Highball vs the Tirpitz

[wuzak]

The Highball version of the bouncing bomb was originally intended for use against the Tirpitz. An attack was originally supposed to take place on teh same night as the Dams Raid, but was delayed by technical issues with the bomb.

The question is, could the Highball bombb have sunk the Tirpitz, or was there insufficient charge (about 500lb HE) to do the job?

 

[pinsog]

500 pounds of HE was smaller than a typical torpedo warhead. I think the US torpedo had 660 pounds of torpex, the Japanese 'Long Lance' had 1,000, the British had many different torpedoes with different warheads, not sure about the Germans. I guess one advantage of the Highball would be that it hits the side of the Tirpitz and then sinks down below the armor below the armor belt and explodes underneath.

Hope this helps. (or brings others into the conversation)

 

[stona]

As the two ton charges dropped under the ship by the X Craft of Operation Source didn't sink her I do wonder what a charge only one quarter that size would have achieved. I know nothing about ships, so I might be missing something.
Cheers
Steve

 

[Garyt]

Enough Bombs will sink almost any ship, or at a minimum cause a mission kill. There is probably some minimum charge based upon the size and armor of the vessel, but 500 pounds of TNT equivalent is very similar to the bursting charge of US 1,000 pound GP bombs, which could certainly kill even an armored vessel.

While some vessels may be well armored, there are vulnerable areas. Damage control is usually subject to damage by bomb hits (be it things like hoses or the crews themselves), and bombs will start fires. Even the Secondary armament of a battleship is generally not very well armored - usually no more than an inch or so - which lends both the secondary turrets vulnerable as well as any ready ammo, possibly even the magazines. Same thing of course for AA armament, but it's not as destructive to a vessel, you are looking more fire than explosive.

The negative I see for this "bouncing" bomb is it's going to hit the main armor belt like a shorter range shell would as opposed to the deck armor a standard bomb would hit. And the Belt armor of the Tirpitz is a lot thicker than the deck armor.

And I would assume a bouncing bomb is contact fused, without much of a delay - so it's going to explode by the thick surface belt. Torpedoes are different, shallow running ones hit the main belt but where it is thinner, and deep running ones hit below the belt where any anti-torpedo blister might be.

A bomb striking the side of a ship at or near the surface will do a lot less damage than a torpedo striking below the surface - something to do with the fact that the water resists the explosion more than air would due to density, thereby channeling more explosive force into the vessel. Near misses can be more dangerous to armored vessels than direct hits - due to the different effects of explosion underwater AND the fact that a battleship is armored far better above the waterline than below.

Though I think a bouncing would have a trajectory as I said more like a shell, which would make it far more like a HE shell than a near miss bomb.

Could enough kill the Tirpitz? I'd think so. Just remember though the Musahi took 10-17* or so bomb hits from 500 and 1000 pound bombs - but was sunk more by the 10-20* torpedoes that struck it. It probably could have survived 20+ bomb hits pretty easily. The Tirpitz was not as big or as well armored as the Musahi - but it was still a very large, very well armored battleship.

*Hits taken by the Musahi is showing the range from the four different sources on the matter.

 

[Juha]

In its operational mode Highball had a loading of 600 pounds (272 kg) Torpex, probably the Swordfishes hitting Bismarck carried 18" torpedo Mk XIIs with the warhead weight of 388 lb (176 kg) TNT, so HB had significantly more powerful charge and it was designed to explose against the ship's side below the armoured belt like a torpedo warhead. Scharnhorsdt was hit by a Mk IX torpedo from HMS Acasta and damaged badly on 8 June 40. The Mk IX had 750 lbs. (340 kg) TNT warhead. Torpex being some 50% more powerful than TNT so HB's charge was something like 408kg TNT.

Juha

 

[stona]

I assume that 'Highball' was given back spin like 'Upkeep' to keep it against the hull of the target ship as it sunk and prevent it bouncing off. It would have been possible to fuse it to explode at a predetermined and suitable depth, just like 'Upkeep' against the dam wall.

