• Visit our partners: Our Partners:
  • Visit our partners: Our Partners:

The Graf Zeppelin: Nazi’s Germany’s Unfinished Aircraft Carrier

Written by Matthew Copes

Flugzeugträger “Graf Zeppelin”. Baustadium Aufgen. am 20.6.1939 Deutsche Werke Kiel https://commons.wikimedia.org/wiki/File:Bundesarchiv_RM_25_Bild-31,_Flugzeugtr%C3%A4ger_%22Graf_Zeppelin%22,_Bau.jpg

Despite the severity of the war on the Eastern Front, by early 1945 the Soviet Union had regained the upper hand in its epic struggle against Nazi Germany.

Meanwhile across Europe, the Wehrmacht, Luftwaffe and Kriegsmarine were struggling for their very survival.

Though the Germans ultimately surrendered on May 7 of 1945, things might have turned out differently had they finished building a series of massive aircraft carriers years before. 

More than 860 feet (260 m) from bow to stern and tipping the scales at a whopping 33,500 tons, the first Graf Zeppelin-class carrier was nearly 10% larger than any similar British or American vessel in service during the Second World War.

Bristling with cannons, protected by heavy belts of armor along her deck and waterline, the Graf Zeppelin was designed to carry more than 40 aircraft.

That said, like many of Nazi Germany’s so-called wonder weapons, she ended up being a huge drain on resources that never entered a service, launched an aircraft, or fired a single shot.

Background

From the sinking of the Bismarck and Pearl Harbor to the Battle of Midway, as the Second World War progressed aircraft carriers became the undisputed kings of naval warfare.

Collectively, Britain, France, America and Japan had hundreds of fleet and escort carriers in service at various times during the war.

Conversely, Germany had none.

With war becoming increasingly likely, in the summer of 1935 Germany and Great Britain signed the Anglo-German Naval Agreement.

Registered with the League of Nations on July 12, 1935, the unpopular and controversial agreement set an arbitrary ratio which limited Kriegsmarine tonnage to just 35% of that in service with the Royal Navy.

But while Germany’s surface and submarine fleets were limited mere fractions of Britain’s gross tonnage, the agreement did permit the construction of aircraft carriers displacing up to 38,500 tons.

Flugzeugträger “A”. Baustadium Aufgen. am 22.3.1939 Deutsche Werke Kiel https://commons.wikimedia.org/wiki/File:Bundesarchiv_RM_25_Bild-29,_Flugzeugtr%C3%A4ger_%22Graf_Zeppelin%22,_Bau.jpg

Likening it to the Treaty of Versailles that had been imposed on Germany after World War I,  Hitler condemned the agreement in the spring of 1939

Under the terms of the Treaty of Versailles, Germany’s defeated navy was restricted to just 15,000 personnel and six capital ships, none of which could exceed 10,000 tons.

The treaty also forbade Germany from building submarines and aircraft carriers, and since new ships could only replace old ones, the number of capital ships in the fleet would remain static.

Needless to say, relegating the Kriegsmarine to perpetual anonymity was seen as an insufferable slight by many patriotic Germans. 

However, decades later the Kriegsmarine set out to rectify the situation by designing and building an entirely new class of four aircraft carriers that would be known as the Graf Zeppelins.

Designated Plan Z, the new carriers would be the crown jewels in Grand Admiral Erich Raeder’s massive rearmament scheme, the ultimate goal of which was to prepare the Kriegsmarine for future hostilities.

If all went according to plan, in less than a decade the Kriegsmarine would be transformed into such a potent fighting force, that it would be able to challenge the Royal Navy’s dominance of the high seas.

Specifications

With a complement of more than 1,700 officers and sailors, the Graf Zeppelin would have also accommodated more than 300 flight personnel including Luftwaffe officers, pilots, and ground crews.

Like all capital ships in the Kriegsmarine at the time, the hulls of the Graf Zeppelin class carriers were divided into 20 watertight compartments.

At the waterline, armor thickness varied between 1.2 inches (30 mm) and 4 inches (100 mm), not including an additional .8-inch (20 mm) anti-torpedo barrier situated just inside the main belt.

But though the Graf Zeppelin’s steel and wood-plank flight deck was 795 feet (242 m) long and 98 feet (30 m) wide, it was protected by less than an inch of armor which made it particularly vulnerable to naval cannons and bombs dropped from attacking aircraft.

Beneath the lower hangar, the thickness of the main armored deck varied between 1.6 and 2.5 inches (40 and 60 mm) to protect the all-important aircraft, magazines and propulsion components.

