Getting P-40 into the air quickly

[The Basket]

That's why the third strike was cancelled cos the Japanese had already achieved military objective and losses were rising so best get when the gettings good.

No way of knowing what's on the horizon or even if there was a trap out there.

My view is USA on 7th December 1941 was on peace mode. Sunday morning is lazy so plenty of troops away for the weekend, and a few troops out nursing hangovers and so compete surprise and trying to find every pilot and mech and tech to get airplanes airborne would be a haphazard task.

1 hour warning or 30 mins would have made a marginal difference.

 

[Greg Boeser]

Couple of observations. There were no B-26s in Hawaii on December 7, 1941. They were in Langley, Virginia; Jackson, Mississippi; and Boise, Idaho. Or sitting on the ramp at Martin Baltimore or Martin Omaha. Many lacked top turrets and propellers. No way to get them to Hawaii even with an hour's notice. B-26Bs of the 69th and 70th Bomb Squadrons took 12 to 14 hours on their ferry flights from Hamilton Field 22 May to 10 June 1942, but had all armament and armor removed to accommodate the four 250 gallon ferry tanks The early birds could reach 300 mph at sea level, balls to the wall, but opening the bomb doors resulted in lots of drag. Pilots reported losing 25 to 35 mph with the doors open. B-26s of the 22nd BG did perform low level attacks against Rabaul in April and May of 1942, notably sinking Komaki Maru at her moorings shortly after her arrival on April 16th. B-26s of the 70th Bomb Squadron were on hand for General Kenney's skip bombing trials in Nandi, Fiji. B-26s of the 28th Composite Group attacked two Japanese destroyers off Kiska on 16 October 1942 using masthead bombing techniques. the Oboro was sunk and Hatsuhara was damaged.

 

[pinsog]

Couple of observations. There were no B-26s in Hawaii on December 7, 1941. They were in Langley, Virginia; Jackson, Mississippi; and Boise, Idaho. Or sitting on the ramp at Martin Baltimore or Martin Omaha. Many lacked top turrets and propellers. No way to get them to Hawaii even with an hour's notice. B-26Bs of the 69th and 70th Bomb Squadrons took 12 to 14 hours on their ferry flights from Hamilton Field 22 May to 10 June 1942, but had all armament and armor removed to accommodate the four 250 gallon ferry tanks The early birds could reach 300 mph at sea level, balls to the wall, but opening the bomb doors resulted in lots of drag. Pilots reported losing 25 to 35 mph with the doors open. B-26s of the 22nd BG did perform low level attacks against Rabaul in April and May of 1942, notably sinking Komaki Maru at her moorings shortly after her arrival on April 16th. B-26s of the 70th Bomb Squadron were on hand for General Kenney's skip bombing trials in Nandi, Fiji. B-26s of the 28th Composite Group attacked two Japanese destroyers off Kiska on 16 October 1942 using masthead bombing techniques. the Oboro was sunk and Hatsuhara was damaged.

All our talk was purely hypothetical so it doesn't matter if they were there or not. Just another 'what if'.

I still don't know what a 1000 pound skip bomb would do to any of the 6 carriers at Pearl Harbor. Would it penetrate any of their hulls? Rupture? Deflect/bounce off? Stick in the hull like a dart? Hit, deflect, sink and burst underwater?

 

[Shortround6]

I still don't know what a 1000 pound skip bomb would do to any of the 6 carriers at Pearl Harbor. Would it penetrate any of their hulls? Rupture? Deflect/bounce off? Stick in the hull like a dart? Hit, deflect, sink and burst underwater?

Depends on the bomb, the ship and/or where on the ship it hits.

The belt armor commonly listed in specifications often only went 3-6 feet above the waterline (some ships at deep draft had the belt entirely submerged.
On many ships the upper sides were either much thinner or not armored at all (soft steel plate).
Armor diagram for Japanese heavy cruiser.

You are going to need an AP bomb (and it had better be moving pretty quick) to get through the side armor but the decks above it are certainly vulnerable to GP bombs.

