British postwar tests on armor

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wadinga
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Re: British postwar tests on armor

Post by wadinga » Mon May 06, 2019 5:30 pm

Hello Alecsandros,
and the Lancasters were targetting the battleship, not the anchorage point.
Very true, but unlike armour piercing bombs where a miss is as good as a mile, earthquakes all around are a debilitating experience. Although the ground was soft mud and this may have absorbed energy. Apparently a loading of 6 by 2000lb AP bombs was considered but earthquake effect was thought worthwhile.

The 2006 very reliable version of Antonio Bonomi posted a map showing 4 more Tallbuoy impacts inside the net barrage but there are many huge misses, even 617 squadron (and friends) weren't perfect. The smoke screen was late but seems to have affected some bombing.

He also said of the earlier KaaFjord LongStraumsneset attack (copyright Antonio Bonomi 2006)
The bomb passed all the way thru the decks like on butter, and exploded on the bottom of KaaFjord, lifting up the whole ship forward.

The bow was totally smashed below water level on the starboard side as photos well shows, juts like a twisted can.
Tirpitz was not able than to sail at more than 8-10 knots, due to water pressure on forward compartments.
No armour on the bow.

All the best

wadinga
"There seems to be something wrong with our bloody ships today!"

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Re: British postwar tests on armor

Post by alecsandros » Mon May 06, 2019 5:45 pm

Off topic, but my opinion is the Nazis lost their most prized battleships over their own serious mistakes. Bismarck was sent on a suicidal mission , against Luetjens's opinion, ultimately had no air, sea or logistical support. Tirpitz was kept as a fleet in being for years on end, ultimately receiving numerous bombardments (staring April 1944 and ending Nov 1944), none of which was apparently intercepted by the dedicated fighter squadron in defence of the behemoth.

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Re: British postwar tests on armor

Post by dunmunro » Mon May 06, 2019 7:37 pm

alecsandros wrote:
Mon May 06, 2019 5:19 pm
Alberto Virtuani wrote:
Mon May 06, 2019 12:53 pm

I hope someone can make clarity over this point regarding the German horizontal protection scheme efficiency against bombs.
I re-read some articles on Scharnhorst and Gneisenau's bombings while at Brest,
and counted 9 bombs hitting them (of 500 and 1000lbs varieties). Damage was considerable, yet all 500lbs bombs exploded on (or above) the MAD, while all the 1000lbs bombs (all 3 hit Scharnhorst in the same night) where all duds (several of them perforating all the way to the sea floor).

Altitude of bombing attacks is given as 3000-3700meters (10.000 -12.000 ft, level bombing).

bomb damage Scharnhorst at Brest:
https://www.scharnhorst-class.dk/scharn ... brest.html

sketchy details of bomb damage Gneisenau at Brest:
https://www.kbismarck.com/gneisenau.html

more details are given in Garzke and Dulin's "Axis Battleships"
The two 500lb HE bombs both penetrated the 2in weather deck and both appear to have penetrated the MAD as it states that one did hole the MAD in the area of maximum thickness while the other caused considerable damage to the deck beneath the MAD.

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Re: British postwar tests on armor

Post by alecsandros » Mon May 06, 2019 7:39 pm

dunmunro wrote:
Mon May 06, 2019 7:37 pm
The two 500lb HE bombs both penetrated the 2in weather deck and both appear to have penetrated the MAD as it states that one did hole the MAD in the area of maximum thickness while the other caused considerable damage to the deck beneath the MAD.
I read the documents differently then you do.
First I see the 500lbs bombs are named armor piercing, and not HE... Second I see no penetration of 500lbs bombs of the MAD...

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Re: British postwar tests on armor

Post by dunmunro » Mon May 06, 2019 7:59 pm

alecsandros wrote:
Mon May 06, 2019 7:39 pm
dunmunro wrote:
Mon May 06, 2019 7:37 pm
The two 500lb HE bombs both penetrated the 2in weather deck and both appear to have penetrated the MAD as it states that one did hole the MAD in the area of maximum thickness while the other caused considerable damage to the deck beneath the MAD.
I read the documents differently then you do.
First I see the 500lbs bombs are named armor piercing, and not HE... Second I see no penetration of 500lbs bombs of the MAD...
???

From the source:
Two bombs were of the 227 kg (500 lb) high-explosive type, the others were 454 kg (1000 lb) semi-armor-piercing type bombs...
...One of the 227 kg (500 lb) bombs hit abeam of the conning tower, just forward of the starboard 150 mm twin turret. It passed through the upper and middle decks before exploding on the armor deck, which remained intact. The first platform deck was torn, with significant bulging in the explosion area. The side-armor plating was deflected outboard about 200 mm, and a small hole was torn in it. Rivets that joined the armored torpedo bulkhead to the main deck were loosened enough to cause leakage.
The First Platform deck was below the MAD.
The other 227 kg (500 lb) bomb fell forward of the after turret, to starboard, 3 meters from the deck edge; it penetrated two decks and exploded on the main armor deck, where it made a small hole.
Most likely the 1000lb bombs were RAF GP bombs, which had some AP capability due to a strengthened casing but did not have AP type fuzes.

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Re: British postwar tests on armor

Post by Dave Saxton » Mon May 06, 2019 8:03 pm

Tirpitz was in Kaa Fjord during the Sept 15th attack when the bow was wrecked. It then was transferred to Tromso. Kaa Fjord is deep. About 40 meters deep. The Tromso anchorage was not deep. It was thought there would only be about 1.5 meters between the keel and the sea bed at the selected anchorage location, but a hole in the sea bed was found there. They planned on filling the hole but the work was not done before the end came.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Alberto Virtuani
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Re: British postwar tests on armor

Post by Alberto Virtuani » Mon May 06, 2019 9:28 pm

Hello everybody,

Garzke-Dulin's description (see posts above) of the La Pallice bombing on Scharnhorst is very different from Whitley's one.
According to Whitley, 15 2000lbs AP bombs and 53 1000 lbs SAP bombs were dropped, of which three 1000 lbs penetrated all decks without exploding (duds) and 2 500 lbs did not penetrate the main armor deck.


Bye, Alberto
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Re: British postwar tests on armor

Post by alecsandros » Tue May 07, 2019 5:33 am

dunmunro wrote:
Mon May 06, 2019 7:59 pm
Most likely the 1000lb bombs were RAF GP bombs, which had some AP capability due to a strengthened casing but did not have AP type fuzes.
You are right about the quotation above. My mistake.

However, it would be a first when level bombers attack capital ships with high explosive bombs.
The loadout was , typically of SAP or AP bombs.

Probably, as Alberto wrote, there is more evidence in Whitley...

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Re: British postwar tests on armor

Post by Thorsten Wahl » Tue Aug 06, 2019 1:25 pm

ballistic test of a PC 500 Bomb vs 120 mm Wotan hart impact Speed 186 m/s
simulated divebomb drop from 1300 m height with aircraft speed 500 km/h
PC 500d.jpg
PC 500d.jpg (38.83 KiB) Viewed 168 times
the casings of german PC and PD (armor piercingt bombs) bomb were sufficent to survive impacts at least from throwing heights of 4000 m completely whole.
These bombs had two fuzes
-delayed fuze
-"safety" fuze ignites at 2000 - 6000 g deceleration (i.e. when the armor stops the bomb)
explosive charge 14 kg

at 325 m/s impact speed the PC 500 pentrates 190 mm Wotan hart.
Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!

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