Carrier based kriegsmarine

[Dorknought]

To be fair though, it’s not like Germany was starting from nothing like the original carrier users did, you would have thought that at least some “lessons learned” could have played into the GZ design, even without going and asking the Japanese?

I think the design component is pretty straight forward. This is what Clement Ader wrote in L'Aviation Militaire in 1909:
"An airplane-carrying vessel is indispensable. These vessels will be constructed on a plan very different from what is currently used. First of all the deck will be cleared of all obstacles. It will be flat, as wide as possible without jeopardizing the nautical lines of the hull, and it will look like a landing field."

Even the RN's first effort at a ship for aircraft had anticipated the correct features with the 1914 Ark Royal, hangar, workshops, clear decks, fuel storage etc. The biggest German problems are organisational, Raeder just regarded a carrier as an 'avgas' tanker. There was no naval airforce, same problem with Italy. Neither the Luftwaffe nor the Kriegsmarine was sufficiently 'jointy' to make sea going naval airpower to work.

 

[Jacarí]

The "heavy bomber theory" will run afoul of the Luftwaffe and nazi politics. Afaik, the only defender of a large(ish) heavy bomber force with any real political/military clout was General Walther Wever, and he died in 1936. After he died, the light/dive bomber mafia took over, backed by medium bombers, and heavy bombers went out the window. It would take the Battle of Britain to show why the Luftwaffe needed them. And you'd pit navy vs air force politics one against the other, even worse than in OTL.

The LW still had a heavy bomber program, only Udet required it to dive bomb... the rest is history.

 

[Jacarí]

There was a fair bit of post WW1 complacency about the effectiveness of ASDIC, but was there evidence to justify a hedgehog type weapon based on WW1 experience?

This is really an allied development question, but the same questions could be asked for any proposed German antisub role, so does stay more or less on topic. A hedgehog style projector and helicopter/ autogyro would be bad news for enemy subs whoever operated it.

The Germans already had part of the equation:

The other was a bit late:

 

[Jacarí]

that is certainly a better program than what was constructed (or under construction) historically. especially the scaled down size carriers would seem a more appropriate and feasible project.

The problem is, the KM was somewhat aware that the smaller carriers were a dead end, basen on RN, IJN and USN experience.

Hence the larger CV, crippled by lack of LW cooperation. I understand the LW refused to provide data on possible aircraft sizes and limited to estipulate that there be a 2m seperation betwwen aircraft and hangar walls.

Just like on land.

my comment has been the KM needed a coherent fleet, how could that be related to any carrier development?

I would disagree on that point, I think the KM needed to be a commerce war oriented navy, carriers would be a huge part of that. Within the confines of the AGNA of course, they had to at least pretend to play ball.

And they could still invest most of the leftover tonnage on these:

 

[Hammerbolt]

The LW still had a heavy bomber program, only Udet required it to dive bomb... the rest is history.

Yeah utter insanity... poor He-177...

 

[JasTysoe]

The problem is, the KM was somewhat aware that the smaller carriers were a dead end, basen on RN, IJN and USN experience.

Hence the larger CV, crippled by lack of LW cooperation. I understand the LW refused to provide data on possible aircraft sizes and limited to estipulate that there be a 2m seperation betwwen aircraft and hangar walls.

Just like on land.


I would disagree on that point, I think the KM needed to be a commerce war oriented navy, carriers would be a huge part of that. Within the confines of the AGNA of course, they had to at least pretend to play ball.

And they could still invest most of the leftover tonnage on these:

But hybrids were utterly impractical, as every design study realised, which is why they were rejected.

 

[Dorknought]

But hybrids were utterly impractical, as every design study realised, which is why they were rejected.

Yes it is a 'timid cruiser' and only realistic as a treaty exception which the USN didn't follow up and built New Orleans class cruisers instead. The RN had figured early on with exercises that it was pointless arming carriers for surface action the trick being to not be caught by enemy cruisers. For other navies there may be a valid need to have the ability to land with wheels at sea. Graf Zeppelin was simply a scaled up cruiser with landing deck and launch by catapult. She had the broadside of a light cruiser, the armour of a heavy cruiser and speed of a destroyer. If your mission is to not get found but to gather recon then a flight deck cruiser is reasonable. AGNA would allow 3 13,000ton hybrids that you could always plan to extend to full deck at a later stage.

