WI: Germany buids two aircraft carriers instead of the Twins?

hmm HMS Renown was the fastest Capital ship in The RN after the Hood was sunk, and may have been faster than the hood in her unmodified state. I don't think you can call her not a very fast ship. She got told off for overloading her boilers when transporting Winston about the place.

How do you know the Graf Zeppelin had 35 knots I don't believe she was ever given sea trials and she did have a bit of a list....

Graf Zeppelin had the most poweful engine output of any german warship ever. She was technically to have a speed of 33,8 knots at full warload, which is faster than the Royal Navy and USN aircraft carreirs of WW2, actually simmilar to the Shokaku and Hiryu classes of Japan only. No captial ship (even Iowa) had such a speed as designed. Most likely the later added improvement on hydrodynamic and shape of the bow would improve speed even, so 35 knots is the most conservative likely speed of the end product, when finished. (Note het orignal had a straight bow and slightly different skegs for th propellorshafts. The lengthened "Atlantic Bug" and more streamlined skegs would have given less drag and a faster hull indeed.)
 

hipper

Banned
Graf Zeppelin had the most poweful engine output of any german warship ever. She was technically to have a speed of 33,8 knots at full warload, which is faster than the Royal Navy and USN aircraft carreirs of WW2, actually simmilar to the Shokaku and Hiryu classes of Japan only. No captial ship (even Iowa) had such a speed as designed. Most likely the later added improvement on hydrodynamic and shape of the bow would improve speed even, so 35 knots is the most conservative likely speed of the end product, when finished. (Note het orignal had a straight bow and slightly different skegs for th propellorshafts. The lengthened "Atlantic Bug" and more streamlined skegs would have given less drag and a faster hull indeed.)

most of the later improvements would seem to slow down the design - Increasing the Beam with bulges to add fuel oil I doubt that she would have been faster than designed. However 200000 on 35,000 T Displacement is a lot so I suspect that she would have been as fast as the twins and perhaps a bit faster.

I think 35 knots is a bit optimistic look at the Horse power curves for similar large ships you have to increase horsepower geometrically to gain increases in speed over 30 knots

Cheers Hipper
 
most of the later improvements would seem to slow down the design - Increasing the Beam with bulges to add fuel oil I doubt that she would have been faster than designed. However 200000 on 35,000 T Displacement is a lot so I suspect that she would have been as fast as the twins and perhaps a bit faster.

I think 35 knots is a bit optimistic look at the Horse power curves for similar large ships you have to increase horsepower geometrically to gain increases in speed over 30 knots

Cheers Hipper

The hullshape was different form the battleships of the Scharnhorst class. Longer and less beam, meaning more a cruiser shaped hull, which is faster by definition. Basically it followed the Admiral Hipper shape of hull, though with far more power installed in it.
 

hipper

Banned
The hullshape was different form the battleships of the Scharnhorst class. Longer and less beam, meaning more a cruiser shaped hull, which is faster by definition. Basically it followed the Admiral Hipper shape of hull, though with far more power installed in it.

Scharnhorst at a displacement of 38,950 metric tons (38,335 tons) (source: "German Capital Ships" by Whitley):
10KSHP = 14 knots
20KSHP = 18 knots
40KSHP = 22 knots
80KSHP = 26 knots
160KSHP = 30 knots

so to Move Scharnhorst at 34 knots you would need to double the power to 320 KSHP

The GZ is lighter and has 200KSHP but I don't see that she will ever get to 35 knots
 
HMS Renown was not a very fast ship anymore after her refit, with a top speed of 28-29 knots at best. A Graf Zeppelin was more powerful in tems of engineering and could do 35+ knots, meaning some 7 knots speedadvantage over the old warhorse. Renown also had to deal withh a weak armament of just six main guns, hardly sufficient for effective fire on fast moving targets. Basically it is th turttle vs the hare.

