Film of Stuka 87G in action

[ozi_digger]

diesel taylor - I'm not denying the loss of a wing of aircraft in exchange for a carrier is not a bad result, but lets translate that into the ground battle where 1:1 losses cannot be accepted(I'm just playing devil's advocate here).

pamak - my interpretation is that the text suggests the target was 10'x10', not 10sqft, i.e. "10 feet square" not '10 square feet'. "Normal to line of flight" suggests it is along a linear gun run.

Driels has the area of effectiveness of a modern 500lb bomb, for fragmentation against a tank, as 450sqft. This is at 45deg impact angle and instantaneous fuzing with no bomb burial. Because the explosive in a modern bomb (H6 etc.) is more powerful than TNT, lets reduce that by say 20%, therefore 360sqft. A 45deg impact angle will create a rectangular burst pattern and a 0deg impact angle will probably not change the area too much, but the pattern will be circular. Effective radius = sqrt(360sqft/pi) = 11ft. For a 2000lb bomb, area =440sqft, lethal radius = 12ft. S'pose a 1000pder is somewhere in between... Add soft soil or a 10millisecond fuze and you can halve that lethal radius to 6ft!

[JasonC]

dt - 26 Stukas perhaps, but 60 bombers overall - there were He-111s too. And she made port despite the damage. Not only that, but she was repeatedly raided while in drydock - (Malta was raided 58 times in one month). And yet repaired enough to put to sea and make it to Alexandria under her own power. Was fully repaired and served later in the Pacific.

[Soddball]

UK carriers had all-metal flightdecks and most were converted from battleship or battlecruiser hulls, hence their impressive resilience. Think of the kamikaze attacks on them in 1945. US carrier hit - flight deck out of operation, hangar on fire. UK carrier hit - one ensign with a broom required to sweep deck clean.

Of course, that meant they held 1/3 the number of planes of US carriers and time has shown that the US system was superior.

[John D Salt]

Originally posted by Soddball:

[snips]

Think of the kamikaze attacks on them in 1945. US carrier hit - flight deck out of operation, hangar on fire. UK carrier hit - one ensign with a broom required to sweep deck clean.

Deeply cunning, too, of the RN to have an Ensign attached from the USN for kamikaze-sweeping purposes, instead of giving the job to a Midshipman.

Yo-ho-ho and a bottle of grog,

John.

[Soddball]

Rank grog.

[Allan Wotherspoon]

Originally posted by Soddball:

UK carriers had all-metal flightdecks and most were converted from battleship or battlecruiser hulls, hence their impressive resilience. Think of the kamikaze attacks on them in 1945. US carrier hit - flight deck out of operation, hangar on fire. UK carrier hit - one ensign with a broom required to sweep deck clean.

Actually, this is incorrect. The UK had one aircraft carrier converted from a battleship (Eagle) and three based on converted cruiser (not battlecruiser) hulls (Furious, Glorious & Courageous). None of these ships had armoured flight decks and 3 of the 4 (Eagle, Glorious & Courageous) were sunk, Eagle and Courageous by torpedos and Glorious by gunfire.

Armoured flight decks did not appear on British aircraft carriers until the Illustrious class, the first of which commissioned in May of 1940. The limited aircraft capacity was the result of a number of factors, not just the armoured deck. Probably most important was Royal Navy doctrine that aircraft would not be stored on the flight deck. That meant that the size of the air group was limited by how may A/C could be packed into the hangar. Second, British CV's had fully enclosed hangars, that is the hangar did not extend all the way out to the side of the ship as it did with US CV's. This limited the size of the hangar and thus the size of the airgroup.

Later in the war British doctrine changed to provide for the storage of aircraft on the flight deck and special outriggers were devloped to allow aircraft to be stored with the tails hanging over the edge of the deck to miminize the loss of space on the deck itself.

[Andreas]

Originally posted by Allan Wotherspoon:

Actually, this is incorrect. The UK had one aircraft carrier converted from a battleship (Eagle) and three based on converted cruiser (not battlecruiser) hulls (Furious, Glorious & Courageous). None of these ships had armoured flight decks and 3 of the 4 (Eagle, Glorious & Courageous) were sunk, Eagle and Courageous by torpedos and Glorious by gunfire.

