The outbreak of the World War I in the summer of 1914 found Germany in possession of a weapon that none of her allies or enemies possessed: the rigid airship. At a time when automobiles were in their infancy, airplanes were little more than a novelty, and many ships still relied on sails for propulsion, these early strategic bombers were a marvel of German ingenuity. Essentially, they were a series of hydrogen-filled bags, supported by a delicate yet surprisingly sturdy framework of duraluminum rings and steel wires in the shape of an elongated teardrop, and enveloped by an outer covering of doped fabric. Six engines, suspended from the bottom of the craft in gondolas, drove the propellers that allowed the ships to attain speeds up to 70 miles per hour. Much larger than the non-rigid blimps of modern times, the largest of these precursors to the Hindenburg were 80 feet in diameter and over 650 feet long--the length of three 747s. At the height of their power in 1915, German Zeppelins cruised at will over England, terrorizing a British populace that had no effective means of stopping them, and erasing time-honored wartime distinctions between combatants and civilians.
The Early Years
In the two decades prior to World War I, a stubborn and determined German aristocrat, Count Ferdinand von Zeppelin, had successfully pioneered and perfected the rigid airship that would forever bear his name, despite scientific skepticism, several disasters, and a severe lack of funds. By 1909, an airline known as DELAG (German Airship Transportation Company) was operating a small fleet of rigid airships making short commercial flights between large German cities. That same year the German army had purchased two airships from Zeppelin’s company on an experimental basis. In 1912, the navy was persuaded to purchase two ships to be used as long range scouts at sea in support of the fleet. In endurance tests the navy ships proved able to stay in the air continuously for at least 35 hours, enough to fly to London and back twice, and in fleet exercises the ships were able to find the "enemy force" well before surface ships could arrive on the scene. By 1914 the Germany was operating seven military rigid airships, using thousands of highly trained personnel, and maintaining airship sheds throughout the country. The closest any other nation in the world could come was a few crude blimps.
Despite the huge technological gap between Germany and her rivals, the German military was not really prepared to effectively utilize the Zeppelin as a weapon of war. The Army, which had six of the seven military Zeppelins operating in July 1914 did not have any kind of plan in place for using them, and indeed would never view the Zeppelins as anything more than a novelty for the duration of the war. Thus it fell to the navy to tap into the fabulous potential of the rigid airship. However, due to skepticism resulting from the loss of its first two Zeppelins in accidents, the Navy only had one operational Zeppelin at the start of the war. The Naval Airship Division’s main base, under construction at Nordholtz, was behind schedule and despite authorizing five flight crews, the Navy had only provided the division with three. Despite Navy plans calling for the use of the airships as bombers in the case of a war, no aerial bombs had been developed yet. Further illustrating the lack of interest in the airship among the upper echelons of the Navy, there was no plan for any further enlargement of the Naval Airship Division beyond this meager force.
Two factors would play a hand in dramatically reversing the Navy’s lackadaisical attitude: the pressures of an all out war and the efforts of a young officer named Peter Strasser. Suddenly face to face with the prospect of a naval war with the British navy, the most powerful surface fleet in the world, the German Admiralty quickly realized the value of the airship as a means of scouting the North Sea to detect the movements of the British. The conventional method of long range scouting called for the deployment of the speedy light cruiser. Although the British had plenty such vessels, the Germans only had six, and they would be required to screen the advance of the larger ships of the line should the main battle fleet be required to put to sea. However, the airship could perform all the scouting duties of a light cruiser for a fraction of the cost and manpower, with the added benefit of being able to see farther and travel faster. Furthermore, while an airship could be built from scratch in six weeks, a cruiser required upwards of two years. Upon the outbreak of the war, the Navy was quick to act. New sheds and airships were ordered wholesale and the Airship Division ballooned from a few hundred men to a few thousand. DELAG and the Zeppelin Company were nationalized and production was dramatically increased. The Zeppelin company, which in 1914 was producing a little more than three ships per year, would by 1916 be turning out a Zeppelin every two weeks.