Tirpitz was hit by one and probably three 12,000 pound 'Tallboys' and also suffered three near misses. The one confirmed direct hit exploded inside the ship in a wing tank outside the port engine room. Other probable hit near turrets 'Bruno' and 'Caesar'. This confirmed hit caused the damage, along with several contributing factors, that eventually caused the capsize. It seems unlikely that a single 1,000 pound bomb would have done this.

Cheers

Steve

 

[Juha]

HB had a single hydrostatic pistol, set to fire at a depth of 27 feet (8 m), each Mossie carried 2 HBs, so the idea was to achieve multible hits.

 

[wuzak]

I assume that 'Highball' was given back spin like 'Upkeep' to keep it against the hull of the target ship as it sunk and prevent it bouncing off. It would have been possible to fuse it to explode at a predetermined and suitable depth, just like 'Upkeep' against the dam wall.

Yes, it did.

As Juha said, the aim for it was to sink below the water line and explode at a set depth. The backspin helped keep the bomb/mine in close proximity to the ship's hull - in the same way that Upkeep hugged the dam wall.


View: https://www.youtube.com/watch?v=8zBp1NCbAr0

DK 290/G showing the twin Highball bombs/mines

One inert Highball punched a hole in HMS Malaya during tests.

The USAAF was also interested in the weapon, and had an A-26B converted to carry a pair of highballs by Vickers. The conversion kit was packed up and sent to the US where it was fitted to an A-26C. Trials with inert Highballs were run in the US, where they discovered the dangers of dropping them a touch too low


View: https://www.youtube.com/watch?v=PCGpzRzY7fY

Highballs were trialled for use against land targets, such as rail tunnels.

 

[wuzak]

The Highball incident

The tube on the lower left side of the picture is the inlet that feeds the air turbine which spins the mines.

 

[stona]

The Germans liked to attach rockets to just about anything! Check out the bomb/missile at about 30 seconds in this video.


View: https://www.youtube.com/watch?v=J1JBYIClEd0

Cheers

Steve

 

[Koopernic]

Exploding a bomb against the side of a Battleship would in general have had limited effect it would take a great many hits, just as a great many torpedo hits would be required, the shock might have hurt a crew member to close, but the structure would stay intact. The armour scheme of a German battleship was as follows: they had a particularly thick armoured belt against the waterline designed to stop massive armour piercing shells of another battleship. German battleships were particularly strong in this regard as the Germans expected to be fighting at short to medium ranges in the poor visibility of the north sea and Atlantic where low trajectory high velocity shells would be the norm. Thick wood and cavities behind provided protection against torpedos and of course bombs such as highball blowing up against the side. Just above the main belt, just above the waterline was a thick (about 6 inches) armour like a tortoishell designed to stop plunging shells or those shells that had penetrated the weaker armour above the waterline. There was another layer of about 3-4 inches of armour in the upper deck. This duel layer of armour was designed to keep the center of gravity low, decap an incoming shell, defuse it, and also yaw it so that it would glance of the tortoishell armour.

However exploding below the water line would likely cause more damage, this could be achieved with a hydrostatic fuse, or perhaps less effectively with a time delay fuse that started timing on impact.

German hopes of an effective anti ship weapon rested on the use of the so called "BT" series of bombs (BT stood for Board Torpedo). These were very pointed bombs that rather than bouncing of the water were designed to spear into it and continue to travel at a fairly flat trajectory. A magnetic or metal detector fuse would then set of the bomb underneath the ship, likely braking its back. The Germans used this method with ordinary bombs, however they lacked the influence fuse and relied on a simple timer (possibly a pressure fuse at times). A special disk was added to the nose to prevent the bomb from bouncing. The bombs slowed down rapidly and so did not travel as far underwater, enough to get directly beneath the ship, thus requiring relatively good accuracy.

The explosion depth was surprisingly deep; 60ft is listed in Fleischers air dropped weapons.