To make the massive ships as fast and streamlined as possible, the original length-to-beam ratio was set at 9.2 to 1.

This would have resulted in an especially narrow profile compared to America’s Midway-class carriers that had ratios of about 8 to 1.

However, as weight gradually creeped up during construction, the addition of deep stability bulges on each side of the Graf Zeppelin’s hull decreased the actual ratio to 8.3 to 1.

Though this reduced top speed and fuel efficiency, it offered more protection against torpedoes and actually extended range, since much of the extra space was used to store an additional 1,500 tons of fuel oil, bringing total capacity to nearly 6,500 tons.

Power came from 16 La Mont high-pressure boilers similar to those used in other capital ships.

Sending power to four shafts, total output was nearly 200,000 horsepower.

Cruising at 19 knots (22 mph – 35 km/h), range was expected to be about 9,700 miles

(15,400 km). 

In close quarters and when traveling below 8 knots (9.2 mph / 15 km/h) like when in port or traversing canals, maneuverability was assisted by two Voith cycloidal propeller-rudders, one in the bow, the other in the stern along the ship’s centerline. 

If the Graf Zeppelin’s main engines became inoperable, they were capable of propelling the ship up to 4 knots (4.6 mph – 7.4 km/h) in calm seas.

When not in use, the bow and stern thrusters were retracted into vertical shafts and protected by water-tight covers.

Housing the charthouse, command and navigation bridges, aircraft control tower, fire control center and a large exhaust shaft, the Zeppelin’s main superstructure or “island” was located on the starboard side of the deck.

To compensate for the superstructure’s weight, the flight deck and sub-deck hangars were offset by nearly 2 feet (.6 m) to the port side of the longitudinal axis.

OLYMPUS DIGITAL CAMERA https://commons.wikimedia.org/wiki/File:Graf_zeppelin_flugzeugtraeger_modell_04.jpg

Aircraft and Hangars

Though armored on top, the Graf Zeppelin’s upper and lower hangars were relatively unprotected on their sides and ends.

Total subdeck hangar space totaled nearly 59,000 square feet (5,500 square meters), which was enough to accommodate approximately 43 aircraft of various shapes and sizes.

Hangars included repair and storage facilities, machine shops and flight crew quarters.

Large Derek cranes were used to transport aircraft within and between hangars, and vertical movements between decks were made by three electric elevators equidistantly spaced between the bow and stern.

Each elevator platform measured 43 by 46 feet (13 x 14 m) and could move up to 5.5 tons.

But though the ship’s various systems were state-of-the-art, many of the aircraft that would be stationed on board were not.

The original complement of aircraft was to include 10 Messerschmitt 109Es, 13 Junkers Ju 87C dive bombers and 20 Fieseler Fi 167 biplane torpedo bombers.

In the fall of 1938, the Ministry of Aviation requested that Messerschmitt design a dedicated carrier variant of the Bf 109E fighter, designated 109T for träger, or carrier.

But while the 109Ts would have been worthy fleet defense fighters, the Junkers and Fieseler aircraft were already nearly obsolete, and would therefore most likely have been replaced by entirely new aircraft.

At the time an even more potent version of the 109T – the Me 155 – was on the drawing board, but despite showing promise the project was canceled when it became apparent that the Graf Zeppelin wouldn’t be commissioned for at least another two years. 

To get its aircraft into the air, the Graf Zeppelin was equipped with compressed air catapults for power-assisted takeoffs.

Just 75 feet (23 m) long, in less than a second each catapult could accelerate a 6,000-pound (2,720 kg) fighter to 90 miles per hour (145 km/h), or an 11,000-pound (5,000 kg) bomber to about 80 miles per hour (128 km/h).

Unlike non-catapult equipped carriers that generally had to turn into the wind to provide extra lift, this wouldn’t have been the case with the Graf Zeppelin,

The catapults themselves were cumbersome, dangerous, maintenance intensive and prone to breakdown, but they would have given the Graf Zeppelin a huge edge in combat situations.

Theoretically, more than a dozen aircraft could have been launched in less than six minutes, after which the catapult’s air tanks would’ve been entirely depleted. 

On the downside, refilling them took an hour, during which takeoffs were limited to those aircraft that could get airborne under their own power.

Hence, rolling take-offs would generally only be performed in emergencies, but such was the size of the Graf Zeppelin that aircraft could have taken off at the front of the carrier, while others simultaneously landed on the aft portion of the flight deck.

