The airplane that did the most to turn the tide of the war.

[Kevin J]

I nominate the Civil Air Patrol.

 

[GrauGeist]

I'm well aware the SO3C was a scout plane (and rescue, ASW etc.) but scout planes were pretty important in WW2 naval combat. Especially for the Americans who really needed their heavy gun-ships (BB's, BC's, CA's and CL's) since their torpedoes didn't work in the first year or two of the war, rendering Destroyers severely weakened in terms of effectiveness.

Also lets be real, scouting, maritime patrol and ASW were a big part of what some of the other planes we are discussing - Swordfish, Albacore, and postwar Gannett - actually did in the war. The TBF sunk some enemy ships but it too spent a lot of time in this kind of role. Certainly that's all it was good for in the 50's, I wouldn't want to see one squaring off with a Mig 15.

The SBD was a "Scouting Bomber" and there were several instances where an SBD on patrol spotted and reported crucial enemy positions.

I would say Coral Sea, Midway, and the Solomons campaign, not just Midway.

The Battle of Coral Sea saw the SBD not only inflict damage to IJN elements, but actively repulsed Japanese attacks in the role of interim fighter. However, Coral Sea was not a decisive battle in the sense that the IJN wasn't hurt and would soon be knocking at Midway's door.

The Solomons was a protracted series of battles that saw a considerable spectrum of factors, from ground fighting the full surface fleet engagements. The SBD did contribute, but it's contributions were only one of dozens of factors.

The Battle of Midway, however, is where the SBD alone was the deciding factor. As no opposing surface engaged, it was a pure aerial battle that dictated the next action of opposing fleets. Had the SBD not carried the day and/or the IJN caught the other two U.S. carriers, the Japanese would have been free to continue their invasion of Midway Atoll.
There were layers of USN and USAAF actions against the Japanese fleet including level bombing and torpedo attacks by land-based bombers, there were Torpedo attacks by carrier-based aircraft, but in the end, it was the Dauntless alone that delivered the lethal blows to the Akagi, Hiryu, Soryu and Kaga - which were all fist line fleet carriers that the IJN relied on and simply could not replace.

In all honesty, I feel that Midway is perhaps one of the very few instances where a single weapon actually effected the outcome of the battle and add to that, a pivotal battle that shifted the enemy from the offensive to the defensive for the duration.

Lethal and versatile.

Agreed.

SBD was one of those planes that was kind of thought of as stop-gap. In a way, similar to the Ju 87. I don't think it was ever realized in the 30's what an important role the Ju 87 was still going to play in the mid 40's.

The SBD originated from the Northrop BT-1, which had many of the characteristics of the later Dauntless, but was always intended to be a multi-role type (Scouting, Divebombing) - the fact that it could stand and fight was a plus.

TBFs and their ilk weren't very good at attacking land targets. Fighters ended up being more useful for that... for the Americans the F4U, the F6F, the P-47, P-40, P-38 and P-51 began taking over a lot of the Tactical bombing of ground targets in the second half of the war, and only medium bombers reconfigured as strafers and skip-bombers continued in their intended role.

Actually, the TBF/M were fantastic at bombing enemy positions with bombs and saw a great deal of use later in the war, as enemy shipping became scarce.

 

[Conslaw]

I'm well aware the SO3C was a scout plane (and rescue, ASW etc.) but scout planes were pretty important in WW2 naval combat. Especially for the Americans who really needed their heavy gun-ships (BB's, BC's, CA's and CL's) since their torpedoes didn't work in the first year or two of the war, rendering Destroyers severely weakened in terms of effectiveness.

Also lets be real, scouting, maritime patrol and ASW were a big part of what some of the other planes we are discussing - Swordfish, Albacore, and postwar Gannett - actually did in the war. The TBF sunk some enemy ships but it too spent a lot of time in this kind of role. Certainly that's all it was good for in the 50's, I wouldn't want to see one squaring off with a Mig 15.



I would say Coral Sea, Midway, and the Solomons campaign, not just Midway.



Lethal and versatile.

