Getting P-40 into the air quickly

[tyrodtom]

I just loaded the aircraft with what I was told to load it with, no one asked my advice. That was decided way above my pay grade.

But IMO, and just IMO, a AP bomb used in the ship bombing at 250 mph isn't going to have nearly the penetration as it would in the verticle mode.
For instance the Dauntless was limited in it's dive by it dive brakes to what ? 250 mph, ??
But the centerline drop rack had the mechanism that projected the bomb to beyond the propeller diameter, because the bomb dropped faster than the aircraft, and picked up speed from the drop point till impact. Impact speed would depend on how far it fell. But I'd guess a great deal more than 250 mph.

 

[pinsog]

I just loaded the aircraft with what I was told to load it with, no one asked my advice. That was decided way above my pay grade.

But IMO, and just IMO, a AP bomb used in the ship bombing at 250 mph isn't going to have nearly the penetration as it would in the verticle mode.
For instance the Dauntless was limited in it's dive by it dive brakes to what ? 250 mph, ??
But the centerline drop rack had the mechanism that projected the bomb to beyond the propeller diameter, because the bomb dropped faster than the aircraft, and picked up speed from the drop point till impact. Impact speed would depend on how far it fell. But I'd guess a great deal more than 250 mph.

I don't think it would need to go deep. Just passing all the way through the outer hull before bursting should be devastating, especially if it was right at the water line and not several feet above the waterline. A hole allowing water to enter along with the damage and destruction of many watertight internal compartments, not including the fire hazard should have been very effective.

 

[GregP]

One of the posts above got me to remembering about the movie "Final Countdown." There was a scene in there where an F-14 was chasing a modified AT-6 (aka "Zero" and they were low. The F-14 rolled quickly and just dropped out of the picture. I was pretty sure they might have lost an F-14 while filming and tried to look it up. A few years later I met one guy who had flown during that picture and he said that scene almost DID cost an F-14.

The guy apparently stalled and pulled out a bare 15 feet over the water, nose-high, blasting a roostertail of spray! So, no F-14 lost, but a close call. An F-14 has no business at low altitude trying to turn with an AT-6! Not in the bucket of maneuvers to use, for sure. Compare wing loading! A bit under 20 lbs per square foot for the AT-6 at mid-weight and a bit over 106 lbs per square foot for the F-14 at mid-weight. A turning fight is no contest!

A second movie issue was the training dogfight in Top Gun where the so-called "hard deck was at 10,000 feet, but the scene shows the F-14s and A-4s jinking just above the ground. There aren't a lot of 10,000 foot hills in California near San Diego. I also laughed when Tom Cruise was supposed to be doing a roll and the oxygen hose was moving around with gravity when the simulator they were filming in rolled over.

Still, both were pretty decent movies ... if you could achieve suspension of disbelief and just enjoy them for what they were.

I had to laugh when they came out with "U-571," and people predictably started hammering it for historical inaccuracy (because the British actually captured the Enigma machine). The director said it all when he said, "It isn't a documentary, it's a war movie!" Sometimes critics are just so dense! As a war movie, it was decent. Not all war movies are about real battles. If they were, we wouldn't have such classics as "They Were Expendable." But nobody trashed THAT ONE because it wasn't a "real battle." Of course, that was when WWII was still a "popular" war.

 

[Schweik]

I am on the other side of this issue. As far as I'm concerned, if they can invent something new and "Hollywood" that tells a better story than the historical event (or of say, something a bit more like a real dogfight) then good for them and I am all for it. But that is rare indeed, 9 times out of 10 when they make a film or a show that is 'based on History' in some way their improvements don't stack up to the real story. Of course you can't be 100% exactly true to history (or contemporary technological reality), but to me films like Top Gun or that silly "Final Countdown" or U-571 fall very short of the goal.

The issue is verisimilitude. It doesn't have to be real to be realistic. Buggs Bunny cartoons back in the day had their own warped logic and pretty well stuck to it, so it wasn't hard to buy in even though it's all completely silly and unrealistic, but they just amde their own kind of intuitive sense. For me with many genre films, I don't go into them looking for flaws, but I'm sort of shoved out of buying into it because they make it too hard to suspend disbelief.