That was it's theoretical speed, given the issues identified during construction of the Graf Zeppelin any claims about its operational performance should be taken with a pinch of salt
 
how is draft figured into speed? any good sensible rule of thumb on that?

noticed the GZ is close to draft of Admiral Hipper-class (in its original version)
 
Scharnhorst at a displacement of 38,950 metric tons (38,335 tons) (source: "German Capital Ships" by Whitley):
10KSHP = 14 knots
20KSHP = 18 knots
40KSHP = 22 knots
80KSHP = 26 knots
160KSHP = 30 knots

so to Move Scharnhorst at 34 knots you would need to double the power to 320 KSHP

The GZ is lighter and has 200KSHP but I don't see that she will ever get to 35 knots

Ship's size is not the issue, it is the shape of the hull.
 

hipper

Banned
Ship's size is not the issue, it is the shape of the hull.

think your point is that you can increase the maximum speed by 2 knots by giving the ship a revamped Bpw.

My point is that in 2 knots increase in top speed is too much for a simple hydrodynamic change, what might happen in my opinion is that the ship would be able to go faster in rougher weather.


However in actuality they were by 1942 thinking about adding Bulges to increase fuel capacity as they found out what real world conditions meant to theoretical Ranges. Bulging the ship would have changed the hull form and slowed it down.

it is however possible that a 33000 T ship with 200000 SHP could have done 33 knots, but there is no way to know what the Graff Spey could actually do because se was never completed. 35 knots is a fantasy.
 
think your point is that you can increase the maximum speed by 2 knots by giving the ship a revamped Bpw.

My point is that in 2 knots increase in top speed is too much for a simple hydrodynamic change, what might happen in my opinion is that the ship would be able to go faster in rougher weather.


However in actuality they were by 1942 thinking about adding Bulges to increase fuel capacity as they found out what real world conditions meant to theoretical Ranges. Bulging the ship would have changed the hull form and slowed it down.

it is however possible that a 33000 T ship with 200000 SHP could have done 33 knots, but there is no way to know what the Graff Spey could actually do because se was never completed. 35 knots is a fantasy.

Shipdesign is rather complex and it does matter a serious lot if you change the shape of a hull, especially the parts underwater to make a ship of a certain size and power fast, or slow. A bulbeous bow for onstance creates less drag, as it moves the bowwave in front of the ship, rather than on the ship's hull, as does the presence of more streamlining of shaftskegs and rudders. Also important is length to beam ratio. The longer a ship is, the faster it gets, if beam is not widened. Graf Zeppelin had a cruiser like narrow hull design, rather than the wide battleship hull of Scharnhorst.
 

hipper

Banned
Shipdesign is rather complex and it does matter a serious lot if you change the shape of a hull, especially the parts underwater to make a ship of a certain size and power fast, or slow. A bulbeous bow for onstance creates less drag, as it moves the bowwave in front of the ship, rather than on the ship's hull, as does the presence of more streamlining of shaftskegs and rudders. Also important is length to beam ratio. The longer a ship is, the faster it gets, if beam is not widened. Graf Zeppelin had a cruiser like narrow hull design, rather than the wide battleship hull of Scharnhorst.

The main Hydrodynamic change planned for the GZ was in fact to add bulges and widen the beam making her slower.
 
Graff Spey


is this jest? you mean Graf Zeppelin or Graf Spee?

Until KM has a hand full of carriers- its pointless to bitch about individual capabilities. I would bet the best carriers they could build would be a number of CVL/CVE based cruisers to escort Capital ships/raiders to facilitate breakout of the GIUK gap.

Hipper class notwithstanding - I'd convert old & captured Kreuzers, so as not to cripple the production of as many surface raiders as possible.
 
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The main Hydrodynamic change planned for the GZ was in fact to add bulges and widen the beam making her slower.

Graf Zeppelin was designed with rather shallow bulges indeed. these were not later added, but included from start, so no loss in performance here. All specifications still call for a perfomance in re range between 34-35 knots, no matter how you see it. Read: Israel, Ulrich H. J.: "Graf Zeppelin", ISBN 3-7822-0602-9, pages 80-82.
 
re-read Fleets of World War II and while not particularly positive about Graf Zeppelin they seemed to endorse idea of carrier/raider (at least during 1940) re-supplied "by subs and air."

while still negative on idea of conventional carrier, Germany had years of experience with seaplane tenders including operation of some huge Blohm and Voss aircraft.

what if ship size of GZ built as fast, super fast (be it 33 or 35 kts.) tender? (with the same OTL CA level of armor protection)
 
The Twins being Scharnhorst and Gneisenau, and the two carriers being around 30000 tons standard, both CVs commisioned during the winter of 1938/39.