SBD was one of those planes that was kind of thought of as stop-gap. In a way, similar to the Ju 87. I don't think it was ever realized in the 30's what an important role the Ju 87 was still going to play in the mid 40's.

Being reliable, lethal and versatile - and a good dive bomber, meant that it was a lot more effective than most other bombers around.

Torpedo planes were only as lethal as the torpedoes they carried, but they never had a particularly good survivability ratio and usually weren't that good at much else.

TBFs and their ilk weren't very good at attacking land targets. Fighters ended up being more useful for that... for the Americans the F4U, the F6F, the P-47, P-40, P-38 and P-51 began taking over a lot of the Tactical bombing of ground targets in the second half of the war, and only medium bombers reconfigured as strafers and skip-bombers continued in their intended role.

SBD was a limited exception, as the A-24 and particularly in Marine hands as the SBD they proved useful in ground attack, because they could hit targets better than fighters and survive sorties about as well.

The SBD was thought of as such a stop gap plane that they never bothered to make a version with folding wings. They figured it soon would be replaced by the SB2C - ha, little did they know . . .

 

[GrauGeist]

The SBD was thought of as such a stop gap plane that they never bothered to make a version with folding wings. They figured it soon would be replaced by the SB2C - ha, little did they know . . .

The SBD didn't have folding wings on purpose - it was to maintain structural integrity.
The Douglas TBD, a torpedo bomber a bit older than the SBD was the first aircraft to have hydraulic-actuated folding wings, so Douglas was very aware of the need and the technology...

 

[Dimlee]

In all honesty, I feel that Midway is perhaps one of the very few instances where a single weapon actually effected the outcome of the battle and add to that, a pivotal battle that shifted the enemy from the offensive to the defensive for the duration.

I feel the same.
So far I can not find examples in this thread (or in my memory) of other instances - at least so vivid and undisputable.
Hence my doubts I expressed earlier in my post #160. It was about the Eastern Front but could relate to other theatres as well.

 

[davparlr]

The Battle of Midway, however, is where the SBD alone was the deciding factor. As no opposing surface engaged, it was a pure aerial battle that dictated the next action of opposing fleets. Had the SBD not carried the day and/or the IJN caught the other two U.S. carriers, the Japanese would have been free to continue their invasion of Midway Atoll.
There were layers of USN and USAAF actions against the Japanese fleet including level bombing and torpedo attacks by land-based bombers, there were Torpedo attacks by carrier-based aircraft, but in the end, it was the Dauntless alone that delivered the lethal blows to the Akagi, Hiryu, Soryu and Kaga - which were all fist line fleet carriers that the IJN relied on and simply could not replace.

In all honesty, I feel that Midway is perhaps one of the very few instances where a single weapon actually effected the outcome of the battle and add to that, a pivotal battle that shifted the enemy from the offensive to the defensive for the duration.

As you indicated, while the SBDs did carry the day and performed heroically, the battle of Midway was a very complex battle with many factors that set up the Japanese for the SBDs to perform the coup de grace. Too often the earlier attacks are dismissed as ineffectual in the battle whereas in reality they were instrumental in setting up the Japanese for defeat. From 0700-on multiple and heroic attacks by Midway based aircraft, TBFs, B-26s, and B-17s kept the Japanese bobbing and weaving which significantly affecting the Japanese ability to launch, land, rearm, and refuel aircraft. And then the fortuitous, for the SBDs but not so much for TBDs, attack that kept the Japanese fighters from reforming to address a high altitude dive bomber attack. The SBDs were great aircraft and performed well in the war but lets not forget all the heroic and sacrificial attacks that set the stage for the SBDs at Midway.

 

[Reluctant Poster]

RP,

Do you have the equivalent Bomber Command chart for a comparison?

Cheers,
Biff

I wish I did

 

[Navalwarrior]

There has been a lot of talk about the relative inability of divebombers to destroy battleships. I submit that it was not necessary for divebombers to destroy battleships to turn the tide of the war. It was necessary for dive bombers to destroy - or at least put out of action - aircraft carriers. Both the D3A and the SBD were good at it when flown by experienced aviators. In addition to sinking the 4 aircraft carriers in the Midway battle, SBDs also sunk the Mikuma and put the Mogami out of action for two years. These two heavy cruisers could have been enough to tip the balance at Guadalcanal later in the year.

