Germans in WWII having Iowa class battleships

[paul.mercer]

Well, I am quite confident about Iowa's AAA gunnery... 80 Bofors and 49 Oerlikons with 20 radar guided heavy AA guns was a lot... And if 2 IOwa's woudl be operating together, they would put up an umbrella of fire from nearly 300 AA guns...

Not enough to stop a massed air attack (with, say, 40-50 bombers), but enough to deal with an incoming squadron of 8-12 (slow) attackers.

I've been reading about hte Channel Dash lately, and the number of Swordfish and Beaufort destroyed by AA artillery was about 50% of the RAF losses that day (14 out of 29)

And that allthough the German formation did not have a massive AA defence that 2 Iowas would have...

Gentlemen,
I was watching a program on Leyte Gulf today and it showed pictures of Yamato and Musashi as well as other Japanese Battleships and it appeared that they were very well armed for AA defence but in the end they both succumed to air attack with Musashi at Leyte Gulf an Yamato later on, so I do wonder if any capital ship was doomed if attacked by torpedo carrying aircraft, I say torpedoes as I'm not sure if even armour piecing bombs such as those carried by carrier planes would sink a battleship on their own.

[alecsandros]

Indeed.
However, 90% of the AA guns of Yamato and Musashi were the 25mm Type91. Effective range up to 1.5km, slow train, poor rate of fire (below 150 rounds/minute/gun). IIRC, the Musashi had about 120 AA guns mounted. So the total output would have been 18.000 shells/minute, but only at a rather low range

That also meant the other ships in the squadron COULD NOT effectively cover Musashi, as their umbrela of fire could reach only 1.5km around the ship (which was many times standard distance between ships..)

The Iowas could put up a devastating barrage of 40mm shells out to 4km effective ( ~ 16000 shells/minute)

Added to this, a second barrage of 20mm shells out to 1km effective (~ 10000shells/minute)

[RF]

That is contingent on the level of the alleged collaboration and trading with the enemy.

The collaboration or alleged collaboration is the tool being used for the motivation in bringing litigation. The objective is to make money and of course the laywers will do that even if the litigants fail. I take a far more cynical view of these claims.

There have also been claims against the Swiss for allegedly aiding the Nazi genocide and allegedly hiding assets placed there by the German government which was stolen property. Switzerland was neutral in WW2 and the reaction of the Swiss government and banks is entirely proper.

[alecsandros]

Suum Cuique.

[Dave Saxton]

I say torpedoes as I'm not sure if even armour piecing bombs such as those carried by carrier planes would sink a battleship on their own.

One of the pivitol hits on Musashi was a bomb dropped by a dive bomber, which took out a turbine room. This cost Musashi quite a bit of speed. If such bomb can defeat the deck protection of a Yamato class battleship what does that say for the others, including the Iowa class?

Arizona was sunk by a bomb which penetrated to the forward magazines.

The old USN battleships were all extremely vulnerable to AP bombs carried by carrier aircraft. For example, West Virginia's main armoured deck was only 38mm of STS laid over 38mm of mild steel in direct contact. It was weaker than the Hood! Just adding some more plates on top of this helped a little but only a little. Plates laid on top of plates in direct contact yield less effective thickness than if the plates are spaced. Iowa's main armoured deck had 120mm STS plates laid over 32mm STS plates. This yields a ~125mm effective thickness. Good thing it had the yaw/bomb deck above it.

Prince of Wales was hit by a 500kg bomb dropped from 9,000 feet. It hit the 5" main armoured deck and exploded. However the flash effects reached all the way to X boiler room, presumably through open ventilation shafts, knocking the only remaining boiler room out of action.

[Dave Saxton]

The Iowas could put up a devastating barrage of 40mm shells out to 4km effective ( ~ 16000 shells/minute)

Added to this, a second barrage of 20mm shells out to 1km effective (~ 10000shells/minute)

I know this a hypothetical placing the late war Iowa into an early war context, but the only thing that is making the Iowas special in this case is the 40mm battery. Light Flak is an add on that can be added and subtracted to any platform (as the Germans added Bofers to many as well). It is mainly the reach of the 40mm Bofers that is significant here.

