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Post by rob06waves2018 on Mar 22, 2019 17:28:19 GMT -6
RN aircraft complement size doctrine has not really changed in years since. The RN aircraft carriers nowadays are based on a smaller air group but at a higher sortie rate. That's why, despite a smaller air group, the new Queen Elizabeth class carriers can project more power than an (admittedly much older) Nimitz class.
On the fuel point, an aircraft carrier is no use if blown up due a a fuel flash fire. This is especially true for an imperial nation that has to protect colonies across the world. It is infinitely better to refuel more often than have a carrier sunk and a replacement at best halfway round the world and at worst still on the slipway.
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Post by generalvikus on Mar 22, 2019 22:32:51 GMT -6
A point for discussion - was it really true that the ranges in the Pacific dictated that land based aircraft would be a minor factor? It seems to me that if any theater of war could make that claim, it was the Atlantic, until sufficiently long-ranged aircraft had been developed; in the Pacific, it seems to me that land-based aircraft were often able to make their presence felt, especially after the beginning of Allied offensive operations in the Central and South Pacific.
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Post by bcoopactual on Mar 23, 2019 0:06:20 GMT -6
It's not a minor factor at all. A significant portion of the Pacific war was based on the need to invade an island to establish an airfield to provide cover for the next island invasion. The New Guinea campaign was essentially the same since there was little to no inland lines of communication.
The difference between the two Theatres, I think, was the distances involved in the Pacific gave more freedom of movement. There were more areas out of reach of land based air than say the Med where it was harder to find a "safe" area out of range of land based bombers.
It should be noted that in the first couple years of the war both the US and Japan considered their carriers to be raiding forces and both avoided slugging it out with major air bases. At least until the US had the ability to field 8 fleet and 8 light carriers carrying about a thousand aircraft total. Then it was a whole different ballgame.
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Post by director on Mar 23, 2019 0:53:14 GMT -6
The Central Pacific route (the US Navy's preferred way) is relatively open; carriers can cover invasions because the islands large enough to hold an airfield are pretty widely separated. The south-west Pacific (MacArthur's preferred way) went up the Solomons chain and bypassed Rabaul to continue up the back of the New Guinea 'bird'. MacArthur had success here because the terrain was extraordinarily difficult, the enemy airfields were fairly small and separated, and he could exploit naval and air mobility to leapfrog past strongpoints and prevent the Japanese from reinforcing, supplying or withdrawing those garrisons. MacArthur repeatedly asked for carriers to cover his advance and was always immediately told, "Not no but Hell no!" The US Navy was absolutely not going to put its fleet carriers in those constricted waters, I speculate because of the short amount of time land-based planes needed to come out from under cover, launch and hit, and because of radar shadow from land masses.
Once the two lines of advance converged at the Philippines, the Japanese had fairly certain knowledge of where the Americans would hit, plenty of air bases and relatively short logistical lines (even if they didn't have a lot of good pilots left). But as bcoop says, even then the carriers could strike and move out of retaliatory range into the open ocean unless they were tied to covering an invasion. That was one of the great advantages of having dozens and dozens of escort carriers - to cover the invasion and let the fleet carriers get on with destroying the enemy fleet.
Operating carriers in the Atlantic is not risky (aside from sub-hunting); Germany never had major air assets covering the Murmansk run and there's no other reason for carriers to close on the mainland until after D-Day. The Med is different (as has been noted by others) because aircraft can reach the major sealane (Gibraltar to Suez) over most of its length for days and days. Running that gauntlet is impossible if the enemy has enough aircraft and difficult and expensive even if he has moderate numbers of aircraft. Fortunately for Britain, the Luftwaffe was mostly busy off in Russia and didn't want to co-operate with the German navy anyway... but when they showed up in force, the Royal Navy took unsustainable losses while resupplying Malta.
Which begs the question, "If carriers couldn't operate in the Med without crippling losses, what could?" I think the answer is, "Nothing." The relevant equation seems to me to involve the number of defending and attacking aircraft, with some randomness as to whether bombs are a near-miss or a critical hit... given enough defending aircraft and few attackers, or few defenders and a lot of attacking bombers, you can pretty well see how the result will come out. As bcoop said, there is nowhere in the Med to really hide (if the enemy controls Sicily). One thing is for certain: the Royal Navy put to the test the pre-War theory that a ship could carry enough AA to defend itself from attack, and proved it was not correct.
