Naval History Forums

Imagine that in late June 1940 Hitler decides to upgun Sharnhorst and Gneisenau. He's seen them be badly outgunned recently by the Renown and now they're back in port after the Norwegian campaign and it's time to improve them.
He orders that they both be fitted with 6x15 inch guns and be ready for operations again by the spring of 1941.

As a result Operation Berlin never happens but Operation Rhine Exercise will consist of 3 battleships with 15 inch guns plus the heavy cruiser Prinz Eugen.
How will the British stop them? Will the aircraft carriers and 5 fast capital ships the British had in May 1941 be enough?

G&D mentions about 2.5 years needed to upgun Gneisenau from 11" to 15", with 300 workers. WIth 500 workers, the time would decrease to about 1.5 years.

I don't know if it would change the war anyways... But not building the Schanrhorst's and panzerchiffes at all, and building 2 more Bismarck's instead might...

alecsandros wrote:G&D mentions about 2.5 years needed to upgun Gneisenau from 11" to 15", with 300 workers. WIth 500 workers, the time would decrease to about 1.5 years.

I don't know if it would change the war anyways... But not building the Schanrhorst's and panzerchiffes at all, and building 2 more Bismarck's instead might...

In February 1942 Gneisenau was severely damaged, but the Germans had finished the repairs by December. They had already started work on strengthening the barbettes and bulkheads, had completed the 2 new bows and built all 6 new gun turrets. The next stage was basically installation. If they'd started in mid 1940 with nothing like the repair work to do first and a target date of the spring of 41 I think they might have done it.

I agree 4 Bismarcks would have been more useful than the 2 Scharnhorsts and 2 Bismarcks but I guess they learned a lot when they built S and G, lessons which then went into the Bismarck class. The armor schemes were very similar.

Saltheart wrote:

In February 1942 Gneisenau was severely damaged, but the Germans had finished the repairs by December. They had already started work on strengthening the barbettes and bulkheads, had completed the 2 new bows and built all 6 new gun turrets.

Installing the bow would take some time. Also, the internal arrangement of the barbettes needed to be changed, IIRC, as the internal space was insufficient to transport 15" shells. So perhaps another year of work ?

alecsandros wrote:

Saltheart wrote:

In February 1942 Gneisenau was severely damaged, but the Germans had finished the repairs by December. They had already started work on strengthening the barbettes and bulkheads, had completed the 2 new bows and built all 6 new gun turrets.

Installing the bow would take some time. Also, the internal arrangement of the barbettes needed to be changed, IIRC, as the internal space was insufficient to transport 15" shells. So perhaps another year of work ?

I'm not sure
I'd always assumed that when Hitler cancelled all work in December 1942 the Gneisenau was only a few months away from completion. But I'm not sure of it so maybe others commenting might have information on that sometime.

Saltheart wrote: I agree 4 Bismarcks would have been more useful than the 2 Scharnhorsts and 2 Bismarcks but I guess they learned a lot when they built S and G, lessons which then went into the Bismarck class. The armor schemes were very similar.

I agree, but they were very costly lessons - 2 x 32.000 tons ships... And immense investment in materials, man-hours, techonlogy...

Everything in changing a capital ship's primary guns takes time. In fact, most of the time, you have to start building the guns and turrets before the ship is laid down because building them takes longer than building the ship. First, the guns have to be made and tested. Then, the whole rotating structure of the turret is built in a gun pit. This includes the whole rotating stalk with its shell and powder hoists. Then, the turret is disassembled and reassembled in the ship. The problem is worsened in a ship already built. In a new ship, you can build around the turret. In an old ship, you have to cut away existing armor to increase barbette size, etc.

Assuming that the twins could be re-armed in time, what Saltheart is proposing is a Operation Berlin in spring 1941 with three capital ships instead of two.

If the three breakout undetected then the convoys as found on Operation Berlin or later could be attacked head on by Bismarck and one of the twins, while the other twin and the Prinz Eugen could form two separate tangential prongs of attack on the merchantmen. If the convoy commander on the escorting battleship cannot identify just how many different attackers he is faced with, a bold attack by all the German ships could cause havoc.

I would suggest that for the above paragraph that we have Marschall as Fleet Commander and not Lutjens.

If they are detected as per Rheinubung then Tovey has to concentrate his ships - Hood and POW on their own would be at a major disadvantage, as any three of the German capital ships on their own could sink Hood, and leave POW facing three 15 inch gun opponents. If Prinz Eugen is in company, then expect Marschall to have POW pounded into a wreck, and then the Eugen finishes matters with its torpedoes.
A DS battle with KGV added to Hollands' force would be interesting - but if Hood is sunk quickly the Germans have the upper hand.

Plus the regunned ships will need the same workup as any other vessel, so a spring 1941 ready date is not likely. Also the RN now has an extra carrier - Glorious - to help counter any KM sorties.

Assuming Glorious didn't get sunk by other enemy forces in the meantime.

RF wrote:Assuming Glorious didn't get sunk by other enemy forces in the meantime.

:)

Well the same can be said for S&G. If they are in a dockyard, the RAF will know exactly where to find them.

True. But after Operation Berlin the RAF did try against the Biscay ports and the job proved to be a very difficult one, with little success in relation to the size of the bomber forces.

Overall Glorious would be more vulnerable than the twins - it could have fallen victim to a U-boat, a mine, Stukas - whereas the twins were two ships both better protected.

Not to be a spoilsport, but a successful raider should avoid enemy warships and attack the convoys. For that 11 in gunned ships available immediately would be much better than 15 in gunned ones in a couple of years.

And while three ships operating together might seem grand, three ships operating independently will find more convoys and threaten in more directions. IMHO, Lütjens should have divided the S & G and let them operate independently, thus threatening more convoys.

But the convoys had substantial escorts, including battleships..... which makes a complete contradiction in terms of avoiding warships and attacking convoys.

A concentration of force, as suggested by Hoffmann and rejected by Lutjens, might have been more productive.