Lack of German Aircraft Carrier

Any line drawings?

Not in that article.

The article was in the March 2007 copy of The Aeroplane.

There is a book published by AJ Press on this subject with plans:

AJ Press EOW 42 - Graf Zeppelin (książka) - 65,00PLN : Jadarhobby

The wreck was discovered by Polish divers in 2006.

shes a beauty

This is interesting German Carrier-Based Aircraft

Dear R Leonard,

this time I need to adress some points of Your post, which I find questionable. You tend to underestimate potential, which is something I cannot agree in after having studied this case for some time. Of course, this is not ment to upset You, as You have well reasoned cases and thus, Your opinion is founded, so we just might enjoi to discuss this properly.

At the root of the problem is the plain fact that the Kriegsmarine had no naval doctrine that included carriers. Great Britain, Japan, and the US, the major players in the aircraft carrier business, had been operating pure aircraft carriers since the 1920's in case of the later two and, without looking it up, about 1918 for Great Britain

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Have You any source, which can confirm the claim that there was no tactical doctrine for an Aircraft carrier? I have some time spend in archives, Freiburg and the Berlin ones and so far, most sources regarding Graf Zeppelins tactical use disappeared. They had existed as the tech.Div. numbers eloquently proof. Just wondering if You had access to them or not.
Germany had plenty of experience with aircraft mother ships going back into ww1. Those had a flightdeck to launch 3 planes but not to land them. SMS STUTTGART was the first prototype. Experience with them was good and casualties are two (total losses) for 283 launchs. Plans to convert the old cruiser SMS ROON were dropped for a more radical design.

"It was then planed to convert the incomplte Italian passenger ship Ausonia - under construction at the Blohm&Voss shipyard in Hamburg - into a Flugzeugdampfer, a design which was a mixture between a aircraft mother ship and an aircraft carrier. This ship was projected to carry up to 19 float planes and 10 land based aircraft. Like other contemporary carrier designs, it had two flight decks, one large landing deck at the stern and a shorter start deck at the bow, where the aircraft could start out of the hangar directly(call it Battlestar Galactica). In difference to the exisiting British carrier, the Ausonia was planed to bet a island-type superstructore on the lfight deck, a feature that was later used on all aircraft carriers."
Ausonia History

In the interwar period, Germany was not allowed to upkeep carriers and armed aircrafts anyway, You cannot blame them for this. Despite this, R&D went forward. As a matter of fact, Heinkel contributed largely to japanese carrierplanes, including all technical details of launching catapults, fuselage strengthening and launch&recovery procedures. The Lufthansa kept three Aircraft motherships in the Atlantic in the late 20´s and early 30´s for postal services. The technical personal of those "experimentators" later can be found in design environment of german carriers.

By "pure carrier" I mean carriers whose airplanes are wheeled, are recovered aboard ship by some sort of arrestor arrangement (however primitive in the early years), and could also be operated from land bases.

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They indeed had no aircraft carriers in commission matching Your definition. But this doesn´t deevaluate the steps they had already done.

Further, the aircraft in use (again except for the very early models) were specifically designed for carrier operations. The navies of these three nations worked out the problems and challenges of carrier operations in the 20's and 30's and became, each in their own way, the best in the business. The feeble attempts of the Germans (and the Italians) to, first of all, develop aircraft carriers, much less carrier aircraft, were, frankly, laughable in retrospect.

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Germany was leading in float planes. The Do-D torpedo bomber of the 20´s was - as a matter of fact- superior to the Swordfish in use by RN in ww2. The Do-22, which emerged just before outbreak of ww2, was competetive to the worlds finest torpedo bomber planes. The Do-22W was build with wheeled undercarriege and it was proposed to use this plane in case the Fi-167 doesn´t become operational in time as carrier attack plane. The Do-22W arguably is one of the finest planes for this purpose by 1940.

All you have to do is look at the main guns and their placement aboard Graf Zeppelin and it's obvious that the Kreigsmarine considered surface vessels as the major threat to their carrier. Imagine, eight 5.9 inch guns in hull mounted barbettes. Probably great for banging away at some British destroyers as they come boiling over the horizon, but since that was a bit unlikely, here was wasted ordnance (read: weight penalty) for no apparent gain

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The 16 x 5.91"/55 QF are indeed misfortunate. But they are necessary! Unlike the RN, IJN USN, the DKM had not enough escort vessels to protect a ship like Graf Zeppelin on independent missions. The DKM was building from almost zero. The geographically problematic situation assured that escorts with proper range speed would almost certainly have been cruiser sized (but underarmed) and thus become impossible. That´s why Graf Zeppelin was armoured and armed like a large cruiser, with good hull protection excellent underwater protection. It had substantially more staying power than f.e. british or US carriers.