Korvettenkapitän Peter Strasser, the second factor in the vast expansion of the Naval Airship Division, was the division’s commander. Although he had ascended to the position against his will in the fall of 1913, Strasser would soon become one of the most ardent defenders of the merits of the rigid airship and would repeatedly and successfully argue for the expansion of the Naval Airship Division throughout the war. Strasser was an articulate officer of great organizational skill, indomitable spirit, great personal charisma, and eventually, unyielding conviction in the military necessity of the Zeppelins he would oversee for the duration of the war. A dutiful officer, he immediately set out to enlarge and enhance the Naval Airship Division entrusted to his care, though it is doubtful that he foresaw the massive raids, far flung bases, and complex operations he would later preside over.
In the opening months of the war the Navy’s growing fleet of Zeppelins were used only for routine scouting missions in the North Sea, but the idea of Zeppelins bombing England was on everybody’s mind. Count Zeppelin’s creation had captured the imagination of Europe in the prewar years and the exploits of the early Zeppelins had been closely followed across the continent. All the combatants had extensive intelligence on the capabilities of the Zeppelins and were well aware of the possibility of long range aerial bombing they presented. In Britain rumors of Zeppelin sightings rapidly spread through the fearful population. The paranoia was fueled by the newspapers, which published many sensational accounts of dark shapes in the sky. News of attempted bombings of troops on the western front by German Army airships added to the tension. The British Army even followed up on a few reports of Zeppelins alleged to have landed in remote parts of the English countryside. No Zeppelins were found, and indeed no Zeppelins had even come near England as 1914 drew to a close.
The German populace could not understand why the Zeppelins were being held back either. To the ordinary citizen, who had seen the majestic DELAG ships soaring overhead and read the propagandistic accounts of their voyages, it seemed a simple enough matter to turn the Zeppelins on England, and indeed the public was clamoring for Zeppelin raids throughout the fall of 1914. Even the children were singing the popular song:
Zeppelin, flieg,
Hilf uns im Krieg,
Flieg nach England,
England wird abgebrannt,
Zeppelin, flieg!
"Zeppelin, fly, help us in war, fly to England, England will be burned, Zeppelin fly!"
In fact, the German Admiralty was equally eager to send the airships against England. The actual cause for the hesitation was the Kaiser, who was reluctant to bring bombs down upon England, a nation where he had spent much time in the happier years of his youth, and a nation ruled by his cousins, the King and Queen of England. Finally, on January 10, 1915, the Kaiser yielded to the desires of his Navy, and approved air raids on Britain. London however, was not to be attacked under any circumstances.
England Under Fire
A mere three days after the Kaiser gave his approval, on January 13, four Zeppelins were cruising across the North Sea, hoping to bomb the docks and factories along the Thames west of London. The leader of the squadron, commanding L 5, was Heinrich Mathy, who would become the greatest airship commander of the war. Although the attempt had to be aborted when the ships ran into a severe storm just of the coast, the first Battle of Britain was now underway. The long-cherished distinction between civilians and soldiers in time of war was about to be shattered forever. The first successful raid came a week later on January 20, when L 3 and L 4 reached the English coast and bombed several villages, killing 4 and causing 7,740 pounds worth of damage. News of the attack electrified Germany and sent a wave of panic throughout England. The Zeppelins had come at last.
The bold men who flew these canvas ships filled with explosive hydrogen gas faced many dangers and difficulties. Despite the hard lessons learned from the accidents of the difficult early years of the Zeppelin, and the resulting technological innovations, the airships were still rather flimsy. Severe storms or winds could tear an airship apart or push it above "pressure height," causing hydrogen to be automatically valved. Losing the lifting power of the escaping hydrogen, the ship would become too heavy to remain airborne, leading to a crash. Engine failures were exceedingly common, as the internal combustion engine was still in its infancy. Should an airship lose too many engines to engine failure, it might not be able to make it home. Thus, most ships turned back immediately upon the failure of a second engine (although one engine down was usually manageable, or repairable). If the temperature were too cold, the ship would "ice up," becoming heavy and losing altitude. The only solution was to release water ballast or bombs, but sometimes this was not enough and the ships would crash. High temperatures were equally dangerous, causing the hydrogen to "superheat" and dramatically increase its lifting power, thus making the ship rise rapidly. The only way to combat this was to valve gas, but when the remaining gas cooled down again, the ship would be short on gas and would face the problem of being too heavy.