The alternative is have two of the Hippers built as "Weser" auxiliary carriers (CV < 10,000 tonne are not counted under treaty). Use these to "trials carriers" to "solve" any carrier problems.

Keep S&G, as escorts, and build B&T as repeat S&G, saving 18 months in slip time, and ships ready much earlier.

Build GZ without 150mm, and start PS 18 months earlier. By time both carrier enter trials, naval air wings are ready.

Therefore have two balance groups of 2 BC, 2 CV & 1 CA. This can form mini scout group of CA & CVL.

Still have lots of cancelled construction (H&P class) to divert into U-boats and DD. That's before allowing for some pre-fab in a high battery snort boat and a more practical 128mm DP DD.

Getting He177B going as 1:2 alternative to He 111, reduces strain on aircrew (half aircrew needed).

With these "big picture" changes, Germany has the assets to challenge local superiority in the Nth Atlantic.

Denmark and Norway can be invaded before Poland, and their Gold reserves captured to pay for a bigger KM.
 
Most posters see rearmament beginning in 1935/36 Hitler years and thus cripple any chance of build descent warship/fleet. A better approach is to start from Naval plan 1928 [1932] and evolve from that POV. This plan was based on building the following fleet by 1938-40.

1 Aircraft Carrier [modeled on HMS Glorious]
6 improved Panzerschiffe [AGS stretched to include third 11"turret]
6 improved Kreuzers [improved L class => M class]
several flotilla's of Gross Torpedoboot [improved GTB 1924]
several flotillas of U-Boats. [Type-I & II ]
9 squadrons of maritime aircraft.

No doubt such a build is possible within the historical framework , but hard choices would be needed. Historically 21 large warships were laid down in the 1930s.
 
The alternative is have two of the Hippers built as "Weser" auxiliary carriers (CV < 10,000 tonne are not counted under treaty). Use these to "trials carriers" to "solve" any carrier problems.

Keep S&G, as escorts, and build B&T as repeat S&G, saving 18 months in slip time, and ships ready much earlier.

Build GZ without 150mm, and start PS 18 months earlier. By time both carrier enter trials, naval air wings are ready.

Therefore have two balance groups of 2 BC, 2 CV & 1 CA. This can form mini scout group of CA & CVL.

Still have lots of cancelled construction (H&P class) to divert into U-boats and DD. That's before allowing for some pre-fab in a high battery snort boat and a more practical 128mm DP DD.

Getting He177B going as 1:2 alternative to He 111, reduces strain on aircrew (half aircrew needed).

With these "big picture" changes, Germany has the assets to challenge local superiority in the Nth Atlantic.

Denmark and Norway can be invaded before Poland, and their Gold reserves captured to pay for a bigger KM.


Bad idea, as that would require a serious shift politcally not to construct big battleships, which was the primary goal of the German Navy in the first place. Politically this plan would be rejected with no hessitation.

Also the role of an aircraft carrier was still unclear, partly due to absense of experience, partly due to the fact the Kriegsmarine was not an ocean going controlling force, like the big Naval powers UK, USA and Japan, but would focus more on tactical usefulness of such a ship, which is already doubdfull and with a lot of uncertaincies.

If a large, or small aircraft carrying warship was to be included, it was purely carrying aircraft for self defense, not offensive duties. The large number of German Hybrid Designs point into that direction as well. Basically the Kriegsmarine followed the later Soviet Navy thinking of the Aircraft Carrying warship to be a cruiser in the first place, with an additional complement of aircraft as well. Graf Zeppelin was excactly such a vessel, with a large number of LA guns included in the design, which took up a lot of space in the hangardecks and internally due to their magazine and ammunitionsupplies. Besides that, the ship was armroed like a cruiser in cruiser style fashion, including an armored deck low in the hull with sloped sides, typical for a cruiser. If not armed with cruiser sized guns, the ship would have been rejected form start, as the Kriegsmarine saw no role for a pure aircraft carrier in tis ranks.

