WI: Bismark damaged in april of '41?

Saphroneth

Banned
Since I assume we're still talking about a breakout into the Atlantic while still docked in Brest, I suspect getting the turrets in from Germany is going to prove a mite difficult.
Unless they do the Channel Dash, fit up on turrets, and do the Channel Dash again.
 
....Taking the old turrets out and fitting the new ones should only have taken a few weeks. It's just a matter of finding a dockyard with a powerful enough crane......

Do they just swap ? or are the 15' mounts more weight ? (and thus needing more support/displacement)

Navweps says [FONT=Arial,Helvetica]1,052,000 kg for 15'twin v [/FONT][FONT=Arial,Helvetica]750,000 kg for 11' triple is that just more protection or are they more weight ?[/FONT]
 
Unless they do the Channel Dash, fit up on turrets, and do the Channel Dash again.
Since Scharnhorst was three months in repair for the damage she took, and Gniesenau was put out of commision in dry dock I think it would be safer trying to transit the turrets across France.
 

Saphroneth

Banned
Do they just swap ? or are the 15' mounts more weight ? (and thus needing more support/displacement)

Navweps says [FONT=Arial,Helvetica]1,052,000 kg for 15'twin v [/FONT][FONT=Arial,Helvetica]750,000 kg for 11' triple is that just more protection or are they more weight ?[/FONT]
...wow, that's an extra 1,000 tonnes on the switch out.

And I think " is the inch, ' is the foot. A 15 foot main turret would be very impressive in a "Battlefleet Gothic" kind of way.


Since Scharnhorst was three months in repair for the damage she took, and Gniesenau was put out of commision in dry dock I think it would be safer trying to transit the turrets across France.
Actually, can you fit a 1050 tonne object with those dimensions on any train whatsoever? The Schwerer Gustav was only 300 tonnes heavier than that and had to be broken down for transport, whereas the 15" turrets are all of a piece.
 
Since I assume we're still talking about a breakout into the Atlantic while still docked in Brest, I suspect getting the turrets in from Germany is going to prove a mite difficult.

Actually, no. I'd forgotten what the thread was about and broken my golden rule about reading before replying. Though my reply to Cryhavoc101's is still valid for alternative histories for the Scharnhorst and Gneisenau.

Transporting the turrets to Brest although difficult is not impossible. If they had existed in 1941 the Germans could have put them on ships and sent them to Brest in the coastal convoys they were running anyway.

Yes the ships could have been sunk en route and if the British had known what the Germans were up to they would have been priority targets in the British campaign against Germany's coastal shipping.

Brest is one of the French Navy's biggest and therefore best equipped dockyards so it will have cranes capable changing the turrets because they would have needed facilities to do that for their own battleships.

Though when I was doing my research for the Axis France thread I found out that the French had tried to send some of their 15" guns to Casablanca so they could be fitted to the Jean Bart. The ship was sunk.
 
Do they just swap ? or are the 15' mounts more weight ? (and thus needing more support/displacement)

Navweps says [FONT=Arial,Helvetica]1,052,000 kg for 15'twin v [/FONT][FONT=Arial,Helvetica]750,000 kg for 11' triple is that just more protection or are they more weight ?[/FONT]

The ships were designed so that they could be rearmed with 15" guns at a later date so I presume that the supports were built to take the weight in the first place.
 
Okay, so turrets go on order before the war starts, to be ready in 1941 at about the same time Bismarck comes online, then they get transited in coastal convoys. Do they have to go into dry-dock to have turrets refitted?
 
Okay, so turrets go on order before the war starts, to be ready in 1941 at about the same time Bismarck comes online, then they get transited in coastal convoys. Do they have to go into dry-dock to have turrets refitted?

Don't know, but Brest has dry docks and if there isn't one big enough there the Normandie Dock at St Nazaire (the only dry-dock on the French Atlantic coast big enough for Bismarck and Tirpitz, hence the St Nazaire raid of 1942) is available.

St Nazaire has the advantage that because it is further south than Brest it is harder for aircraft based in Britain to bomb and easier to launch an Atlantic sortie from, but a more dangerous starting point for the Channel Dash.
 
Hm, I wonder if it might not be a better idea to only convert 1 of the sisters, so one can break convoys, while the other covers their escape in case the British do come up with proper BBs while they're out there.
 
Turrets are not installed in one piece, they are fabricated. It was normal practice to construct the entire turret in the Gun works using a gun pit to fit the trunk machinery. Before it is then broken down again and shipped to the shipyard for installation on the ship. As an aside the filling in of gun pits between the wars severly constricted the UK big turret making capability when rearmement started. So most if not all of the component pieces could probably be transffered to a French construction port by rail. All in all whilst stripping out the old turrets and their amumition handling kit and then refitting the new ones is a major job it is possible to do in France. One additional problem is that there is a limited workforce with the knowlege and skill to carry out such a project and if they are sent to France then they are unavailable to complete ships in Germany. Further the crew of the twins would require considreble time to 'work up' to proficency with the new Armement.
 
Turrets are not installed in one piece, they are fabricated. It was normal practice to construct the entire turret in the Gun works using a gun pit to fit the trunk machinery. Before it is then broken down again and shipped to the shipyard for installation on the ship. As an aside the filling in of gun pits between the wars severely constricted the UK big turret making capability when rearmament started. So most if not all of the component pieces could probably be transferred to a French construction port by rail. All in all whilst stripping out the old turrets and their ammunition handling kit and then refitting the new ones is a major job it is possible to do in France. One additional problem is that there is a limited workforce with the knowledge and skill to carry out such a project and if they are sent to France then they are unavailable to complete ships in Germany. Further the crew of the twins would require considerable time to 'work up' to proficiency with the new Armament.

