Highball vs the Tirpitz

[parsifal]

I don't think any attack on the Tirpitz can be said to have "run riot" on the great ship. She had no fighter protection, but she was perhaps the most heavily defended target in Europe otherwise, and to boot, enjoyed massive advantages from the topography that surrounded her. Smoke effects were particaualrly useful given the enclosed nature of her anchorage, and the elevated bluffs gave the Flak gunners an enormous firing advantage. The cliffs prevented effective torpedo and any other form of low level attack. high level bombing was never really effective against ships, even stationary one, but low level skip bombing was effective. Skip bombing could not be used against the Tirpitz because of the geography.

Though no LW units were committed to either the defence or any counterattack during operation Tungsten on the RN ships delivering the attack, they still had units in the area, and the RN was forced to divert significant forces to cover such eventualities.

Lastly, the nature of the target itself dictated relatively high level bomb release altitudes, if there was to be any hope of anything other than minor damage inflicted

Planning for the raid on Kaafjord began in December 1943. Vice Admiral Bruce Fraser, the commander of the Home Fleet, was highly pessimistic on the chances of success, and had to be persuaded to undertake the operation by First Sea Lord Sir Andrew Cunningham.

The attack was originally scheduled for mid-March 1944, shortly before the time Allied intelligence believed Tirpitz would become operational. However, it was delayed by two weeks while Victorious was fitted with new radars. The British considered cancelling Operation Tungsten in February as Victorious was also needed in the Indian Ocean to counter a build-up of Japanese warships at Singapore. To enable the attack to proceed, the United States Navy agreed to temporarily transfer USS Saratoga to the Eastern Fleet so that Victorious could be retained in the North Sea.

The plans for the raid were centred around two dive-bombing attacks by Fleet Air Arm Fairey Barracuda aircraft. Each of the attacks was to involve 21 Barracudas escorted by 40 fighters, evidence of the RN concerns about LW fighter intervention, Vought F4U Corsairs flying from Victorious would provide protection against German aircraft while Grumman F4F Wildcat and F6F Hellcats operating from Furious and the escort carriers HMS Emperor, Pursuer and Searcher were to strafe anti-aircraft batteries near Tirpitz, as well as the battleship herself. Nearly 75% of the air resources allocated to the raids were therefore diverted to suppression or escort functions of one type or another. Further aircraft flying from Furious and the escort carrier HMS Fencer would protect the fleet against attack by German aircraft or submarines. While carrier aircraft had previously lacked a bomb capable of penetrating a battleship's thick deck armour, it was hoped that the recently developed 1,600-pound (730 kg) armour-piercing bomb would be able to pierce at least the first layer of Tirpitz's armour if they were dropped from an altitude of 3,500m or higher. The damage caused by such hits was expected to put the battleship out of service. Nine of the Barracudas were to be armed with 1,600-pound bombs and a further 22 would each carry three 500-pound semi-armour-piercing bombs that were capable of penetrating the lightly protected upper decks of the ship if dropped from above 2,000m . The remaining ten aircraft would be armed with 500- and 600-pound general-purpose bombs and with anti-submarine bombs intended to inflict casualties among the battleship's crew and cause underwater damage if they exploded in the water near her hull. These aircraft were cleared to come in relatively low (about 2000 ft) The aircraft carrying high-explosive bombs were to initiate the dive bombing of Tirpitz as it was hoped that these weapons would knock out at least some of the battleship's anti-aircraft guns before the main attack commenced. It was anything but an easy target, calling for a very high degree of accuracy and skill and precise timing on the part of the raids various elements

The Fleet Air Arm units selected for Operation Tungsten conducted intensive training from February 1944 but were anything but experienced CAGs. A high proportion of the airmen were inexperienced, and the captain of Victorious estimated that 85 per cent of the aircrew embarked on his ship had not previously operated at sea. The training program was centred around Loch Eriboll in northern Scotland which, like Kaafjord, was surrounded by steep hills. Flying from RNAS Hatston in the Orkney Islands, the aircrew practiced manoeuvring around this terrain to familiarise themselves with the tactics needed to avoid German anti-aircraft guns and successfully attack Tirpitz. The Royal Navy drew on intelligence on the defences of Kaafjord to make the exercise range as similar to the conditions around Tirpitz as was possible, and the aircrew were extensively briefed on the locations of German positions. An area the size of the battleship was also marked out on an island in the centre of the loch and repeatedly bombed. Results obtained during the course of training were disheartening to say the least

In addition to the forces already listed, it is untrue to say Tirpitz was not protected by airborne assets. there were around 40 fighters stationed near to the ship, which explains why the RN allocated so many resources to their suppression, fortunately for the RN, these aircraft were without fuel on the day of the attack.