Success at Midway allowed the Americans to take Guadalcanal in a defensive offensive action. It was defensive because failure to take Guadalcanal would have allowed Japan to control the direct supply lines to Australia if Japan had gotten the airfield operational. The F4F defended the air around Guadalcanal, but it was primarily the SBD that defended the sea approaches to Guadalcanal and made sure the Japanese could not conduct day operations for a couple hundred miles up the slot. The repeated failure of the Japanese to neutralize Henderson Field and the SBDs flying from it doomed the Japanese effort to retake the island. The Wildcats would not have been able to defend the island if the Tokyo Express would have been able to approach the island and bombard the airstrips with impunity. As it was, the Toyko express came close to bombarding the island out of service. Had these ships been able to arrive earlier and stay later, it might have made the crucial difference.

Resp:
The Fairey Swordfish didn't sink the German Battleship, the Bismarck. But it did disable it long enough to allow it to be destroyed(?) by British warships. It did its intended job.

 

[Reluctant Poster]

The SBD was a "Scouting Bomber" and there were several instances where an SBD on patrol spotted and reported crucial enemy positions.

The Battle of Coral Sea saw the SBD not only inflict damage to IJN elements, but actively repulsed Japanese attacks in the role of interim fighter. However, Coral Sea was not a decisive battle in the sense that the IJN wasn't hurt and would soon be knocking at Midway's door.

The Solomons was a protracted series of battles that saw a considerable spectrum of factors, from ground fighting the full surface fleet engagements. The SBD did contribute, but it's contributions were only one of dozens of factors.

The Battle of Midway, however, is where the SBD alone was the deciding factor. As no opposing surface engaged, it was a pure aerial battle that dictated the next action of opposing fleets. Had the SBD not carried the day and/or the IJN caught the other two U.S. carriers, the Japanese would have been free to continue their invasion of Midway Atoll.
There were layers of USN and USAAF actions against the Japanese fleet including level bombing and torpedo attacks by land-based bombers, there were Torpedo attacks by carrier-based aircraft, but in the end, it was the Dauntless alone that delivered the lethal blows to the Akagi, Hiryu, Soryu and Kaga - which were all fist line fleet carriers that the IJN relied on and simply could not replace.

In all honesty, I feel that Midway is perhaps one of the very few instances where a single weapon actually effected the outcome of the battle and add to that, a pivotal battle that shifted the enemy from the offensive to the defensive for the duration.


Agreed.


The SBD originated from the Northrop BT-1, which had many of the characteristics of the later Dauntless, but was always intended to be a multi-role type (Scouting, Divebombing) - the fact that it could stand and fight was a plus.


Actually, the TBF/M were fantastic at bombing enemy positions with bombs and saw a great deal of use later in the war, as enemy shipping became scarce.

According to the United States Strategic Bombing Survey the USN attacks on Japanese factories were more effective than the B29 attacks.

 

[Reluctant Poster]

How much it can carry is one attribute.

The "box score" of how much damage a type did to the enemy needs an awful lot of research. For the British they built 800 Albacores and 2391 Swordfish. Just the law of averages tells you the Swordfish should have caused 3 times the damage (it did far more than average).

I also prefer actual ranges rather than rough estimates if we can find them.

Wiki is a terrible source in this regard as it tends to list the maximum of everything, max speed when clean, max range with max fuel (often without bombs) max bomb load (even if the range is absurdly short) like for the B-17.

• Short range missions (<400 mi): 8,000 lb (3,600 kg)
• Long range missions (≈800 mi): 4,500 lb (2,000 kg)
• Overload: 17,600 lb (7,800 kg)

That 17,600lbs is technically correct but it took six of the already mentioned 1600 AP bombs in the bomb bay and two 4000lb bombs under the wings on external racks to get to that weight of bombs. An almost useless payload as the range of the B-17 so loaded was barely enough to cross the channel and the two bombs have different trajectories so they can't be dropped at the same time in the same target (unless it is an area target but then why are you using AP bombs?)