Even pre-war, the RN, IJN, and USN could have told them that that was a waste of time and effort; that the real threat to the ship was in the air.

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Not before 1941. Experience showed that a large cruiserforce was avaiable to the RN. Whether or not the 5.91" would be useful in the intended role is unclear. but they give some credible self defense against ships, which were considered indeed a big thread.

Unlike the dual-purpose 5 inchers on the Essex types (and they were, in the reality of their usage, single purpose AA guns) the Graf Zeppelins 5.9's were not optimized for antiaircraft defense and would have been essentially worthless for that purpose.

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The 5.91"/55QF had an elevation of -10 /+ 37 degrees and thus were no high angle weapons. But they have been used against torpedoplanes by Bismarck, Scharnhorst, Gneisenau, Prinz Eugen and Tirpitz. Against dive bombers, they are virtually useless, agreed. The general benefit might be questioned due to the low rate of fire (6-8rpm) and the low rate of training. The navy worked on it´s own 5.91"DP gun, but development was abandoned when Graf Zeppelin was cancelled in 1940.

The USN went down that road with Lexington class and their 8" turrets. By the mid 1930's it was recognized that those guns were so much dead weight. Note that as soon after the Japanese attacked Pearl the 8-inchers were removed and replaced on Saratoga with 5-inch dual purpose and on Lexington with temporary 1.1 in AAA mounts (Lexington was scheduled to receive 5-inch mounts, but she was sunk at Coral Sea before that could happen).

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Upgrades are thinkable for Graf Zeppelin as well. You cannot say whether or not the armement would have remained identic. The 5.91" twin deck mounts were anyway replaced by 4.1"/65 DP´s.

Another major failing in the Graf Zeppelin design was in an incomprehensibly low avgas storage capacity. The smallest and oldest carrier in the IJN, Hosho, had a capacity of 98,000 gallons and carried but 22 planes. Essex class carrier contemporaries of Graf Zeppelin had up to 240,000 gallons avgas capacity and, in practice, were replenished every three to four days during combat operations. And Graf Zeppelin . . . carried a paltry 65,000 gallons. How do you suppose they were planning on replenishing their avgas supply, not to mention their bunker fuel?

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If You check the number of planes and the relevant fuel load, you will see that Graf Zeppelin isn´t worser. The replenishment was tasked to the Etappendienst.


Which brings us to the following 3 questions:

1.)was the carrier technically feasable?
2.)was it logistically feasable?
3.)Did it make strategic sense?

Let me examine these questions in detail:

I think that the 109T would have suffered a huge accident rate.

Just like the Seafire.

1) Was it technically feasible?

Unlike ships of the first world war, german capital ships in the second world war were designed to act independently in the open ocean. Crew accomodations were mediocre, working environment excellent (except very congested machinery spaces, a side effect of minutelike subdivision as those executed in Graf Zeppelin). Graf Zeppelin was subject to several innovative shipbuilding techniques, such like extensive use of welding instead of riveting. Much intention was put to keep the vitals "safe" and Graf Zeppelin is one of very few carriers with a good metacentric height (for that matter better than even Shinano) and thus good stability and less listing in heavy seas(altough not as good as a BB, of course).
However, while this was an advantage in the enclosed waters of the North Sea or Baltic, this characteristic would normally lead to great personnel discomfort in open ocean seas and therefore reduce their efficiency and endurance in stormy weather (while the maximum list is LESS, the roll period is SHORTER).
That does not mean that they were limited out of confined waters, Graf Zeppelin was fully able for extended voyages in rough seas. Her high freeboard and the good stability made her dry in even heaviest weather, altough uncomfortable.
Data for Graf Zeppelin give a range of 8000nm @19 Kts and about 6.500nm @ 24 Kts, which not only give a significant advantage in high speed cruise range over japanese,british US carriers of that time but also give a range for independent atlantic operations.
The degree of mechanical safety in the launching recovery plants of Graf Zeppelin exceeded the necessary figure by a large margin. Much emphasis is put on the twin compressor catapults slips, which allow starting planes to retract their gears (in this case the Bf-109 only) before take off giving them a much superior speed advantage over common procedures. It would also allow to start overloaden planes and the mechanical reliability of these devices is prooven on the aircraft mother ships Falke Bussard, which both used that slip to launch Do-18, Do-22 and BV138, planes with up to 20 metric tons take off weight(!). It is technically entirely possible start overloaden Do-217/317 medium bombers with them. That gives a significant potential for future development on Graf Zeppelin.
The ship had three main elevators and a sophisticated damage controll system with much emphasis put on fireproof construction and fire countermeasures. One reason why the total avgas load was reduced is the deliberate limitation for a higher degree of survivability, esspeccially against possible surface ship encounters.