Tirpitz's crew suffered heavy casualties in the attack, but the battleship suffered only moderate damage. Overall, 438 crew were killed or injured representing 15 percent of the battleship's crew. Many of the casualties were anti-aircraft gunners who were killed or wounded by machine-gun fire from the British fighters. While two bombs that exploded in the water near Tirpitz opened holes in her hull and caused flooding, none of the 15 bombs that struck the battleship penetrated her main deck armour belt, mostly because the bombs were dropped at too low altitude. . As a result, her guns, magazines, and machinery did not suffer serious damage. Most of the damaged areas of the battleship were located in her superstructure and between her armoured decks. The starboard aircraft catapult and crane were destroyed, as were both Tirpitz's Arado floatplanes. The number two starboard 150-millimetre (5.9 in) gun turret was destroyede, and the number three port 150 mm turret knocked out and incurred significant damage. The officers' mess and several galleys were wrecked, and the ship was filled with smoke. Tirpitz's funnel was also struck by bomb fragments that badly damaged all of the boiler intakes. While the starboard turbine was knocked out by shock damage and two of the boilers were disabled after being contaminated by salt water used for firefighting, the battleship was still capable of steaming within Kaafjord.

The British fighters also damaged four patrol craft and a large repair ship; the captain of an armed trawler died and 13 other sailors on board these vessels suffered wounds. Torstein Raaby of the Allied Secret Intelligence Service group in Alta reported a few hours after the raid, that no civilian casualties had resulted from the attack, and that the local population was "... extremely impressed by the bombing." A further report six days after the operation relayed that the Germans estimated that it would take months to repair the damage inflicted on Tirpitz.

 

[parsifal]

Part (II)

Grand Admiral Karl Dönitz, directed that the damage caused to Tirpitz during Operation Tungsten be repaired. It was considered desirable to retain her in service in order to tie down Allied naval resources.Repair work began in early May after a destroyer transported equipment and workmen to Kaafjord from Germany, and Tirpitz was able to steam under her own power by 2 June. She was capable of undertaking gunnery practice by the end of June, and all repairs were completed in mid-July. During this period the battleship's anti-aircraft armament was augmented by fitting her with additional 20-millimetre (0.79 in) cannons, modifying the 150 mm guns so they could be used to attack aircraft and supplying anti-aircraft shells for her 380-millimetre (15 in) main guns. The defences of Kaafjord were also improved during this period. Additional radar stations and observation posts were established, and the number of smoke generators located around Tirpitz was increased.

Following Operation Tungsten, British intelligence assessed that Tirpitz would be repaired within six months. Accordingly, Cunningham directed Fraser on 13 April to launch another attack on the battleship. While Cunningham did not believe that Barracudas could carry weapons capable of sinking Tirpitz, he hoped that further air strikes would increase the period the battleship was out of service and harm her crew's morale. Fraser initially resisted Cunningham's order, arguing that the prospects for a successful raid were poor as the Germans would have reinforced the defences around Tirpitz and weather conditions were likely to be worse than those encountered during Operation Tungsten. frasers assessment proved remarkably accurate. but he eventually relented, and Vice Adm Moore sailed from Scapa Flow on 21 April to attack Kaafjord again. This raid, designated Operation Planet, was called off on 24 April due to bad weather over the target area. Two other attacks, Operation Brawn and Operation Tiger Claw, also had to be cancelled on 15 and 28 May respectively again because of adverse weather. by this time the air groups inexperience was denying the RN of one it long held advantages; its ability to operate in all weather conditions. Further carrier raids were attempted in July and August after Allied intelligence determined that the repairs to Tirpitz were nearing completion. During Operation Mascot a force of 42 Barracudas and 40 fighters attacked Tirpitz on 17 July, but did not score any hits as the battleship was hidden by a smokescreen. A further four carrier raids were conducted against Kaafjord between 22 and 29 August during Operation Goodwood, but these caused only light damage to the battleship.

