Zeppelin

A Zeppelin is a type of rigid airship pioneered by the German Count Ferdinand von Zeppelin in the early 20th century. It was based on designs he had outlined in 1874 and detailed in 1893. His plans were reviewed by committee in 1894 and patented in the United States on 14 March 1899. Given the outstanding success of the Zeppelin design, the term zeppelin in casual use came to refer to all rigid airships. Zeppelins were operated by the Deutsche Luftschiffahrts-AG (DELAG). DELAG, the first commercial airline, served scheduled flights before World War I. After the outbreak of war, the German military made extensive use of Zeppelins as bombers and scouts.

The World War I defeat of Germany in 1918 halted the airship business temporarily. But under the guidance of Hugo Eckener, the deceased Count's successor, civilian zeppelins became popular in the 1920s. Their heyday was during the 1930s when the airships LZ 127 Graf Zeppelin and LZ 129 Hindenburg operated regular transatlantic flights from Germany to North America and Brazil. The Art Deco spire of the Empire State Building was originally if impractically designed to serve as a dirigible terminal for Zeppelins and other airships to dock. The Hindenburg disaster in 1937, along with political and economic issues, hastened the demise of the Zeppelin.

Principal characteristics

Picture - The pink ovals depict hydrogen cells inside the LZ 127, the magenta elements are Blaugas cells. The full-resolution picture labels more internals.

The most important feature of Zeppelin's design was a rigid metal alloy skeleton, made of rings and longitudinal girders. The advantage of this design was that the aircraft could be much larger than non-rigid airships (which relied on a slight overpressure within the single gasbag to maintain their shape). This enabled Zeppelins to lift heavier loads and be fitted with more and more powerful engines.

The basic form of the first Zeppelins was a long cylinder with tapered ends and complex multi-plane fins. During World War I, as a result of improvements by the rival firm Schutte-Lanz Luftschiffbau, the design was changed to the more familiar streamlined shape and empennage of cruciform fins used by almost all airships ever since. Within this outer envelope, several separate balloons, also known as "cells" or "gasbags", contained the lighter-than-air gas hydrogen or helium. For most rigid airships the gasbags were made of many sheets of goldbeater's skin from the intestines of cows. About 200,000 were needed for a typical World War I Zeppelin. The sheets were joined together and folded into impermeable layers. Non-rigid airships do not have multiple gas cells.

Forward thrust was provided by several internal combustion engines, mounted in nacelles (cowlings) connected to the skeleton. The R101 airship used diesel engines, which were then an untried technology for powering aircraft; they were unsuccessful. The Graf Zeppelin used spark-ignition engines, but fuelled with a natural gas called Blaugas, which was stored uncompressed. It was similar to propane and was named after its inventor rather than its colour (Blau is German for "blue"). The advantage of Blaugas for airships was that it weighed more or less the same as air and so as the fuel was used up, it did not affect the trim of the airship.

Apart from the fins, zeppelins were also steered by adjusting and selectively reversing engine thrust.

A comparatively small compartment for passengers and crew was built into the bottom of the frame, but in large Zeppelins this was not the entire habitable space; they often carried crew or cargo internally for aerodynamic reasons.

History

The first generations

Count Ferdinand von Zeppelin became interested in constructing a "Zeppelin balloon" after the Franco-Prussian War of 1870-1871, where he witnessed the French use of balloons to transport mail during the early part of the war. He had also encountered Union Army balloons in 1863, during the American Civil War, where he was a military observer. He first wrote of his dirigible interest in 1874 and began to seriously pursue his project after his early retirement from the military in 1890 at the age of 52.

Convinced of the potential importance of aircraft designs, he started working on various designs shortly after leaving the military in 1891. He had already outlined an overall system in 1874, and detailed designs in 1893 that were reviewed by committee in 1894, and that he patented on 31 August 1895, with Theodor Kober producing the technical plans. After hearing about the rigid airship constructed by David Schwarz and witnessing its trial flight at the Tempelhof Airfield near Berlin on November 3, 1897, he proceeded to buy the patent rights from the widow of the prematurely deceased Schwarz, in order to allow Carl Berg to supply aluminium. However, Schwarz's design was "radically different from Zeppelin's" and in December 1897 Zeppelin admitted the Schwarz design could not be developed. Sean Dooley speculates on the indirect benefits Zeppelin gained from Carl Berg and Schwarz's work. In 1899, Zeppelin started constructing his first airship from his own designs.

One unusual idea, which never saw service, was the ability to connect several independent airship elements like train wagons; indeed, the patent title called the design Lenkbarer Luftfahrzug (steerable air train).

An expert committee to whom he had presented his plans in 1894 showed little interest, so the count was on his own in realizing his idea. In 1898 he founded the Gesellschaft zur Fx¶rderung der Luftschiffahrt (Society for the promotion of airship flight), contributing more than half of its 800,000 Mark share capital himself. He assigned the technical implementation to the engineer Theodor Kober and later to Ludwig Dx¼rr.

Construction of the first Zeppelin began in 1899 in a floating assembly hall on Lake Constance in the Bay of Manzell, Friedrichshafen. This location was intended to facilitate the difficult launching procedure, as the hall could easily be aligned with the wind. The prototype airship LZ 1 (LZ for Luftschiff Zeppelin, or "Airship Zeppelin") had a length of 128 metres (420 ft), was driven by two 14.2 horsepower (10.6 kW) Daimler engines and was controlled in pitch by moving a weight between its two nacelles.

Picture - The first ascent of LZ1 over Lake Constance (the Bodensee) in 1900

The first Zeppelin flight occurred on 2 July 1900 over Lake Constance (the Bodensee). It lasted only 18 minutes before LZ 1 was forced to land on the lake after the winding mechanism for the balancing weight failed. After it was placed back in the hangar an apparatus used to suspend it broke. Upon repair, rigid airship technology proved its potential in subsequent flights (the second and third flights were on 17 October 1900 and 24 October 1900) beating the 6 m/s velocity record of the French airship La France by 3 m/s. Despite this performance, the shareholders declined to invest more money, and so the company was liquidated, with Count von Zeppelin purchasing the ship and equipment. The Count wished to continue experimenting, but he eventually dismantled the ship in 1901.

It was largely due to support by aviation enthusiasts that von Zeppelin's idea got a second (and third) chance and would be developed into a reasonably reliable technology. Only then could the airships be profitably used for civilian aviation and sold to the military.