 

[Jacarí]

But hybrids were utterly impractical, as every design study realised, which is why they were rejected.

Actually the RN concluded that it was the perfect trade protection vessel... and raider! Which is why they opted to not introduce the type in order to not give other people ideas.

The IJN was about to (Soryu was going to be VERY different) when they decided to just quit the treaties instead and simply make more carriers.

The USN played a lot with the concept throughout the 1930s, but in the end decided against it.

 

[Jacarí]

Yes it is a 'timid cruiser' and only realistic as a treaty exception which the USN didn't follow up and built New Orleans class cruisers instead. The RN had figured early on with exercises that it was pointless arming carriers for surface action the trick being to not be caught by enemy cruisers. For other navies there may be a valid need to have the ability to land with wheels at sea. Graf Zeppelin was simply a scaled up cruiser with landing deck and launch by catapult. She had the broadside of a light cruiser, the armour of a heavy cruiser and speed of a destroyer. If your mission is to not get found but to gather recon then a flight deck cruiser is reasonable. AGNA would allow 3 13,000ton hybrids that you could always plan to extend to full deck at a later stage.

GZ was a full carrier, not a cruiser.

The catapult was a must since, if chased, GZ would not get the luxury of choosing direction meaning a launch without wind assistance. Same foe the speed and armament.

Hybrid cruiser tonnage would come from cruiser tonnage, not CV tonnage, and anything would be more useful than a Hipper.

 

[Dorknought]

GZ was a full carrier, not a cruiser.

The catapult was a must since, if chased, GZ would not get the luxury of choosing direction meaning a launch without wind assistance. Same foe the speed and armament.

Hybrid cruiser tonnage would come from cruiser tonnage, not CV tonnage, and anything would be more useful than a Hipper.

GZ is more of a 'corsair' like the ideas behind the 1920's carriers that everyone had moved on from. Even changes to the design added armament not aircraft and her airgroup was only 40. Not exactly a 'full carrier' by leading naval standards.

From the 1st London Treaty 25% of cruiser tonnage could be 'hybrid' landing on only. From AGNA's perspective this would amount to 3 10,000ton ships. From total cruiser tonnage of 85000 tons including existing 6 6,000ton light cruisers you have 49,000 tons left so you could build 3 flight deck and 2 heavy cruisers. I'd still use the Carrier tonnage for similar hybrids and 4 'battleships' also designed as long range heavy gun cruisers, something like the O-Class 35 knots and 6 15" guns.

 

[CaptainCalvert]

Actually the RN concluded that it was the perfect trade protection vessel... and raider! Which is why they opted to not introduce the type in order to not give other people ideas.

The IJN was about to (Soryu was going to be VERY different) when they decided to just quit the treaties instead and simply make more carriers.

The USN played a lot with the concept throughout the 1930s, but in the end decided against it.

Given the shortage of practical experience, it only has to look like it should work to be potentially acceptable.

 

[Jacarí]

GZ is more of a 'corsair' like the ideas behind the 1920's carriers that everyone had moved on from. Even changes to the design added armament not aircraft and her airgroup was only 40. Not exactly a 'full carrier' by leading naval standards.

From the 1st London Treaty 25% of cruiser tonnage could be 'hybrid' landing on only. From AGNA's perspective this would amount to 3 10,000ton ships. From total cruiser tonnage of 85000 tons including existing 6 6,000ton light cruisers you have 49,000 tons left so you could build 3 flight deck and 2 heavy cruisers. I'd still use the Carrier tonnage for similar hybrids and 4 'battleships' also designed as long range heavy gun cruisers, something like the O-Class 35 knots and 6 15" guns.

The changes to the armament intended to replace the 15cm casemantes with more 10cm flak, when it was judged impossible, they added the 6th 10cm mount on deck.

GZ had a larger hangar area than Ark Royal, larger in fact than any non-IJN carrier in the world, they could have carried more aircraft had they wanted and would have quickly corrected that in service.

Germany was not a signatory of the London treaty, just the AGNA and the 1937 one, therefore they are not so limited... or they can lie and do it anyways.