Armoured flight decks did not appear on British aircraft carriers until the Illustrious class, the first of which commissioned in May of 1940. The limited aircraft capacity was the result of a number of factors, not just the armoured deck. Probably most important was Royal Navy doctrine that aircraft would not be stored on the flight deck. That meant that the size of the air group was limited by how may A/C could be packed into the hangar. Second, British CV's had fully enclosed hangars, that is the hangar did not extend all the way out to the side of the ship as it did with US CV's. This limited the size of the hangar and thus the size of the airgroup.

Actually, it appears some of this is incorrect too. Ark Royal had an armoured flight deck and a full-length hangar, at least according to the website below. Of course like all things on the Interweb it maybe full of rubbish.

Ark Royal

[Soddball]

Clearly I failed to include enough 'buts', 'excepts', and 'nearlys' in my general, light-hearted statement about the resilience of British aircraft carriers.

Several of the webpages I've seen cite Furious, Glorious & Courageous as 'battlecruisers', 'heavy cruiser' or 'light battlecruiser'.

[pamak1970]

pamak - my interpretation is that the text suggests the target was 10'x10', not 10sqft, i.e. "10 feet square" not '10 square feet'. "Normal to line of flight" suggests it is along a linear gun run.

Perfect!!

I did not understand this when i read your first post.

Yes, this "ten feet square" instead of "10sq feet" gives much more logical results and things are more consistent now,plus the size of the target for strafing fits well with images i recall from modern airforce training centers.

Now using the same method i described earlier to calculate effectiveness during strafing ,i still get more accurate results for rockets but the difference is not so big as before.

I do accept the relation between size of target and percentage of hits which you have hesitations to accept .

Here is what i find.

A ten feet square is 11.11 Sq yards surface.

The percentage of rockets hits according to strafing table is 0.045/8= 0.0056=0.56%.

Now the panther size is 50 sq yards .

That means that compared to the strafing target size (11.11 sq yards) ,it is about 4.5 times larger (four and a half times larger)

Using the relation of percentage of accuracy and size of target i see in the first case ,i expect that a target like a panther during strafing with rockets ,will receive 4.5 X 0.5 =2.25% hits.

Now we need to find the number of rockets nessesary to have a 50% chance to acheive one hit when the percentage of accuracy is 2.25 %.

The formula for answering the above question is the following.

P=1-(1-a)^X

The symbol ^x means that x is the exponent or power and the (1-a) is raised to that power x

The letters-symbols of the above equation represent the following data.

X = the number of rockets we try to calculate in order to have a 50% chance to acheive a hit

(actually the exact phrase is in order to have AT LEAST one hit).

P= the probability of acheiving at least one hit after firing x rockets.

In this case we have set this value to 50% so P=0.5

a= the percentage of hits we get for each specific target according to tables data.

In our case it is 2.25% ,so

a= 0.0225

So the final equation is

0.5=1-(1-0.0225)^X

So now we can calculate the value of x and after solving the equation we find that x= 30 rockets.

Therefore number of sorties is 4 (since each sortie has 8 rockets).

Two notes .

If you ask me how do i know that this is the correct type of equation, i can not give an answer without going to mathematical details which do not have any place in this forum.

However you might be convinced that this type of equation is the one the author uses in order to claculate his results in the first case.

Simply use the same equation and use the numbers the tables provide in the first place to test if results are the same.

If you use a calculator and the data of previous tables you will find that results are the same.

You can also test my results to see if i did any miscalculation.

So for example (1-0.0225)^30=(0.9775)^30 must be equal with 0.5

[John D Salt]

Originally posted by Allan Wotherspoon:

[snips] Actually, this is incorrect. The UK had one aircraft carrier converted from a battleship (Eagle) and three based on converted cruiser (not battlecruiser) hulls (Furious, Glorious & Courageous).

Jackie Fisher may have called them "large light cruisers" to get round the Cabinet ruling about not building any more capital ships, but anything mounting 15-in or 18-in guns and displacing over 20,000 tons is a battlecruiser. Conway's lists them as "light battlecruisers" under the "capital ships" section.

Their Lordships doubtless remembered the success of this subterfuge when, in the 1970s, they insisted with equal success that what were very obviously aircraft carriers were really "through-deck cruisers", because the treasury could afford a new class of cruisers, but not a new class of aircraft carriers.