Donations, the profits of a special lottery, some public funding, a mortgage of Count von Zeppelin's wife's estate and a 100,000 Mark contribution by Count von Zeppelin himself allowed the construction of LZ 2, which took off for the only time on 17 January 1906. After both engines failed, it made a forced landing in the Allgx¤u mountains, where the anchored ship was subsequently damaged beyond repair by a storm.

Incorporating all usable parts of LZ 2, the successor LZ 3 became the first truly successful Zeppelin, which by 1908 had travelled a total of 4,398 kilometres (2,733 mi) in the course of 45 flights. The technology then interested the German military, who bought LZ 3 and redesignated it Z 1. She served as a school ship until 1913, when she was decommissioned as obsolescent.

Picture - Wreckage of LZ 4. It was destroyed when a storm broke the zeppelin from its mooring, causing it to crash into a tree and catch fire.

The army was also willing to buy LZ 4, but requested a demonstration of her ability to make a 24-hour trip. While attempting to fulfill this requirement, the crew of LZ 4 had to make an intermediate landing in Echterdingen near Stuttgart. During the stop, a storm tore the airship away from its anchorage in the afternoon of 5 August 1908. She crashed into a tree, caught fire, and quickly burnt out. No one was seriously injured, although two technicians repairing the engines escaped only by making a hazardous jump. This accident would have certainly knocked out the Zeppelin project economically had not one of the spectators in the crowd spontaneously initiated a collection of donations, yielding an impressive total of 6,096,555 Mark. This enabled the Count to found the Luftschiffbau Zeppelin GmbH (Airship Construction Zeppelin Ltd.) and a Zeppelin Foundation.

Before World War I

Picture - A monument near Bad Iburg commemorating the 1910 LZ 7 crash

Before World War I, a total of 21 Zeppelin airships (LZ 5 to LZ 25) were manufactured. In 1909 LZ 6 became the first Zeppelin used for commercial passenger transport. The world's first airline, the newly founded DELAG, bought seven Zeppelins by 1914. The airships were given names in addition to their production numbers, four of which were LZ 8 Deutschland II (1911), LZ 11 Viktoria Luise (1912), LZ 13 Hansa (1912) and LZ 17 Sachsen (1913). Seven of the twenty-seven were destroyed in accidents, mostly while being moved into their halls. There were no casualties. One of them was LZ 7 Deutschland which made its maiden voyage on 19 June 1910. On 28 June it began a pleasure trip to make Zeppelins more popular. Among those aboard were 19 journalists, two of whom were reporters of well known British newspapers. LZ 7 crashed in bad weather at Mount Limberg near Bad Iburg in Lower Saxony, its hull getting stuck in trees. The crew then let down a ladder to allow all the passengers to leave the ship. One crew member was slightly injured on leaving the craft.

All together, the several airships traveled approximately 200,000 kilometres (120,000 mi) and transported about 40,000 passengers.

The German Army and Navy purchased 14 Zeppelins, who labeled their airships Z 1/2/... and L 1/2/..., respectively. During the war, the Army changed their scheme twice: following Z XII, they switched to using LZ numbers, later adding 30 to obscure the total production. When World War I broke out, the military also took over the three remaining DELAG ships. By this time, it had already decommissioned three other Zeppelins (LZ 3 "Z 1" included). Before the war the Army had lost three zeppelins to accidents, in which two people had died. The Navy lost two, both in 1913: a storm forced Navy Zeppelin LZ 14 or "L 1" down into the North Sea, drowning 14; LZ 18 or "L 2" burst into flames following an engine explosion, killing the entire crew. These accidents deprived the Navy of a large number of experienced personnel.

By 1914, state-of-the-art Zeppelins had lengths of 150 to 160 metres (490 to 520 ft) and volumes of 22,000-25,000 m, enabling them to carry loads of around 9,000 kilograms (20,000 lb). They were typically powered by three Maybach engines of around 140 to 210 horsepower (100 to 160 kW) each, reaching speeds of up to 80 kilometres per hour (50 mph).

During World War I

The German airships were operated by both the Army and Navy as two entirely separate divisions. Over the course of World War I, the Zeppelins were mainly used in reconnaissance missions for the Navy. Bombing missions, especially those targeting London, captured the public's imagination, but in the end proved to have only psychological value, and were not a military success. These were executed by both Navy and Army aircraft.

1914-1918 naval patrols

The main use of the craft was in reconnaissance over the North Sea and the Baltic, where the endurance of the craft led German warships to a number of Allied vessels. Zeppelin patrolling had priority over any other airship activity. The majority of airships manufactured were commissioned by the Navy. During the war almost 1,000 patrols were made over the North Sea alone, compared to about 50 strategic bombing raids. The German Navy had some 15 Zeppelins in commission in 1915 and was able to have two or more patrolling continuously at any one time, almost regardless of weather. They prevented British ships from approaching Germany, spotted when and where the British were laying mines and later aided in the destruction of those mines. Zeppelins would sometimes land on the sea next to a minesweeper, bring aboard an officer and show him the mines' locations. Before the widespread availability of incendiary ammunition made commerce raiding too risky, they would also land or hover close to a merchant ship suspected of carrying contraband, order all ship's hands to leave in boats, then inspect the ship, and either destroy it or take it back to Germany as a prize.

1915 bombing raids

Picture - 1917 watercolour by Felix Schwormstx¤dt - translated title: "In the rear engine gondola of a Zeppelin airship during the flight through enemy airspace after a successful attack on England"

Picture - British WWI poster of a Zeppelin above London at nighttime, with the text "It is far better to face the bullets than to be killed at home by a bomb. Join the army at once & help to stop an air raid. God save the King".

At the beginning of the conflict the German command had high hopes for the aircraft, which were almighty comparing to the contemporary light fixed-wing machines - they were almost as fast, could carry machine guns (even multiple ones), had a greater bomb-load and enormously greater range and endurance. Contrary to the previous beliefs, it was not easy to ignite the hydrogen using standard bullets and shrapnels. Later in the war, only with the invention of incendiary ammunition Allies started to exploit the Zeppelin's great weakness of flammability.