In late August it was decided that further Fleet Air Arm attacks should not be attempted as the Germans were now able to cover Tirpitz in smoke before Barracudas could reach the battleship, and these aircraft could not carry bombs large enough to inflict heavy damage. As it was still seen as desirable to destroy Tirpitz, the task was assigned to Bomber Command. On 15 September a force of heavy bombers attacked Kaafjord after refuelling at bases in northern Russia and inflicted irreparable damage on the battleship. Following this raid she was towed to an anchorage near Tromsø to be used as an immobile coastal defence battery. Another heavy bomber attack on 29 October caused only minor damage, and a third raid was mounted on 12 November in which Tirpitz was struck by several Tallboy bombs and capsized with heavy loss of life among her crew.

 

[stona]

On that last raid Tirpitz was definitely hit by one Tallboy and probably two others. She also suffered three near misses. There are several reasons she capsized, but the lack of counter flooding to counteract the ingress of water caused by the one definite Tallboy hit is probably the most crucial. Why the Germans didn't counter flood is not clear and still debated today.

As for air support for the ship on 12th November.

0800: Bombers reported in area of Bodoe. Tirpitz immediately connected to air raid warning centre at Tromsoe.

0815: Additional warnings received. Tirpitz requested fighter protection but receives no acknowledgement.

0854: Air raid warning sounded for Tromsoe and Tirpitz. The ship readied itself for action.

0915: Two separate groups of aircraft sighted, from a range of 55 miles they head directly towards Tirpitz.

0920: Request for fighter protection repeated by Tirpitz. The fighters take off immediately.

0934: Heavy flak opens fire on the attacking formations at a range of about seven miles.

0936: Medium and light flak open fire.

0938: A 'closed bomb carpet' of 29 Tallboys dropped on Tirpitz with well known consequences.

It seems to me unlikely that in the eighteen minutes between the second request for fighter protection (to which the fighters did react, they could have been airborne within a few minutes) and the fall of bombs that there was any chance of a successful interception being made. I don't know where the ideas that the Luftwaffe didn't know where Tirpitz was or that the fighters couldn't find her come from, but they don't fit the facts.

Cheers

Steve

 

[parsifal]

Steve, i think that the tirpitz was not counter flooded in November, because she was no longer a functional ship. the really telling damage, that removed her even as potentially a functional unit, occurred at the hands of BC, but following the raids on 15 September. after that the ship was reduced to the status of flak and static coastal defence platform. She no longer had any possibility of putting sea after September. with reduced crew, which i suspect meant she had no effective DC crews on board any more

 

[stona]

The order to counter flood was given after the first strike(s) and as the ship started to list. An order was also given to evacuate the lower decks and it is unclear whether the controls were abandoned before the valves could be opened. It seems unlikely that the well disciplined crew of Tirpitz abandoned them without orders. There were no reports of panic aboard the ship during or after the attack. Repair Parties also had standing orders to open the sea valves to counter flooding tanks when a list reached only 5 degrees.
The problem was most likely that any valves that may have been opened did not have the capacity to pass enough sea water to compensate for the rapidly increasing list and that when it reached 35 degrees, quickly, the inlets were clear of the water. Nothing now prevented the list increasing first to 60 degrees and then, with the capsize, 135 degrees.
Cheers
Steve

 

[parsifal]

This is very good information, but there are still some cautionary statements to make. firstly, whilst I accept orders to counterflood were given, that does not necessarily mean the people ordered to do it were properly trained, or even knew what they were doing . Secondly, tirpitz's crew was no better trained than those on the bismarck, and at the end for the bismarck there was sheer chaos in the ranks, as sailors ran about the place in apparent confusion, readily abandoning their posts and and thereby hastening the loss of the ship. there was a marked tendency in the kriegsmarine for their crews, often stuck in ports for years at a time, to fall apart like that. And tirpitz's crew were certainly well within that demographic. There were no reports of panic on the bismarck either, but we know that there was panic. its not something that would be likely to arise in an official after action report, but the sailors themselves might be more forthcoming. It would not be reported, because it could not be verified one way or another, and after action reports for ships are all about verifiable facts

with regard to the orders given to the repair parties on board, well that is more or less standard procedures in most DC situations. The fact that the entry of seawater was too great is very revealing. It can mean a number of things, perhaps a bit of all of them. in the first instance, it suggests too few crewman available to undertake damage repairs to reduce the inflow of water, or the proper control of crews to ensure actions were properly prioritised. it sound like they were running around doing anything without regard to threat assessment, and that smacks of poor training, insufficient numbers, excessive damage, or perhaps a combination of all of these.