GP bombs tended to either bounce off armor or break up (split open) or both. Depends on thickness of armor to bomb size and impact angle. Sticking like a dart would be a near miracle. Fuses on GP bombs tended towards a higher dud rate on armor.

Against the carriers skip bombing could put bombs through the unarmored hanger sides.

 

[pinsog]

Depends on the bomb, the ship and/or where on the ship it hits.

The belt armor commonly listed in specifications often only went 3-6 feet above the waterline (some ships at deep draft had the belt entirely submerged.
On many ships the upper sides were either much thinner or not armored at all (soft steel plate).
Armor diagram for Japanese heavy cruiser.
View attachment 548593

You are going to need an AP bomb (and it had better be moving pretty quick) to get through the side armor but the decks above it are certainly vulnerable to GP bombs.

GP bombs tended to either bounce off armor or break up (split open) or both. Depends on thickness of armor to bomb size and impact angle. Sticking like a dart would be a near miracle. Fuses on GP bombs tended towards a higher dud rate on armor.

Against the carriers skip bombing could put bombs through the unarmored hanger sides.

Very nice. So AP or maybe semi AP? How fast would you consider 'pretty fast'? I would have wanted to use A20's and short wing B26's because of higher speed, diving down from 3-5000 feet to level out for the final 1500 yards or so to keep speed at 300 mph or a little better. I'm guessing bomb impact around 250 mph.

 

[Schweik]

As Shortround and I have discussed before in another thread, true AP bombs were pretty rare, and carried a small charge, but semi-AP (meaning just a bomb inside a 10-20mm thick steel casing) were fairly widely available.

 

[wuzak]

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]

Some footage from the Bismarck Sea engagement, with a camerman standing behind the pilot seat in a beaufighter

 

[Schweik]

B-25 strafers in action, New Guinea

 

[GrauGeist]

As I mentioned before, there were only the A-20, B-18, B-17 and one B-24A at Pearl on that Sunday morning.

Plus, the US didn't start skip-bombing until Pappy Gunn's guys used the technique against the Japanese several months later.

 

[Schweik]

I was just talking about skip-bombing (including against heavier warships) in general, no opinion on the Pearl Harbor scenario.

 

[GrauGeist]

One of the key factors of detonating the bomb (regardless of yield) alongside a ship, is the hydraulic pressure caused by the bomb exploding will cause more damage than the bomb itself.

 

[The Basket]

The question of whether an individual weapon is going to sink a ship is very much a wide open question.
Look at torpedoes. Plenty of capital ships took torpedoes and survived and plenty didn't. So will a ship sink with a torpedo strike? The answer is yes and no.

HMS Royal Oak is a yes and her sister ship HMS Ramilies is a no.

Merchant ships or destroyers have no armour to speak of in comparison to say Yamato so any hit on a merchant is going to be bad news especially if its a tanker.

I believe that AP bombs are speed dependent so hitting the water first is going to be a disadvantage. A near miss underwater explosion is going to be bad news against any ship.

 

[Reluctant Poster]

Depends on the bomb, the ship and/or where on the ship it hits.

The belt armor commonly listed in specifications often only went 3-6 feet above the waterline (some ships at deep draft had the belt entirely submerged.
On many ships the upper sides were either much thinner or not armored at all (soft steel plate).
Armor diagram for Japanese heavy cruiser.
View attachment 548593

You are going to need an AP bomb (and it had better be moving pretty quick) to get through the side armor but the decks above it are certainly vulnerable to GP bombs.

GP bombs tended to either bounce off armor or break up (split open) or both. Depends on thickness of armor to bomb size and impact angle. Sticking like a dart would be a near miracle. Fuses on GP bombs tended towards a higher dud rate on armor.

Against the carriers skip bombing could put bombs through the unarmored hanger sides.