To facilitate rapid launches and increase operational readiness, between eight and 10 aircraft would have been kept on deck except in particularly bad weather or rough seas.

Since aircraft engines are heavy and contain copious amounts of oil, preheating the blocks and fluids before flight was imperative, but also time consuming.

To minimize preparation in cold and windy conditions, the deck was equipped with a number of steam heaters that kept the engine blocks and oil at a relatively constant 158 °F (70 °C).

During normal operation, engine oil would have been stored in separate steam-warmed holding tanks and transferred into the aircraft engines by hand pump just before taking off.

For landings, four tensioned arrestor wires were positioned at the rear of the flight deck, with additional emergency wires located both behind and ahead of the midship elevator.

To assist with night landings, the arrester wires would have been illuminated by neon lights.

Since towering carrier decks are susceptible to strong sustained winds and erratic gusts, a number of retractable barriers were positioned around the flight deck to provide more stable air during both takeoffs and landings.

About 13 feet (4 m) and 10 feet (3 m) wide, the wind barriers were constructed with slotted steel to permit some air to flow through them, and when not in use they could be lowered flush with the deck.

https://picryl.com/media/loading-mail-bag-to-airship-c0582e

Armament

Each carrier in the Graf Zeppelin class would have been armed with both low and high-angle guns of various calibers to provide adequate defense against aircraft and other surface vessels.

Though this made sense when it came to defense, it was a radical departure from carriers in service with the world’s other major navies.

Most were generally only equipped with relatively small caliber anti-aircraft guns, because they relied on their own aircraft and escort ships to protect them from surface threats.

In the anti-ship role, armament consisted of 16, 5.9-inch (150 mm) cannons paired in eight heavily armored casemates that were positioned around the perimeter of the upper hangar deck. 

But though this freed up vital space on the flight deck, it made the batteries susceptible to being “washed out” in heavy seas, particularly those guns located in the bow.

Primary anti-aircraft protection came from 12, 4.1 inch (105 mm) guns paired in six turrets – three forward of the superstructure and three aft. 

Secondary anti-aircraft weapons included a dozen 1.5 inch (37 mm) cannons mounted on sponsons located along edges of the flight deck.

Of these, four were positioned on the starboard side, six on the port side, and one on the forecastle near the bow’s peak.

Flight Testing

In the spring of 1938 the Luftwaffe began testing a number of aircraft that were under consideration for use on the Graf Zeppelin.

Trials were carried out at Travemünde on the Baltic Coast, but since the ship was little more than a skeleton, landings were executed on a traditional runway painted to match the outline of the Zeppelin’s flight deck.

Initial testing involved Heinkel He 50 dive-bombers and Arado Ar 195 torpedo bombers, both of which were obsolete biplanes.

Nonetheless, thanks to their twin wings the plans and ample lift and low stall speeds which made them perfect for testing the unproven system.

To simulate the rapid deceleration associated with carrier landings, the makeshift flight deck was equipped with arresting cables attached to electromechanical braking devices.

After a number of initial teething issues, pilots collectively racked up a landing success rate of about 85% out of more than 1,800 attempts.

The planes initially took off as normal land-based aircraft, but later a pneumatic catapult was installed on a barge moored in the Trave River Estuary.

Designed and manufactured by Heinkel, the catapult was capable of accelerating aircraft to 90 miles per hour (145 km/h) and getting them airborne in less than 100 feet (30 m).

Like they would be on the Graf Zeppelin and other carriers of the class, the aircraft were first positioned by crane onto detachable launch dollies.

Both the takeoff and landing systems worked remarkably well, and by June of 1938 Luftwaffe and Kriegsmare officials were adequately satisfied to begin forming operational fighter, reconnaissance and dive-bomber units. 

Flugzeugträger “A”. Baustadium Aufgen. am 22.3.1939 Deutsche Werke Kiel https://commons.wikimedia.org/wiki/File:Bundesarchiv_RM_25_Bild-30,_Flugzeugtr%C3%A4ger_%22Graf_Zeppelin%22,_Bau.jpg

Construction

Building the ships was a top priority for the Kriegsmarine, but due to limitations imposed by the Treaty of Versailles, neither the navy nor domestic shipbuilders had much experience designing or building aircraft carriers.

With the likelihood of war becoming increasingly likely, a number of German delegations including naval architects, Kriegsmarine officers and representatives from various shipyards began the arduous process of studying Japanese designs.

In the fall of 1935, one such delegation not only visited Japan, but spent days touring the 37,000-ton carrier Akagi.