A good useful bomb load does beat a lighter useful bomb load. Useless bomb loads just to reach a high number mean nothing (B-26 Marauder 5200lbs, made up of one 2000lb topedo and two 16000lb AP bombs) nice number but you have to drop the torpedo first (preferably from under 200 feet) and the climb to altitude where the 1600lb will actually penetrate armor.

perhaps the SBC2 did out range the Avenger at times but it takes a certain set of circumstances. Both planes used essentially the same engine and Wiki seems to list the last models, the 1942/43 versions of both planes used 1700hp engines (Wright had only built about 175 of the 1900hp versions by the end of Sept 1943).
The Avenger had 335 gallons of internal fuel and while the Helldiver could hold 330 (on early versions). Both could use drop tanks, at least after a while and both were also rigged to use fuel tanks mounted in the bomb bay, so total fuel load an vary considerably.
The Japanese B5N didn't have a prayer of out ranging the Avenger.
For the B6N we get back into the "it depends" arena.

The later Avengers (-3) had the 1900hp engine, it was possible to fit them with a pair of 100 gallon underwing drop tanks leaving the bomb bay clear. for "scouting" use it was possible to fit a 275 gallon tank in the bombay. Providing the proper tanks were available (and they may not have been a number of times) the Grumman wins hands down.

Just what could out range it in 1942-43 as far as load carrying carrier aircraft?



They operated Avengers from jeep carriers. The SBD had nowhere near the range, at least until they fitted more powerful engines to the SBD in the -5 and -6 models.
Sure you could put 260 gallons into the tanks of the SPD-3 and fly 1000 miles, you just didn't do it with a bomb under the plane. which puts the Kill at long distance back on the shelf.




Since the TBD lasted until well into the 50s as an operational aircraft it must have been of some use. There were a lot of contradictory requirements but at the time it was one of the best carrier borne strike aircraft in the world. the failure of the torpedo should not be blamed on the Avenger. And unfortunately the "fix" was always just a few weeks (or months) away and not the well over one year if finally took.

The Admiralty conducted an appraisal (Report No.9/44 "Achievements of British and American Escort Carriers in the Anti Submarine Role 1943" reproduced in The Fleet Air A in World War II Vol 2) of the merits of the Avenger and the Swordfish and came down firmly on the side of the Avenger.

The Advantages of the Avenger:
1. Most surprising to me, the wastages rate was 1/7(!) of that of the Swordfish. Apparently the Avenger undercarriage was more robust. Some of this wastage was due to the fact that the British operated in the main convoy routes in the rougher northern latitudes while the US operated mostly south of 40 N.
2. The Avenger had 1 ½ time the endurance.
3. The Avenger could be catapulted; an advantage in low wind and allowing heavier loads to be carried.
4. The Avenger had a much higher speed (230 vs. 120 knots) allowing it to catch U-boats on the surface and reducing the danger from flak. Avenger converted 78% of its sightings into attacks while the Swordfish only did 35%. Sighting to kills was 38% to 17%. Higher speed also meant more follow up attacks

Disadvantages of the Avenger

1. Not as good look out positions.
2. Heavier and more difficult to deck handle
3. More maintenance

It was considered that the advantages greatly out weighed the disadvantages

At night the Avenger had a more visible exhaust, inferior radar and was less maneuverable in the radar approach. The first 2 items were in the process of being corrected and at that point the recommendation was to adopt the Avenger as the standard type.

 

[alsaad]

Anyone mentioned Swordfish? Or Sturmovik?

 

[Navalwarrior]

According to the United States Strategic Bombing Survey the USN attacks on Japanese factories were more effective than the B29 attacks.

Resp:
I would like to know more about the USN attacks on Japanese factories. Do you have a good source? Thanks.

 

[Reluctant Poster]

The standard bomb used by the Japanese was a 550 lb bomb and the one most often mentioned as used by the SBD was a 1,000 lb bomb. Neither your 1600 lb bomb nor your 1,760 / 800kg bomb are known to me. It is sometimes referred to as a 'semi-armor piercing' bomb.

