroyers (plus Exeter heavily damaged). The Japanese suffered no losses. They were greatly aided by their float planes, which were able to spot their fall of shot for them, and keep track of the position of the Allied force. The ABDA force had no float planes, having landed them in anticipation of a night battle.
On March 1st, Exeter and destroyers HMS Encounter and USS Pope were caught off Surabaya by Japanese planes and the four heavy cruisers of the Nachi class (13,000t, 10-8in guns), and sunk by shellfire and torpedoes. Almost the entire ABDA force ultimately suffered a similar fate. Individually, the smaller Allied cruisers were no match for the large Japanese cruisers.
After the outbreak of World War II, when the London Treaty no longer applied and the warring nations could build any size cruisers they could afford, the British remained true to their small cruiser policy. They launched 31 cruisers, none over 8,900t, and none carrying guns larger than 6in.
Unfortunately, in practice, this emphasis on very high speed resulted in high powered but temperamental machinery, lowered hull strength due to imprudent attempts to save weight by lightening structures and fittings, reduced armor protection, poor habitability, and decreased range. Eventually these deficiencies became apparent, and the finest of the Italian heavy cruisers, the four ships of the Zara class, were a slower but better balanced design.
The Zaras came about mostly as a result of the naval rivalry with France, whom the Italians viewed as their most likely opponent in the next war. France and Italy had conflicting goals in regards to their African colonies. With the Zara class, Italy attempted to build 32 knot ships with 8-8in guns and heavy armor. Unfortunately, this could not be accomplished on the treaty limit of 10,000t. The result was ships considerably over the limit, even though they reduced protection, reduced the size of the superstructure, adopted lighter weight machinery, and omitted torpedo tubes from the final design. Zara exceeded the limit by almost 17% when she was completed in 1931. The following specifications are for Zara in 1940 (from Encyclopedia of the Worlds Warships):
This class was more heavily armored than her rivals at the time, and even later classes of heavy cruisers were hard pressed to match these ships. The French Algerie was built in response to the Zaras, and the total weight of her armor came to 2,567t, as compared to 2,700t for Zara. The Zaras also carried heavier armor than the very large German Hipper or Japanese Mogami classes. It was not until the American Wichita of 1939 that a marginally better protected heavy cruiser appeared.
The Italian 8in/53 Mod 29 gun had a very high muzzle velocity, which made for high projectile energy, but short barrel life. It fired a 125kg (275lb) shell at 3080fps MV to 34,400yds. The Italians claimed an unusually high rate of fire for this gun: 3.5 rounds per minute. 2 to 3 rounds per minute would be typical for most similar guns.
In appearance, they were typical of Italian cruisers, with a heavy superstructure, heavy tripod main and fore masts, and a stepped hull design with a short forecastle. They carried their seaplane and its catapult on the forecastle, directly in front of "A" turret's guns. Altogether, despite being long and lean, they were not particularly handsome ships.
The Zaras war records are not inspiring. Their most famous engagement came in March of 1941 in the battle of Cape Matapan, when Zara and Fiume, on their way to assist Pola (who had caught a British carrier plane's torpedo in her engine room and was stopped), were caught by surprise at night at point blank range by British battleships and torn apart by shellfire. Pola sank after being torpedoed by British destroyers. The last of the class, Gorizia, was taken over by the Germans after the collapse of Italy, and eventually sunk in port by Italian "chariots" (manned torpedoes used by frogmen).
The losses at Cape Matapan were due to the lack of radar on the Italian ships, and poor training for night engagements, rather than a design deficiency in the ships themselves.
The good points of the Zara class were their heavy armor and their main battery. They were well suited for daylight operations in home waters.
During World War II, torpedo tubes proved to be advantageous on cruisers, especially in conditions of darkness or poor visibility. Their omission on the Zaras reduced their fighting capability. Their relatively short range would have become a tactical limitation had the need for offensive operations arisen. One on one in a daylight gunnery battle, the Zaras would likely have proven superior to the heavy cruisers of their Mediterranean adversaries.
In 1935 Britain agreed to allow the new German Navy to build up to 35% of the British warship tonnage in all classes of surface ships (45% in submarines), and the Germans at this time regarded France as the likely enemy. Once again, France needed to secure her Atlantic, as well as her Mediterranean, interests. The first of the 35,000t battleships (Richelieu) was ordered that year. By 1937-38, the French Navy had a major building program in hand. Most of those ships were not completed in time. The war started in September of 1939, and France signed an Armistice with Germany in June, 1940.
Algerie was a treaty cruiser, built to the 10,000t standard, although her normal displacement was about 10% over the limit. She was well armored, and especially well protected against aerial bombs and torpedoes. Her main battery guns fired a new, more effective AP shell (the older model weighed 271lbs and had a MV of 2763fps; whatever improvement was made was unspecified). Let's take a look at her basic specifications (courtesy of Conway's):
Algerie had a torpedo bulkhead which ran from the bottom of the ship to the armored deck, separated from the main belt by coal and oil bunkers. On trials she made 31.7kts at 12,000t. In 1940-41, while under Vichy control, her 37mm AA battery was doubled, and 20 more 13.2mm machine guns were installed. At the same time her aircraft and tripod mast were removed. In 1942 she received radar, but it was all for nought. Later in 1942 she was scuttled at Toulon. Her short career was similar to that of many French warships in W.W.II. In appearance, unlike most French cruisers, Algerie had a flush deck and a low profile, except for her tower superstructure. Her boat and aircraft cranes stuck up around her pole mainmast, giving her a somewhat cobby appearance.
It is interesting to speculate on what might have been. In the Mediterranean, her most worthy adversary would have been the Italian Zara class. She was slightly smaller than the Zara, yet she was her approximate equal in speed, protection and fire power. Her fire control was probably on a par with the Italian ship. Her modest torpedo battery would give her an edge in certain situations. On paper, their capabilities are otherwise very similar.
In the Atlantic, her most dangerous adversary would have been one of the Hipper class. Compared to the German ship, her one advantage was her somewhat heavier armor. In speed, and main and secondary batteries, they were virtually equal. Her light AA battery was inferior to the German cruiser, not only in numbers but also in quality: the French 37mm gun was inferior in performance to the German equivalent (the improved Mod 33 was still being tested when France fell). Her fire control was also inferior. Her torpedo battery was certainly inferior, and she was considerably smaller. Algerie was certainly close enough to make it interesting, but in most circumstances, the German ship would have the advantage.
Admiral Erich Raeder, Commander in Chief of the navy for its formative years, and into W.W.II, believed in a policy of commerce raiding by surface ships. Atlantic warfare, not coastal defence in the Baltic Sea, was to become the strategy and operational goal of the Kriegsmarine. The long range "pocket battleships" (Deutschlands) were an ideal weapon to implement this policy.
After 1933, when Adolph Hitler became chancellor, a powerful fleet became necessary to help implement his aggressive foreign policy. The "Z" plan was the result. This called for the construction of 4 aircraft carriers, 8 battleships, 5 battlecruisers, 8 heavy cruisers, 13 light cruisers, 22 scout cruisers (small fast cruisers), 68 destroyers, 249 submarines, and various light craft. This ambitious plan was to be completed by 1948. It was beyond the capability of the Reich to produce, without severe dislocations throughout the economy, and beyond Hitler's patience to wait for its fruition.
Copyright 1997, 2016 by Chuck Hawks. All rights reserved.