A deep detonation of high ball would have caused enormous damage, not an immediate sinking but certainly a crippling. Unlike a torpedo it could be deli vered at high speed, unlike a bomb it didn't have to be released at an exact range.

Tirpitz wasn't really operational in 1944 when it was sunk. It had been too badly damaged by repeated bombing raids etc, however it did distract the Royal Navy and Air force who were obsessed with getting her.

The anti aircraft defences were reasonably good by then, the Germans upgraded as did everyone else, the biggest weakness being the insufficient armour protection for the gunners. A problem with all battleships since for some bizarre reason Navy planners hadn't conceived of fighter planes strafing up the decks of ships to clear the way for torpedo and dive bombers. Tirpitz at sea would have been far more formable than Bismarck in her FLAK defences.

The German "version" of highball was code named "kurt"

 

[wuzak]

Exploding a bomb against the side of a Battleship would in general have had limited effect it would take a great many hits, just as a great many torpedo hits would be required, the shock might have hurt a crew member to close, but the structure would stay intact. The armour scheme of a German battleship was as follows: they had a particularly thick armoured belt against the waterline designed to stop massive armour piercing shells of another battleship. German battleships were particularly strong in this regard as the Germans expected to be fighting at short to medium ranges in the poor visibility of the north sea and Atlantic where low trajectory high velocity shells would be the norm. Thick wood and cavities behind provided protection against torpedos and of course bombs such as highball blowing up against the side. Just above the main belt, just above the waterline was a thick (about 6 inches) armour like a tortoishell designed to stop plunging shells or those shells that had penetrated the weaker armour above the waterline. There was another layer of about 3-4 inches of armour in the upper deck. This duel layer of armour was designed to keep the center of gravity low, decap an incoming shell, defuse it, and also yaw it so that it would glance of the tortoishell armour.

However exploding below the water line would likely cause more damage, this could be achieved with a hydrostatic fuse, or perhaps less effectively with a time delay fuse that started timing on impact.

Highball was not designed to explode against the side of a ship. Instead, like Upkeep, it was to sink below the surface with the backspin holding the mine in close contact with the ships hole and explode via hydrostatic fuzes.

A deep detonation of high ball would have caused enormous damage, not an immediate sinking but certainly a crippling. Unlike a torpedo it could be deli vered at high speed, unlike a bomb it didn't have to be released at an exact range.

Going too deep would have lessened the explosive effect. The whole point of the weapon was to have it remain in contact with the hull so that the easiest path for the explosive shock to take was through the ship.

Highball would still need to be released within certain parameters of speed, height and range, otherwise it wouldn't work.

Tirpitz wasn't really operational in 1944 when it was sunk. It had been too badly damaged by repeated bombing raids etc, however it did distract the Royal Navy and Air force who were obsessed with getting her.

You could argue that the Tirpitz wasn't really ever operational. To the best of my knowledge the Tirpitz only had one combat sortie - against a shore weather station. The Tirpitz did pose a threat to the supply convoys to Russia, which is why the obsession.

The anti aircraft defences were reasonably good by then, the Germans upgraded as did everyone else, the biggest weakness being the insufficient armour protection for the gunners. A problem with all battleships since for some bizarre reason Navy planners hadn't conceived of fighter planes strafing up the decks of ships to clear the way for torpedo and dive bombers. Tirpitz at sea would have been far more formable than Bismarck in her FLAK defences.

That may be, but the Tirpitz was basically paralysed after the Bismark was sunk.

The German "version" of highball was code named "kurt"

We know.

 

[Koopernic]

Highball was not designed to explode against the side of a ship. Instead, like Upkeep, it was to sink below the surface with the backspin holding the mine in close contact with the ships hole and explode via hydrostatic fuzes.

Going too deep would have lessened the explosive effect. The whole point of the weapon was to have it remain in contact with the hull so that the easiest path for the explosive shock to take was through the ship.

Highball would still need to be released within certain parameters of speed, height and range, otherwise it wouldn't work.