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Post by vonfriedman on Mar 23, 2019 3:00:50 GMT -6
What kind of aircraft carrier would Germany have built, if it had continued on the path started with the Graf Zeppelin? Excluding Aquila and Sparviero, which were modified transatlantic liners, what kind of aircraft carrier would be built in Italy, in the long run? Similar to the Essex or similar to the Illustrious? Graf Zeppelin have main armour deck on level of lower hangar.
Main issue for Germany was no experience at all. It takes time, years, decade, to test new weapon platform and find ways to operate it effectivelly.
Area of hangars of Graf Zeppelin was similar to HMS Ark Royal, yet Graf Zeppelin was much larger ship.
The Graf Zeppelin had two catapults and, from the photos, it appears that these protruded out from the flight deck, hindering or making it more dangerous, in my opinion, any take off operation without catapult. Captain Goldrick, in a paper already cited by me, writes "It was British doctrine that each aircraft had to be struck down in the hangar deck after it had landed on before the next would be allowed onto the flight deck. This meant an interval between aircraft of up to three minutes, between four or six times more than the intervals achieved by the other navies. Conversely the British .... could not allow aircraft to start and warm their engines up [in their enclosed hangars] before they were brought up to the flight deck. All of these factor added up lenghtened the reaction times.... and reduced the effective operational range."" It therefore seems to me that the operating methods of the carriers of a Navy constitute an element to be simulated in the game, as it is done in RTW about improvements in gunnery.
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Post by oldpop2000 on Mar 23, 2019 10:07:08 GMT -6
The Central Pacific route (the US Navy's preferred way) is relatively open; carriers can cover invasions because the islands large enough to hold an airfield are pretty widely separated. The south-west Pacific (MacArthur's preferred way) went up the Solomons chain and bypassed Rabaul to continue up the back of the New Guinea 'bird'. MacArthur had success here because the terrain was extraordinarily difficult, the enemy airfields were fairly small and separated, and he could exploit naval and air mobility to leapfrog past strongpoints and prevent the Japanese from reinforcing, supplying or withdrawing those garrisons. MacArthur repeatedly asked for carriers to cover his advance and was always immediately told, "Not no but Hell no!" The US Navy was absolutely not going to put its fleet carriers in those constricted waters, I speculate because of the short amount of time land-based planes needed to come out from under cover, launch and hit, and because of radar shadow from land masses. Once the two lines of advance converged at the Philippines, the Japanese had fairly certain knowledge of where the Americans would hit, plenty of air bases and relatively short logistical lines (even if they didn't have a lot of good pilots left). But as bcoop says, even then the carriers could strike and move out of retaliatory range into the open ocean unless they were tied to covering an invasion. That was one of the great advantages of having dozens and dozens of escort carriers - to cover the invasion and let the fleet carriers get on with destroying the enemy fleet. Operating carriers in the Atlantic is not risky (aside from sub-hunting); Germany never had major air assets covering the Murmansk run and there's no other reason for carriers to close on the mainland until after D-Day. The Med is different (as has been noted by others) because aircraft can reach the major sealane (Gibraltar to Suez) over most of its length for days and days. Running that gauntlet is impossible if the enemy has enough aircraft and difficult and expensive even if he has moderate numbers of aircraft. Fortunately for Britain, the Luftwaffe was mostly busy off in Russia and didn't want to co-operate with the German navy anyway... but when they showed up in force, the Royal Navy took unsustainable losses while resupplying Malta. Which begs the question, "If carriers couldn't operate in the Med without crippling losses, what could?" I think the answer is, "Nothing." The relevant equation seems to me to involve the number of defending and attacking aircraft, with some randomness as to whether bombs are a near-miss or a critical hit... given enough defending aircraft and few attackers, or few defenders and a lot of attacking bombers, you can pretty well see how the result will come out. As bcoop said, there is nowhere in the Med to really hide (if the enemy controls Sicily). One thing is for certain: the Royal Navy put to the test the pre-War theory that a ship could carry enough AA to defend itself from attack, and proved it was not correct. I would agree about the British concept of protection being AAA. The British Royal Navy, as we all know, lost many good officers to the RAF when it's aircraft arm was combined. They did not have the fighters with sufficient performance to deal with land based fighters. So they opted for AAA, and without good fire control based on radar, it just wasn't effective. That's why they bought our F4F's and F6U's. However, their carrier designs for the Mediterranean Sea were effective except that two of the carriers lost, did not have torpedo protection systems installed. The submarine was the problem for the British and I don't believe they planned for the German's to send their type VIIC's into this area. I would have to research this issue a little more though. Nice post, right on the money. Another issue is that the Pacific Island did not always have good protected deep water ports nor did they have the extensive areas that runway's could be installed on and serviced. For runways, generally you need two runways with one crossing the other due to a wind change. For the IJN, they had to use their scarce quantity of tankers to support even Truk. They were also lacking in good construction skills. We might want to examine some of the island topography and see what they held. I have the time and information, I just have to put it together.