Of course there are many other elements to making a good film than verisimilitude but to me most of the best war movies do have it. War movies featuring air combat are a bit more challenging I think because the general public just knows so little about the subject.

If you took just the combat part of the best of say any three episodes of that old show 'Dogfights', and compared that to the dogfighting in just about any war movie in the last 50 years, the latter fares poorly by comparison.

 

[Schweik]

As for the new Top Gun coming out, I'm not gonna hold my breath...

 

[wuzak]

One of the posts above got me to remembering about the movie "Final Countdown." There was a scene in there where an F-14 was chasing a modified AT-6 (aka "Zero" and they were low. The F-14 rolled quickly and just dropped out of the picture. I was pretty sure they might have lost an F-14 while filming and tried to look it up. A few years later I met one guy who had flown during that picture and he said that scene almost DID cost an F-14.

The guy apparently stalled and pulled out a bare 15 feet over the water, nose-high, blasting a roostertail of spray! So, no F-14 lost, but a close call. An F-14 has no business at low altitude trying to turn with an AT-6! Not in the bucket of maneuvers to use, for sure. Compare wing loading! A bit under 20 lbs per square foot for the AT-6 at mid-weight and a bit over 106 lbs per square foot for the F-14 at mid-weight. A turning fight is no contest!

On the DVD bonus features that manoeuvre was discussed. I can't recall the pilot feeling that he was going to crash, but he definitely went lower than he meant to.

The footage of that was shown to his wife, who screamed. The scream was mixed in with the jet noise in the final film.

Also, the refuelling scene was filmed from the tail gunner's position of a B-25. The F-14 got so close the camera man tried to touch it, with his feet IIRC, and got an almighty static shock!

 

[GreenKnight121]

My gist is that on the day of infamy, there was a radar report of large group of aircraft. That report was rejected. So in essence, it wasn't a surprise attack just an ignored one. So my query is had the report been taken seriously and history been different...what would have happened with the battle?

One problem I remember was that the radar station seemed to be under the misguided impression that the radar-returns were B-17.

The radar techs (Private George Elliot and Private Joe Lockard) up on the mountain were certain that the return was far too large for the expected B-17s.
The duty officer (1st Lt. Kermit A. Tyler) they reported to was:
1. recently arrived from the US (he had been on Hawaii about a week).
2. Standing his very first watch at the Fort Shafter radar information center (actually an observer-trainee, he had never spent a full day there) - with NO one senior to him present in the offices (even though he was supposed to be observing an experienced officer)!
3. Almost completely ignorant of what radar was, how it worked, or what it could do - his pre-watch walk-through/briefing Wednesday was the first time he had been involved with radar in any way.

 

[GreenKnight121]

Japan was supposed to declare war on USA before the attacks on Pearl so that would have given a few minutes.
Also the idea that the Western powers had broken IJN codes so the attack may have been known. All adds to the flavour.

Actually, all that the Japanese message said (even the part of the report whose translation delayed delivery) was that was Japan was breaking off negotiations.

There was NO mention of a declaration of war... NONE.

 

[GreenKnight121]

I believe the "big muthas", Kaga and Akagi, were built on battleship hulls, and probably had pretty heavy armor. IIRC, Hiryu and Soryu were on cruiser hulls, so probably armored as well. Shokaku and Zuikaku, were, I think, dedicated thin skinned carriers. I don't think all this detail was known at the time. The last two were purportedly equivalent to a US Essex class carrier, which we didn't even have deployed yet.
Cheers,
Wes

No!
In contrast to some earlier Japanese carriers, such as Akagi and Kaga, which were conversions of battlecruiser and battleship hulls respectively, Sōryū was designed from the keel up as an aircraft carrier and incorporated lessons learned from the light carrier Ryūjō.