Navigation was crude at best. The only instruments in the control gondola other than ship controls were a small liquid compass, an simple altimeter, a thermometer, and an airspeed meter. To determine their location, the commanders had to use dead reckoning, relying on what landmarks were visible from high altitude, and a highly inaccurate system of radio bearings, in which the airship would call for bearings and various stations in Germany would measure and compare the direction of the radio waves and estimate the vessel’s location. Not only did this crude system have a margin of error of several miles, but it also helped the British track the Zeppelins with astonishing accuracy, by listening in on the German frequencies. As a result of these navigational difficulties, German airships found the targets they were aiming for only about ten percent of the time. A vast majority of German bombs were wasted on empty fields, minor villages, or even the sea. Even when the airships did manage to get over an industrial city, they had no way to aim their bombs at specific buildings, and most landed on streets, or strategically unimportant residential areas. The Germans had no way of knowing just how inaccurate their navigation was (the British certainly were not going to tell them), and a high confidence in the efficacy of the raids was sustained in large part by the reports of the commanders which always insisted that a valuable target was bombed. This was not dishonesty – the commanders often truly believed they had bombed important targets – but rather the result of uncertainty combined with wishful thinking.
The raids continued into the summer of 1915 with varying degrees of success, at a rate of about two per month, weather permitting. When not raiding, the airships continued to undertake routine scouting operations in the North Sea almost daily, as they would continue to do for the duration of the war. Although the airship proved a valuable scouting tool and undoubtedly played a part in deterring the British from being overly bold with their superior surface fleet, the airship began to reveal some of its limitations. Bad weather easily kept the fragile airships out of the equation, when present, and even in clear weather the airship commanders often misidentified surface vessels, providing highly inaccurate intelligence at times – understandable of course, due to the high altitudes at which they operated. Nevertheless, in the rigid airship, the Germans had a scouting device vastly superior to anything the British could deploy, and the German Admiralty continued to regard it as an essential part of all their naval endeavors.
Finally, in June, French air raids by airplane on German cities provided the Kaiser’s advisors with the final straw they needed to pressure his Majesty into permitting raids on London. Given free reign at last, the airships raided the British capital as often as the weather permitted. For the rest of 1915 the German airships held an unchallenged reign of terror over the city. Although the British were constantly increasing their defenses, which consisted primarily of powerful searchlights and antiaircraft guns, their efforts were woefully inadequate. It was nearly impossible to bring down a rapidly moving Zeppelin at 10,000 feet up with a large, difficult to aim cannon. Even were a shell to pierce the Zeppelin, chances are the ship would be well on its way back to Germany before a significant amount of hydrogen was lost, allowing the ship to make it back safely with ease. Airplanes usually did not have the ceiling to reach the high flying Zeppelins and when they could, their bullets proved ineffective at causing any significant damage. In one particularly notable raid on September 8, Mathy, commanding his lucky ship L 13, managed to bomb central London, causing massive fires. The damage eventually amounted to 534,287 pounds, of which only 3,500 was caused by the other three ships in the raid combined. The raid made Mathy a hero throughout Germany and would turn out to be the most successful raid of the war.
The raids over London continued on much the same into early 1916. As the Airship Division received more Zeppelins, the raids included greater numbers of airships. A January 31 raid included 9 Zeppelins. The newer Zeppelins were larger and could carry more bombs. With more Zeppelins at his disposal, Strasser began to order attacks on other cities in England while continuing to bomb London. However, the Zeppelins’ unchallenged dominance of the skies was coming to an end. In December of 1915 Britain’s Ministry of Munitions had begun to experiment with new explosive and incendiary bullets. The explosive bullets were able to pierce the thick hides of the massive vessels, while the incendiary bullets served to ignite the hydrogen that leaked out. By the summer of 1916 a new breed of high flying aircraft, armed with a mix of the two new types of ammunition, took to the skies in defense of Britain, spelling the beginning of the end for the Zeppelins as effective weapons of war.
