Bizmark and Tirpitz sail together

I cannot speculate as to their expectations, but there is precedent for a battleship at anchor being sunk by arial bombs only dropped by carrier aircraft (Pearl Harbor) so I suspect they hoped history might repeat it self. Certainly a damaged ship unable to sortie is the next best thing to sinking their target.

 

Geisenau was reduced to an unsavageable wreck when a bomb detonated her forward magazine, so where Marat and of course Roma. Once you start using 500Kg or heavier bombs the chances of a critical hit are pretty good, against a ship in port big bombs are probably more likely to completely destroy a battleship than torpedoes, many port configurations give ships a chance of beaching itself preventing catastrofic damage from flooding.

 

Unless engines at rest...I've always wandered on the damage of Royal Oak...not really read up on it...but always thought if the intitial damage was beyond redemption...or if engines were warmed up could she have beached...? Probably went down fast though...anyone know?

 

As I recall one bomb dropped by the British (perhaps by the RN) did penetrate Tirpitz's deck and ended up in a location where it would have done a lot of damage if it had gone high order. However it failed to detonate. That being the case several such hits could if not sink surely be a severe inconvienince to the ship hit. It is however as has been pointed out difficult to sink a battleship with bombs.

 

12:58...Impact firing. The boat lurched as one, two, three ton-and-a-half G7e torpedoes went overboard on blasts of compressed air, electric motors winding up, accelerating toward 30 knots. U-47’s hydrophone operator called, "Torpedoes on their way."
Then it was just Spahr, counting off the seconds: five, ten, fifteen....
Aboard the Royal Oak nearly the entire crew was asleep, including visiting Admiral H.E.C. Blagrove, commander of the Second Battle Squadron. Few of them were much disturbed by the first dull explosion, shortly after one A.M. Something had cut the starboard anchor chain, which ran out noisily into the water.
A bomb? A mine? Many thought something inflammable had exploded in the paint shop, though there was no fire. The ship did not seem to be listing or settling at the bows. Most of the 1200 men, getting no duty call, went back to bed. But several reported air venting under high pressure. Royal Oak was taking on water.
On U-47 Prien and his crew thought they’d hit the Repulse. The two torpedoes meant for the Royal Oak had either missed or misfired, a not-uncommon flaw. There was still the stern tube. About! Torpedo fired from stern.
Again Spahr’s voice counting; again no result. It wouldn’t be the last time Prien had trouble with faulty torpedoes.
A more timid captain might have decided fate was against him. Surely the alarm would be raised any second; to bring the boat about for another shot was pushing it. But Dönitz had chosen the right man. Prien turned U-47 around. The forward torpedo-room crew had hurriedly reloaded; Endrass centered the aimer’s crosshairs on Royal Oak’s midships. "Tube, fire."
Three torpedoes from the bow. Three long minutes for them to zero in on the hulking Royal Oak. At 1:16 A.M. all three slammed into her starboard side, and all three–2,400 pounds of TNT–exploded. Tons of water leaped the height of Royal Oak’s mast; black smoke gushed from the colossal hole in her midships. Her lights went out and she immediately began to heel over. "Flames shot skyward, blue...yellow...red," recalled Prien. "Like huge birds, black shadows soared through the flames, fell hissing and splashing into the water...huge fragments of the mast and funnels."
Royal Oak had taken a hit in an aft magazine. With the power out the only light came from blazing cordite searing through her vents–"like looking into the muzzle of a blow lamp" was how one Marine put it–illuminating a hellish scene of screaming, horribly burned men, stumbling about like lost souls in the flickering maze.
Royal Oak leaned over 45 degrees. The great gun turrets wrenched around, barrels splashing into the water. Her mast snapped off and smashed her big liberty launch, which might have carried hundreds of men to safety. A last few men managed to scramble out through the portholes onto the port side, even as water gushed in through those on the starboard. For maybe four minutes the ship hung near 90 degrees. Then, amid the hundreds of sailors floating in the frigid, oil-slick water, she rolled ponderously over. One survivor remembered "the tremendous noise; it was like a huge tin full of nuts and bolts, slowly turning over. Racks of shells must have been coming loose, and other gear, so that anybody still inside had no hope."
There were over 800 men still inside, including 24 officers and Admiral Blagrove. For any yet alive there remained only darkness, cold, and small pockets of air gradually running out.
Prien had looked from the blazing innards of the Royal Oak down into the quiet, dark interior of his own boat. "I felt as never before my kinship with these men below who did their duty silently and blindly, who could see neither the day nor the target and who died in the dark if it had to be."
He called down to them, "He’s finished."