You could argue that the Tirpitz wasn't really ever operational. To the best of my knowledge the Tirpitz only had one combat sortie - against a shore weather station. The Tirpitz did pose a threat to the supply convoys to Russia, which is why the obsession.




That may be, but the Tirpitz was basically paralysed after the Bismark was sunk.




We know.

I was going through the reasoning. Exploding below the ship directly below in the middle, which was the objective of magnetic torpedos, the German BT series and the so called German turnip tactics with a normal bomb fitted with a time delay and a so called anti bounce rings is highly effective with 60ft being a good depth to use, I would suggest more effective than remaining in contact and blowing up at the edge of a ships hull, somewhat below the waterline as you seem to be suggesting for highball. An explosion beneath the ship can actually break the ship in two. Modern torpedo warheads use a double explosive; with a smaller initial one designed to lift the ship and the second one to break its as it falls. I suggest the flat undersides of the ship prevent the force of the explosion being deflected into the air or by the corner shape created by the shape of the ship, instead the force is absorbed into the structure by the flat underside. The explosions engergy can't go anywhere, can't be turned into producing a fountain of water.

Tirpitz was operational, it may have only undergone a few operations, but it was operational. It shot down a few Albacore Torpedo bombers at one point while escaping unscathed.

Some folks may be newbies and not aware of "kurt."

Rocket boosters were added to Kurt to project it ahead of the Fw 190 fighter bomber since there was a danger that a bomb could bounce back into the aircraft. I thought for some reason highball was immune from this effect due to spin but, as per your posted link, a Douglass A-26 was destroyed in tests this way so it must have been more serious concern.

 

[parsifal]

One of the problems facing any attack against the Tirpitz was its location. The sheer cliffs either side of it, coupled with the most extensive anti-torpedo netting, smoke machines, EW defences and nearly a full flak regiment defending it ruled out most types of low level attack, whether it be a torpedo attack, a low level divebomber attack, or a low level "skip bombing" attack, or this near equivalent, an attack by Lancasters carrying specially developed low level ordinance. A side hit, or plunging fire would not have sunk a ship as sophisticated as the Tirpitz but would still have done a lot of damage, and as the germans found, repairing ships far from good facilities took a long time to complete. There were reasons for the timing of the constant attacks on her. She was never allowed to become operational for any length of time, but the germans were equally careful never to expose her to unreasonable risk. She managed to tie down enormous forces for 2 years though hitlers constant rantings showed that he failed to appreciate the "fleet in being" role that she so successfully completed. The loss of the Scharnhorst points to one alternative. the wholesale scrapping or laying up of much of the german surface fleet after the fiasco of 31 December 1942 points to the other likely fate.

Tirpitz completed a thankless and unglamorous mission superbly.

Tirpitz - Kåfjord, near Alta, Norway - Then Now

 

[wuzak]

Rocket boosters were added to Kurt to project it ahead of the Fw 190 fighter bomber since there was a danger that a bomb could bounce back into the aircraft. I thought for some reason highball was immune from this effect due to spin but, as per your posted link, a Douglass A-26 was destroyed in tests this way so it must have been more serious concern.

Altitude was the key.

One of the Lancasters used in Upkeeep trials had damage to its elevators from the splash of he bomb hitting the water. In the case of the A-26, it was extremely low - much lower than any of the Msoquito Highball videos I have seen.

 

[Glider]

Killing the Tirpitz is one thing, doing significant structural damage another. When the X craft charges exploded the reports at the time talked about the ship being lifted by the explosion. These charges were smaller but would be next to the hull magnifying the impact. My guess is that two or three hits stood a good chance of causing serious damage. The chances of a hit are a lot higher than with a torpedo so it would have been a very effective weapon.

 

[parsifal]

I found this online...apparently tests of a naval variant of the highball bomb were undertaken in April 1944, with the following description

The film record of secret experiments by the Royal Navy in April 1944 to test a variant of the bouncing bomb devised by Barnes Wallis and used by the Royal Air Force in the famous April 1943 'Dambusters' raid.