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Post by axe99 on Mar 23, 2019 16:09:13 GMT -6
One thing is for certain: the Royal Navy put to the test the pre-War theory that a ship could carry enough AA to defend itself from attack, and proved it was not correct. I'm not sure (but could be wrong) the RN ever thought (in the 30s at least) that enough AA could be carried to reliably defend itself from attack - my understanding was that pre-radar, the difficulties of vectoring defending fighters onto attacking bombers was such that it was very difficult to be confident that enemy aircraft wouldn't get through (even with radar, Lexington's cap iirc wasn't able to intercept all the attackers, at least in part because of similar issues (the CAP being at different altitudes to attackers and the radar at that stage not being much chop for height finding, unless I'm hallucinating). So the thinking pre-radar was "the attackers will get through - what's the best that can be done about it" - and the answer was ships that could take a beating and as much AA as could be packed on. As for the Med though, once radar-directed fighter control got a bit better, carriers had a lot more success. While the net results of Operation Pedestal were touch-and-go, to say the least, this was due primarily to submarines, mines and coastal forces (with the greatest impact of enemy air taking place after the remaining fighter-direction ships had been knocked out by said elements, leaving the convoy unable to effectively coordinate with friendly aircraft operating from Malta). Of three carriers, the best that over 400 axis sorties could manage (more sorties than was sent against Yamato at the end of the war, just - although the 400 sorties were spread around a bit more, with more enemy ships to attack) was to damage one of them (albeit seriously enough to prevent flight operations). I'm not suggesting carriers could operate persistently in that kind of environment (there's no way they could - a land airfield can just fill in/flatten out a shell crater, while any hit to a carrier risks rendering it unable to continue flight operations), but the power of land-based air is the 'persistent pressure' that weight of aircraft with a reliable source of fuel and munitions can project - so while the aircraft might not get you on Monday or Tuesday, sooner or later, maybe Wednesday, maybe Thursday, they'll get a hit, as long as they can keep putting up those sorties (and the impact of that hit on a carrier is so much more than on an airfield). The land-based air will be likely (assuming their supporting economy isn't complete rubbish) to have the supplies of fuel, munitions and aircraft to fly sorties more persistently and, if their training is comparable, will eventually get through. As best I understand it, it's only in situations of significant imbalance of numbers and technology (such as the US had in the latter part of WW2 relative to Japan) where air forces can be near-'hard stopped'. Going from even wobblier memory now, but I think one of the interesting concepts Japan had later on in the war was a 'front line' of (preferably) armoured carriers, supported by smaller, unarmoured light carriers (and Shinano, which doesn't really qualify as unarmoured!), back far enough that they were at much less risk of being attacked, with the eye that the 'supporting line' assisted with fuel and supplies and replacement aircraft to be a half-way house between 'sortie, strike and return to base' and 'persistent replenishment at sea' (as the US refined so well later in the war).
