Post by laplace420 on Apr 28, 2021 23:31:23 GMT -5
I agree that the increased cost of armored carriers can be prohibitive but if you are willing to build very large ships in the late game(50s onward) having 4.5+ inches of armor on the flight deck does make your carriers more survivable. This particular US 50s-era design survived a number of aerial bomb and torpedo hits and was heavily damaged, but survived. Although I am relative newcomer to RTW2, after playing several games with different nations I've noticed having a lot of fighters(and good air-to-air fighters, emphasize speed/maneuverability over other design categories) matters the most when it comes to protecting your CVs from air attack. Additionally, having a large number of screening CLs and DDs with good anti air capability also factors heavily in how well your carriers are going to hold up to air attack. The skill of your crews and level of damage control technology matters somewhat, but definitely less so. I once lost a 40s-era 50,000 ton BB with TPS4 and full late-game damage control tech after it had only taken 2 torpedo hits and was able to retreat from the battle while not under attack at a leisurely 10 knots due to the "average" crew not being able to contain the flooding. As a side note, the name of this ship class is from a decisive battle my navy fought in the late '30s against the British off the coast of Canada. This battle was won when roughly two dozen of my DDs ambushed the main British fleet at night and sunk 5+ BBs in a mass torpedo attack.
The problem here is context, which is why this is a fascinating game but not a sim. In the 1930s, all three carrier navies now had some experience in operating carriers, especially in full force on force war games. What they discovered was that carriers were 1) very vulnerable, and 2) "the bomber will always get through". Even with the circular cruising formation adopted by the USN, destroyer and aircraft pickets just didn't give enough warning to get fighters in the air to block an incoming airstrike. All three navies were also about to build their second generation fleet carriers (Ark Royal, Yorktown and Soryu, Ranger and Ryujo were really experiments).
The RN went down the path of the armored carrier. There were a number of reasons.
1) Strategically and operationally, the future enemy was Japan. War with the US was unthinkable and there was no European power that could threaten the British Empire. The RN expected to execute a war plan very similar to "War Plan Orange", with the Japanese conquering British concessions in China (Hong Kong, Shanghai, etc) and parts of the empire in South-East Asia (Brunei, etc). The RN would sail to Singapore (if complete, the base was basically capable w/ a floating dock in 1932, with the dry dock opening in 1938) or to Colombo and Trincomalee and from there begin a campaign to recover British possessions and initiate a distant blockade of Japan. Once Hong Kong was recovered, the blockade could close in and bases for bombers established. Eventually the Japanese fleet would come out to break the blockade, they would refight Jutland, the British would defeat and drive the Japanese back into their ports. At that point, the British expected the Japanese to do the rational thing and negotiate a peace. Until the rise of Fascist Italy and then Nazi Germany as a threat, the RN between 1919-1936, was designed for this war.