Watch the video again, note that some of the bombs simply skid and would obviously hit the belt. There is no control over the trajectory.
In any case the objective of bombing wasn't to sink the enemies aircraft carrier. In fact the USN was surprised at what happened at Midway. The objective was to destroy the enemies flight deck rendering the carrier useless. This was why both the USN and IJN concentrated on dive bombing.
Dive bombing also poses a much more difficult interception problem than a sea level attack. A skip bombing attack against a task force protected by fighters is going to result in heavy casualties

 

[Reluctant Poster]

Very nice. So AP or maybe semi AP? How fast would you consider 'pretty fast'? I would have wanted to use A20's and short wing B26's because of higher speed, diving down from 3-5000 feet to level out for the final 1500 yards or so to keep speed at 300 mph or a little better. I'm guessing bomb impact around 250 mph.

Hitting the water will reduce the retained energy of the bomb dramatically. Next time you're at the beach see how far you can throw a stone vs skipping it. It is more likely that the bomb is traveling at a much lower speed.

 

[GrauGeist]

From "Destroyer Report
Gunfire, Bomb and Kamikaze Damage Including Losses in Action 17 October, 1941 to 15 August, 1945"
(Destroyer Report - Gunfire, Bomb and Kamikaze Damage)

Page 11, section 2-21:

2-21 Bombs of the sizes generally used against naval targets in the past war seldom produced serious blast damage to structure beyond a radius of about 20 feet. The detonation in a destroyer of a 500-pound SAP bomb usually carried away several adjacent decks and bulkheads as in KILLEN (DD593). The near misses which were effective detonated directly under a ship or within a few feet of the side. Fragments of near misses detonating in the water quickly lost velocity and were not a source of serious damage. The shock of a near miss detonating underwater close aboard, however, frequently caused a flexural vibration which buckled structure remote from the blast itself. The bombs carried by Kamikaze planes, particularly where large general purpose types were used, caused much more severe structural damage than did the impact of the plane.

This is the reason why detonation either by torpedoes or bombs cause such extensive damage. It's not the holing of the hull that causes such catastrophic damage, it's the amplification of the detonations caused by hydraulic pressure.

Near misses can be, at times, more destructive than a direct hit.

 

[pinsog]

From "Destroyer Report
Gunfire, Bomb and Kamikaze Damage Including Losses in Action 17 October, 1941 to 15 August, 1945"
(Destroyer Report - Gunfire, Bomb and Kamikaze Damage)

Page 11, section 2-21:

This is the reason why detonation either by torpedoes or bombs cause such extensive damage. It's not the holing of the hull that causes such catastrophic damage, it's the amplification of the detonations caused by hydraulic pressure.

Near misses can be, at times, more destructive than a direct hit.

I agree with you. Did you see in one of my above posts I suggested they should have built a 1000 pound skip bomb designed to hit the hull then sink and detonate at 20-25 feet. We all know that pound for pound a torpedo was much much more damaging than a bomb (unless a magazine was hit or a full squadron of fueled and armed planes was in the hanger)

 

[pinsog]

Hitting the water will reduce the retained energy of the bomb dramatically. Next time you're at the beach see how far you can throw a stone vs skipping it. It is more likely that the bomb is traveling at a much lower speed.

I certainly won't argue. Best guess of impact speed starting at 300 mph when leaving the plane? Too many variables to count? As GrauGeist posted below and I posted above, hitting the side, sinking and detonating below water would probably be more damaging anyway

 

[pinsog]

I would in most cases agree with this, but A20's and B26's were both extremely fast down low. I believe the A20 was actually faster than a Zero and the B26 was maybe dead even, possibly a bit faster. Both bombers were very tough and the B26 had great defensive firepower. Japanese AA was pretty bad early in the war (I wouldn't want to skip bomb Yamato in 1944-45) so, I think a reasonably large scale attack at say Midway, say 4 planes per carrier, would have had a great chance for success.

 

[pinsog]

I would in most cases agree with this, but A20's and B26's were both extremely fast down low. I believe the A20 was actually faster than a Zero and the B26 was maybe dead even, possibly a bit faster. Both bombers were very tough and the B26 had great defensive firepower. Japanese AA was pretty bad early in the war (I wouldn't want to skip bomb Yamato in 1944-45) so, I think a reasonably large scale attack at say Midway, say 4 planes per carrier, would have had a great chance for success.