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Post by director on Mar 23, 2019 20:01:32 GMT -6
axe99 - I didn't mean to imply that idea was British or peculiar in any way to the Royal Navy. It was - if I may exaggerate - something the fearful battleship sailors of all of the major naval powers told each other over cocktails. I was merely musing that the Crete campaign (in particular) seemed to show that naval operations under enemy-controlled airspace were infeasible. You make a very good point about multiple methods of attack synergizing with each other. Sea-denial and sea-control should always address multiple avenues; one is almost certain to be more effective than the others, and it is hard to predict which it will be. Does anyone have any hard information on how many attack planes the Axis deployed against the Malta convoys? And perhaps some numbers for how many fighters were available from carriers? Japan tried a variation on that theory in the Marianas battle, using land bases as staging, refueling and shuttle bases. They wanted to fly planes from carriers, hit US carriers, fly on to land bases to refuel/rearm, and then attack again on their way back to the carriers. An elegant way to get maximum sorties in a short period of time... but theory and practice are the same in theory, not in practice, and Japan's naval leaders once again failed to assume the enemy would be acting instead of reacting. Massive carrier strikes on the land bases, and massive well-coordinated fighter cover, simply attritted the Japanese strikes to nothing.
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Post by oldpop2000 on Mar 23, 2019 20:14:41 GMT -6
let's see, we have three nations that produced, deployed and lost carriers in WW2. We have the RN, whose carriers had armored decks( not all did), enclosed hangars and only about 48 aircraft due to the heavy armored deck which limited the size of the deck itself. They did not have two hangers stacked on atop one another so this had a negative effect on aircraft handling and how quick the British could spot the deck. They did not use a deck park partially because tying down wooden biplanes would be dangerous. The reasons for the British choices were A. They had lost many good officers to the RAF during their combining with them. B. Economics. Since their outdated aircraft were no match for the land based fighters, they opted for increased AA and fire control to try to protect the carriers along with escorts.
On the side of the issue is the US. We opted for unarmored flight decks and made the hangar deck the strength deck. This allowed for a much larger hangar and larger air wings. The hangars were open so they could warm up the engines and refuel inside the hangar and incase of emergency, jettison ordnance over the side and allow other ships to use their fire control sprayers to feed water into the hangar if it were on fire. The US believed in power projection and the best way to do that is with a larger air wing on their carriers.
Now, the Japanese were somewhere in the middle. They adopted the worst of both sides, when combined. No armored deck, but multiple hangars atop each other. They used a forced air ventilation system so incase of a fire no ordnance could be jettisoned over the side and the fire control system was totally ineffective incase a bomb penetrated the flight deck which occurred at Midway. In fact, Richard Best's 1000 LBS. GP bomb penetrated Akagi's flight deck and then went through the upper hangar deck and then exploded in the lower hangar. As one author states "its like putting a firecracker in a tin pot". Japanese warships were overweight and were thus very unstable. They also had tall profiles due to the stacked hangars. The Japanese did suspect some structural weakness and the Shokaku's tried to remedy this. The Japanese also believed in power projection and did use, on occasion, a deck park to refuel and rearm fighters and dive bombers. However, the torpedo bombers were always loaded in the hangar.
Well, does that about sum up the whole issue. Wait, one more issue that I have researched, but not extensively. In Kamikaze attacks, and in the Med, the British armored deck did reduce crew casualties by a substantial amount. I am referring to the carriers that had armored decks of which the Illustrious was the first. Both US carriers, Bunker Hill and Franklin suffer over 700 casualties. A fun note; Bunker Hill was used at North Island docked at the northeastern end at the bay entrance, as an electronic test platform. I used to drive by her on my way to the Test Line. Eventually, she just disappeared.