Moreover, the biggest problem remained poltics, as the war simply started too soon for teh Kriegsmarine to have a fightingforce to use against its enemies. The only way to deal with it was to use what it had at the time and what was likely to be completed at short notice, rather than fighting with paper things not even started with. Submarines were simmilarly at short notice, though a crash building program started quickly to increase production rapidly as well as training a growing number of personel for it. Even that would take up time, so no wonders here as well.
 
Most posters see rearmament beginning in 1935/36 Hitler years and thus cripple any chance of build descent warship/fleet. A better approach is to start from Naval plan 1928 [1932] and evolve from that POV. This plan was based on building the following fleet by 1938-40.

1 Aircraft Carrier [modeled on HMS Glorious]
6 improved Panzerschiffe [AGS stretched to include third 11"turret]
6 improved Kreuzers [improved L class => M class]
several flotilla's of Gross Torpedoboot [improved GTB 1924]
several flotillas of U-Boats. [Type-I & II ]
9 squadrons of maritime aircraft.

No doubt such a build is possible within the historical framework , but hard choices would be needed. Historically 21 large warships were laid down in the 1930s.

Cancel the carrier was more likely still. One aircraft carrier with no reserve is a failure to happen anyway. The idea to continue building cruisers with 28 cm artillery was a flawed project, after the French Dunkerque was started with adn other navies also announced starting to build fast battelships of around 28 -30 knots. In the OTL the battleships of the Scharnhorst class were build as a response to the Dunkerque, provoking the British to develop their King George V as fast (28 knots) battleship, where earlier it was a slow battleship on paper with 23 knots. France answered to the Scharnhorst, as well as the Italian Littorio, by building the Richelieu class, which resulted in Germany starting the Bismarck class (After that the British came with Lion)

M-type cruisers were an integral part of the Plan-Z, though purely seen as supportships for the H-Class battleships, not so much the independant raider, untill the slightly smaller Spah-Kreuzer came around, releasin ghte M-type to become a pure merchant hunter, liek the Great War period SMS Emden had performed well. That means: no H-Class BB's, no M-Class cruisers, as the type was not very well thought through as fighting ship in the first place and weak compared to contemporary designs abroad.

Also missing completely is the Destroyer program, as the "Gross Torpedoboote" were not seen as destroyers by the Kriegsmarine, due to their offensive purpose. A more Multi-purpose design was missing still, which eventually became the large Zerstörer types, with their flawed powerplants. As a design these ships were a bit large, but well thought through, plagued by unforseen technical problems, which did plague more than just these nice looking ships btw.

In the U-Boote, the Type I was a flawed design, being not addaptable for mass production, compared to the slightly smaller Type VII. Also the Type I and Type II lacked range to cover the Atlantic, forcing the need to also create a long range type as well (Type IX). Likewise Type II, Type VII and also Type IX were relatively easy to construct and maintain, besides tough.
 
re-read Fleets of World War II and while not particularly positive about Graf Zeppelin they seemed to endorse idea of carrier/raider (at least during 1940) re-supplied "by subs and air."

while still negative on idea of conventional carrier, Germany had years of experience with seaplane tenders including operation of some huge Blohm and Voss aircraft.

what if ship size of GZ built as fast, super fast (be it 33 or 35 kts.) tender? (with the same OTL CA level of armor protection)

forgot to mention the Swedish Gotland https://en.wikipedia.org/wiki/HSwMS_Gotland_(1933) which was considered revolutionary at the time, albeit without many imitators.

a ship the size of Graf Zeppelin would allow for enclosed hanger, left out of Gotland final design and of course more aircraft.
 
This basically.

I maintain that Germany should leverage what they are good at - Aeroplanes and submarines 'not' aircraft carriers.

Why did the u-boats fail in WW1 - the Convoy system.

Whats the best way to find those convoys - LRMP Aircraft - Germany had a pretty good LR Aircraft which it could use as a basis for a VLR MPA - the Condor.

Build more of them and improve upon the design.

Amen.

I guess if you kill off Goering early enough somehow, that might clear the logjam enough to...theoretically have a couple carriers nominally in commission by 1939, and maybe even some planes to operate off them. But how would Germany realistically operate them with any success? They just don't have the two decades of hard earned lessons in carrier aviation that Japan, the UK and the US had by then.

Better to spend the money on submarine development, and long range aircraft. And maybe a fruit basket.
 
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