Picture - The observation car preserved at the Imperial War Museum

At the beginning of the war, Captain Ernst A. Lehmann and Baron Gemmingen, Count Zeppelin's nephew, developed an observation car for use by Zeppelin dirigibles. The car was equipped with a wicker chair, chart table, electric lamp, compass, telephone, and a lightning conductor. With the Zeppelin sometimes within, sometimes above the clouds and unable to see the ground, the observer in the hanging basket would relay orders on navigation and when and which bombs to drop. Defenders could hear the engines but their searchlights and artillery fire could not reach the airship. The LZ26's basket was lowered from the airship on a specially constructed tether 1000 metres long; other airships may have used one approximately 750 metres long. The tether was high-grade steel with a brass core insulated with rubber to act as the telephone cable.

From 1915, a number of Zeppelin raids was conducted. The majority were against Britain, leading the way in bombing techniques and also forcing the British military to bolster its air defences. The possibility of airship raids was approved by the Kaiser on 19 January 1915, although he excluded London as a target and further demanded that no attacks be made on historic, government buildings, or museums. The night-time raids were intended to target only military sites on the east coast and around the Thames estuary, but after blackouts became widespread, many bombs fell at random on East Anglia.

The first attack was planned for 13 January 1915. Four Zeppelins were launched but bad weather forced all the craft to abandon the raid. The first successful raid was on the night of January 19-20, 1915, in which two Zeppelins, L.3 and L.4, were directed towards the Humber but, diverted by strong winds, dropped twenty-four 50 kg high explosive bombs and ineffective 3 kg incendiaries on Great Yarmouth, Sheringham, King's Lynn and the surrounding villages. In all 4 people were killed and 16 were injured. Monetary damage was estimated at £7,740.

The Kaiser allowed the bombing of London docks from February 1915, but no raids took place on London until May. The first two London raids failed owing to poor weather - L.8 crashed near Ghent on 26 February and a four airship raid by the Army ran into fog on 17 March and was abandoned. One Army airship was damaged on landing and three more were lost in the next few weeks. With two Navy raids failing due to bad weather on 14 April and 15, it was decided to hold off further action until the more capable P-class Zeppelins were in service. The Army received its P-class Zeppelins first and undertook the first raids. Erich Linnarz commanded LZ.38 on a raid over Ipswich on April 29-30 and again on May 9-10, attacking Southend; it also attacked Dover and Ramsgate on May 16-17, before returning to bomb Southend on May 26-27. These four raids killed 6 people and injured 6, causing property damage estimated at £17,000. Twice Royal Naval Air Service (RNAS) aircraft tried to intercept LZ 38 but on both occasions the zeppelin was either able to outclimb the aircraft or was already at too great an altitude for the aircraft to intercept - the BE2 took some fifty minutes to climb to 10,000 feet (3,000 m).

Picture - Crater of a Zeppelin bomb in Paris

The Kaiser extended the, so far theoretical, ambit of the London raids in May 1915, allowing attacks anywhere east of the Tower of London. On 31 May Captain Linnarz again commanded LZ.38 on the first London raid; LZ.37 was also to be part of the raid but suffered structural damage early on and returned to Namur. Flying from Evere LZ.38 crossed the English coast near Margate at 21:42 before turning west once over Southend. London police were warned of an incoming raid around 23:00; a few minutes later small incendiaries began to fall. The devices were a simple metal canister filed with a mix of thermite, tar, and benzol; the exterior was wrapped in tarred rope and a simple fuse was fitted. The first device fell on a house at 16 Alkham Road, others were scattered around residential streets as the Zeppelin flew south over Stoke Newington and then Hoxton. Two incendiaries fell on Shoreditch Empire Music Hall and as LZ.38 turned southeast explosive bombs were dropped on Spitalfields and a whiskey distillery in Commercial Road. Turning northeast the remaining load was dropped on Stepney, Stratford and finally, around 23:30, five bombs fell on Leytonstone. LZ.38 then headed back towards Southend, crossing the coast near Foulness. In total some 120 devices were dropped, totalling 3,000 pounds (1,400 kg), including 91 incendiaries, 28 bombs and two 'grenades'. 7 people were killed, 35 were injured; forty-one fires were started, burning out seven properties, damage was priced at £18,596. The RNAS had fifteen aircraft in the air, but only one even sighted the Zeppelin; no ground-based guns fired and no searchlights found the airship. This marked failure by the capital's defences led to the British government implementing strong press restrictions on the reporting of air-raids.

The Naval airships also tried to raid London. L.10 attempted to reach the city on 4 June, strong winds led the commander to misjudge his position and the bombs were dropped on Gravesend. L.9 was also diverted by the weather on June 6-7, attacking Hull instead of London and causing considerable damage. On the same night an Army raid of three Zeppelins also failed because of the weather; in an added blow, as the craft returned to Evere they coincided with a pre-planned raid by RNAS aircraft flying from Furnes, France. LZ.38 was destroyed on the ground while LZ.37 was intercepted in the air by R. A. J. Warneford in his Morane Parasol, he dropped six 20 pounds (9.1 kg) Hales bombs on the zeppelin which caught fire and crashed into the convent school of Sint-Amandsberg. Two nuns were killed and the entire crew of the Zeppelin also died except for one man. Flight S/L Warneford was awarded the Victoria Cross for his achievement. As a further consequence of the raid both the Army and Navy withdrew from all bases in Belgium; the vulnerability of such sites was now clear.

The short summer nights discouraged further raids for some months, after an ineffective attack by L.10 on Tyneside on June 15-16. In the same period the remaining Army Zeppelins were re-assigned to the Russian Front. The Navy returned to raids on Britain in August. On August 9-10 four Zeppelins were directed against London; none reached their target and one, L.12, was damaged by ground fire while near Dover and ditched into the sea off Zeebrugge. Despite eight attacks by RNAS aircraft the craft was towed into Ostend where it was abandoned and later dismantled. The four-Zeppelin raid was repeated on August 12-13; again only one craft made landfall, L.10 dropped its bombs on Harwich. A third four-Zeppelin raid again tried to reach London on August 17-18, two turned back with mechanical problems, one bombed Ashford, Kent on 10 August in the belief it was Woolwich, but L.10 became the first Navy airship to reach London. L.10 was also misnavigated, mistaking the reservoirs of the Lea Valley for the Thames, and consequently dropping the bombs on Walthamstow and Leytonstone. 10 people were killed, 48 injured, property damage was estimated at £30,750 by the London Fire Brigade. A number of guns fired at L.10 and a few aircraft were launched (two Caudron G.3s crashed on landing after their search), but the Zeppelin suffered no damage in the raid (L.10 was destroyed a little over two weeks later in a thunderstorm over the North Sea; it crashed off Cuxhaven and the whole crew was killed).

