Ark Royal vs Bismark

[delcyros]

500 lbs GP bombs are unable to defeat main secondary gun positions, or even the armoured weatherdeck. they may hit the superstructures and wreac havoc except where armoured (CT's).
while traditional, her TDS was effective. much more than many newer, more sophisticated TDS were in action (WASHINGTON's, LITTORIO's, POW's YAMATO 's failed when tested in service). Had BM blundered into AR then the result would have been one carrier sunk. any direct engagement with capitalships killed the carrier (GLORIOUS GAMBIER BAY respectively).

 

[Nikademus]

500 lbs GP bombs are unable to defeat main secondary gun positions, or even the armoured weatherdeck. they may hit the superstructures and wreac havoc except where armoured (CT's).
while traditional, her TDS was effective. much more than many newer, more sophisticated TDS were in action (WASHINGTON's, LITTORIO's, POW's YAMATO 's failed when tested in service). Had BM blundered into AR then the result would have been one carrier sunk. any direct engagement with capitalships killed the carrier (GLORIOUS GAMBIER BAY respectively).

I don't think one can say that Bismarck's TDS was "more effective" than the other TDS systems mentioned given that it was never seriously tested. The only torpedoes that struck Bismarck prior to her crippling hit in the stern ran too shallow and struck the armor belt near amidships greatly decreasing the blast effect. The stern hit, while a vulnerable place for any warship was particularily so for the class.

Yamato, as mentioned faced far more powerful ordinance (TORPEX has twice the explosive power of the traditional TNT based torpedoes + the warheads were larger) and the torpedoes were set at the proper depth hitting under the armor belt. Under such conditions, Yamato still held up very well. Musashi in particular absorbed more torpedoes than any other battleship and remained afloat for hours thx to superb damage control. A Bismarck class would have surcombed from far less IMO.

Littorio's system actually worked as designed, it might be noted too that her steering gear and props had superior redunancy and spacing built into the design vs. Bismarck's. A disabling hit in VV's stern was repaired at sea (granted, sea conditions were lesser) and the ship resumed under her own power to base.

Prince of Wales TDS was well designed if basic but the spacing proved to be inadequate to contain the blast from a theoretical 1000llb charge. However, like Bismarck, what doomed her was a torpedo hit beyond her TDS system that damaged a prop and caused a runaway situation which loosened stuffing glands all the way back to one of her primary engine rooms causing extensive flooding. Poor damage control exaserbated the flooding as many WT hatches were left open.

Washington was not struck by torpedoes but her sister North Carolina was. This torpedo hit occured abreast turret #1 where the TDS was constrained by the narrowing hull shape and could not obtain full effectiveness. The Japanese torpedo was also far more powerful than the ones that struck Bismarck. Still, NC showed great resiliancey in being able to steam at speed out of the battlefield, her only major damages being her search radar. It was recommended that her #1 turret not fire under any circumstances save a dire emergency lest it weaken the bulkheads further.

 

[Kurfürst]

TORPEX has twice the explosive power of the traditional TNT based torpedoes

How come...?

Torpex was iirc a mixture of 50% TNT and 50% Hexogene or RDX if you like. And though I don't have my terrorist bookie handy, which has the specs, I don't recall RDX in its pure form would be twice as powerful (not to mention there are different criteria to measure the "useful work" of HE) as TNT; a fifty-fifty has even less chance for that. It wasn't a wonder mixture, plus many torps in the war had some kind of mixture with some more-potent-than-TNT rather than pure TNT filling.

 

[tail end charlie]

from wikepedia


"Torpex is a secondary explosive 50% more powerful than TNT by mass[1]. Torpex is composed of 42% RDX, 40% TNT and 18% powdered aluminium. It was used in the Second World War from late 1942. The name is short for 'Torpedo Explosive', having been originally developed for use in torpedoes. Torpex proved to be particularly useful in underwater munitions because the aluminium component had the effect of making the explosive pulse last longer, which enhanced the destructive power. Torpex was used only in critical applications, e.g. torpedoes and the Upkeep, Tallboy and Grand Slam bombs. It was also used in the Operation Aphrodite drones. Torpex has long been superseded by H6 and PBX compositions. It is therefore regarded as obsolete, so Torpex is unlikely to be encountered except in the form of legacy munitions or unexploded ordnance."

I know nothing about explosives but I would expect an explosive specifically designed for torpedos would be more effective than others at the time.

 

[Nikademus]

How come...?

Torpex was iirc a mixture of 50% TNT and 50% Hexogene or RDX if you like. And though I don't have my terrorist bookie handy, which has the specs, I don't recall RDX in its pure form would be twice as powerful (not to mention there are different criteria to measure the "useful work" of HE) as TNT; a fifty-fifty has even less chance for that. It wasn't a wonder mixture, plus many torps in the war had some kind of mixture with some more-potent-than-TNT rather than pure TNT filling.