My answer to question 1 is Yes, it was feasable.

Del,

The purpose of an AC carrier is to perform aircraft operations.

If it has a limited av gas store.... or a limited aircraft capacity, then its not performing that role.

Events in the Pacific proved that the carriers were better served in the long run by carrying more AC and less armor and guns.

I partly agree, Syscom. But the Pacific is very different to the Atlantic. If You file down carrier operations in the North Atlantic, You will see what I mean.The Avgas on GZ was only low in absolute numbers, not in relative ones. The Essex could carry fuel for up to 120 planes, GZ for only about 40. It would be better to compare her in this respect to british carriers or US escort carriers, which had a comparable airwing.

The limitation on AC was a tradeoff. Not ideal for an CV but necessary in the strategic environment. Comparable thoughts lead to a lower AC numbers for later british carriers. As I said, the Atlantic was very different.

delcyros said:

I partly agree, Syscom. But the Pacific is very different to the Atlantic. If You file down carrier operations in the North Atlantic, You will see what I mean.The Avgas on GZ was only low in absolute numbers, not in relative ones. The Essex could carry fuel for up to 120 planes, GZ for only about 40. It would be better to compare her in this respect to british carriers or US escort carriers, which had a comparable airwing.

The limitation on AC was a tradeoff. Not ideal for an CV but necessary in the strategic environment. Comparable thoughts lead to a lower AC numbers for later british carriers. As I said, the Atlantic was very different.

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Comparing it to the US escort carriers is interesting. A ship that costs a fration to build as compared to a fleet carrier (GZ) carries the same number of aircraft.

The KM might have been served better served by having several smaller carriers than a single large fleet carrier.

Comparing it to the US escort carriers is interesting. A ship that costs a fration to build as compared to a fleet carrier (GZ) carries the same number of aircraft.

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Yes it is. At least from the point of view of avaible airpower. But those CVE, we talk about were found totally unsuited for Atlantic conditions and relegated to secondary duties, mostly as attack supporting group in the Pacific, where they could wreac havoc. They are too slow to be consedered a suitable for the german side and vulnarable. The difference is about 10+ Kts more speed, more range, much better protection, Air controll systems, and short range defense.

The KM might have been served better served by having several smaller carriers than a single large fleet carrier.

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Small carriers with 33+ Kts speed (necessary to disengage BB´s and most cruisers) and range for the Atlantic (at least 4000nm @ 24 Kts) could very well displace more than 20.000t. despite having an airwing as low as 24 planes. This doesn´t make them small. If they could afford a smaller speed, let´s say 20.000 SHP for ~20 Kts instead of 240.000 SHP for 35 Kts), they could safe space and weight for additional AC´s. That´s the trade the large CVE made. Unfortunately, such a trade isn´t possible in the Atlantic theatre of war, the large number of cruisers would hunt them down too easily. Such an CVE could be useful in the Baltic and maybe in Norway, too from the german perspective but not for the Atlantic theatre.

delcyros said:

Yes it is. At least from the point of view of avaible airpower. But those CVE, we talk about were found totally unsuited for Atlantic conditions and relegated to secondary duties, mostly as attack supporting group in the Pacific, where they could wreac havoc. They are too slow to be consedered a suitable for the german side and vulnarable. The difference is about 10+ Kts more speed, more range, much better protection, Air controll systems, and short range defense.


Small carriers with 33+ Kts speed (necessary to disengage BB´s and most cruisers) and range for the Atlantic (at least 4000nm @ 24 Kts) could very well displace more than 20.000t. despite having an airwing as low as 24 planes. This doesn´t make them small. If they could afford a smaller speed, let´s say 20.000 SHP for ~20 Kts instead of 240.000 SHP for 35 Kts), they could safe space and weight for additional AC´s. That´s the trade the large CVE made. Unfortunately, such a trade isn´t possible in the Atlantic theatre of war, the large number of cruisers would hunt them down too easily. Such an CVE could be useful in the Baltic and maybe in Norway, too from the german perspective but not for the Atlantic theatre.