Looking at this list of Japanese bombs on Wikipedia it mentions their Type 99 No.25 550 lb bomb (132 lbs of special high explosive) which can penetrate 50mm of armor and their Type 98 No.25 bomb (211 lbs of explosives) which can penetrate 400 inches of reinforced concrete. These were both I assume 'semi-armor piercing'

List of Japanese World War II navy bombs - Wikipedia

However, a bomb did not have to penetrate all the way down to engineering spaces, fuel cells or engine room to cripple or sink a ship. Once ammunition, fuel, or various flammable fluids get burning well enough in a ship, the steel itself will catch fire. If you have read books like Neptune's Inferno you'll know a bit about what that is like. Many large ships were destroyed when their scout / float plane fuel caught fire (the Japanese used to jettison it before battle to prevent this).

Superstructures and the bridge etc. were typically vulnerable to bomb hits as well.

The website you were quoting from has some interesting and helpful estimates as to the effectiveness of bombs:

"The Americans estimated that three hits with 500 lb (227 kg) GP bombs would almost certainly sink a 1630-ton destroyer and had a 70% chance of sinking a 2100-ton destroyer. Three hits with 1000 lb (454 kg) GP bombs had a 95% chance of sinking a relatively lightly protected Atlanta-class light cruiser and a 30% chance of sinking a 10,000-ton heavy cruiser. Six hits with the 1000-lb bomb gave a 80% chance of sinking a heavy cruiser.

Nine Allied cruisers were sunk by general-purpose bombs during the Second World War. A single bomb hit required an average of six to seven weeks in a shipyard to repair, and a particularly damaging hit (such as the 500kg or 1100 lb hit on British cruiser Suffolk that forced her to beach) could take up to eight months to repair."

So by that math, if it took three hits for a 30% chance sink a heavy cruiser of 10,000 tons, and 6 hits for an 80% chance, the 50,000 ton Bismarck was probably going to require about 12-15 bomb hits to sink or be sufficiently crippled so as to no longer fight back. This wouldn't be hard for a large formation of SBD's given that it was a single large target with no escorting ships and no air support.

Anyway that website you linked mentions two types of bombs probably carried by the SBD.

"Much more widely used was the Mark 33, introduced in October 1942, which weighed 1000 lbs (454kg) of which 150 lbs (68 kg) was high explosive. The Mark 33 could penetrate a 5" deck from 10,000' (3050m) or from 6500' (1980m) when dropped from a dive bomber in a 300 knot 60 degree dive. "

Then they give us more helpful estimates:

"The Americans estimated that seven penetrating bomb hits would be enough to sink a battleship, while the Japanese estimated that 12 to 16 penetrating hits were required. American operational analysts later revised their estimates, concluding that the Mark 33 could sink a battleship only if it hit a magazine, which worked out to a 79% chance of sinking a battleship with six penetrating hits.

Semi-armor-piercing bombs were a compromise between the penetrating ability of an armor-piercing bomb and the large explosive charge of a general purpose bomb. They were useful against lightly armored ships and reinforced concrete structures."

So my estimate was a bit over-conservative, it sounds like 6 good hits with true AP bombs (Mark 33) would probably sink the Bismarck, maybe 12-15 hits with the more common 'semi-armor piercing" bombs.

As a bonus, I found a diagram of the Mk 33

View attachment 529761


TL : DR Yes the Dauntless could have sunk the Bismarck. Probably in one strike, maybe 2 or 3.

You can't sink the Bismark in May 1941 with a weapon that didn't appear until Oct 1942.
The reality is that dive bombers never sunk a battleship or even came close. The 6 PENETRATING hits you mention would be extremely difficult to obtain on a ship at sea. Bombs that hit are not guaranteed to penetrate. Note that the Yamato and Musashi were sunk by the water taken on board from the many torpedo hits. The bomb damage was instrumental in destroying the ships ability to fight back but never threatening to the survival of the ships. SAP bombs would have no chance of sinking a battleship they could never penetrate a maganzine. Lastly the Swordfish attacks took place in near darkness conditions that would make it near impossible for a successful dive bomber strike.

 

[Shortround6]

According to the United States Strategic Bombing Survey the USN attacks on Japanese factories were more effective than the B29 attacks.