Better yet, they were sent home with a number of helpful blueprints, after which the delegation got to work determining preliminary design specs for the new class of carriers.

However, one of the many barriers to rapid development was that no clear mission objectives had been established.

In short, it was unclear if the carriers would be used primarily for reconnaissance, task force defense, commerce raiding, or as offensive weapons.

Though the carriers would be capable of performing each of these roles, it was initially decided that they’d be used primarily as reconnaissance platforms.

This made some sense, but the idea was later scrapped, largely because Britain, Japan and America had all discovered years before that their carriers were the most effective when used offensively.

Another hurdle was incessant intra-service bickering between Kriegsmarine and Luftwaffe brass, each of which wanted the sole responsibility of operating the aircraft onboard the carriers.

To placate each branch, it was initially determined that the Kriegsmarine would operate the aircraft, but that the Luftwaffe would train the pilots and assist in developing the aircraft themselves.

As an esteemed naval engineer and professor at the Technical University of Berlin, Wilhelm Hadeler was tasked with assembling a team and drafting preliminary designs for the new carriers in 1934.

Hadeler’s first design was a 22,000-ton vessel capable of accommodating 50 aircraft and steaming at an almost unprecedented 35 knots (40 mph / 65 km/h).

Later however, the design was reduced to less than 20,000 tons to free up tonnage for use elsewhere while technically staying in compliance with the terms of the Anglo-German Naval Agreement.

To withstand bombardment from air and other surface ships, the carrier would be protected by armor similar to that on the Kriegsmarine’s heavy cruisers. 

In late 1935, Adolf Hitler officially announced that Germany would commence construction of the new carriers, and by early the following year the design had been largely finalized.

Just a few months later in the spring of 1936, the keel of the first Graf Zeppelin, Flugzeugträger A (German for aircraft carrier A) was laid at the Friedrich Krupp Germaniawerft shipyard in the port of Kiel in north-central Germany, with an ambitious launch date of July 1940.

By mid-1938 Flugzeugträger B had also been commissioned, and the Kriegsmarine planned two additional Graf Zeppelin-class carriers designated C and D, both of which were planned to be operational by 1943.

Construction proceeded relatively quickly in the early going, but with Britain’s declaration of war in early September of 1939, U-boats became a much bigger priority.

By then Flugzeugträger A’s hull had only been completed up to the armored deck.

Rusty, unsightly and far from finished, in February of 1940 Admiral Raeder ordered the ship cut up for scrap.

However, the ship would sit idle until early 1942, during which time other nation’s carriers continued to prove their worth in naval engagements around the globe.

In May, Hitler ordered the German Naval Supreme Command to resume work on the carrier once again.

But as the war dragged on, the Graf Zeppelin’s fate was sealed as Hitler diverted more and more resources elsewhere as he became increasingly disenchanted with the Kriegsmarine’s lackluster performance. 

Flugzeugträger “Graf Zeppelin” Stapellauf 8.12.1938 Deutsche Werke Kiel Platte Nr. 17395 https://commons.wikimedia.org/wiki/File:Bundesarchiv_RM_25_Bild-27,_Flugzeugtr%C3%A4ger_%22Graf_Zeppelin%22,_Stapellauf.jpg

End

With raw materials, labor and funding for large-scale projects becoming increasingly scarce, many of the Kriegsmarine’s largest ships were taken out of service late in the war.

As such, no construction was carried out on the Graf Zeppelin after early February of 1943, and all aircraft were subsequently returned to regular Luftwaffe units.

Had it been completed, the first Graf Zeppelin-class carrier would most likely have been renamed after the head of naval airships in World War I, Peter Strasser.

But as the war drew to a close, the unfinished carrier was scuttled by retreating German troops to prevent it from falling into enemy hands.

Adding insult to injury, two years later in 1947 the overhyped and largely unbuilt ship was raised by the Soviets, towed out to the head of the Hel Peninsula and used for target practice by aircraft and naval guns.

Slipping beneath the waves one last time to its final resting place 260 feet (80 m) down, the Graf Zeppelin wouldn’t be discovered until five decades later, when unsuspecting divers employed by a Polish oil exploration firm stumbled onto it entirely by chance.  

Related Articles

LEAVE A REPLY

Please enter your comment!
Please enter your name here

Stay Connected

51,067FollowersFollow
868,000SubscribersSubscribe

Random Article

00:18:17

Walls of Constantinople: The Last Great Ancient Fortification

Over the last few years, there has been much discussion over the building of walls. Some see them as vital structures built to defend...

Latest Articles