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Build several of them on a light cruiser design which would give you 25 knots speed and to carry 40 or so aircraft.

If operated in pairs, you have the equivelant airpower from a large carrier.

And it wouldnt need to worry about being slower than a BB or CA...... the attack aircraft would be sufficent to put the fear of god into them.

2.) Was it logistically feasable?

The German Navy in ww1 had a competent Etappen-Dienst, which differed a bit from the service in ww2. The Etappendienst provided timely coordinated resupply of warships with food, fuel, fresch water and ammunition on remote anchorages or in quiet bays along the coastlines of west African and South America (or Greenland or even Newfoundland for that matter!) despite the huge numerical superiority of the allied forces in both wars. It is not convincable why avgas shouldn´t have been provided while fuel and ammo could.
In addition, international law regarding the refueling of belligerent warships in neutral waters made clear that warships loose in the Atlantic could have re-provisioned and obtained fuel in many places -- including, conceivably, ports on the United States eastern seaboard (until declaration of war) or ports under japanese controll on the west asian seaboard later in the war (DKM Scheer ventured in the indic ocean, also).

My answer to question 2.) is yes, a carrier could be resupplied effectively.

Build several of them on a light cruiser design which would give you 25 knots speed and to carry 40 or so aircraft.

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CL´s do not have the stability required for a top weighted ship like an CVE and more worrisome, they have not the internal space required.
Most CVE´s were rebuild from merchant ships, which gave low speed (14-18 Kts typically) but enough space for the hangar related structures under the flightdeck. Space, I think, is critical here.

A reasonable option would be to rebuild fast passenger ships. These are stable enough, reasonably fast and have the required space. Unfortunately, they are very large. Scharnhorst, Gneisenau, Europa and Bremen come to mind for this purpose.

delcyros said:

CL´s do not have the stability required for a top weighted ship like an CVE and more worrisome, they have not the internal space required.
Most CVE´s were rebuild from merchant ships, which gave low speed (14-18 Kts typically) but enough space for the hangar related structures under the flightdeck. Space, I think, is critical here.

A reasonable option would be to rebuild fast passenger ships. These are stable enough, reasonably fast and have the required space. Unfortunately, they are very large. Scharnhorst, Gneisenau, Europa and Bremen come to mind for this purpose.

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The Cleveland class hulled CL's worked out fine.

There was no reason the KM couldnt come up with a similar design.

There was a reason why all Independence class CL have been deployed to the Pacific. The Cleveland hull was way to top heavy and an unpleasant seaboat in it´s carrier reborne. It lacked stability.
France overtook one Independence CL in post wartimes (for about 10 year) but had to reduce the airwing and increase ballast to make her suitable for the Atlantic. Even then La Fayette was considered both, unstable and very congested. The details of unprotected ammunition and avgas storage would not for a moment have been tolerated by the Kriegsmarine, at least from a ship of identic size to their pocket battleships (11500t. standart and little over 14.000t. full load).

3.) did it strategically make sense?

For discussion purposes, let us first ignore the fact that Göring would never have sanctioned an independent airwing on Graf Zeppelin!
If the true goal of the operation were solely commerce raiding with a goal of interrupting Britain's supply lines, then I would say that such a plan did NOT make sense. Sending out a Graf Zeppelin centered Task Force to roam the open ocean in search of individually-sailing merchant ships would have been futile indeed. What were the rest of the squadron supposed to do while one of their number searched and sank the occasional tramp steamer they jointly came across? Britain had a substantial advance in carriers and as we must suppose, had an experience advantage, also.
Graf Zeppelin, following german post ww1 design practice, was fast enough to disengage most surface combatants as long as GZ remained undamaged. That points to risks from above or below the waterline. While the RN had some credible submarines, this danger is of secondary nature and airplanes become the major thread. I have wondered about how swordfishs will do against GZ. The suprisingly poor performance of the Bismark's FLAK is probably at least in part attributable to an incorrect setup caused by having two different 105mm gun mounts with different characteristics that were not accounted for in her setup. The Bismark carried both the Dop. L. C/31: Dop. L. C/37 mounts. The earlier mount was actually an upgunned 88mm turret while the latter was purposely designed for the larger high velocity 105mm gun. They were both relatively sophisticated, triaxially stabilized units (compensating fully for the motion of the ship). The Bismark had Dop. L. C/31 on the front four pairs of FLAK and the 25% faster traversing Dop. L. C/37 mounts on the rear. Tirtpitz GZ had only Dop L. C/37 all round. From what is known about Tirpitz, she defended herselve quite well in 1942 during the Victorious air attack in the open ocean, downing two planes, GZ should be estimated to do not worser with more FLAK than Tirpitz. The same instance showed that Tirpitz headed with 30 Kts into the wind and the Albacore (successors of the Swordfishs) had a long time to catch her. GZ with it´s 35 Kts speed could elongate the approaching time even more, against slow Swordfishs up to the point when it becomes hopeless (depending on windfactor, but an approaching speed of 20-40 mp/h at best will make good target´s out of You for the light medium AAA).