Meanwhile several factors caused to the Germans to cling ever more strongly to their hopes that the Zeppelin would prove a decisive means of ending the war. As 1916 dragged on the war on attrition on the western front was beginning to turn against the Germans. Major allied offensives that summer, while disastrous for both sides, signified to the Germans that they had lost the initiative in deciding where and when battles would occur. Meanwhile, the general failure of the German fleet to stand up to the British at Jutland eliminated any waning hopes of breaking the naval blockade. Additionally, a brand new line of "super-Zeppelins" with a capacity of two million feet of hydrogen - almost twice that of their predecessors – and six engines instead of four, seemed to hold unlimited promise for the future success of Zeppelin raiding. Two forces – German super-Zeppelins and British super-ammunition – were headed for a clash over London. The Zeppelins were to be the losers.
On September 2, 1916, Strasser sent out 12 ships to raid England. Joined by four Army airships the raid was the largest ever. That night Army airship SL 11 was shot down in flames over London by a young pilot named Leefe Robinson flying a biplane armed with explosive and incendiary bullets. The ship took many minutes to fall from the sky and burned so brightly that she could be seen from 100 miles away. SL 11 was the first ship every to be shot down by an enemy airplane, but she was only the first of many. Although Strasser was aware that SL 11 had been shot down by aircraft he was unfazed, perhaps chalking up its loss to Army incompetence. In any case, he sent out 12 ships again three weeks later in a disastrous raid that cost him two of his best commanders - Alois Böcker, who was captured when his airship was shot down but did not explode, and Werner Peterson, whose airship went down in flames over London. One week later, the great Mathy was killed in action. The mighty Zeppelin had been made mortal at last. The puny airplane had taken its place as king of the skies.
Until the Bitter End
Due in no small part to the consistent exaggeration and wishful thinking in the reporting of bombing successes, and the heavy censorship of British newspapers that prevented the Germans from learning the true nature of the damage inflicted by their bombs, the German Admiralty remained convinced that the Zeppelin was helping them win the war. In actuality the Zeppelins were facing increasing losses for diminishing returns. Back in 1915, using vessels vastly inferior to the "super-Zeppelins" deployed in 1916, the Germans had flown 47 sorties over England and caused 815,866 pounds worth of damage. In 1916, despite almost quadrupling the number of sorties to 187 and dropping five times as many bombs due to increased payloads, the Zeppelins only caused 594,523 pounds worth of damage. The Germans had no way of knowing these disappointing figures. They did know however, that something would have to change if the Zeppelin were to remain a viable weapon. To this end, they developed a new class of Zeppelin that the British dubbed the "height-climber."
The development of the height-climbers resulted from a January 17, 1917 letter from Strasser to the Admiralty suggesting that the Zeppelins be somehow lightened from their present weight to enable them to achieve a ceiling of 16,500 feet instead of the current ceiling of 13,000. At this altitude, the Zeppelins would be 2,500 feet higher than the highest an airplane could fly. After several conferences between Strasser, the Admiralty, and the Zeppelin company, a design was developed with an estimated ceiling of an unprecedented 20,000 feet. This ceiling was achieved by streamlining the gondolas, reducing the fuel load from a 36 hour supply to a 30 hour supply, removing the ineffective machine gun mounts and gun platforms, reducing the bomb payload by half, reducing the amount of hull girders (and thus weakening the hull), and completely eliminating the crew’s quarters. Illustrating wartime efficiency, the first of the Zeppelins built to these new specifications,L 42, was commissioned only a month later, on February 28. With minor alterations the height-climber specifications were the standard for the remainder of the war.
With the height climbers, the Germans once again had airships that were impervious to anything the British sent at them. However, the Germans would learn over the course of 1917 that the disadvantages of the height climbers precluded any chance at achieving the type of success the Zeppelins had met with in 1915. Besides the halved bomb payloads, the technical difficulties associated with flying at 20,000 feet proved overwhelming. The weather at high altitudes proved unpredictable for the German weather service, causing many raids to be abandoned after running into high altitude gales undetectable at lower altitudes. It was intolerably cold at 20,000 feet, with temperatures dropping as low as –20o F. There was no artificial heating in the semi-enclosed gondolas so the only defense against the cold was to wear more clothing. Even with heavy fur-lined coats and helmets the men still suffered from frostbite and stiffened joints. Some even tried stuffing newspaper inside their clothes, but nothing was enough. The men suffered from altitude sickness, causing severe headaches and nausea, as well as lack of oxygen, causing lethargy or lack of judgement similar to a state of drunkenness. The latter affliction was ameliorated to some extent by the use of compressed oxygen canisters but soon the men refused to use them as they were often contaminated with glycerin that caused them to become severely ill. It was not until liquid air was introduced in late 1917 that this problem was solved. The ships’ performance suffered at high altitudes as well. Engines could not get enough oxygen either and lost as much as half their power. Ships capable of reaching 62 m.p.h. at sea level could not surpass 45 m.p.h. at 20,000 feet. Furthermore, oil and coolant lines would freeze up, and many engine parts would become brittle and break, all of which lead to more frequent engine failures.