2) Based on this strategic and operational rational, the mission of the RN's aviation and supporting RAF elements were to find the Japanese fleet, inflict enough damage to slow it so that the RN could close in and destroy it, while protecting the fleet. While the RN had delved in aerial spotting, by the early thirties, the plan was to close to "decisive range" (12,000-16,000 yds), accepting that the Japanese might have a range advantage (the RN knew that the IJN had practiced aerial spotted gunfire to 30,000 yds) and accepting damage to get to the decisive range where they would then overwhelm the Japanese with concentrated fires from superior numbers. The spotting mission was thus rolled into other missions such as scouting and torpedo/level bombing. (one wonders if the issues with the three gun turret and light weight shell in the 16" Mk.I, even with Mk.II rifling drove this decision or the fact that only Nelson and Rodney had "modern" surface fire control before Warspite was rebuilt, also, this was the reason for increasing deck armor on British capital ships, not the threat of air attack, having to withstand enemy long range fire while closing)
3) The RN expected only to deal with carrier-based aviation. They believed that the IJN (this is the early '30s) was certainly not technologically more advanced then themselves (given their start point was the RN mission in 1920-21) and that their (RN) training and personnel would have an advantage so that they expected to win the air battle (both USN and RN intelligence, from 1919 to the end of 1945, on the IJN went from good to abominable and was often laced with racist views of the Japanese). At this time, the IJN had yet to build its formidable land-based bomber component. There were two ways to attack ships at this time: torpedoes and level bombing. Dive bombing was a new technique. As far as level bombing, the aircraft of the time could not carry bomb loads that could threaten an armored ship and the RN expected that it would be difficult to hit a maneuvering target. Level bombers would have to carry a number of bombs to maximize hitting an enemy ship, and carrier aircraft were limited in their ordnance load outs, so the largest bomb expected was a 500lbs (this was an RAF supported decision that resulted in the RNAS and RAF not having large SAP/AP bombs resulting in adoption of USN bombs). Dive bombing as everyone was coming to find, was much more accurate, but, except in the USN, nobody expected carrier based dive bombers to carry any bombs larger than 500 lbs. This was that given the limits on weight and size for carrier operations, dive bombers traded structural weight (strengthened frames and wings) for ordnance loads. The threat was the torpedo, since it was the weapon that could actually sink ships.
4) The RN had a mistaken belief in the efficacy of their AA gunnery. They had introduced auto AA in numbers before any other navy, with the 2pdr Mk.VIII in octuple mounts and the .50 MG in quad mounts. They had a large number of AA guns, generally 4" Mk.V HA and, what they thought, was a viable fire control system, the High Angle Control System (HACS). Later when remote control targets became available, they were disabused of this belief (the HACS, even after numerous add-ons and mods, barely exceeded the Mk.19 FCS the USN introduced in 1928, because the British adopted a non-tachometric solution) . Another issue was that unlike the USN remote controlled targets, the RN's drones could not execute a dive attack, so that the RN was surprised by the effectiveness of the Stukas and D3A1s in the Med and in the Indian Ocean.
5) Even the USN, with its circular cruising formation and destroyer pickets, couldn't guarantee sufficient warning of attack to get fighters in position. Through numerous fleet problems, the RN, USN and IJN experienced the difficulties in using fighters for defense in the pre-radar period. Experiments with air pickets were not successful. So when facing limited size air groups, the RN opted for strike and scout aircraft over pure fighters. In all three navies, fighters were intended to escort strikes, not defend carriers, which is why their numbers were limited even in the USN. In 1939, a typical US fleet carrier carried only 18 fighters, roughly in line with the fighter strength of Japanese carrier air groups. The RN also went with two seat fighters, so the fighter had a navigator, since the RN rejected the use of radio beacons, it being RN doctrine at the time to minimize radio use as a source for enemy SIGINT. The result was that when effective radar was introduced the RN had to adapt RAF single seaters like the Gladiator, Hurricane and Spitfire, while buying Martlets and Corsairs, for the fleet defense role, its ultimate two-seat fighter, the Firefly, becoming a strike fighter (and later ASW aircraft).
6) The RN had experimented with deck parks and dropped them under pressure from the RAF during a period of disarmament and limitation treaty negotiations in the late 1920s and early 1930s, which featured limitations on the total number of aircraft a nation could have, so the RAF wanted to minimize RN numbers. This meant the RN continued to plan its air groups around hanger space, which meant there was insufficient room to carry single mission aircraft, which is one reason RN aircraft were multi-mission like the Skua and Swordfish. In the USN, the big fleet carriers in the early 1930s carried a squadron (18 a/c) of single seat fighters, one with fighter-bombers (wing bombs up to 100lbs), one with scouts (some could carry 500lb bombs), one with heavy dive bombers (1,000lb bombs) and one with level/torpedo bombers (3 x 500lbs bombs as level bombers) or 90 a/c in total. The largest RN air group was the 48 a/c on HMS Glorious and Courageous, which was why their loss so early in the war was a heavy blow to the RNAS.