Originally designed as the sister ship of Sōryū, Hiryū's design was enlarged and modified in light of the Tomozuru and Fourth Fleet Incidents in 1934–35 that revealed many IJN ships were top-heavy, unstable and structurally weak. Her forecastle was raised and her hull strengthened. Other changes involved increasing her beam, displacement, and armor protection.

Hiryu & Soryu were purpose-built carriers... just smaller than the other 4 (halfway between the USN's Yorktown class and USS Wasp in size).

 

[michael rauls]

It is interesting to contemplate what the Japanese reaction would have been had the radar warning been heeded, planes scrambled, and I would presume in this instance a substantial loss of Japanese aircraft, much less damage to Pearl, and depending on the winds of luck quite possibly the sinking of a Japanese carrier or two.
What could the reaction possibly have been. " Oh sorry, just kidding. Didn't really mean it"?
I suspect they would have carried on in the Philippines etc. but seems like that would have really taken the wind out of their sales.

 

[Schweik]

Actually, all that the Japanese message said (even the part of the report whose translation delayed delivery) was that was Japan was breaking off negotiations.

There was NO mention of a declaration of war... NONE.

When you are putting a strangling embargo on somebody, or ever tightening "sanctions" that never relent, sometimes there comes a breaking point and if that is a big surprise maybe it shouldn't be. It's a lesson that we seem to have trouble learning...

 

[GrauGeist]

Also, the Enterprise was not far away from Pearl that morning. She was operating with strict radio silence was under full war conditions...which is why VS-6 and VB-6 were fully armed when they arrived during the attack.
Had there been advance warning, the USN had a carrier at their disposal, as the Enterprise was not far from Oahu by 7:00 a.m. that morning.

 

[Reluctant Poster]

3 different bomb types, GP, semi AP, AP against 3 different hull types, battleship, cruiser and unarmored. Shokaku and Zuikaku wouldn't be a problem.

Do you have a best guess on what a 1,000 pound GP skip bomb hitting the Kaga and Akagi hull at say 250 mph would do? Penetrate? Break up? Bounce off? Would a Semi AP penetrate or deflect? Would AP penetrate or deflect?

I think they would penetrate Hiryu and Soryu hulls as well but I think I would be inclined to use semi AP or AP bombs.

Your thoughts on all of this?

Should we do a separate thread?

 

[Reluctant Poster]

Skip bombing was a tactic used against merchantmen vessels and minor warships. It was never used against major warships. In order to penetrate armor you need velocity added by a fall from great height.
A 1600 lb Mk 1 AP bomb needed a velocity of 400 feet per second (272 mph) to penetrate 2 inches of armor. I don't believe a B-25 could get near that speed at sea level. Add to that the effect of hitting the water which slows down the bomb considerably and the odd attitudes the bombs often developed upon skipping there is no chance of penetrating the armor of even the lightly protected Soyru (1.8' belt), with a 1600 Lb AP let alone anything smaller.
Watch how rapidly the bombs lose velocity and the odd angles some of them develop in the following video:
Skip Bombs

 

[pinsog]

Skip bombing was a tactic used against merchantmen vessels and minor warships. It was never used against major warships. In order to penetrate armor you need velocity added by a fall from great height.
A 1600 lb Mk 1 AP bomb needed a velocity of 400 feet per second (272 mph) to penetrate 2 inches of armor. I don't believe a B-25 could get near that speed at sea level. Add to that the effect of hitting the water which slows down the bomb considerably and the odd attitudes the bombs often developed upon skipping there is no chance of penetrating the armor of even the lightly protected Soyru (1.8' belt), with a 1600 Lb AP let alone anything smaller.
Watch how rapidly the bombs lose velocity and the odd angles some of them develop in the following video:
Skip Bombs

Very nice info. Thank you. I was leaning toward an A20 or early short wing B26 for delivery due to higher speed than B25, plus a shallow dive from say 5,000 feet down to sea level just before release to keep release speeds above 300 mph, BUT as you pointed out, the bomb may not strike squarely and would also lose speed as soon as it was released.

Do you think a 1000 pound bomb delivered as above would partially penetrate? Bounce off/deflect?