START 00:00:00 Reel 1. Three views filmed with high-speed and normally-running cameras at different locations on a Royal Navy test range somewhere in the United Kingdom (possibly the Royal Navy test range at Aberporth in the Bay of Cardigan) showing small round 'Highball' projectiles painted black and white to aid visibility bouncing across the surface of moderately choppy waters before disappearing beneath the waves.

00:01:38 Nine views filmed on land with high-speed and normally-running cameras of the projectiles being propelled with the assistance of rocket charges from a firing platform in a cove on the seashore and skimming along the surface in calm seas (some more successfully than others) before sinking. Test firing #4, which is successful, and test firing #9, which is not, provide the best film coverage.

00:07:26 Reel 2. Fifteen views filmed on land with high-speed and normally-running cameras of small round 'Highball' projectiles being fired from a converted 21-inch torpedo tube (?) mounted on a barge and skimming with varying degrees of success over the water before disappearing into the sea. At the end of many of these experiments, the camera pans and tilts unsteadily to a cue card which shows the number of the test firing and the date. They start at Shot No. 18, dated 17 April 1944, and end at Shot No. 37 dated 20 April 1944. Test firings #2, #8, #10, and #12, all of which are successful, and test firings #14 and #15, which are failures, provide the best film coverage.

00:17:52 Reel 3. Four views filmed on land and two views filmed on board a boat showing 'Highball' projectiles being fired from the projector on board the barge and bouncing with varying degrees of success across the water before sinking beneath the waves. Test firings #3 and #5 provide the best film coverage, especially the latter which clearly shows the projectile spinning as it flies through the air and skims off the sea.

00:23:07 Scenes filmed on board the barge fitted with the projector (a specially-adapted 21-inch torpedo tube ?) showing a detachment consisting of three naval ratings and a Royal Navy Volunteer Reserve (RNVR) Lieutenant in charge of preparing the weapon for firing. Filmed from various angles, they are seen ramming a spherical 'Highball' projectile into the tube with the help of planks of wood. A heavy circular breech cover is then installed and sealed tight by fitting two semi-circular top and bottom steel clips which are then screwed tightly together. The actual propellant charge, similar in appearance to an electrical filament in a light bulb, is then inserted into the centre of the circular breech cover and locked in place.

00:26:34 Reel 4. As seen from the headland astern of the barge fitted with the projector, there are eight test firings showing the smoke from the propellant charge each time a 'Highball' projectile is fired. Circular splash patterns appear each time the projectiles bounces off the sea.

source; TRIALS ROYAL NAVY VERSION 'HIGHBALL' BOUNCING BOMB Allocated Title (ADM 1105)

Doesn't appear to have been all that successful to me.

 

[Koopernic]

One of the problems facing any attack against the Tirpitz was its location. The sheer cliffs either side of it, coupled with the most extensive anti-torpedo netting, smoke machines, EW defences and nearly a full flak regiment defending it ruled out most types of low level attack, whether it be a torpedo attack, a low level dive-bomber attack, or a low level "skip bombing" attack, or this near equivalent, an attack by Lancasters carrying specially developed low level ordinance. A side hit, or plunging fire would not have sunk a ship as sophisticated as the Tirpitz but would still have done a lot of damage, and as the germans found, repairing ships far from good facilities took a long time to complete. There were reasons for the timing of the constant attacks on her. She was never allowed to become operational for any length of time, but the germans were equally careful never to expose her to unreasonable risk. She managed to tie down enormous forces for 2 years though hitlers constant rantings showed that he failed to appreciate the "fleet in being" role that she so successfully completed. The loss of the Scharnhorst points to one alternative. the wholesale scrapping or laying up of much of the german surface fleet after the fiasco of 31 December 1942 points to the other likely fate.

Tirpitz completed a thankless and unglamorous mission superbly.