What i do know is that in the attacks in April the ship had suffered nearly 500 casualties, and the attacks in September and after, a further 400 casualties. Dont know the losses foir the attacks in June, but say 100. all up that gives a loss figure of 900 sailors. some may have returned, but some may also have been drafted to man the flak ringing the ship and which had also suffered losses in the hundreds. I have read reports that crew numbers were down by 50% for the final attack. That would be entirely consistent with what you are describing above....not enough resources, poor co-ordination, a lack of specialist training. The pounding she had endured over the preceding year was very likley to be having an effect on manning as casualties mounted.

 

[stona]

Massive damage was done by the Tallboys.

From a US report, the then definite hit,

"went through all decks and armour before detonating in a filled wing tank near the torpedo bulkhead of the port engine room. In way of the port engine room (for about one third of the ship's breadth) the bilge keel, shell plating and inclined armour were demolished. In this location the edges of the shell were spread outwards and the edges of the torpedo bulkhead bent inward and torn wide open."

It has been calculated that as loaded, with only 3,000 tons of fuel and water (30%) the ships stability was compromised, as the empty tanks were not ballasted with sea water. With this and the minor flooding at the bow and stern from earlier damage, the ships displacement was calculated at 42,000 tons with a mean draft of 29'. The 1 degree list to port was not corrected (by counter flooding) to maintain reserve buoyancy.

The damage caused, principally by the bomb mentioned above caused immediate flooding of the after engine room, the after middle fire room and all spaces between frames 83 and 154.5 beneath the armoured deck and to the port of the centreline. The detonation of the bomb undoubtedly compromised the water tight integrity of upper deck spaces in the immediate vicinity.

Essentially this one Tallboy caused the ship to ultimately capsize, though the other two strikes and the unexplained explosion of turret 'Caesar' certainly didn't help.

Cheers

Steve

 

[Garyt]

Wuzak Wrote:

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.

Just my thoughts, without any knowledge of testing.

I would think this would not be the most efficient way to deliver explosives, to rely on it to bounce properly and then relying on the bomb to stick by the ship until it reaches detonation depth. I would also think that seas with any degree of roughness would make it far more difficult to use.

It seems it's best application would be against stationary targets in rather calm waters.

Torpedoes had enough problems with proper detonation against ships - and this was with inertia or magnetic pistols, hydrostatic pistols were even less reliable. I'd think that the bouncing bombs would be somewhat unreliable even in calm waters.

 

[Koopernic]

I don't think any attack on the Tirpitz can be said to have "run riot" on the great ship. She had no fighter protection, but she was perhaps the most heavily defended target in Europe otherwise, .

I really don't know on what basis you can say that. The German Navy judged the ship to be inadequately protected by FLAK differences and were desperately trying to obtain a significant increase in shore batteries.


Below are several photographs of the Tirpitz in Kåfjord where she was attacked by operation Tungsten. Note the complete lack of obvious evidence of shore based FLAK.

The terrain might have slightly impeded torpedo attack and nets prevented them entirely but it did nothing to stop dive bombers (Baracudas released at 3500ft well above fjord mountain height). The Tirpitz was over 800ft long, a Spitfire could turn inside a 700ft circle so given the fjord was 4-6 times bigger than the Tirpitz there was enough room for the more manoeuvrable Wildcats and Hellcats to manoeuvre. Diving down onto the ship to strafe the FLAK crews was not impeded much at all.]

Perhaps the only effect of the fjord was to calm the winds a enough for the smoke generators to obscure the Tirpitz.

The Royal Navy dedicated 4 aircraft carriers and nearly 100 aircraft to this raid, more than enough to overwhelm any battleship. The actual attack lasted 7-10 minutes during which the Tirpitz's 16 10.5cm guns (8 turrets with a pair of guns) could have fired at most 1600 rounds, less given only half the weapons face the oncoming bombers and fighters. Given the rule of thumb the USN noted of 2000 rounds to obtain a hit its not surprise so few of the attackers were shot down (that damaged and ditched Corsair was probably one), The medium FLAK consisted of 8 pairs of duel 37mm guns able to fire 60rpm per mount, fairly mediocre. The most effective guns were the large number of quad 20mm guns.

Lets pretend that instead of a Bismarck Class that a Iowa class battleship was put there instead and subject to the same attack. The Iowa class has by far got the best AAA defences of any WW2 battleship with the most advanced fire control. This is a little unfair incidently, the more advanced replacement for the Bismarck class the H or Hindenburg class had their keels laid down the same time as Iowa and Missouri. The Germans scrapped the keels after 2 x 4000 tons had been laid, the Americans kept building.