A 20mm is ample to destroy most aircraft but the Oerlikon didn't have the reach, or the accuracy. The German 20mm weapons are not the same as the Oerlikon 20mm, because the German 20mm was an order of magnitude more accurate and had three times the effective reach.

But destroying Swordfish is not so easy with any light Flak because a Swordfish can be riddled and keep flying. A few hits of 20mm or 40mm can more easily bring down a more robust metal aircraft. Dealing with the Swordfish presents a problem kind of like the Kamikaze, in that you can hit it with light Flak, but that may not stop it, or keep it out of torpedo range.

I read some interesting information on the proximity fuse shells recently. A USN 1944 study showed that among 5"/38 VT fused shells fired: 13% were duds, 54% that exploded exploded prematurely, and only 33% exploded as designed. Among those, they had to be placed within 20 meters of the target to be effective. This was something that MK4 radar with the MK38 director could not do consistently.

[alecsandros]

One of the pivitol hits on Musashi was a bomb dropped by a dive bomber, which took out a turbine room.

Indeed,
But Musashi did not have the AA capability of an Iowa.

Moreover, the Iowas had the 38mm "yaw deck", which probably could trigger the fuze of an AP bomb, which would probably explode in contact with the heavy armor deck.

[alecsandros]

I read some interesting information on the proximity fuse shells recently. A USN 1944 study showed that among 5"/38 VT fused shells fired: 13% were duds, 54% that exploded exploded prematurely, and only 33% exploded as designed. Among those, they had to be placed within 20 meters of the target to be effective. This was something that MK4 radar with the MK38 director could not do consistently.

Well, I am not saying they were the perfect war machines,
Just that they were very very good in AA combat.

The 5" guns had a rate of fire of 20 shells/minute, were radar guided, and could engage an incoming Swordfish squadron out to 8 or 9km. Given the slow rate of approach of the Swordfishes (160km/h or 2.6km/minute), they would require at least 5 minutes to get into effective launching range. IN 5 minutes, a single Iowa would put up 2000 x 127mm shells.
And at 4km, the 16.000 x 40mm shells / minute would create another wall. At least 20.000 shells of 40mm would be fired before the Swordfishes would come into launching range.

The German 20mm had longer range thant the Oerlikon 20mm, but it was far less effective in range and hitting power than the 40mm Bofors.

For example, imagine Tirpitz in March 1942 equipped with 60 x 40mm Bofors instead of the 58 x 20mm Mausers. Imagine the devastation it would have done amongst the Albacores...

[Dave Saxton]

Moreover, the Iowas had the 38mm "yaw deck", which probably could trigger the fuze of an AP bomb, which would probably explode in contact with the heavy armor deck.

Unforunately, the distance between upper and main deck is too small.

[Dave Saxton]

For example, imagine Tirpitz in March 1942 equipped with 60 x 40mm Bofors instead of the 58 x 20mm Mausers. Imagine the devastation it would have done amongst the Albacores...

It wouldn't have made any difference because the Albacores were hidden by cloud and could not be taken under fire by light Flak until they popped out only 1000 meters off. In that case RMB 20mm vierlings were just about the perfect weapon to have.... next to some FW-190s armed with 20mm of course.

It would have been not so good had a USN BB been there in place of Tirpitz sporting early 1942 USN light Flak.

[alecsandros]

... the Bofors 40mm shell was far more devastating than the 20mm round.
40mm shell: 0,9kg with 92 grams of hexotonal
20mm shell: 0,15 kg with 20 grams of high explosive.

The Albacores would have been swept out of the sky...

[Wordy]

Yeah but I'd imagine the training and evelating speed on a 20mm would've been greater than a larger 40mm mount?

[alecsandros]

Probably; but the Albacores were slow, weren't they ?

[Thorsten Wahl]

The german 20 mm had an effective range of about 1200m dropping distance of torpedoes mostly above this distance to steer clear above the effective range of this weapon.

[tommy303]

As Thorsten hints, the problem with the 2cm was the effective range was short of the range at which an attacking aircraft would be dropping its ordnance--in other words, by the time the 20s could engage effectively, the enemy bomb or torpedo was already on its way