 

[XBe02Drvr]

Do you think a 1000 pound bomb delivered as above would partially penetrate? Bounce off/deflect?

Remember, you don't have to sink Kido Butai on the spot, just render as many of the major combatants as possible un-deployable, to throw a monkey wrench into Japan's war plan. The kind of heroic dockyard work that returned a bombed-out carrier to seaworthy condition between Coral Sea and Midway was not likely in Japan.
Cheers,
Wes

 

[pinsog]

Remember, you don't have to sink Kido Butai on the spot, just render as many of the major combatants as possible un-deployable, to throw a monkey wrench into Japan's war plan. The kind of heroic dockyard work that returned a bombed-out carrier to seaworthy condition between Coral Sea and Midway was not likely in Japan.
Cheers,
Wes

I agree. I have wondered about skip bombing larger ships such as carriers with 1000 pound bomb with a crushable nose, essentially they slam into the side of the ship, don't penetrate but instead they sink next to the ship and detonate at say 20-25 feet.

I had a crazy idea to use the British 'Highball' (smaller mosquito version)on Japanese ships when skip bombing, but of course it was developed mid-war, too late for early battles.

 

[Schweik]

I'm sorry but I think a 1,000 bomb skip-bombed into the hull of even a major warship will cause problems. Multiple hits of that type is likely to disable the ship. Even if it cant crack the armor belt it is likely to burst bulkheads, start fires, and generally break stuff. Keep in mind major warships including carriers were often damaged even by near misses. A 1,000 lb bomb slamming into side could definitely cause havoc.

They sank more than just merchant ships with skip-bombing, the real limitation was the effectiveness of flak / air defense. Part of the skip bombing strategy, at least as implemented by the 5th Air Force under Kenney, was to use strafers, multiple medium bombers or fighter bombers like Beaufighters, B-25s, A-20s, and I think even B-26's, the bomber types fitted with extra heavy machine guns and sometimes howitzers, all used to suppress flak on a warship. You didn't need all that to skip-bomb a merchantman.

The idea is you have say, 10 B-25s coming in at top speed and mast height, and they all open fire at roughly the same time at about maximum effective distance, something like 800-1,000 yards, and keep firing until all the nose guns run out of ammunition or jam (quite a few of them would jam). When they get close enough they release the bombs. If it's a fleet of enemy ships all the nearby ships should (ideally) also be strafed to suppress the light AAA. Later they also added rockets to the mix.

Without the heavy-duty strafing, and sometimes even with it, the medium bombers and larger fighter bombers were highly vulnerable to AAA from a major warship and took very heavy casualties. With the strafing, sometimes, they could get away with it.

Also B-25s may not have been able to top 280 mph at Sea level but I think A-20s (also used) could get pretty close to that. So could Beaufighters.

 

[tyrodtom]

Just recently on picture of the day on this forum there was a picture of a B-25 brought down during a skip bombing mission.

the B-25 followed too close behind another skip bombing B-25, and was brought down by that aircraft's bomb.

Skip bombing even by single aircraft required delay fuses, or even the dropping aircraft could be damaged, or worse.

The bigger the bomb, the longer the delay would need to be.

A mass attack by several aircraft skip bombing would require some very precise timing between the aircraft, which I don't think could be attained on the spur of the moment as it would be under combat conditions.

 

[Schweik]

It did require training and careful coordination. Apparently the first US use of skip bombing was with B-17s of all things, in Oct 1942 against "Japanese Warships" at Rabaul though it doesn't say what kind.

They seem to have sunk a few destroyers during the Battle of the Bismarck Sea, wherin RAAF Beaufighters faked the warships escorting the transports, into turning toward them by pretending to be Blenheims on a torpedo run, then strafed the hell out of them wiping out a lot of the AAA. Then immediately afterwards two squadrons of B-25s and two of A-20s (one Aussie one US) attacked into the sides with mast-top and skip-bombing attacks against both destroyers and transports. They got 8 transports and 4 (out of 8) destroyers, though no heavy warships were in the action.