All the best,

John.

[dieseltaylor]

JC

"dt - 26 Stukas perhaps, but 60 bombers overall - there were He-111s too. And she made port despite the damage. Not only that, but she was repeatedly raided while in drydock - (Malta was raided 58 times in one month). And yet repaired enough to put to sea and make it to Alexandria under her own power. Was fully repaired and served later in the Pacific."

I posted because of the accuracy of the Stukas - perhaps you chose to miss that point : ).And I can confirm to you without fogging up the point of the post that Malta received many more bombs by number and weight than London during the war.

[dieseltaylor]

Regarding aircraft carriers - I think some credit might be given to the designers that sea conditions in the Atlantic/North Sea would not be conducive to storing aircraft on deck. Even openings below deck could give problems to aircraft storage and weather effects.

Given the proximity to land that the carriers were to routinely to operate then armoured decks really became a necessity.

It would have been nice if they had been bigger and better but for the time very acceptable.

[JasonC]

John - You speculated they "may have called them "large light cruisers" to get round the Cabinet ruling" on capital ships. I doubt it, I think the reason for the terminology was the naval disarmament rules negotiated by Britain, the US, and Japan after WW I, later joined by Italy and France. All cruisers were limited to 10,000 tons. "Heavy" ones were limited to 10 inch guns, most actually using 8 inch. "Light" ones were defined as those with 6 inch guns or smaller and were far less restricted as to numbers one could have within the limits. The US and Britain both fielded quite large cruisers with 6 inch armament after these rules went into effect. (More exactly, the lights "counted" independently of the "heavies", each being limited to a fixed ratio, UK-US-Japan).

[SgtMuhammed]

I don't believe carriers were mentioned in those rules because no one thought they would amount to anything.

[JasonC]

Correct. The rules encouraged several conversions of capital ships to carriers, since the hulls would have been scrapped otherwise. And no restrictions were placed on new carrier construction.

[JasonC]

Specifically, the capital ships converted to aircraft carriers were -

Akagi, a 34,364-ton aircraft carrier, was built at Kure, Japan. Begun as a battle cruiser, she was completed as one of Japan's first two large aircraft carriers in March 1927. Massively reconstructed in 1935-38,

Kaga, a 33,693-ton aircraft carrier, was built at Kobe and Yokosuka, Japan. Launched as a battleship, she was completed as Japan's first large aircraft carrier in March 1926. Kaga was thoroughly reconstructed in 1934-35, receiving a full-length flight deck.

USS Saratoga, a 33,000-ton aircraft carrier, was converted from the battle cruiser (CC-3) while under construction at Camden, New Jersey. Commissioned in November 1927.

USS Lexington, a 33,000-ton aircraft carrier, was converted while under construction from the battle cruiser of the same name. Built at Quincy, Massachusetts, and commissioned in December 1927.

Two British capital ship conversions predated the naval agreements -

HMS Eagle, laid down as a battleship in 1914, finised as a carrier in 1918.

HMS Furious, reconstructed as CV from a battlecruiser in 1917, further work completed 1925.

Two others were converted after the naval agreements, from mothballed capital ships -

HMS Courageous was converted from a decommission battlecruiser in the mid 1920s

HMS Glorious, sister ship of the previous was converted at the same time as HMS Courageous from a sister ship, mothballed battlecruiser.

[Michael Emrys]

Originally posted by ozi_digger:

"Normal to line of flight" suggests it is along a linear gun run.

Perhaps. But the word 'normal' in scientific lingo usually means perpendicular. I.e., a ray of light striking a surface at 90° is said to be normal to it. So in this case, I take "Normal to line of flight" to mean the target, presumably a 10'X10' sheet of canvas or plywood, is mounted in an upright or nearly upright position with the aircraft flown straight at it. This is a believeable scenario because it is the way that ground strafing was taught to fighter pilots. So they would probably already have a mountain of statistics from training sessions to analyze and compare to the performance of trained pilots, since both the equipment and methodology already existed.

Michael

[Michael Emrys]

Originally posted by dieseltaylor:

Regarding aircraft carriers - I think some credit might be given to the designers that sea conditions in the Atlantic/North Sea would not be conducive to storing aircraft on deck. Even openings below deck could give problems to aircraft storage and weather effects.