Two Army Zeppelins successfully bombed London on September 7-8, SL.2 dropped bombs on the Isle of Dogs, Deptford, Greenwich and Woolwich. LZ.74 was forced to drop weight on its approach and scattered 39 bombs over Cheshunt, before heading on to London and dropped devices on Bermondsey, Rotherhithe and New Cross. 18 people were killed and 28 injured, property damage totalled £9,616. Fog and mist prevented any aircraft being launched but a number of anti-aircraft guns fired at LZ.74 with no effect.

The Navy attempted to follow up the Army's success the following night. Three Zeppelins were directed against London and one against an ironworks at Skinningrove. L.11 turned back early with engine trouble; L.14 suffered the same problem while over Norfolk, its bombs were dropped on East Dereham and the Zeppelin returned home. L.13 reached London, approaching over Golders Green, Kapitx¤nleutnant Heinrich Mathy began bombing around 22:40. Amongst the bomb-load was a 300 kilograms (660 lb) device, the largest yet carried by a significant margin. It exploded on Bartholomew Close, did much property damage, gouged a crater eight feet deep and killed two men. The Zeppelin was repeatedly caught by searchlights and all twelve anti-aircraft emplacements in London were active - but every shell exploded too low and the falling shrapnel caused both damage and alarm on the ground. Three aircraft were in the air. None even saw the Zeppelin; one crashed on landing killing the pilot. The raid took 22 lives and injured 87. The wavering line of destruction through central London caused damage estimated at £530,787.

After three more raids were scattered by the weather a five-Zeppelin raid was launched by the Navy on 13 October, the "Theatreland Raid." Arriving over the Norfolk coast around 18:30 the Zeppelins encountered new ground defences installed since the September raid under the guidance of Sir Percy Scott. These new gun sites proved ineffectual. Indeed a 13-pounder near Broxbourne was actually put out of action by three bombs dropped from L.15. L.15 continued on to London and began bombing over Charing Cross, the first bombs striking the Lyceum Theatre and the corner of Exeter and Wellington Streets, killing 17 and injuring 20. Further bombs were dropped on Holborn, as the airship neared Moorgate it was engaged by a new 75 mm gun sited at the Honourable Artillery Company. L.15 quickly recognised this new threat and dumped ballast, dropped only three more bombs (one landing on Aldgate High Street causing much damage) before departing, having suffered some engine damage from the shells. L.13 dropped its bombs around Guildford and later near Woolwich. L.14 dropped bombs on Otterpool Army Camp, killing 14 soldiers and injuring 12, and later bombed Tonbridge and East Croydon, on its return path it almost collided with L.13 over Bromley. Both the other Zeppelins, L.16 and L.11, were even further off course, L.16 dropped up to fifty bombs on Hertford and L.11 scattered a few bombs over Norfolk before heading home. In total 71 people were killed and 128 injured. This was the last raid of 1915, as bad weather coincided with the new moon in both November and December 1915, and continued into January 1916.

There were twenty raids in 1915, in which 37 tons of bombs were dropped, killing 181 people and injuring 455.

Italian raids against Austro-Hungarian Empire

Italy was the only country other than Germany to use lighter-than-air craft for bombing purposes, against tagets in the Austro-Hungarian Empire. Italian airships were "semi-rigid dirigibles," they were different from the "rigid" Zeppelins in that they had a keel only, as opposed to the entire frame favoured by the Germans. Their first bombing raid was on 26 May 1915, three days after entering the war, when they crossed the Adriatic to attack Sebenico, which was attacked by a dirigible again the following day. On 8 June 1915, the Cittx  di Ferrara took off from an airfield in Pordenone to bomb the Whitehead torpedo factory and the oil refinery at Fiume (later Rijeka, Croatia), killing one civilian, injuring several other people, but only causing slight damage. After Cittx  di Ferrara turned for home, it was intercepted and shot down by a Lohner L flying boat (pennant number L-48) of the Austro-Hungarian Navy, over Kvarner Gulf, near the island of Lussino. This was the first time that an airship had been destroyed in air combat.

1916 raids

British ground defences were divided between the Royal Navy and the British Army at first, before the Army took full control in February 1916, and a variety of sub 4-inch (less than 102 mm) calibre guns were converted to anti-aircraft use. Searchlights were introduced, initially manned by police, whose inexperience led to a number of illuminated clouds being mistaken for attacking airships. In January 1916 a set of two defensive rings was proposed for London with 490 guns and 490 searchlights divided between them. This grand scheme was soon reduced, and by mid-1916 there were nationally 271 anti-aircraft guns and 258 searchlights.

Aerial defences against Zeppelins were haphazard, and divided between the RNAS and the Royal Flying Corps (RFC), with the Navy engaging enemy craft approaching the coast while the RFC took responsibility once the enemy had crossed the coastline. The lack of an interrupter gear in early fighters meant the basic technique of downing them was to drop bombs on them (a technique which was to resurface in World War II). Initially the War Office also believed that the Zeppelins used a layer of inert gas to protect themselves from incendiary bullets, and discouraged the use of such ammunition in favour of bombs. The initial trials of incendiary bullets in mid-1915 were unimpressive. Incendiary ammunition also underwent several separate development tracks. The first bullet was designed by John Pomery, but by mid-1916 the RFC also had Brock, Buckingham and 'Sparklet' incendiary cartridges. Ten 'home defence' squadrons were organised from February 1916, with London's defences assigned to No. 19 RAS at Sutton's Farm and Hainault Farm (renamed No. 39 (Home Defence) Squadron in April 1916, who were also allocated North Weald Bassett airfield in August 1916). The actual number of aircraft varied: in February there were only eight squadrons and less than half the number of aircraft expected, and by June the number of squadrons had been cut to six and only No. 39 Squadron was at full strength and equipped with newer aircraft - BE12s with interrupter gear and Lewis guns firing a mix of explosive, incendiary and tracer rounds.

Picture - A plaque, (located on 61 Farringdon Road, London), commemorating a World War I Zeppelin raid on London.

Raids continued in 1916. In December 1915 new Q-class airships were delivered to both the German Army and Navy as well as additional P-class Zeppelins. The Q-class simply added two more gas cells to the P-class, lengthening the craft to 585 feet (178 m), adding 100,000 cubic feet (2,800 m) of gas, and improving both ceiling and bomb-load.