Lets pretend the Luftwaffe attacks, say using 80-100 Fw 190F or G fighter bombers, maybe Me 410 dive bombers or Ju 87, and Fw 190A9 fighters. The Fw 190A9 fighters dive down and strafe using 2 x 13.2mm machine guns and 4 x 20mm MG151 canon firing mixed armour piercing and HE shells. Certainly far more powerful than the 6 x 12.7mm browning of the Hellcats.

The Fw 190F dive down at 65 degrees (same angle they used at Anzio) and attack with a mix of HE and AP bombs ranging from 500kg to 1000kg that damages the week superstructure of the "all or nothing armour" concept on the Iowa and with it much fire control. The Fw 190F has a device called a bomb automat to help the Fw 190 release the bombs at the right moment and pull out. It's accurate enough to do dive bombing.

The Iowa has an advantage in that the 5 inch DP gun crews are on a fully enclosed protected turret so might not be killed by the strafing though I suspect the 20mm AP round might penetrate the top of the turret and fire control directors when fired from the steep angle. The Tirpitz's 10.5cm gunners are in the open and vulnerable to air attack(was to be remedied in the H class) though her 6 inch secondaries are also dual purpose but is limited to a ROF of 8RPM and elevation of 48 degrees. The US gun also had a proximity fuse. Both Iowa and Tirpitz had AAA radar (the Tirpitz had a single Wurzburg) and the 3 x Seetakt Radar by this time had height finding abilities as well as range and blind fire in azimuth and could be tied in with the heavy FLAK guns.

Assuming the proximity fuse was 4.5 times better kill rate we might get 4 fighters damaged or destroyed instead of one.

The 5 inch DP guns would be able to fire about 45 seconds before the Iowa is being strafed if they open up at 7km range.

The Quad 40mm bofors on the Iowa is excellent with its lead computing sight. Each one can fire 560 40mm rounds per minute compared to the German twin mount firing 60. However the crews are in open mounts and many might soon be injured or dead due to bombs and canon fire.

However the German quad 20mm mount is better more capable mount than the hand pointed 20mm Oerlikons on the Iowa and the quad FLAK is mounted in larger numbers and fulfils much of the role of the US 40mm bofors.

The Iowa would shoot down a few more aircraft, but not many more unlikely to deter the attack of 80-100 fighter bombers.

A KGV class such as Duke of York would also not fare any better the Iowa. The Pom Pom has inferior ROF and ballistics to the bofors though good fire control due to Type 284 radar and the RN 5.25 inch DP gun ROF is only about 8 rpm and little better than the German 150mm gun. The 5.25 gun wasn't fixed post war till Valiant was commissioned.

The Tirpitz was inadequately protected, any battleship, in the same situation would have suffered the same fate.

It needed air support from closer by squadrons.

The Luftwaffe could have conducted the equal of Operation Catechism (Tallboy raid) using Do 217 or He 177. No bombs as big as tallboys but I suggest the 1800kg PCX1800 (4000lb AP) would be quite destructive as would the PC1400 either in a free fall or Fritz-X form. There was also a 2500kg bomb (5500lbs)



Tirpitz - Gallery - Theme - The Tirpitz in Kåfjord, Norway

 

[stona]

'Tungsten' caught Tirpitz by surprise. Why that should be so is another question. She was supposed to have several destroyers as additional protection which were absent. The British may have 'overwhelmed' the ship but she was repaired in less than four months.
After the utter failure of various other FAA raids to do any meaningful damage the task was turned over to Bomber Command who certainly could and did do the job, as demonstrated in Operation Paravane (where the Tirpitz's best defence was a smoke screen) and then Catechism.

As one immediate post war report concluded:
"The loss of Tirpitz indicates the effectiveness against large combatant vessels of giant bombs, properly fused, and containing massive explosive charges."

I wonder whether 'Highball' was big enough to seriously damage or sink a vessel like Tirpitz.

Hitting even a large, stationary target is not as easy as it seems. I remember watching the RAF and Fleet Air Arm trying to bomb the wreck of the oil tanker Torrey Canyon with equivocal results in 1967.

Cheers

Steve

 

[Juha]

Wuzak Wrote:



Just my thoughts, without any knowledge of testing.

I would think this would not be the most efficient way to deliver explosives, to rely on it to bounce properly and then relying on the bomb to stick by the ship until it reaches detonation depth. I would also think that seas with any degree of roughness would make it far more difficult to use.

