World War Two Battleship development
Since the laying down of the Italian battleship the Conte di Cavour in 1910, the Tirpitz in 1933 and the King George in 1937 designers had attempted to gain an advantage over their probable future enemies by increasing main gun size with a corresponding increase in the armor thickness. Into this mix was thrown the necessity of increasing ship speed in order to evade or intercept enemy ships. The Italian ship the Conte di Cavour, completed during WWI and reconstructed in 1933-7, wound up with a ten inch armor belt, the armor on her decks four inches thick. By contrast the Tirpitz laid down in 1936 and completed in 1940 had a twelve point six to eight point seven inches of armor belt around her waist and two to three inches on deck.
It is interesting to note that the US tended ,beginning with the Arkansas class, to use light deck armor .By contrast the Japanese Kongo class, laid down in 1911-12 and reconstructed in the 1927-30 period and then again in 1933-40, had decks varying from four point seven to two inches thick. The Arkansas sported eight three inch AA guns while the Nagata class sported twenty five AA guns. Could it be that the Japanese had a greater appreciations of the coming role of the bomber aircraft , specifically the dive bomber as these would most likely damage the decks , level bombers more suited to land targets, torpedo planes more of a threat to a ships belt armor
After the battle of Midway and the sinking of four Japanese carriers the carrier versus carrier war was virtually over as from this time on the US and Britain were the only powers with a credible carrier force .Actions now tended towards aircraft carrier versus battleship ,cruiser, destroyer type of actions. A study of the various AA mountings will show how the navies of the world viewed the Arial threat .Japan had the greater concentration of purely anti-aircraft weapons .Britain and the US were mostly equipped with dual purpose weapons ,the US dual purpose weapons superior in the AA role ,those of the British in the anti-ship role.
Prior to the 1921 treaty the limitations on battle ship size was of a purely technical nature as all were free to build ships of any size. Main calibers grew from eleven inch and twelve inch , fourteen inch to fifteen inches, finally reaching sixteen and eighteen inch calibers. Following World War One the financial climate was such that it was deemed necessary, in order to prevent bankruptcy , to limit the size of capital ships thus halting the arms race between Great Britain ,the US and Japan. The Washington conference of 1921 bought about a treaty known as the Washington Treaty where it was agreed that maximum ship displacement should be set at 35,000 tons standard displacement and that the caliber of all ships guns should be no greater than sixteen inches. This treaty created a battleship holiday during which no ships were built for ten years, those in commission limiting future ship construction. A ratio for new battleship construction was
arrived at as in the below.
•Great Britain and the USA -5
•Japan -3
•France and Italy -1.75
Germany was not included as under the terms of the Versailles surrender terms she could only build ships of less than 10,000 tons displacement ,her navy limited to coastal defense .This bought about a great deal of modernizing of World War One ships where it was deemed that range of the large guns could be no greater than during the Dreadnought era.Armoured decks were introduced as protection against air attacks ,areas around the magazines were given armor as was that surrounding machinery. Some of the light guns were replaced with AA batteries.
During the 1920s early 1930s period Germany began a program of battle ship construction keeping within the limits of the Treaty of Versailles and not restricted by the Washington Treaty. The pocket battleships, of greater speed and gun caliber, posed a threat to both Great Britain and France due to the 26Kt speed limitation imposed upon them by the Washington Treaty; both navies now also outgunned.
There was a five years extension of the battleship holiday known of the London Treaty; this however did not apply to France and Italy as their capital ships were older than the ships of Great Britain, the USA and Japan. France built the Dunqurqe class of ships , Italy countering with the Littorio class, these being the first to approach the limits set by the Washington Treaty.
Britain had waited until the last moment in order to once again be in the arms race watching what the Europeans were about. In addition she did not want to antagonize the Japanese into building larger ships able to threaten her far eastern possessions, the US and Japan concerned only with what the other was doing. The end result was that Britain laid down a fourteen inch gun caliber ship, the US one of sixteen inch and Japan one of eighteen inch caliber.
The 35,000 ton limit displacement was not enough to support these guns. Also not taken into account was the fact that the larger caliber shells would bring about a need for thicker armor protection. Also to be taken into to account was the fact that a flank speed of 22-23knots ,common during the era, was insufficient for a ship to stay out of trouble .Extra power was obtained by use of light weight high speed steam turbines .This however created a long ship needing extra protection in the machinery areas. Destroyers equipped with torpedoes and shore and ship based aircraft also posed a threat resulting in torpedo bulges appearing around the bilge of ships hulls plus extra deck armor. Britain and the US had stayed within the limits set by the Washington Conference and so were outgunned in addition to only having protection against fourteen inch guns and 2knots slower than treaty violators, Japan being the first country to ignore the treaty limits
regarding gun caliber.