My mistake, I should have said 50% more powerful. A couple sources in my ownership label Torpex twice as powerful but Clay Blair's "Hitler's Uboat-War" and the online navweapons website clarify it specifically as "50% more powerful" than TNT.

 

[Bernhart]

so none of the aircraft available had bombs?

 

[RCAFson]

so none of the aircraft available had bombs?

The Swordfish could carry up to a 1500lb bomb load including at least two 500lb bombs, and as I mentioned was fully stressed for dive bombing.

 

[pinsog]

Was ithe Swordfish any good at divebombing? I had never heard of it being used in that manner.

 

[RCAFson]

Was ithe Swordfish any good at divebombing? I had never heard of it being used in that manner.

It was used as a bomber on many occasions, but I don't have specifics. At Taranto 10 of the 21 Swordfish were armed with bombs:
Fairey Swordfish aircraft profile. Aircraft Database of the Fleet Air Arm Archive 1939-1945
However, against most naval targets the weapon of choice would have been the very efficient and reliable 18in torpedo.

 

[timshatz]

Anybody know if the Ark Royal had surface search radar in 1941? If yes, anybody have a clue as to how effective it was?

I'm thinking if the Ark Royal gets the Bismark on it's radar as 25K yards, it can turn around and run for it before the Bismark can get an effective shot in. But it would be close. Wiki says they both have the same top speed.

 

[tail end charlie]

It was used as a bomber on many occasions, but I don't have specifics. At Taranto 10 of the 21 Swordfish were armed with bombs:
Fairey Swordfish aircraft profile. Aircraft Database of the Fleet Air Arm Archive 1939-1945
However, against most naval targets the weapon of choice would have been the very efficient and reliable 18in torpedo.

One reason the torpedo attacks on the Bismark were successful is that the Swordfish could fly beneath the level of the the guns. I think trying to dive bomb the Bismark in a swordfish would be suicide. The Yamamoto AA defences were overwhelmed when it was attacked, you cant do that with about 30 biplanes.

 

[Nikademus]

Was ithe Swordfish any good at divebombing? I had never heard of it being used in that manner.

On August 13, 1940 a Swordfish on ASW patrol caught the U-64 at anchor in Herjangs Fjord, Norway. The plane "dived" at the uboat and sank it with 2 100lb ASW bombs. [Blair - Hitler's Uboat war vol 1]

This is described by some websites as the first FAA "dive bombing" attack of the war but i don't feel this should be taken too litterally. Blair, among other authors in ASW actions often describe the decent phase of an aircraft that is attacking a sub on the surface as "diving" down onto the target in order to build up speed. This includes level bombers, even the big B-24's used on ASW duty. Most likely the Swordfish executed what would technically be called a "glide bombing" attack which is much shallower than the angles used by dedicated DB's like the Stuka, D3A or SBD. (65 - 80 degrees etc.....a GB attack would be more along the lines of 30-45 degrees)

A glide bombing attack is easier to execute and puts less strain on an airframe. It's not as accurate nor will the bomb get as much momentum for purposes of armor piercing.

 

[parsifal]

One reason the torpedo attacks on the Bismark were successful is that the Swordfish could fly beneath the level of the the guns. I think trying to dive bomb the Bismark in a swordfish would be suicide. The Yamamoto AA defences were overwhelmed when it was attacked, you cant do that with about 30 biplanes.

Some of the attacking Swordfish operated as divebombers at taranto. They did not suffer very heavy losses. in fact it was the torpedo carriers that took all the losses in that battle IIRC.


Swordfish were remarkably resistant to AA fire, despite their obviously obsolete technology.

 

[parsifal]

On August 13, 1940 a Swordfish on ASW patrol caught the U-64 at anchor in Herjangs Fjord, Norway. The plane "dived" at the uboat and sank it with 2 100lb ASW bombs. [Blair - Hitler's Uboat war vol 1]

This is described by some websites as the first FAA "dive bombing" attack of the war but i don't feel this should be taken too litterally. Blair, among other authors in ASW actions often describe the decent phase of an aircraft that is attacking a sub on the surface as "diving" down onto the target in order to build up speed. This includes level bombers, even the big B-24's used on ASW duty. Most likely the Swordfish executed what would technically be called a "glide bombing" attack which is much shallower than the angles used by dedicated DB's like the Stuka, D3A or SBD. (65 - 80 degrees etc.....a GB attack would be more along the lines of 30-45 degrees)

A glide bombing attack is easier to execute and puts less strain on an airframe. It's not as accurate nor will the bomb get as much momentum for purposes of armor piercing.

Divebombing, in part, is accurate because of the slow speed of the attacking aircraft. This gives more time to aim, and control the attack run better.

The steepness of the dive reduces the margins for error, but requires aircraft that are exceptionally strong to withstand the stresses of pulling out of the dive.

The swordfish as an airframe was strong....veryu strong. Thi9s is what enabled them to operate in conditions that grounded most other aircraft, and made them the mount of choice in the higher altitudes, such as where the arctic convoys were operated.