It seems it's best application would be against stationary targets in rather calm waters.

IIRC it was designed to be used against heavy ships in the harbours surrounded by torpedo nets. Backspin was used to keep the bomb against the side of the ship while the bomb sinks same way as the Upkeed dambuster bomb worked.

Torpedoes had enough problems with proper detonation against ships - and this was with inertia or magnetic pistols, hydrostatic pistols were even less reliable. I'd think that the bouncing bombs would be somewhat unreliable even in calm waters.

Cant say, they usually worked well with the depth charges

 

[Koopernic]

'Tungsten' caught Tirpitz by surprise. Why that should be so is another question. She was supposed to have several destroyers as additional protection which were absent. The British may have 'overwhelmed' the ship but she was repaired in less than four months.
After the utter failure of various other FAA raids to do any meaningful damage the task was turned over to Bomber Command who certainly could and did do the job, as demonstrated in Operation Paravane (where the Tirpitz's best defence was a smoke screen) and then Catechism.

As one immediate post war report concluded:
"The loss of Tirpitz indicates the effectiveness against large combatant vessels of giant bombs, properly fused, and containing massive explosive charges."

I wonder whether 'Highball' was big enough to seriously damage or sink a vessel like Tirpitz.

Hitting even a large, stationary target is not as easy as it seems. I remember watching the RAF and Fleet Air Arm trying to bomb the wreck of the oil tanker Torrey Canyon with equivocal results in 1967.

Cheers

Steve

Highball's advange was unlike torpedos it could not be stopped by torpedo nets. I believe Barnes Wallis didn't invent the skip bomb concept or at least the spin concept. It likely came from AVRO chief aerodynamicist (Sir) George Edwards who was a keen cricket player. Conceivably the more powerful Upkeep could have been used against Tirpitz, a considerable risk to the Lancaster due to its physically larger size. Perhaps extra armour could be added.

It was spin bowling that inspired Upkeep and Highball, the likely reason it was a British idea than a German one (Germans now play cricket incidentally) since spin on a golf ball is not as focused upon. One idea of the spin was to provide a sort of lift and standoff range.

The Germans fell a little behind in Naval Radar, but not much, the Tirpitz's late 1944 or Prinz Eugene's late 1944 fitout compares quite well in terms of blind fire capability etc. FLAK defences were a little down but these two capital ships were 100% of their capital ships.

Below is the FMG 45 RETTIN, a night fighter radar added to a Quad FLAK gun to give accurate ranging and blind fire capability, it didn't see service as far as I know of but was close. There was to be a land and naval version. Below that the FuMO 231 Euklid, shown on a 1944 Type Z52/CLA1-6 destroyer where you can see 4 radar dishes, Euklid had 1.5m dish, built around a 27cm disk triode but was being converted to a 3cm magnetron that were being fitted to destroyers being built the end of the war. Lots of work on this radar to track a low flying target in the presence of wave chop, ghosting from indirect reflections. It could automatically track and direct direct heavy FLAK and medium FLAK. A few were delivered and may even have been fitted to destroyers under construction. It's this kind of equipment that was needed. The 40mm Bofors was however magic on its own.

 

[stona]

I still can't see 600lbs of Torpex sinking the ship. The two ton charges placed under her keel didn't do it and there was not much water under the keel. The 5,200lbs of Torpex in a single Tallboy exploding inside the ship did the trick.

Cheers

Steve

 

[stona]

Highball's advange was unlike torpedos it could not be stopped by torpedo nets. I believe Barnes Wallis didn't invent the skip bomb concept. It likely came from AVRO chief aerodynamicist (Sir) George Edwards who was a keen cricket player.....

It was spin bowling that inspired Upkeep and Highball, the likely reason it was a British idea than a German one (Germans now play cricket incidentally) since spin on a golf ball is not as focused upon. One idea of the spin was to provide a sort of lift and standoff range.

So Barnes Wallis' daughters recollections of the skipping marble experiments (no spin) are incorrect?

Cheers

Steve

 

[Juha]

I still can't see 600lbs of Torpex sinking the ship. The two ton charges placed under her keel didn't do it and there was not much water under the keel. The 5,200lbs of Torpex in a single Tallboy exploding inside the ship did the trick.