Tirpitz - Kåfjord, near Alta, Norway - Then Now

The salient history of the many attacks on the Tirpitz by the RAF and RN Fleet air arm is that non of the 5-6 (so many to count) 1944 attacks were intercepted by the Luftwaffe. The Fleet air arm effectively ran riot during operation Tungstan using Barracuda dive bombers and staffing Corsairs to inflict terrible casualties and considerable damage, opposed only by FLAK. It probably can't be blamed on the Luftwaffe since they just didn't have many assets in the area though one poor fighter pilot was scape goated. It didn't help that the Kriegsmarine (German Navy) didn't have "marineflieger" or a sort of autonomous fleet air arm that it had in WW1 and had to rely on the Luftwaffe which was invariably distracted elsewhere.

I used to think that the bombing of Tirpitz displayed remarkable accuracy by No 9 and 617 squadron using their SABS Mk II sights: 29 tallboys dropped and 2 hits with 1 near miss. But the June 1943 attack on Convoy Juno by 3 Fw 200C using Lotfe 7 from around 12000-15000ft on targets moving at 14 knots got the following score: out of 12 bombs dropped there were 4 direct hits. Of the 8 misses 4 were straddles that were part of the stick of 4 bombs of the direct hits, 2 were amidships straddles that might have been hits had they been more closely released while the other 2 was dodged by a destroyer accelerating and turning. During their retreat a single Fw 200 attacked a destroyer about 50km away and missed by 20 yards.

Tirpitz was a target around 900ft by 90ft and an attack from 15000ft represents accuracy of 6% by 0.6%. I imagine the practice range CEP of the SABS II at this altitude must have been under 100ft. The German FLAK maybe didn't hit shoot down any Lancasters (one crash landed in Sweden) but probably did degrade the crews accuracy below their undoubted abillity. However a hit by a tallboy isn't likely to give too many second chances and there were 29 of these nasties.

Bottom line is Tirpitz or any docked battleship was a fat sitting duck for level bombers equipped with these sorts of computing bomb sights and attacking at altitudes heavy FLAK was fairly ineffective. The Low level attacks however did lead to the loss of RAF and fleet air arm aircraft.

My estimation is that Highball would have been about as effective as a battleship hitting a mine and more dangerous for the carrier aircraft to use than level bombing. Short range and Medium FLAK (the German 20mm quad FLAK) is more dangerous than Heavy FLAK at 15000ft so a high ball attack would have been more dangerous for the Mosquito. The Dambusters lost 9 out of 18 aircraft and I highball attack might have been as costly unless there was some very effective FLAK suppression. The German conclusion after that raid was that they needed a powerfull single hit to kill weapon that could destroy aircraft before they released their ordinance rather than after and they developed a 5.5cm computer/predictor aimed gun called the Garaet 58 whose principles the Soviets adopted as their post war 57mm weapon.

 

[Milosh]

The Fleet air arm effectively ran riot during operation Tungstan using Barracuda dive bombers and staffing Corsairs...

First time I read of Corsairs were used in Operation Tungsten.

 

[Koopernic]

First time I read of Corsairs were used in Operation Tungsten.

This was a complicated operation consisting of two raids, Broadly Barracuda acted as dive bombers, Wildcats and Hellcats strafed up the Tirpitz to kill her FLAK crews while Corsairs provided top cover. Extra armour had been ordered to improve the protection of the crews but that had not been completed. One corsair was damaged and lost though the (pilot survived), one hellcat lost (pilots survived) and one Barracuda with its three crew members lost.

During operation Catechism (Talboy raid that sank Tirpitz) the Luftwaffe hadn't been told that Tirpitz had been moved so they were unable to infer the target let alone know it needed protecting. Fighter ace Heinrich Ehrler, a man with 208 victories, was scape goated and sentenced to 3 years for the loss though eventually exonerated, grudgingly it seems.

If the Fw 190's had of intercepted any of the inbound raids they may have fallen apart. The Fw 190 was at its optimal altitude.