There were ways of negating the rules regarding gun caliber. One of them was to stay within the limits set but to mount extra barrels in each turret. Prior to 1921 only the US and Italy had triple gun mounts. By 1939 it had become standard .France and then Britain went on to mount quadruple turrets. Germany continued to use twin turrets. Quadruple mount allowed for extra firepower to be concentrated within a smaller space ;however the greater number of guns end result was the slower rate of fire as each turret had to share a loader with some of the smaller guns. Range was now 25,000 feet as opposed to that of 12,000 at the battle of Jutland .Radar was also a deciding factor, the RN victory over the German Scharnhorst largely due to this invention. Multiple purpose guns also came into being in order to circumvent the limits imposed upon displacement .These guns could be used against both aircraft and surface craft. The US 30 caliber weapon was more
efficient against aircraft; Britain’s 50 caliber guns more adept at sinking small surface craft and surfaced U boats
In the area of protection all navies, with the exception of Germany, went in for all or nothing armor protection. What this entailed was a thick armor belt around the middle of the ship, its decks, gun turrets, gun barbettes and conning tower and the area around the rest of the ship left unprotected. The bulkhead forward of the most forward main guns was armored as was the area aft of the aftermost turret, the rest of the ship, but for the area around the steering gear, left bare.
The work done in ship design was bought to naught due to the fact that the various naval staffs had failed to foresee the complete revolution that had occurred in naval warfare during the between war years. During the earlier conflict the aircraft carrier was mainly a carrier of seaplanes which were either catapulted from the deck or winched down from the deck when ready to be used, to be winched aboard at the end of the flight. True there was a land plane component which took off from fixed decks to be used with great effect during the attacks on the Zeebruge canal complex located in Belgium. However the full importance of the aircraft as regards fleet actions had never been proven as there were never enough carriers to make in a viable proposition .Aircraft allied with ships were seen as most valuable in the role of reconnaissance, the naval mind unable to grasp the coming revolution about to be bought about by the use of naval aircraft.
At the opening stages of the war Britain had few aircraft carriers in service and so was involved in some of the last great battle ship upon battle ship contest, mainly in the North Sea off the coast of Scandinavia. Even here the aircraft carrier set the stage for the coming ship to ship combat with the sinking of the Tirpitz by obsolete biplane carrier borne aircraft. The sinking of the American battle ship force at Pearl Harbor was the final nail in the coffin which was to confine the grand battleship on battleship fight to Davey Jones locker. What had been assiduously planned for over a period of nearly half a century came to naught as the planers failed to see the forest for the trees neglecting to include in their calculations the improved punch and range of the naval aircraft force.
Aircraft Carriers listed in Spring Styles publications.
Aircraft Carrier Preliminary Design Drawings
During WWII the USN put out a book misleading called 'Spring Styles' which was a cover for official ideas in warship design. Seventeen of the 75 preliminary design drawings in the 1939-1944 'Spring Styles' book are related to aircraft carriers and ships with characteristics similar to aircraft carriers. There are several studies beginning during December 1939 January 1944 with three final attempts in the quest to design a flight deck cruiser. Two schemes deal with the Essex (CV-9 )class one dated September 1941.In addition to the Essex class ships there are three plans of relatively small aircraft carriers dated July 1940 which appear to be an improved version of USS Wasp(CV-7).In a separate unrelated study dated August and September 1941 two drawings for a carrier conversion of the many Cleveland (CVL-55)class .This train of thought led eventually to the Independence class comprised of nine ships (CL-22).The final design decided upon was
greatly different from the actual one depicted in the drawings
Early in the war between January and August 1942 other conversions of gun-armed warships were also studied, among them a large cruiser (CB-1 class), an Iowa (BB-61) class battleship and a heavy cruiser (CA-68 class) .Only the last of these lead anywhere to become the Saipan (CVL-48) class.
The earlier wartime experiences of the British in the Mediterranean prompted studies of a large aircraft carrier with an armored flight deck. Four "Spring Styles" drawings for such ships are in this album, dated from December 1940 to September 1941. This effort eventually produced the Midway (CVB-41) class, the largest carriers built by the Navy during the World War II years.
The first divergence from purely battle ship design by the US was during the concept program period with the laying down of the Lexington class of ships - large battle cruisers cancelled under the Washington Treaty prior to launch to be redesigned and completed as carriers. The original hull remained essentially unchanged, a large hangar fitted, the largest on USN carriers until the CVA 59 postwar ships. Exhausts were routed into huge starboard-side funnel, a massive island constructed forward of the funnel. These ships had an inherent list to starboard due to weight of the funnel & island. The flight deck was long but very narrow forward. A cruiser gun battery was provided for defense against surface ships at close range. If fired these guns would have damaged the ships on board aircraft and flight deck, but were intended only as a last-ditch measure after the flight deck had been destroyed by enemy action. These were the only prewar carriers
considered suitable for independent operations, the largest carriers in the world until the Midway class appeared.
The ships were reclassified from CC to CV at the start of their conversion, the first US carriers designed as fleet rather than experimental units. The ships were identical at completion; variations on the original design occurring during the 1930's and onwards into WWII. Minor modifications, mainly in the addition of light AA gun during the 1930's, were undertaken, the AA armament again updated at the start of the war. Both ships needed major overhauls and modernizations immediately prior to WWII, but they could not be spared from the active fleet due to the shortage of large carriers. Experience with these ships proved the value of larger carriers vs. small designs such as Ranger. They played a key role in developing US naval aviation tactics and equipment. Both saw extensive fleet service prior to WWII, Saratoga very active throughout the war. The surviving ship was old, outdated, overloaded and worn out by the end of WWII, making her unsuitable for further service. She was destroyed as a target ship in the Bikini Atoll atom bomb tests.