Certainly conditions in those two sea areas were not ideal for carrier ops. Nevertheless, the USN operated carriers in the North Atlantic and both navies operated escort carriers there. All with deck parking and semi-open hangers.

I agree with you about the expectation of operating within range of landbased enemy air would place a premium on deck armor. BUSHIPS of the USN must have thought so as well, since US carriers also had deck armor equivalent to their British colleagues. But for various reasons, some good some not so good, placed under the hanger rather than above.

Michael

[Stalin's Organ]

The reason for putting the armoured deck under the hanger was to keep the centre of gravity lower.

[John D Salt]

Originally posted by JasonC:

John - You speculated they "may have called them "large light cruisers" to get round the Cabinet ruling" on capital ships.

Not speculating, reporting what it says in "Conway's All the World's Fighting Ships".

Originally posted by JasonC:

I doubt it, I think the reason for the terminology was the naval disarmament rules negotiated by Britain, the US, and Japan after WW I,

Not very likely, given that the acquisition of the "large light cruisers" was undertaken while WW1 was still on, and Jackie Fisher was dead by the time of the Washington Treaty.

All the best,

John.

[JasonC]

Ah, they were battlecruisers even, I see. I had reacted to the term rather than looking carefully at the context it came up. Happy to be corrected.

[Sergei]

This thread has exceeded 300 posts. I would suggest starting a new one, unless you feel there's no reason to drag on.

[SgtMuhammed]

Originally posted by Stalin's Organ:

The reason for putting the armoured deck under the hanger was to keep the centre of gravity lower.

That and American carriers expected to operate in more open waters and under a strong cap and so maximized air group size. The Brits expected to be in close waters with less reation time.

[John Kettler]

Troops,

A few thoughts on various matters in this thread.

British carriers with armored flight decks

From what I've read, German operational experience from attacking them found that 1000 kg armor piercing bombs were the smallest munition actually effective. 500 kg and smaller wouldn't even penetrate.

Rudel type AT Stukas

Years ago, I got to hear ordnance expert and former tanker Jim Steuard (of AFV-G2 magazine fame to some of you) speak on German AT aircraft. He had the actual German ordnance manuals. The special 37mm ammo (6 rounds per gun; should've had 7 but feed problems prevented this) came in boxes bearing

the legend "Nur fur gegen panzer" (Only for use against tanks) and was APCR/HVAP, I believe. The BK-37 cannon was a long barreled high velocity weapon, essentially a reworked flak weapon, NOT a

short barreled relatively low velocity job like what the Hurricane AT versions carried. Figure on

a 37mm L/60 (longer than the Pak-36) firing tungsten ammo. The Ju-87G2s, though stripped of their oxygen systems and almost everything else thought surplus in an effort to shave weight, were so ungainly that hard jinking was out. Only weaving laterally was doable. Also, the bird was so exhausting to fly that fatigue related crashes on landing far exceeded combat shootdowns. As for effectiveness, I seem to recall that the famously hardass Field Marshall Schoerner (refused Iron Cross request from regimental commander for personally leading recapture of his (reg. cmdr.) own CP on grounds of "that's what regimental commanders do") considered Rudel's squadron to be "worth a regiment of ground troops." I seem to recall some German radio intercepts heard lots and lots of angry Russian troops screaming at the Red Air Force for not protecting them from fierce attacks. This should, if it really happened, show up in the logs of the German signal intercept units in the areas where the tankbuster Stukas fought.

OR data on black powder muskets and smoothbore

cannon

Such data exist and are covered in wonderful detail in FIREPOWER, by Col. H.C.B. Rogers? (may have wrong author, but title's right). Known ammo expenditures and casualty rates in several historical battles are compared to not one, but several period firing trials against canvas walls of the same width and height as typical infantry formations of the pre rifled musket era. I believe that the tests are from the Napoleonic Wars and the Sepoy Rebellion. Particularly noteworthy is what an actual infantry company looks like at various ranges to a cannon gunner. Let's just say that angular subtense becomes significant at more than a few hundred yards.

Regards,

John Kettler

[Sergei]

I was not heard correctly. I shall repeat:

This thread has exceeded 300 posts. Start a new one, or you will be tazed.