The first raid of 1916 was organised by the Navy. Nine Zeppelins were sent to Liverpool over the night of 31 January - 1 February. A combination of poor weather, difficult navigation and mechanical problems scattered the aircraft across the English Midlands and several towns were bombed. A total of 61 people were reported killed and 101 injured by the raid. Despite ground-fog, twenty-two aircraft were launched to find the Zeppelins but none succeeded. In attempting to land in the poor conditions, sixteen aircraft suffered various degrees of damage and two pilots were killed. One airship, the L.19, crashed in the North Sea because of engine failure and damage from Dutch ground-fire; all 16 crew were lost. Further raids were curtailed by an extended period of poor weather and also by the withdrawal of the majority of Naval Zeppelins in an attempt to identify and remove the recurrent mechanical failures. Three P-class Zeppelins did attack Hull on March 5-6, causing significant property damage.

On July 28-29 the first 'Super Zeppelin', the 650 ft M-class L.31, appeared in English skies. Powered by six engines and capable of operating at 13,000 ft (4,000 m), (with another 5,000 ft (1,500 m) to its maximum ceiling), while carrying up to four tonnes of bombs. Part of a ten-Zeppelin raid that achieved very little, four returned home early and the rest wandered over a fog-shrouded landscape before giving up. Adverse weather dispersed the next raid on July 30-31 and again on August 2-3. On August 8-9 two M-class Zeppelins were part of a nine craft raid that did much damage to Hull. The sixth successful London raid was on August 24-25, thirteen Navy Zeppelins were launched and Heinrich Mathy's L.31 reached London, flying above low cloud, thirty-six bombs were dropped in ten minutes on West Ferry Road, Deptford Dry Dock, the station at Norway Street and homes in Greenwich, Eltham and Plumstead. 9 people were killed, 40 injured and £130,000 of damage was caused. L.31 suffered no damage in the attack but several weeks of repair-work was needed following a rough landing.

Picture - British propaganda postcard, entitled "The End of the 'Baby-Killer'".

The biggest raid so far was launched on September 2-3, twelve Navy craft and four Zeppelins from the Army took part. A combination of rain and snowstorms scattered the craft while they were still over the North Sea. None of the Naval craft reached London. Only the Army's LZ.98 and the newly commissioned SL.11 achieved their objective. SL.11 came in over Foulness with the intention of looping around and attacking the capital from the north-west. The craft dropped a few bombs over London Colney and South Mimms. At about 01:50 it was picked up by a searchlight over Hornsey and subjected to an intense but ineffective barrage. Sl.11 was lost in cloud over Wood Green but rediscovered by the searchlights at Waltham Abbey as it bombed Ponders End. At around 02:15 one of the three aircraft in the sky that night finally came into range - a BE2c piloted by Lt. William Leefe Robinson flying from Suttons Farm. Robinson fired three drums of ammunition from his Lewis gun, one on each of three passes. After emptying the third drum the airship began burning from the stern and was quickly enveloped in flames. It fell to the ground near Cuffley. There were no survivors. Four Naval Zeppelins which had regrouped over Hertfordshire saw the fate of SL.11 and quietly slipped away. For the first Zeppelin downed on British soil and the first 'night fighter' victory Leefe Robinson received the Victoria Cross. The pieces of SL.11 were gathered up and sold by the Red Cross to raise money for wounded soldiers.

The loss of SL.11 ended the Army's interest in raids on Britain. The Navy remained aggressive and a twelve Zeppelin raid was launched on September 23-24, eight older craft bombing targets in the Midlands and four M-class Zeppelins (L.30, L.31, L.32, and L.33) attacking London. L.30 did not even cross the coast, dropping its bombs at sea.

L.31 approached London from the south, dropped a few bombs on Kenley and Mitcham and was picked up by a number of searchlights. Forty-one devices were then dropped in rapid succession over Streatham, killing 7 and wounding 27. More bombs were dropped on Brixton before crossing the river and dropping ten bombs on Leyton, killing another 8 people and injuring 30. L.31 then headed home. Also coming in from the south was L.32, running late due to engine problems, it dropped a few bombs on Sevenoaks and Swanley before crossing Purfleet at about 01:00. The Zeppelin then came under anti-aircraft fire as it dropped bombs on Aveley and South Ockendon. Shortly thereafter, at 01:10, a BE2c piloted by 2nd Lieutenant Frederick Sowrey engaged L.32. He fired three drums of incendiaries and succeeded in starting a blaze which quickly covered the entire craft. The Zeppelin crashed to earth at Snail's Hall Farm, Great Burstead. The entire crew was killed, with some, including the commander Oberleutnant-zur-See Werner Peterson, chosing to jump rather than burn.

L.33 dropped a few incendiaries over Upminster before losing its way and making a number of turns, heading over London and dropping bombs on Bromley at around midnight. As the bombs began to explode, the Zeppelin was hit by an anti-aircraft shell fired from the guns at either Beckton, Wanstead, or Victoria Park despite being at 13,000 feet (4,000 m). Dropping bombs now to shed weight, a large number fell on homes in Botolph Road and Bow Road. As the craft headed towards Chelmsford it continued to lose height, coming under fire at Kelvedon Hatch and briefly exchanging fire with a BE2c. Despite the efforts of the crew, L.33 was forced to the ground at around 01:15 in a field close to New Hall Cottages, Little Wigborough. The Zeppelin was set alight and the crew headed south before being arrested at Peldon by the police. A close inspection of the wreckage enabled the British to understand where their own rigid airship designs had been deficient. Furthermore, one 250 hp (190 kW) engine recovered from the wreck subsequently substituted for two (of four) 180 hp (130 kW) engines on a Vickers-built machine, the hitherto underpowered R.9.

The next raid came on 1 October 1916. Eleven Zeppelins were launched at targets in the Midlands and at London. As usual weather played a major role and only L.31 under the experienced Heinrich Mathy, on his fifteenth raid, reached London. Approaching from Suffolk, L.31 was picked up by the searchlights at Kelvedon Hatch around 21:45; turning away, the craft detoured over Harlow, Stevenage and Hatfield before cutting its engines and drifting with the wind over Hertford. As the airship neared Cheshunt at about 23:20 the engines were restarted and the craft was quickly picked up by six searchlights. Three aircraft of No. 39 Squadron were in the air and closed on L.31. Mathy ordered the dumping of bombs, (fifty fell on Cheshunt), in order to gain altitude. A BE2c piloted by 2nd lieutenant Wulstan Tempest engaged the Zeppelin around 23:50; three bursts were sufficient to set L.31 ablaze and it crashed near Potters Bar with all nineteen crew dying - although again many decided to jump rather than burn (including Mathy, whose body was found near the wreckage, embedded some four inches in the softened earth). Tempest had had to dive out of the way of the stricken craft and, over-wrought, had crashed on landing, suffering minor injuries.