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Post by axe99 on Mar 23, 2019 22:43:06 GMT -6
axe99 - I didn't mean to imply that idea was British or peculiar in any way to the Royal Navy. It was - if I may exaggerate - something the fearful battleship sailors of all of the major naval powers told each other over cocktails. I was merely musing that the Crete campaign (in particular) seemed to show that naval operations under enemy-controlled airspace were infeasible. You make a very good point about multiple methods of attack synergizing with each other. Sea-denial and sea-control should always address multiple avenues; one is almost certain to be more effective than the others, and it is hard to predict which it will be. Does anyone have any hard information on how many attack planes the Axis deployed against the Malta convoys? And perhaps some numbers for how many fighters were available from carriers? Japan tried a variation on that theory in the Marianas battle, using land bases as staging, refueling and shuttle bases. They wanted to fly planes from carriers, hit US carriers, fly on to land bases to refuel/rearm, and then attack again on their way back to the carriers. An elegant way to get maximum sorties in a short period of time... but theory and practice are the same in theory, not in practice, and Japan's naval leaders once again failed to assume the enemy would be acting instead of reacting. Massive carrier strikes on the land bases, and massive well-coordinated fighter cover, simply attritted the Japanese strikes to nothing. Sorry, I write a long-ish reply with info I dug up from JD Brown's Carrier Operations of World War II and then managed to lose it (when I dropped my mouse - I need an armoured mouse!) Short answer, as have to scoot, is to scoot by Armoured Carrier's page on Pedestal, I imagine they'll have all the info there. Sorry to misinterpret. Fully agree difference between theory and practice, and would go as far as to suggest Japan had a bit more of an issue here than other navies when it came to tactics and planning. www.armouredcarriers.com/operation-pedestal-august-10-12-1942oldpop2000 - Three of the British carriers (the two Implacables, and Indomitable) had twin hangars, but they were a bit limited in usefulness as they were a bit of a compromise design-wise and a bit short, limiting the aircraft they could hold (but they did mean the carriers could carry more aircraft overall - from memory, they also meant that the hangar 'armoured box' was changed to just be an armoured deck, but I could be off here - again, I'm sure the Armoured Carriers site would have more detailed info. Here's a pic of Bunker Hill disappearing for you
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Post by director on Mar 23, 2019 22:49:56 GMT -6
oldpop2000 - my best recollection is that Bunker Hill and Franklin were both fully repaired and then put into long-term storage. Eventually, they were scrapped instead of being further modernized. From the Wiki: "Bunker Hill and Franklin were the only Essex-class ships never recommissioned after World War II. Stricken from the Naval Vessel Register in 1966, Bunker Hill served as an electronics test platform for many years in San Diego Bay, and was sold for scrap in 1973. An effort to save her as a museum ship in 1972 was unsuccessful." "Franklin was sold for scrap in 1966."
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Post by oldpop2000 on Mar 24, 2019 10:49:21 GMT -6
oldpop2000 - my best recollection is that Bunker Hill and Franklin were both fully repaired and then put into long-term storage. Eventually, they were scrapped instead of being further modernized. From the Wiki: "Bunker Hill and Franklin were the only Essex-class ships never recommissioned after World War II. Stricken from the Naval Vessel Register in 1966, Bunker Hill served as an electronics test platform for many years in San Diego Bay, and was sold for scrap in 1973. An effort to save her as a museum ship in 1972 was unsuccessful." "Franklin was sold for scrap in 1966." I know about the Bunker Hill, I used to drive past her almost weekly and sometimes daily. Here is a picture of her docked on North Island. The road leading to the test line runs right past her from left to right and crosses the main runway. www.navsource.org/archives/02/021735.jpg - This picture was taken after she was converted to an electronic test laboratory. www.navsource.org/archives/02/021721.jpg - This is a photo take from the sand beach between the road and the ship.
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Post by oldpop2000 on Mar 24, 2019 10:54:38 GMT -6
axe99 - I didn't mean to imply that idea was British or peculiar in any way to the Royal Navy. It was - if I may exaggerate - something the fearful battleship sailors of all of the major naval powers told each other over cocktails. I was merely musing that the Crete campaign (in particular) seemed to show that naval operations under enemy-controlled airspace were infeasible. You make a very good point about multiple methods of attack synergizing with each other. Sea-denial and sea-control should always address multiple avenues; one is almost certain to be more effective than the others, and it is hard to predict which it will be. Does anyone have any hard information on how many attack planes the Axis deployed against the Malta convoys? And perhaps some numbers for how many fighters were available from carriers? Japan tried a variation on that theory in the Marianas battle, using land bases as staging, refueling and shuttle bases. They wanted to fly planes from carriers, hit US carriers, fly on to land bases to refuel/rearm, and then attack again on their way back to the carriers. An elegant way to get maximum sorties in a short period of time... but theory and practice are the same in theory, not in practice, and Japan's naval leaders once again failed to assume the enemy would be acting instead of reacting. Massive carrier strikes on the land bases, and massive well-coordinated fighter cover, simply attritted the Japanese strikes to nothing. Sorry, I write a long-ish reply with info I dug up from JD Brown's Carrier Operations of World War II and then managed to lose it (when I dropped my mouse - I need an armoured mouse!) Short answer, as have to scoot, is to scoot by Armoured Carrier's page on Pedestal, I imagine they'll have all the info there. Sorry to misinterpret. Fully agree difference between theory and practice, and would go as far as to suggest Japan had a bit more of an issue here than other navies when it came to tactics and planning. www.armouredcarriers.com/operation-pedestal-august-10-12-1942oldpop2000 - Three of the British carriers (the two Implacables, and Indomitable) had twin hangars, but they were a bit limited in usefulness as they were a bit of a compromise design-wise and a bit short, limiting the aircraft they could hold (but they did mean the carriers could carry more aircraft overall - from memory, they also meant that the hangar 'armoured box' was changed to just be an armoured deck, but I could be off here - again, I'm sure the Armoured Carriers site would have more detailed info. Here's a pic of Bunker Hill disappearing for you The British realized that their air wings were too small and aircraft were no good for combat air patrols. So, they bought our aircraft and while building the Implacables and Indomitable, waiting for armor, the modified her design. According the Armoredcarrier website they had to reduced the thickness of the armored hangar and deck. I don't think that was a good trade off. Deck load might have solved the whole issue.