But in 1941/42, ww2 had long since seen the introduction of convois and the only reasonable purpose to sortie that many capital ships as a group would be to overwhelm a heavily defended convoy guarded by heavy ships. A task force centered around Graf Zeppelin should include the twins preferably then (they are fast, too.). But still, this doesn´t make much sense to me. A Task Force is an attractive target and the RN repeatedly showed it´s ability to trap forces.

A unified squadron made up of BC´s, CA´s and Graf Zeppelin would have been forced to spend the majority of their time between regularly scheduled meetings with supply ships to keep their bunkers full rather than aggressively running down every ship on the ocean to send to the bottom. When it comes to destroying merchant ships there was nothing that a carrier could do out on the wide Atlantic that a couple of light cruisers on the loose couldn't have done equally well, except that Graf Zeppelin projects a larger effective fighting zone into the Atlantic with air ops.

Other situation if the reason was to send out GZ onto the broad Atlantic sea lanes in order to disperse the Home Fleet, then it doesn´t need to be covered by big ships but instead could operate independently on a sole base. Realistically spoken, the German Naval Command had to reckon with the eventual loss of the ships sent out on such mission.

A single German carrier located somewhere between Cape Cod and Liverpool would have been enough to paralyze shipping between North America and Europe and force the Royal Navy to send out massive search forces. Synergetical effects might be estimated on a timely planned breakout of Tirpitz and / or the Twins or Prinz Eugen on independent raids in the Atlantic.
Let us hypothetically assume that the Germans in late 1941 decided to use Graf Zeppelin in such a capacity. Her appearence on the Atlantic would have forced the RN to send out large forces to search her. By this time, Renown KGV were the only remaining fast ships of the RN, which could tackle GZ (both beeing slower by 5-6 Kts). Other ships, which could compete with her speed were hopelessly underarmed underprotected to tackle GZ(32000t 35 Kts, 40 planes).
The Royal Navy had the following CV´ s at it´s disposal:

1.) HMS Argus (14.000t. 20 Kts, 20 planes)
2.) HMS Eagle (22.000t. 24 Kts, 21 planes)
3.) HMS Victorious (23000t 31 Kts, 33 planes)

4.) HMS Audacity (11.000t. 15 Kts, 6 planes) -CVE-
5.) HMS Archer (16000t. 17,5 Kts, 16 planes) -CVE-

Other non avaiable:

1.) HMS Furious (22.000t 30 Kts, 36 planes) under refit (drydocked) in the US
2.) HMS Hermes (11.000t 25 Kts, 15 planes) in transfer, sheduled for drydocking in the UK
3.) HMS Formidable (23000t 31 Kts, 33 planes) under repair (drydocked) in the US.
4.) HMS Illustrious (23000t 31 Kts, 33 planes) under refit (drydocked) in the US.
5.) HMS Indomitable (23000t. 30.5 Kts, 45 planes) sea trials, working up

The avaiable RN carriers are a very inconsistent group by late 41. Their speed ranges from 15-31 Kts, all having individually less endurance, less protection, less speed and a SMALLER airwing than the larger german carrier Graf Zeppelin.
Even the RN newest CV, HMS Indomitable, has a comparably sized airwing and comparable avgas storage (not considered a problem here) but for expanse in protection, endurance and speed. Graf Zeppelin does not compare unfavourably. To cover the most lucrative areas for German naval and / or carrier interdiction ( West Indies, Western Approaches, and mid-Atlantic narrows) would thus have required at least 6 fleet carriers -- approximately twice the number of ships that the British had aviable. Mathematically and strategically from a raiders perspective, it was wiser to send ONE ship than it was to send four!!!

Good analysis Delc.

The GZ needed a few more years to realy get going, but realy the program was doomed. I would have to say she had to meny guns on the decks that appear to be more for surface actions then AA. A fleet carrier that had the speed like GZ would have been very good in the open ocean with the u-boats and large surface ships.