With the next raid on November 27-28, the Zeppelins avoided London for targets in the Midlands. But again the aircraft and the incendiary bullet proved lethal - L.34 was shot down over the mouth of the Tees and L.21 was attacked by two aircraft and crashed into the sea off Lowestoft. There were no further raids in 1916 although the Navy lost three more craft, all on 28 December - SL.12 was destroyed at Ahlhorn by strong winds after sustaining damage on a poor landing, and at Tondern L.24 crashed into the shed while landing and the resulting fire destroyed both L.24 and the adjacent L.17.

There were 23 airship raids in 1916 in which 125 tons of ordnance were dropped, killing 293 people and injuring 691.

1917 raids

Anti-aircraft defences were becoming tougher and new Zeppelins were introduced with an increased operating altitude of 16,500 feet (5,000 m) and a maximum ceiling of 21,000 feet (6,400 m). The first S-class Zeppelins entered service in February 1917. They were largely a modification of the M-class, sacrificing weight for improved altitude. The surviving M-class Zeppelins were converted to S-class, notably by reducing the number of engines from six to five. To avoid searchlights, they flew above the clouds whenever possible, lowering an observer through them in a Spx¤hkorb (observation gondola) to direct the bombing. The improved safety was counteracted by the extra strain on the airship crews who became more prone to altitude sickness and exposure to extreme cold and high altitude winds.

The first raid of 1917 did not occur until March 16-17 and the five high flying Zeppelins encountered very strong winds and none reached their targets. This experience was repeated on May 23-24. Two days later twenty-one Gotha bombers attempted a daylight raid on London. They were halted by heavy cloud but the effort led the Kaiser to announce that airship raids on London were past; under pressure he later relented to allow Zeppelin attacks to continue under "favourable circumstances".

On June 16-17 another Zeppelin raid was attempted, only two out of six Zeppelins reached England in the face of strong winds. L.42 bombed Ramsgate, hitting a munitions store. The month-old L.48, commanded by Korvettenkapitx¤n Franz Eichler, but with Korvettenkapitx¤n Viktor Schutze also on board, suffered from both engine problems and compass malfunction. It was forced to drop to 13,000 feet (4,000 m) where it was caught by four aircraft and destroyed, crashing near Theberton, Suffolk. This was the last Zeppelin raid to explicitly target London.

After ineffectual raids on the Midlands and other targets in the north of England on August 21-22 and September 24-25 the last major Zeppelin raid was launched on October 19-20 with thirteen airships headed for Sheffield, Manchester and Liverpool. Two Zeppelins did not launch and the remainder quickly found themselves badly affected by powerful headwinds which made navigation extremely difficult. L.45 was trying to reach Sheffield, instead it dropped bombs on Northampton and London. Undetected and with no warning its bombs did great damage - the first few fell on Hendon Aerodrome but the rest, dropped at random from 16,000 feet (4,900 m), struck in Piccadilly, Camberwell and Hither Green. L.45 then reduced altitude to try and escape the winds but was forced back into the higher air currents by a BE2e. The craft then had mechanical failure in three engines and was pushed by the wind out over France, eventually coming down near Sisteron; it was set ablaze and the crew surrendered. L.44, L.49, and L.50 were also lost to anti-aircraft fire or the weather over France. L.55 was badly damaged on landing and later scrapped.

There were no more raids in 1917, although the airships were not abandoned but refitted with new, more powerful engines.

1918 raids

There were only four raids in 1918, all against targets in the Midlands and northern England. The final raid on 5 August 1918 resulted in the loss of L.70 and the death of its entire crew under the command of Frigattenkapitx¤n Peter Strasser, head of the Imperial German Naval Airship Service and the Fx¼hrer der Luftschiffe. Crossing the North Sea during daylight, the airship was intercepted by a Royal Air Force DH.4 biplane piloted by Major Egbert Cadbury, and shot down in flames.

On 5 January 1918 a fire at Ahlhorn destroyed four of the specialised double sheds along with four Zeppelins and one Schutte-Lanz. The British had begun bombing the Zeppelin production lines and their sheds in Cologne and Dx¼sseldorf as early as September/October 1914. This was followed by the Cuxhaven Raid, which included Zeppelins as its targets, on Christmas Day 1914. In July 1918, the Tondern Raid conducted by the RNAS, destroyed two Zeppelins in their sheds.

Supply

In 1917, the German High Command made an attempt to deliver much needed supplies using a dirigible to Lettow-Vorbeck's East African Campaign in German East Africa. L.59 Zeppelin travelled over 6,400 km (4,000 miles) in 95 hours, but in the end failed to deliver the supplies. The craft had been purpose-built and was intended to be broken up and used on arrival. It never attempted the mission again, and was converted into a bomber.

Technological progress

Strategic issues aside, Zeppelin technology improved considerably as a result of the increasing demands of warfare.

The pre-war M-class designs were quickly enlarged, first to the 530 feet (160 m) long duralumin P-class, which increased gas capacity from 880,000 cubic feet (25,000 m) to 1,130,000 cubic feet (32,000 m), introduced a fully enclosed gondola, and extra engines. these modifications added 2,000 feet (610 m) to the maximum ceiling, over 10 mph to the top speed, and greatly increased crew comfort and hence endurance. Twenty-two P-class craft were ordered and the first, LZ.38, was delivered to the Army on 3 April 1915.

In 1916 the Zeppelin Company, having spawned several dependencies around Germany with shipyards closer to the fronts than Friedrichshafen, delivered airships of around 200 m (660 ft) in length (some even more) and with volumes of 56,000-69,000 m. These M-class dirigibles could carry loads of 3-4 tons of bombs and reach speeds of up to 100 to 130 kilometres per hour (62 to 81 mph) using six Maybach engines of 260 hp (190 kW) each.