The outcome was that the RN decided that it would armor the hanger (no British armored carrier had an fully armored flight deck, the flight deck armor covered only the hanger). This included the hanger sides. This restricted the size of the hanger(s) (when the RN tried to increase their air groups, they went with multiple hangers, not deck parks, with low ceilings that limited aircraft size) because of the need to limit the weights carried high in the hull. During air ops, aircraft would be brought up for take off and struck down immediately after landing. When facing air attack, the air group would be "safe" in its armored hanger and the fleet would defeat the air attack with maneuver and AA. Since air groups were limited, focus was placed on the missions of scouting and strike, especially torpedo attack. Dive bombing came into use as a way to suppress enemy AA and to attack enemy carriers.
In the early '30s this may have been the correct decision. The USN and IJN saw aviation as a supporting arm of the fleet. The important thing was air supremacy over the battle line, so that aerial spotting would allow engagement of the enemy at 30,000 yards or more. Even the range limited USN BBs could be efficiently used by laying a smoke screen between the opposing battle lines, blinding the enemy, while the US battle line shot through and over the screen. Air supremacy would be achieved by getting in the first strike, which gaming showed was critical, and sinking the other side's carriers. The IJN went for longer range aircraft, depending on floatplanes from escorting surface ships for scouting, while the USN went for larger air groups allowing the use of carrier aircraft as scouts. The IJN line of effort was driven by their retention of air groups sized to hangers, where the refueled and armed their aircraft (the IJN never adopted permanent deck parks). It was then supplemented by long range land based medium bombers. The USN sought initially to augment their air groups with flying boats as bombers (PB), as in the early '30s, there was little difference in performance between aircraft with floats or flying boats and fixed landing gear carrier aircraft. but the advances in aircraft performance into the late '30s made this a dead end. But the outcome was that IJN and USN carriers were vulnerable and in an operational sense, after initial combat, the IJN could have lost its carriers while the RN's survivable carriers remained in operation, to scout for the enemy battle fleet and slow it down with torpedo strikes. Small air strikes were better than NO air strikes and the loss of their carriers would reduce the IJN's ability to establish air supremacy and employ aerial spotting, reducing the danger zone from 30,000 yards in, to the optical horizon of 22,000-26,000 yards on a good day. This is also why the RN trained so hard on night combat, as illumination rounds would be limited to ~15,000 yards and searchlights to 8,800 yards, allowing the RN battle line to engage at decisive range without having to negotiate a "kill zone".
Radar is what changed this paradigm. And combat at sea in the Med and North Atlantic against large and effective land based air forces, which the RN had not designed its carriers for. With effective radar detecting incoming strikes up to 150 nm away and the development of efficient fighter control using light weight and reliable VHF radios, fighter CAPs could be maintained and reinforced by deck alert fighters, to be directed into the path of an oncoming strike group. Thus the correct decision in the early 1930s became the wrong decision in the early 1940s. The armored hangers severely limited air group size. Adopting deck parks allowed for larger air groups and more fighters, but reduced combat endurance. The Illustrious class could carry 50 or so aircraft with a deck park, but fuel and ordnance stowage was designed for 33 aircraft of less performance and could not be reasonably expanded, while supporting larger numbers of Seafires, Corsairs, Barracudas and Avengers. The result was that these carriers went from being able to generate 3 or more strikes during operations to barely 1.5 and a need to refuel with AVGAS and replace expended ordnance. Since the RN depended on its network of bases for logistics sustainment, when the Pacific Fleet undertook continuous ops, it had to rely on the USN for some of its forward logistics because it lacked the form of robust fleet train that the USN had build to fight its war across the Pacific. The other issue was that, even in the mid-1930s, dive bomber loads became more effective, the USN adopting 1,000 lbs bombs, when the IJN retained the 250kg. USN carrier operating methods allowed the growth of aircraft size and weight while retaining viable large air groups. The continuing growth in engine power also allowed for larger carrier aircraft able to carry larger loads, such as 1,600lbs and even 2,000lbs bombs. The RN armored hangers were proof against 500lbs/250kg bombs from level or dive bombers. The Stukas, being land-based, didn't need to make the same trade-offs as carrier aircraft, so could carry a 500kg SAP/AP bomb that could penetrate into the armored hanger. But the Stuka didn't become a threat until 1939 or even 1941, by which time the RN was fully committed to the armored hanger. It should also be noted that the "unarmored" carriers of the Colossus, Magnificent and Hermes classes were initially planned as "fighter carriers", to augment to smaller air groups of the "armored" fleet carriers. Another outcome of the "armored" carrier decision was that insufficient numbers could be built, so that the RN found itself using even escort carriers for fleet missions.