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Post by oldpop2000 on Mar 24, 2019 11:16:09 GMT -6
Let’s compare some carrier specifications. Illustrious, Yorktown and Shokaku
Illustrious -Completed in 1939 Length: 753 ft 3 in. Beam: 95 ft 9in LtoB- 7.8 to 1 Draught: 28 ft 6 in. Max speed: 30.5 kt. Armored Deck: 3 in.
Yorktown – Completed in 1937 Length: 810 ft Beam: 110 ft. LtoB – 7.36 to 1 Draught: 25 ft Max speed:33 Kt. Hangar Deck: 1.5 in.
Shokaku- Completed 1941 Length: 845 ft. Beam: 85 ft. LtoB – 9.94 to 1 Draft:29 ft Max speed: 34kt. No Flight Deck and Hangar Deck armor
So, what do we draw from these specifications which are not totally complete? Well, Shokaku was a little faster than the other two, but our carrier was wider. Our carrier was 14 feet wider than the British, and 24 feet wider than the Japanese. 14 feet will make a difference in how many birds you can put in the hangar but more importantly, it gives the ground and maintenance crews more room to work on the birds especially if they have folding wings. It allows the ordnance crews to move the torpedoes and bombs faster in between the aircraft. This speeds up reloading, refueling and movement to the elevators.
The speed difference is minor but the draft might make a difference when moving into a harbor, how much I can’t say. There are more specifications to examine with detailed drawings. But also ratio of officers to enlisted, damage control functions, location of fire fighting hoses and CO2 tanks makes a difference.
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Post by oldpop2000 on Mar 24, 2019 19:22:00 GMT -6
I’ve been wondering if the armored deck on British carriers might not go the full deck length. We know that the Illustrious deck length was 740 ft. and the length of the hangar was 456 ft. For the other two ships in the class, the second hangar was 168 ft and 208 ft. respectively. We know that the flight deck was made of 3 in. of armor. The question is whether that deck was armored the full length or just over the hangar. It would mean that 284 ft. of her flight deck was not protected by armor or 142 ft. at the bow and 142 ft. at the stern. I found that only two-thirds of the deck was armored. This is 492.84 ft with the other 247.2 ft. was not armored. A one-thousand-pound bomb could easily penetrate 3.5 in. of armor from about 4500 feet. Which it did, on January 10,1941. The original report states that Hit No. 2 went through the flight deck forward on the port side. This might mean that that hit did, in fact, pierce the unarmored forward portion of the deck. The first hit the after lift which would be unarmored. The lift would not be armored because it would be too heavy. Anyway, here is the link to the document - www.armouredcarriers.com/adm26783/2014/10/16/illustrious-january-10-damage-report-bomb-shellI am not making a point, just attempting to investigate the value of the armored deck. It was dive bombed, and pierced by a 1000 lbs. bomb which is exactly the bomb the specification states the armor was supposed to protect against at 4500 ft. Your conclusions. We have proof that the armored flight deck, possibly due to weight restrictions could not and possibly should not run the full length of the flight deck and if it doesn't, but just covers the hangar deck, what is its value? It was pierced.
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