To avoid enemy defences such as British aircraft, guns and searchlights, Zeppelins became capable of much higher altitudes (up to 7,600 metres (24,900 ft)) and they also proved capable of long-range flights. For example, LZ.104 L.59, based in Yambol, Bulgaria, was sent to reinforce troops in German East Africa (today Tanzania) in November 1917. The ship did not arrive in time and had to return following reports of a German defeat by British troops, but it had traveled 6,757 kilometres (4,199 mi) in 95 hours and thus had broken a long-distance flight record.

A considerable, frequently overlooked, contribution to these technological advancements originated from Zeppelin's only serious competitor, the Mannheim-based Schutte-Lanz airship construction company. While their dirigibles never became comparably successful, Professor Schx¼tte's more scientific approach to airship design led to a number of important innovations copied, over time, by the Zeppelin company. These included the streamlined hull shape, the simple yet functional cruciform fins (replacing the more complicated box-like arrangements of older Zeppelins), individual direct-drive engine cars, anti-aircraft machine-gun positions, and gas ventilation shafts which removed excess hydrogen.

End of the war

The German defeat in the war also marked the end of German military dirigibles, as the victorious Allies demanded a complete disarmament of German air forces and delivery of the remaining airships as reparations. Specifically, the Treaty of Versailles contained the following articles dealing explicitly with dirigibles:

Article 198
The armed forces of Germany must not include any military or naval air forces. [...] No dirigible shall be kept.
Article 202
On the coming into force of the present Treaty, all military and naval aeronautical material [...] must be delivered to the Governments of the Principal Allied and Associated Powers. [...] In particular, this material will include all items under the following heads which are or have been in use or were designed for warlike purposes:
[...]
Dirigibles able to take to the air, being manufactured, repaired or assembled.
Plant for the manufacture of hydrogen.
Dirigible sheds and shelters of every kind for aircraft.
Pending their delivery, dirigibles will, at the expense of Germany, be maintained inflated with hydrogen; the plant for the manufacture of hydrogen, as well as the sheds for dirigibles may at the discretion of the said Powers, be left to Germany until the time when the dirigibles are handed over. [...]

Dirigibles able to take to the air, being manufactured, repaired or assembled.
Plant for the manufacture of hydrogen.
Dirigible sheds and shelters of every kind for aircraft.

On 23 June 1919, a week before the treaty was signed, many war Zeppelin crews destroyed their airships in their halls in order to avoid delivery. In doing so, they followed the example of the German fleet which had been scuttled two days before in Scapa Flow. The remaining dirigibles were transferred to France, Italy, Britain, and Belgium in 1920.

A total of 84 Zeppelins were built during the war. Over 60 were lost, roughly evenly divided between accident and enemy action. 51 raids had been undertaken, in which 5,806 bombs were dropped, killing 557 people and injuring 1,358 while causing damaged estimated at £1.5 million. It has been argued the raids were effective far beyond material damage in diverting and hampering wartime production, one estimate was that the due to the 1915-16 raids "one sixth of the total normal output of munitions was entirely lost," and diverting 12 fighter squadrons and over 10,000 personnel to air defences.

After World War I

Renaissance

Count von Zeppelin had died in 1917, before the end of the war. Dr. Hugo Eckener, a man who had long envisioned dirigibles as vessels of peace rather than of war, took command of the Zeppelin business. With the Treaty of Versailles having knocked out their competitor Schutte-Lanz, the Zeppelin company and DELAG hoped to resume civilian flights quickly. In fact, despite considerable difficulties, they completed two small Zeppelins: LZ 120 Bodensee, which first flew in August 1919 and in the following two years actually transported some 4,000 passengers; and LZ 121 Nordstern, which was envisaged being used on a regular route to Stockholm.

However, in 1921, the Allied Powers demanded these two Zeppelins be delivered as war reparations, as compensation for the dirigibles destroyed by their crews in 1919. Further Zeppelin projects could not be realized, partly because of Allied interdiction. This temporarily halted German Zeppelin aviation.

Eckener and his co-workers refused to give up and kept looking for investors and a way to circumvent Allied restrictions. Their opportunity came in 1924. The United States had started to experiment with rigid airships, constructing one of their own, the ZR-1 USS Shenandoah (see below), and ordering another from the UK when the British R38 (ZR-2) was cancelled. However, the R38 (based on the Zeppelin L70, ordered as ZR-2) broke apart and exploded during a test flight above the Humber on 23 August 1921, killing 44 crewmen.

Under these circumstances, Eckener managed to acquire an order for the next American dirigible. Of course, Germany had to pay the costs for this airship itself, as they were calculated against the war reparation accounts, but for the Zeppelin company, this was secondary. So engineer Dr. Dx¼rr designed LZ 126, and using all the expertise accumulated over the years, the company finally achieved its best Zeppelin so far, which took off for a first test flight on 27 August 1924.

Picture - ZR-3 USS Los Angeles over southern Manhattan

No insurance company was willing to issue a policy for the delivery to Lakehurst, which, of course, involved a transatlantic flight. Eckener, however, was so confident of the new ship that he was ready to risk the entire business capital, and on 12 October 07:30 local time, the Zeppelin took off for the US under his command. His faith was not disappointed, and the ship completed her 8,050 kilometres (5,000 mi) voyage without any difficulties in 81 hours and two minutes. American crowds enthusiastically celebrated the arrival, and President Calvin Coolidge invited Dr. Eckener and his crew to the White House, calling the new Zeppelin an "angel of peace".

Under its new designation the ZR-3 USS Los Angeles (the former LZ 126), became the most successful American airship. She operated reliably for eight years until she was retired in 1932 for economic reasons. She was dismantled in August 1940.

Picture - The USS Los Angeles, a US Navy zeppelin built by the Zeppelin Company

Golden age

With the delivery of LZ 126, the Zeppelin company had reasserted its lead in rigid airship construction, but it was not yet quite back in business. Acquiring the necessary funds for the next project proved a problem in the difficult economic situation of post-World-War-I Germany, and it took Eckener two years of lobbying and publicity work to secure the realization of LZ 127.

Another two years passed before 18 September 1928, when the new dirigible, christened Graf Zeppelin in honor of the Count, flew for the first time. With a total length of 236.6 metres (776 ft) and a volume of 105,000 m, she was the largest dirigible yet.