This may be a bit contentious as I am not sure what metric/s we are using and even if the statistical sample is big enough.

For instance:

"Three-quarters of the 6,740 tons of bombs dropped by carrier planes on the Japanese home islands were directed against airfields, warships, and miscellaneous military targets, and one-quarter against merchant shipping and other economic targets. Most of the warships sunk in home ports had already been immobilized for lack of fuel. The accuracy of low-level carrier plane attack was high, being at least 50 percent hits within 250 feet of the aiming point. The attack against the Hakodate-Aomori rail ferries in July 1945 sank or damaged all twelve of the ferries, 17 steel ships, and 149 smaller ships. "

Italics by me.

The argument of the accuracy of low level bombing is indeed hard to counter and I am not trying to. However what is not mentioned is the losses. In just a few days (July 24-28 and they did not fly attack missions on all of those days) The Americans and British lost 133 aircraft and 102 crewmen attacking targets in the Japanese homeland. Granted a very large part of those casualties were taken on the attacks on the Naval Base at Kure and the air base and port at Osaka which would be much more heavily defended than industrial and economic targets in general.

Compared to the fire raids

"In a period of 10 days starting 9 March, a total of 1,595 sorties delivered 9,373 tons of bombs against Tokyo, Nagoya, Osake, and Kobe destroying 31 square miles of those cities at a cost of 22 airplanes. The generally destructive effect of incendiary attacks against Japanese cities had been demonstrated. "

Granted the loss of 22 B-29s might have cost more money and certainly more crew lives but the destructive effect was certainly much higher.

 

[Kevin J]

Resp:
I would like to know more about the USN attacks on Japanese factories. Do you have a good source? Thanks.

I put down Swordfish a while back for its work in the war against the U Boats in the North Atlantic.

 

[Schweik]

Compared to the fire raids

"In a period of 10 days starting 9 March, a total of 1,595 sorties delivered 9,373 tons of bombs against Tokyo, Nagoya, Osake, and Kobe destroying 31 square miles of those cities at a cost of 22 airplanes. The generally destructive effect of incendiary attacks against Japanese cities had been demonstrated. "

Granted the loss of 22 B-29s might have cost more money and certainly more crew lives but the destructive effect was certainly much higher.

Against civilians. If your goal is to incinerate people and 'dehouse' the population or whatever the euphemism is, fire raids are very effective.

But four engine bombers didn't sink a lot of ships - they did sink a few and help sink some more. But the ratio is very high for low level attackers to four engined heavies. Probably 50 or 100 to 1. For the Anglo-Americans combined together the SBD did the most real damage compared to all the four engine heavies combined. The only other one that comes close would be the Beaufighter.

Four engine bombers also had a pretty dismal record against Tactical and Operational targets, (enemy tanks, troops, gun positions, and supply columns etc.) quite often being involved in "friendly fire" incidents and on many other occasions just being useless.

From Shores Mediterranean Air War I'll admit though I was surprised at how useful the American four-engined bombers were at wrecking airfields (with heavy air cover) but those were relatively low altitude strikes, and the medium (B-25) seemed to do just as well.

And they were good for maritime patrol. But I think it's highly debatable how useful they were in the overall war effort. I notice there were precious few if any nominations for the B-17, B-24 or Lancaster as a war-winner in the thread so far. I think maybe one or two for the B-24?

 

[alsaad]

"The Americans estimated that three hits with 500 lb (227 kg) GP bombs would almost certainly sink a 1630-ton destroyer and had a 70% chance of sinking a 2100-ton destroyer. Three hits with 1000 lb (454 kg) GP bombs had a 95% chance of sinking a relatively lightly protected Atlanta-class light cruiser and a 30% chance of sinking a 10,000-ton heavy cruiser. Six hits with the 1000-lb bomb gave a 80% chance of sinking a heavy cruiser.

These estimations were given for so called skip bombing and GP bombs hitting the ship sides near the waterline after bouncing off the water surface upon being released from the extreme low level flight. I doubt that 3 500 lbs GPs would sink a destroyer when dropped from dive bombing and hitting armored decks. Crippling yes, but sinking hardly.