Cheers

Steve

As I wrote the idea behind Highball was to achieve multible hits, enough torpedo hits sunk IJN Yamato and HB had almost as powerful charge than the warhead of the late war US Mark 14 torpedo had. Problem of course was to achieve required number of hits. Probably T would only have been damaged but the KM's problen would have been, that there were no docks large enough in Norway, so if the hull and torpedo defences would have been ruptured the repairs would have been difficult. The X-craft charges were not laid directly under T's hull, so they lost much of the effect of the air bubble and IIRC the charges were Amatol, which is different HE than Torpex. It was decades ago when I handled military explosives so I cannot say how much more powerful than Amatol Torpex is, but it is clearly more powerful because TNT is powerful than Amatol.

 

[stona]

X6 dropped both charges whilst hard up against Tirpitz's port side roughly by B turret. X7 dropped one hard up alongside Tirpitz's port side in a similar position before moving about 180' aft (to where Place estimated X turret to be) and dropped its second charge under the ships keel.
Because the Germans had seen X6 (Cameron's boat) on the port side it was deemed probable that any explosive charge would have been laid on that side and Tirpitz's bows were hauled over to starboard with her anchors and cable-holders. The stern was secured by shore wires and it was not practical to move it. As a result the second charge, dropped by X7 did explode more or less underneath Tirpitz's keel.
I think that the explosive used in the charges was amatol too, but I'm not sure.

We shouldn't forget that the one Tallboy hit about 50' from Tirpitz's bow, scored during Operation Paravane, did such considerable damage that the decision was taken by the Germans not to make Tirpitz ready for sea again. Another hit (Catechism) would sink her later in any case, but not before more damage was done by Operation Obviate.
No bombers were lost to enemy action in these operations. I doubt the same would have been the case had Highball attacks been made, certainly not if Chastise is anything to go by.

Cheers

Steve

 

[beaupower32]

I still can't see 600lbs of Torpex sinking the ship. The two ton charges placed under her keel didn't do it and there was not much water under the keel. The 5,200lbs of Torpex in a single Tallboy exploding inside the ship did the trick.

Cheers

Steve

I dont see 600lbs sinking the ship either. Even a 12,000 lb bomb going through the ship and exploding didnt sink the ship. It did keep the Tirpitz from going out to sea again, but it didnt sink the ship. After that, it finally took 2 more direct hits to send her down, but even the best of battleships could hardly survive a 12,000 lb bomb.

Actually the 5,443 kg (12,000 lb) bomb hit Tirpitz's bows about 15 meter (50 feet) back from the stem and went through the upper deck to emerge well below the waterline on the starboard side before exploding. The resultant damage was the flooding of the forward part of the ship and the shaking of much of the machinery, main and auxiliary.

A German document found after the war could have set the minds of the British at rest:

It was estimated that repairs, if they could be carried out without interruption, would take at least 9 months. It was eventually decided at a conference on 23 September 1944 at which the C-in-C and Naval Staff were present, that it was no longer possible to make the Tirpitz ready for sea and action again . .

In the final attack, she received 2 direct hits.

2 direct hits were achieved on the port side, one level with the bridge and the other alongside "C" turret which seems to have started a fire. Tirpitz listed about 20° to port after the first hit and then further over after the second, aggravated by a number of near misses along the port side, until she was listing to almost 70°. At about 0950, just after the last bomb had fallen, there was a violent explosion and "C" turret blew out completely. it was found some 12 meter (40 feet) from where it would have been expected and appears to have been the result of an internal explosion, not a hit by a bomb. Tirpitz rolled over to port and capsized.

Info from: Tirpitz - Menu

 

[Shortround6]

Different people can come up with the same idea at about the same time while working independently.

I believe (and could be wrong) that the idea behind Highball was to get a torpedo sized (and torpedoes varied quite a bit)warhead/charge past torpedo nets. Now torpedo nets are only used on stationary ships/targets or ships moving at slow speeds. Moving at speed in a seaway creates a lot of drag and the nets/booms tend to get carried away.

Attacking a ship in fjord is a bit harder than Koopernic seems to believe. For one thing the Spitfire did NOT have a turning circle of 700ft, it was a turning RADIUS of 700ft (roughly) and that is on the ragged edge of a stall. At 250mph and a 4 "G" turn the radius is closer to 1000-1100ft. The fjord just got a lot narrower
Torpedoes have to be dropped with the airplane flying straight and level, at least for a few seconds, or the gyros won't stabilize and keep the torpedo going straight. Dropping nose down or nose up affects entry into the water and can either break the torpedo or cause some wide fluctuations in depth until the torpedo can stabilize in depth (one reason torpedoes often had minimum run distances of several hundred yds/meters).