The working up period might not be a problem. M. J. Whitley in his books about German warships say Admiral Raeder insisted on working up periods that Whitley thought were longer than necessary. E.g. Tirpitz might not have achieved the standard of efficiency Raeder wanted by May 1941, but it may have been good enough.

However, were German 11" shells more reliable than their 15" projectiles? If they were then there is no point in rearming them with a heavier shell that doesn't work.

I take your point about the turrets being assembled in sections. It also reduces the risk of an entire turret being lost is it sent by sea if the ship carrying it is sunk. However, can the number of sections be reduced to a minimum to shorten the reassembly time? If so what would that minimum be?
 
As to swapping the turrets on the twins it was not just a simple pull it out put the new ones in process. The new turrets required more power and the electrical generating and distribution system had to be re-engineered. The barbette foundations had to be strengthened. The hull had to be lengthened by 10 meters forward to add buoyancy and correct trim and draft problems. New turrets had to be designed and built as the Bismarck turrets were too big for the barbettes. When work began on Gneisenau after her bomb damage it was estimated in would take 75,000 man days for the gun exchange and a further 45,000 man days of work on rebuilding the damaged bow.
 

Saphroneth

Banned
As to swapping the turrets on the twins it was not just a simple pull it out put the new ones in process. The new turrets required more power and the electrical generating and distribution system had to be re-engineered. The barbette foundations had to be strengthened. The hull had to be lengthened by 10 meters forward to add buoyancy and correct trim and draft problems. New turrets had to be designed and built as the Bismarck turrets were too big for the barbettes. When work began on Gneisenau after her bomb damage it was estimated in would take 75,000 man days for the gun exchange and a further 45,000 man days of work on rebuilding the damaged bow.
...holy crap, ten extra metres?
That's... wow.
That's a fair way to just building a new ship, right?
 
As to swapping the turrets on the twins it was not just a simple pull it out put the new ones in process. The new turrets required more power and the electrical generating and distribution system had to be re-engineered. The barbette foundations had to be strengthened. The hull had to be lengthened by 10 meters forward to add buoyancy and correct trim and draft problems. New turrets had to be designed and built as the Bismarck turrets were too big for the barbettes. When work began on Gneisenau after her bomb damage it was estimated in would take 75,000 man days for the gun exchange and a further 45,000 man days of work on rebuilding the damaged bow.

Do you know if the turrets were completed?

75,000 + 45,000 = 120,000 man days. Put 1,000 workers on the job and that's 120 days or 4 months or 250 men a year. Except its probably not as simple as that and do they have the men with the required skills and the steel to repair the damaged bow. Does anybody know how men were on Graff Zeppelin in 1942-43?
 
Do you know if the turrets were completed?

75,000 + 45,000 = 120,000 man days. Put 1,000 workers on the job and that's 120 days or 4 months or 250 men a year. Except its probably not as simple as that and do they have the men with the required skills and the steel to repair the damaged bow. Does anybody know how men were on Graff Zeppelin in 1942-43?

According to Garzke and Dulin, Krupp finished the armor for one turret when the project was canceled. The guns and all the turret machinery for all turrets had been delivered to the shipyard and was later sent to be used in coast defense installations
 
According to Garzke and Dulin, Krupp finished the armour for one turret when the project was cancelled. The guns and all the turret machinery for all turrets had been delivered to the shipyard and was later sent to be used in coast defence installations

That suggests to me that the Germans were building 15" guns and mountings in reasonable numbers for coast defence purposes in any case. If that is correct then it would have been relatively easy to have another set of turrets made for the Scharnhorst. Is my deduction correct? If the refits are done consecutively in the same yard that is a grand total of 240,000 man days or 8 months to do the pair with 1,000 men, but it probably isn't that simple.
 
That suggests to me that the Germans were building 15" guns and mountings in reasonable numbers for coast defence purposes in any case. If that is correct then it would have been relatively easy to have another set of turrets made for the Scharnhorst. Is my deduction correct? If the refits are done consecutively in the same yard that is a grand total of 240,000 man days or 8 months to do the pair with 1,000 men, but it probably isn't that simple.


The agreement with the Soviets required the delivery of guns and turrets to the Soviets. None were ever delivered but maybe at least they were built, even if Hitler never intended them to be sent East.
 
I just come up with a scenario where the train carrying vital and difficult to replace components for the 15" turret replacements for the twins are tracked across occupied France on their way to the West Coast and a cunning resistance / SIS attack derails the train allowing for a high risk attack by a group of Mosquitoes to try and destroy the cargo leaving the now weapon-less S and G Stuck in France.
 
I just come up with a scenario where the train carrying vital and difficult to replace components for the 15" turret replacements for the twins are tracked across occupied France on their way to the West Coast and a cunning resistance / SIS attack derails the train allowing for a high risk attack by a group of Mosquitoes to try and destroy the cargo leaving the now weapon-less S and G Stuck in France.

The raid would have to happen in 1941 to fit in with the timeline. Was the Mosquito in service with the RAF then? The first Whirlwind squadrons might be ready though.

Whirlwind Squadron, a Mirsch Films production of 1969, starring Cliff Robertson or David McCallum.
 

Saphroneth

Banned
The raid would have to happen in 1941 to fit in with the timeline. Was the Mosquito in service with the RAF then? The first Whirlwind squadrons might be ready though.

Whirlwind Squadron, a Mirsch Films production of 1969, starring Cliff Robertson or David McCallum.

No, no, no.

Reap The Whirlwind.
 
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