So I would argue that that the swordfish was capable of what might be termed 'near" dive bombing attacks. They were no stuka, but they were something better than say a B-25 glide bombing.

I have seen photos of swordfish in dive angles of 50-70 degrees, which is at least comparable fighter Bomber dives.....,

 

[Nikademus]

Divebombing, in part, is accurate because of the slow speed of the attacking aircraft. This gives more time to aim, and control the attack run better.

The steepness of the dive reduces the margins for error, but requires aircraft that are exceptionally strong to withstand the stresses of pulling out of the dive.

Yes, but another important component in a DB attack is momentum. Go too slow and the bomb will not have enough momentum to effect adequate penetration for the bomb type being used. Go too slow, and/or too shallow and you greatly increase vulnerability to AA defenses. Another important component is training. Training is critical when conducting a steep DB attack, more so against a moving target. If you don't have it, and practice it, it'll be a difficult maneuver to pull off, as was the case with the VMSB squadron at Midway flying SB2U's. Due to inexperience they conducted a GB attack vs a traditional full on DB attack.

The swordfish as an airframe was strong....veryu strong. Thi9s is what enabled them to operate in conditions that grounded most other aircraft, and made them the mount of choice in the higher altitudes, such as where the arctic convoys were operated.

So I would argue that that the swordfish was capable of what might be termed 'near" dive bombing attacks. They were no stuka, but they were something better than say a B-25 glide bombing.

I have seen photos of swordfish in dive angles of 50-70 degrees, which is at least comparable fighter Bomber dives.....,

Your probably correct, but I don't personally feel it's practical hence the dearth of definitive examples vs targets at sea. The SW's slow max speed and biplane nature would make it at best an indifferent DB. The 500lb bombs discussed would not be a serious threat to a battleship like Bismarck....certainly not worth the risk. A torepedo, even a weak one is far greater threat and typical Anti ship sorties by SW equipped planes usually used torps. I would also question how many of the SW pilots have full on DB training and/or practice it regularily....hence it was mainly used in it's primary role...a TB and ASW platform, but in the later case it's actions were not typically described as full on "Dive bombing" attacks but standard ASW attacks same as with LB's

 

[Markus]

Yes, but another important component in a DB attack is momentum. Go too slow and the bomb will not have enough momentum to effect adequate penetration for the bomb type being used. Go too slow, and/or too shallow and you greatly increase vulnerability to AA defenses. Another important component is training. Training is critical when conducting a steep DB attack, more so against a moving target. If you don't have it, and practice it, it'll be a difficult maneuver to pull off, as was the case with the VMSB squadron at Midway flying SB2U's. Due to inexperience they conducted a GB attack vs a traditional full on DB attack.

A small nitpick. The sqn. flying SB2U was fully trained and did a dive bombing attack but the Vindicator could not dive as steeply as an SBD. The SBD sqn. was composed of pilots with next to no hours on the SBD and zero dive bombing training.

By the way, even the USN did not regard dive bombers as capital ship killers. Their job was to suppress the triple-A, so the torpedo bombers would have a better chance.

 

[Nikademus]

A small nitpick. The sqn. flying SB2U was fully trained and did a dive bombing attack but the Vindicator could not dive as steeply as an SBD. The SBD sqn. was composed of pilots with next to no hours on the SBD and zero dive bombing training.

By the way, even the USN did not regard dive bombers as capital ship killers. Their job was to suppress the triple-A, so the torpedo bombers would have a better chance.

According to Lundstrom's book and Parshall and Tully's Shattered Sword, the Marine pilots flying the SB2U's were also green causing them to conduct the shallower Glide bombing attack.

Yes, USN doctrine of the time considered the torpedo to be the heavy Anti-ship weapon of the carrier. Early on in the war only Enterprise even carried any dedicated AP bombs for the SBD's and only a limited #. These were in actuallity converted 14inch AP shells. Only later in the war was a dedicated AP 1000lb bomb (Mk-33) deployed to the carriers.

 

[tail end charlie]

Some of the attacking Swordfish operated as divebombers at taranto. They did not suffer very heavy losses. in fact it was the torpedo carriers that took all the losses in that battle IIRC.


Swordfish were remarkably resistant to AA fire, despite their obviously obsolete technology.

I think the Taranto raid was done in the dark with flares, not really an option in the middle of the atlantic. In the raid they made the deck was pitching 50ft up and down, hardly conditions for a night landing. I am sure a raid could have been launched to drop bombs but the losses compared to possible success probably wouldnt be worth it.

 

[Markus]

Right, the Vindicators were also from VMSB-241. I did not find much in either book but they would not have given skilled pilots the "wind indicators" and rookies the good planes.

By the way, what kind of bombs were the 1,000lb bombs used at Midway? SAP or GP?

 

[Nikademus]

Judging by the overall land component battle, I don't think most if not all of them were particularily experienced (Including the fighter defense of Midway).

The SBD's slepped around GP mostly.