The USN later adopted a heavy, armored flight deck in the Midway class, as increasing the size allowed for both an armored flight deck and a viable sized air group. This was not an armored carrier per se, the hanger sides remaining open, the USN depending on the heavy 5" single mounts along the hanger sides to provide some level of protection. It turned out that even the Midways weren't large enough, having low freeboard and being "wet" ships through their careers with the USN. They were, however, the only carriers in the world that could efficiently operate first and second generation jet aircraft before the angled deck. The RN went the other way with its last WW2 fleet carrier design, the Maltas, which had an armored deck on an open hanger, like the Midways and were similar in displacement and size (both Friedman and Brown argue that it would have been better to abandon the Eagle class and used the funding to build a couple of "Maltas", the problem being the condition of British finances and infrastructure at the time).
One additional issue with armored carriers became evident in the mid-1950s. Converting HMS Victorious (Illustrious class single hanger armored carrier) with steam catapults and a new angled deck was expensive enough to swear off the RN from its late 1940s plan to modify its armored carriers (even without having to take the new flight deck back off to replace the engines, a major mistake that almost doubled the cost of the conversion). Where the USN was to get a couple of decades of further service from its "Essex" class, which proved easier to modify (not to mention the advantage of a larger flight deck to start), the RN simply scrapped its huge investment in armored carriers. This also why USN carriers grew to the size they are. To build a warship able to survive the most common threat and carry an effective air group takes large dimensions and displacement and is why the USN has continually rejected down-sized carriers.
My simple reminder to all that the armored deck was only one link in the chain for the aircraft carrier system. Some of those links were external, like inadequate signal intelligence, poor tactical and operational planning, inadequate support ships for ASW and AA support. For the carrier, design was a link, poor damage control, inadequate carrier deck operations, and lack of an adequate fighter force to both support the attacks and provide combat air support to protect the carrier. The list of links in this chain is very long. But one failure in the link could in fact cause the loss of a carrier.
Illustrious had a 3 inch deck that was supposed to prevent 1000 lbs. bombs. But the elevators were armored and dive bombers can be very accurate. We also know that explosions in the hangar, warped the deck.
I urge everyone to examine the carriers losses and reasons, then assess where the links broke. Most carriers were lost due to torpedoes, primarily from torpedo bombers and submarines. The first means inadequate fighter support to prevent the torpedo bombers from getting close, the second is poor ASW. The first reason can also be ascribed to a lack of adequate scouting, as in Midway. Gather the numbers based on torpedoes, bombs and sources of those weapons. I can tell you that AAR reports on Lexington show that she was lost due to poor damage control. Here AV gas tanks on the side of the ship leaked into an air-conditioning plant which had not been shut down. The spark from the motors set off the gas and boom, she was lost.
Examine the damage to carriers at Okinawa.
USS Bunker Hill
None were sunk but did require in many cases extensive repairs. Some were repaired at Ulithi and ready for more work at Okinawa. There were light carriers and escort carriers. They were all damaged.