From Uboat.net

 

I believe that bomb landed in an electrical distribution/switching room, and if it had gone high order would have left the ship without electrical power for some time. IIRC, it was a during the carrier attack on August 24, 1944, and was a 726 kilo bomb.

and

That is all true, but the British were using mostly 227 kilo bombs to attack the Tirpitz. They did use heavier bombs for their carrier aircraft, but never in great quantity. The Arizona and Roma both succumbed to bombs that were far heavier, but the bomb the hit Gneisenau was just under 500 kilos. Still, the Gneisenau was not reduced to an "unslavagable wreck," she could have been rebuilt with her standard fittings in a reasonable amount of time, except the Germans chose to modify her with 15-inch guns which would require major rework, this was compounded by the changing war priorities, As such, she was left a wreck even though reconstruction was already begun. You just have to look to the USS West Virginia to see what can be accomplished with the proper resources.

 

That sounds right. Was the final location such that the hull might have been breached?

I thought the plans to upgrade the amrament on the twins were rejected.

 

I think postponed would be a more accurate description, for a more propitious moment during or after the war, which of course never came.

 

The modificatioins would have had to have been pretty significant and I'm not sure that they would have been all that much more capable. My impression is that the Germans came to the same conclusion. I seem to recall some fairly extensive discussions of this over on both kbismarck and the axishistory forums.

 

I would guess that if the Arizona had been hit else where and the magazine had not gone off the bomb hit would not have been catastrophic

 

Remember that the Renown had her deck armor strengthened, which the Hood never got. So the same kind of lucky hit on the Renown might not have happened.

Also, the USS Yorktown was on "Neutrality Patrol" in the Atlantic with a full air compliment from about May 12, 1941, sailing with the USS New Mexico and a compliment of CA's and DD's. Consider SBD's and TBD's against the KM fleet? Might have gotten very messy for the Germans if they twitched wrong.

 

Only if both ships were very very lucky, and the British had suffered a terrible beating.

While the USS Yorktown did arrive at Bermuda on May 12, 1941, she did not leave on her first "Neutrality Patrol" until May 31, 1941 - 4 days after the Bismarck was sunk by the British. Even then her patrol route kept her to the south and west of the Azores. Also, the USS Yorktown was not carrying SBDs at the time, she had the "infamous" Vought SB2U Vindicator(aka "Vibrator") of VS-41 aboard for the carrier's first neutrality patrol. The Yorktown had swapped most of her Air Group with the USS Ranger, then returning from a neutrality patrol, the Yorktown sent over VF-5, VB-5, and VS-5, and took aboard the Ranger's VF-41 & VS-41.

 

I have to question if the Yorktown Group would even attack Bismark unless she presented a clear a present danger to a convoy. Simply sailing along, even in the Western Atlantic would itself not be enough to risk being the provocateur in a war. Attacking a U-boat is one thing, a 45,000 ton battleship another. I suspect Yorktown would shadow Bismark hoping she either fired the first shot or became a direct threat to an American flag vessel until a RN Battle group could make an appearance.

 

No, the Yorktown group would never attack the German battleship without a declaration of war. If the Yorktown had found the Bismarck, then presumably she would have shadowed Bismarck with her air group and relayed to the British the German battleship's whereabouts - just as the USCG cutter Modoc is presumed to have passed such information along to Swordfish torpedo bombers flying from HMS Victorious. Although, it is more likely that the carrier and battleship never would have crossed paths and that the extent of Yorktown's contribution would be telling the British where the Bismarck is not and to search elsewhere - much the same as performed by USS Texas.

 

The exception could be if the German battleships were threatening a convoy with US ships in it. Particularly one in the Western Atlantic.

 

"Threatening" is a loaded word here, the Germans surface raiders usually followed the conventions so an air strike in a "stop and be boarded" situation is likely to cause a greater loss of life, besides being of questionable legal status, firing on an unidentified sub is very different from launching a strike againt a surface squadron.
The pesence a US escort would probably prevent the Germans from attacking US flags ships but the letter of the treaties didn't allow the USN to anything legally to protect Commonwealth flag ships. (A nice point for the lawyers would be if US (neutral) warships would make the convoy "escorted", IIRC under the rules of blockade warships could not fire first on unescorted merchs, they had to board and search for contrabband.

 

For some reason the board didn't want to post my response so here's a shortened version of it.
FDR's shoot on sight orders stated German (or Italian) "warships" not submarines. It did apply to the US declared neutrality zones but those took up a pretty significant chunk of the Atlantic by the Fall of 41. They also didn't limit the attacks to force escorting convoys. Any German or Italian warship in the declared zones were subject to the "shoot on sight" order.

 

Bismarck and Tirpitz had three Seetakt radar sets in 1941 each. Range ~ 30 km

 

On the otherhand the Germans were often reluctant to use their radars much.

 

The British had radar detecting devices. The pulses from the radar could be detected at far greater distances as the ship could detect enemy activity. Especially if you use aircraft. Due to the small size of the german navy, attacks must be concealed as long as possible to keep the element of surprise and at least temporary local superiority.