 

[Shortround6]

Against civilians. If your goal is to incinerate people and 'dehouse' the population or whatever the euphemism is, fire raids are very effective.

But four engine bombers didn't sink a lot of ships - they did sink a few and help sink some more. But the ratio is very high for low level attackers to four engined heavies. Probably 50 or 100 to 1. For the Anglo-Americans combined together the SBD did the most real damage compared to all the four engine heavies combined. The only other one that comes close would be the Beaufighter.

Four engine bombers also had a pretty dismal record against Tactical and Operational targets, (enemy tanks, troops, gun positions, and supply columns etc.) quite often being involved in "friendly fire" incidents and on many other occasions just being useless.

From Shores Mediterranean Air War I'll admit though I was surprised at how useful the American four-engined bombers were at wrecking airfields (with heavy air cover) but those were relatively low altitude strikes, and the medium (B-25) seemed to do just as well.

And they were good for maritime patrol. But I think it's highly debatable how useful they were in the overall war effort. I notice there were precious few if any nominations for the B-17, B-24 or Lancaster as a war-winner in the thread so far. I think maybe one or two for the B-24?

The comment was made that that navy aircraft were noted as being more effective in a "Strategic Bombing Survey" which has darn little to do with sinking ships or blowing up tanks on the battlefield.

 

[alsaad]

...quite often being involved in "friendly fire" incidents ...

Got that right...highest officer killed by friendly fire was Lesley McNair killed by th B17 in Operation Cobra.

 

[Schweik]

You can't sink the Bismark in May 1941 with a weapon that didn't appear until Oct 1942.
The reality is that dive bombers never sunk a battleship or even came close. The 6 PENETRATING hits you mention would be extremely difficult to obtain on a ship at sea. Bombs that hit are not guaranteed to penetrate. Note that the Yamato and Musashi were sunk by the water taken on board from the many torpedo hits. The bomb damage was instrumental in destroying the ships ability to fight back but never threatening to the survival of the ships. SAP bombs would have no chance of sinking a battleship they could never penetrate a maganzine. Lastly the Swordfish attacks took place in near darkness conditions that would make it near impossible for a successful dive bomber strike.

Ok lets be real:

• Semi-Armor Piercing bombs would have been sufficient. The superstructure on battleships is not armored sufficiently to protect against 1,000 lb bomb hits. Nor was all of the deck. Nor were the AA guns. Nor were, necessarily, the turrets.
• The attack didn't have to be at night - it really shouldn't have been. As it was they would have sunk the Sheffield by accident if the magnetic detonators had worked. Swordfish took advantage of having radar. Attacking at night was safer in airplanes doing 100 mph 200 feet over the water. But SBD's could have attacked that ship in relative safety. Certainly SBD strikes were made against much more heavy AAA defenses without suffering heavy casualties. SBD also had much greater range, and was roughly twice as fast getting to the target, meaning it was more likely to spot the enemy ship more quickly.
• Yamato was wrecked and became unable to defend itself due to bomb hits. In the first attack, quoting from the wiki: "the Yamato was hit by two armor piercing bombs and one torpedo. One of the bombs started a fire aft of the superstructure that was not extinguished." Fires that "are not extinguisehd" aren't good for warships. It was then hit by 8 torpedoes and 15 more bombs. Again quoting the wiki: "The bombs did extensive damage to the topside of the ship, including knocking out power to the gun directors and forcing the anti-aircraft guns to be individually and manually aimed and fired, greatly reducing their effectiveness " Clearly the bombs had an impact, pun intended. No mention of any of them 'bouncing off'.
• They didn't need to blow up the magazine of the Bismarck, all they had to do was make it incapable of defending itself, then the ships could have finished it off. As it was in the real event, they only hit with one torpedo right? But jamming the rudder and causing a list was sufficient to cripple the mighty Battleship so that it's lesser rivals could finish it.

A battleship like the Bismarck, with no air cover and no flak screen from friendly warships, would have been dead meat from a squadron or two of SBD's. The Swordfish was a versatile old biplane, but it wasn't in the same league as a ship killer. Not even close.