Ultimately, the height-climbers were a failure. Ships were lost at an even higher rate after the introduction of the height climbers, not due to enemy aircraft but because of an increase in accidents brought about by the harsh conditions of high altitudes, and in many cases, the inability of the men to perform their duties at said altitudes. One airship crashed upon landing for example, because the men in the rear propeller car failed to reduce the speed of the rear engine when so ordered. It turned out they had passed out due to carbon monoxide from a faulty engine. The malfunction had never been noticed because the oxygen-deprived crewman in charge of inspecting the engine was too ill to complete his inspection. Furthermore, by the end of 1917, the British and the French were both developing planes that could reach altitudes in excess of 20,000 feet and thus challenge even the height-climbers. In the whole year of 1917, the Zeppelin raiders only caused 87,760 pounds worth of damage to England, a mere fraction of the damage Heinrich Mathy had inflicted upon London on one night in 1915.
Strasser, undaunted and still strong in his faith that the Zeppelins could win the war, pressed on with the raids into 1918. The airship program suffered a huge setback on January 5 when five of the newest Zeppelins mysteriously blew up in their sheds at the new main base at Ahlhorn. Although it seemed to be an accident, sabotage cannot be ruled out, as the cause of the explosions was never satisfactorily established. With a reduced number of Zeppelins due to diminishing production, the raids became smaller and less frequent during 1918 and faced mounting losses. These raids were almost entirely ineffective. The final death blow came on August 5, 1918, when L 70, the newest, largest, most technically advanced airship in the German Navy, was shot down off the coast of England by a high-altitude seaplane. Aboard her was Korvettenkapitän Peter Strasser, commanding officer of the German Naval Airship Division. Without its most insistent voice to defend it, the Zeppelin was finished. Airplanes now performed most of the scouting for Germany, and the airships never set off on a raid again. The era of the rigid airship as a weapon of war was over. Three months later the Great War was over as well.
Ultimately, the Zeppelins must be considered a failure as a weapon of war. As a naval scout they proved unreliable and as a raider they prove disastrously incapable. Over the course of the entire war, at the cost of 53 airships and 379 highly trained officers and men-–forty percent of the picked flight crews-–the Zeppelin raiders inflicted a paltry 1,527,544 pounds worth of damage on the British–-about the cost of 10 airships. The air raids did not weaken the resolve of the British people to fight. In fact, it probably hardened their resolve, as the raids were used to vilify the Germans as "murderers," "Huns," and "baby-killers" and Zeppelins were often depicted on recruiting posters to spur men to fight. It must be noted that the Zeppelin raids did tie down a significant number of men, guns and planes required to defend England that could otherwise have been employed on the western front. In January 1917 there were 17,341 officers and men and 110 airplanes retained in Britain exclusively for defense against the Zeppelins. However, these are relatively small numbers compared to the massive amount of manpower, money, and raw materials that went into researching, developing, and maintaining a fleet of Zeppelins. However, in the end it must not be forgotten that for two years from 1914-1916, the rigid airship was the premier long range reconnaissance and assault aircraft, surpassing the airplane in all aspects of performance, and was in fact a formidable weapon that, for a brief moment, struck terror into the hearts and minds of the people of greatest nation on the planet at that time. Nor does the ultimate failure of the rigid airship as a weapon of war invalidate the courage and suffering of those who fought on and against those fabulous and fantastical giants of the skies.
Sources
Wilbur Cross. Zeppelins of World War I. 1991.
Ray Rimell. Zeppelin! : A Battle for Air Supremacy in World War I. 1984.
Douglas Robinson. The Zeppelin in Combat: A History of the German Naval Airship Division, 1912-1918. 1980.