Dive bomber attack routes are somewhat limited by the terrain. IF the dive bomber releases at 3500ft and 350mph and instantly starts to pull out at 6 "G"s can it get to level flight before hitting the walls of the fjord? Spitfire in those conditions has a 1400ft truing radius, it may be level by th etime it reaches 2000-2100ft. 400mph changes the radius to 1800-1900ft. 400mph is 566fps so even a few tenths of second delay in staring pull out (and you don't reach the 6 "G" rate instantly) can loose a 100ft or so.

And then we have weather;

Some days the Germans didn't need smoke

 

[stona]

Different people can come up with the same idea at about the same time while working independently.

Like Newton and Leibniz, but they both thought the other had 'cheated'.

Koopernic may believe that the concept originates with Edwards, but what's the evidence for this? I think it is acknowledged that Edwards contributed to the development of the concept and certainly the idea of spinning the device, but that's not the same as the original idea.
The idea did not come to two people working independently at about the same time, it came to Barnes Wallace. Like any idea many more people contributed to a greater or lesser extent in its development towards, in this case, a workable weapon.

Cheers

Steve

 

[RCAFson]

Part (II)

Grand Admiral Karl Dönitz, directed that the damage caused to Tirpitz during Operation Tungsten be repaired. It was considered desirable to retain her in service in order to tie down Allied naval resources.Repair work began in early May after a destroyer transported equipment and workmen to Kaafjord from Germany, and Tirpitz was able to steam under her own power by 2 June. She was capable of undertaking gunnery practice by the end of June, and all repairs were completed in mid-July. During this period the battleship's anti-aircraft armament was augmented by fitting her with additional 20-millimetre (0.79 in) cannons, modifying the 150 mm guns so they could be used to attack aircraft and supplying anti-aircraft shells for her 380-millimetre (15 in) main guns. The defences of Kaafjord were also improved during this period. Additional radar stations and observation posts were established, and the number of smoke generators located around Tirpitz was increased.

Following Operation Tungsten, British intelligence assessed that Tirpitz would be repaired within six months. Accordingly, Cunningham directed Fraser on 13 April to launch another attack on the battleship. While Cunningham did not believe that Barracudas could carry weapons capable of sinking Tirpitz, he hoped that further air strikes would increase the period the battleship was out of service and harm her crew's morale. Fraser initially resisted Cunningham's order, arguing that the prospects for a successful raid were poor as the Germans would have reinforced the defences around Tirpitz and weather conditions were likely to be worse than those encountered during Operation Tungsten. frasers assessment proved remarkably accurate. but he eventually relented, and Vice Adm Moore sailed from Scapa Flow on 21 April to attack Kaafjord again. This raid, designated Operation Planet, was called off on 24 April due to bad weather over the target area. Two other attacks, Operation Brawn and Operation Tiger Claw, also had to be cancelled on 15 and 28 May respectively again because of adverse weather. by this time the air groups inexperience was denying the RN of one it long held advantages; its ability to operate in all weather conditions. Further carrier raids were attempted in July and August after Allied intelligence determined that the repairs to Tirpitz were nearing completion. During Operation Mascot a force of 42 Barracudas and 40 fighters attacked Tirpitz on 17 July, but did not score any hits as the battleship was hidden by a smokescreen. A further four carrier raids were conducted against Kaafjord between 22 and 29 August during Operation Goodwood, but these caused only light damage to the battleship.

In late August it was decided that further Fleet Air Arm attacks should not be attempted as the Germans were now able to cover Tirpitz in smoke before Barracudas could reach the battleship, and these aircraft could not carry bombs large enough to inflict heavy damage. As it was still seen as desirable to destroy Tirpitz, the task was assigned to Bomber Command. On 15 September a force of heavy bombers attacked Kaafjord after refuelling at bases in northern Russia and inflicted irreparable damage on the battleship. Following this raid she was towed to an anchorage near Tromsø to be used as an immobile coastal defence battery. Another heavy bomber attack on 29 October caused only minor damage, and a third raid was mounted on 12 November in which Tirpitz was struck by several Tallboy bombs and capsized with heavy loss of life among her crew.

On 24 August 1944 an FAA Barracuda scored another 1600lb AP bomb hit. The bomb penetrated all of Tirpitz's armoured decks but then failed to explode. IIRC, a German navy team determined that the bomb was defective from the factory and was partially filled with sand!