 

[Dorknought]

GZ had a larger hangar area than Ark Royal, larger in fact than any non-IJN carrier in the world, they could have carried more aircraft had they wanted and would have quickly corrected that in service.

IJN, Hosho, had a capacity of 98,000 gallons avgas and carried 22 planes
IJN Shokaku, 150,000 gallons, USN Essex class 240,000 gallons avgas and replenished every three to four days during combat operations.
Graf Zeppelin had 65,000 gallons, less than Hosho for an airgroup twice the size.

 

[Jacarí]

IJN, Hosho, had a capacity of 98,000 gallons avgas and carried 22 planes
IJN Shokaku, 150,000 gallons, USN Essex class 240,000 gallons avgas and replenished every three to four days during combat operations.
Graf Zeppelin had 65,000 gallons, less than Hosho for an airgroup twice the size.

Yes, GZ had a similar air group as an Illustrious and a similar fuel capacity.

Which means that if the KM increased its air group, the 15cm casemates would have to go and the magazine space used for avgas.

 

[thaddeus]

If what the Germans wanted is ships to be the eyes of the fleet how about a hybrid of their merchant raiders and a CAM ship? I can see that appealing to the Germans and lot easier to disguise than building carriers.

If the objective is spotting and surveillance, at what point do autogyros and helicopters become viable to use in Baltic and in North Atlantic conditions? And what then does this permit in terms of a fast light vessel that can help extend the effective scouting range?

As merchant raiders go, kind of hard to hide compared to a few fixed weapons.

Yeah. And seaplanes do not make good strike aircraft: too slow to recover, if the catapult fails they are either stuck or have to be lowered to the water, slowing things down, limited payload...

missed this exchange but thought it worth revisiting. the merchant raiders needed some aviation component, but fell victim to the latter two points, it alerted nearby ships a raider was present and the aircraft were cumbersome to launch and somewhat fragile (with the methods used on the converted ships)

the prescient strategy would be autogyros/helicopters across a wide range of ships from raiders and other large commercial ships. build more Dithmarschen-class tankers (they have commercial value during the interwar period) to launch seaplanes and flying boats.

without disrupting the KM fleet build too much the Hipper-class could be reconfigured to handle more seaplanes?

 

[Jacarí]

without disrupting the KM fleet build too much the Hipper-class could be reconfigured to handle more seaplanes?

A Tone would make more sense for the KM than a Hipper:

A hybrid would be even better, but the best that could be done would be to get rid of the rear turrets and embrace the mediocrity.

 

[Hammerbolt]

missed this exchange but thought it worth revisiting. the merchant raiders needed some aviation component, but fell victim to the latter two points, it alerted nearby ships a raider was present and the aircraft were cumbersome to launch and somewhat fragile (with the methods used on the converted ships)

the prescient strategy would be autogyros/helicopters across a wide range of ships from raiders and other large commercial ships. build more Dithmarschen-class tankers (they have commercial value during the interwar period) to launch seaplanes and flying boats.

without disrupting the KM fleet build too much the Hipper-class could be reconfigured to handle more seaplanes?

A Tone would make more sense for the KM than a Hipper:

A hybrid would be even better, but the best that could be done would be to get rid of the rear turrets and embrace the mediocrity.

A "Tone/Hipper" would be excelent! They could use it to launch Me-109s with extra tanks; since most of their "work" would be in the North Sea, the fighters would stand a good chance of heading to land.

 

[Garrison]

missed this exchange but thought it worth revisiting. the merchant raiders needed some aviation component, but fell victim to the latter two points, it alerted nearby ships a raider was present and the aircraft were cumbersome to launch and somewhat fragile (with the methods used on the converted ships)

the prescient strategy would be autogyros/helicopters across a wide range of ships from raiders and other large commercial ships. build more Dithmarschen-class tankers (they have commercial value during the interwar period) to launch seaplanes and flying boats.

without disrupting the KM fleet build too much the Hipper-class could be reconfigured to handle more seaplanes?

Ah you I take it you missed the next part of that exchange where the discussion did move onto discussing the use of helicopters. There were a couple of designs that would have been useful. The Japanese did try adding lots of extra catapult launchers to some cruisers, not a stellar success overall.