Picture - Zeppelin docking tower in Recife, Brazil - the only one preserved in its original form

Eckener's initial concept was to use Graf Zeppelin for experimental and demonstration purposes to prepare the way for regular airship traveling, by carrying passengers and mail to cover the costs. In October 1928 the first long-range voyage brought her to Lakehurst, where Eckener and his crew were once more welcomed enthusiastically with confetti parades in New York and another invitation to the White House. Graf Zeppelin toured Germany and visited Italy, Palestine, and Spain. A second trip to the United States was aborted in France due to engine failure in May 1929.

In August 1929 LZ 127 departed for another daring enterprise: a circumnavigation of the globe. The growing popularity of the "giant of the air" made it easy for Eckener to find sponsors. One of these was the American press tycoon William Randolph Hearst, who requested the tour officially start in Lakehurst. As with the October 1928 flight to New York, Hearst had placed a reporter, Grace Marguerite Hay Drummond-Hay, on board who therefore became the first woman to circumnavigate the globe by air. From there, Graf Zeppelin flew to Friedrichshafen, then Tokyo, Los Angeles, and back to Lakehurst, in 21 days 5 hours and 31 minutes. Including the initial and final trips Friedrichshafen-Lakehurst and back, the dirigible traveled 49,618 kilometres (30,831 mi).

Picture - US Air Mail 1930 picturing Graf Zeppelin

In the following year, Graf Zeppelin undertook a number of trips around Europe, and following a successful tour to Recife, Brazil in May 1930, it was decided to open the first regular transatlantic airship line. This line operated between Frankfurt and Recife in 68 hours, and later, between Frankfurt and Rio de Janeiro, with a stop in Recife. Despite the beginning of the Great Depression and growing competition from fixed-wing aircraft, LZ 127 would transport an increasing volume of passengers and mail across the ocean every year until 1936. The ship pursued another spectacular venue in July 1931 with a research trip to the Arctic. This had already been a dream of Count von Zeppelin twenty years earlier, which could, however, not be realized at the time due to the outbreak of war.

Eckener intended to supplement the successful craft by another, similar Zeppelin, projected as LZ 128. However the disastrous accident of the British passenger airship R101 on 5 October 1930 led the Zeppelin company to reconsider the safety of hydrogen-filled vessels, and the design was abandoned in favour of a new project. LZ 129 would advance Zeppelin technology considerably, and was intended to be filled with inert helium.

Picture - airship LZ 127 "Graf Zeppelin"

Hindenburg, end of an era

Following 1933, the establishment of the Third Reich in Germany began to overshadow the Zeppelin business. The Nazis knew very well dirigibles would be useless in combat and thus chose to focus on heavier-than-air technology.

On the other hand, they were eager to exploit the popularity of the airships for propaganda. As Eckener refused to cooperate, Hermann Gx¶ring, the German Air minister, formed a new airline in 1935, the Deutsche Zeppelin-Reederei (DZR), which took over operation of airship flights. Zeppelins would now display the Nazi swastika on their fins and occasionally tour Germany to play march music and propaganda speeches for the people from the air.

Picture - The Hindenburg on fire in 1937

On 4 March 1936, LZ 129 Hindenburg (named after former President of Germany Paul von Hindenburg by Eckener) made her first flight. The Hindenburg was the largest airship ever built. However, in the new political situation, Eckener had not obtained the helium to inflate it due to a military embargo; only the United States possessed the rare gas in usable quantities. So, in what ultimately proved a fatal decision, the Hindenburg was filled with flammable hydrogen. Apart from the propaganda missions, LZ 129 began to serve the transatlantic lines together with Graf Zeppelin.

On 6 May 1937, while landing in Lakehurst after a transatlantic flight, in front of thousands of spectators, the tail of the ship caught fire, and within seconds, the Hindenburg burst into flames, killing 35 of the 97 people on board and one member of the ground crew. The actual cause of the fire has not been definitively determined; it is likely that a combination of leaking hydrogen from a torn gas bag, the vibrations caused by a swift rotation for a quicker landing to have started static electricity in the duralumin alloy skeleton and a flammable outer coating similar to rocket fuel accounted for the fact that the fire spread from its starting point in the tail to engulf the entire airship so rapidly (34 seconds).

Whatever caused the disaster, the end of the dirigible era was due to politics and the upcoming war, not the wreck itself, though it surely led to some public misgivings. Despite everything, there remained a list of 400 people who still wanted to fly as Zeppelin passengers and had paid for the trip. Their money was refunded in 1940.

Graf Zeppelin completed more flights, though not for overseas commercial flights to the U.S., and was retired one month after the Hindenburg wreck and turned into a museum. Dr. Eckener kept trying to obtain helium gas for Hindenburg's sister ship, Graf Zeppelin II, but due to political bias against the airship's commercial use by the Nazi leadership, coupled with the inability to obtain helium gas in sufficient quantities due to an embargo by the United States, his efforts were in vain. The intended new flagship Zeppelin was completed in 1938 and, inflated with hydrogen, made some test flights (the first on 14 September), but never carried passengers. Another project, LZ 131, designed to be even larger than Hindenburg and Graf Zeppelin II, never progressed beyond the production of some single skeleton rings.

The career of Graf Zeppelin II was not over. She was assigned to the Luftwaffe and performed about 30 test flights prior to the beginning of World War II. Most of those test flights were carried out near the Polish border, first in the Sudeten mountains region of Silesia, then in the Baltic Sea region. During one such flight LZ 130 crossed the Polish border near the Hel Peninsula, where she was intercepted by a Polish Lublin R-XIII aircraft from Puck naval airbase and forced to leave Polish airspace. During this time, LZ 130 was used as an electronic scouting airframe and was equipped with various telemetric equipment. From May to August 1939, she performed flights near the coastline of Great Britain in an attempt to determine whether the 100-metre towers erected from Portsmouth to Scapa Flow were used for aircraft radio localization. Photography, radio wave interception, magnetic and radio frequency analysis were unable to detect operational British Chain Home radar due to searching in the wrong frequency range. The frequencies searched were too high, an assumption based on the Germans' own radar systems. The mistaken conclusion was the British towers were not connected with radar operations, but formed a network of naval radio communications and rescue.

After the German invasion of Poland started the Second World War on 1 September, the Luftwaffe ordered LZ 127 and LZ 130 moved to a large Zeppelin hangar in Frankfurt, where the skeleton of LZ 131 was also located. In March 1940 Gx¶ring ordered the destruction of the remaining airships and the Duralumin fed into the Nazi war industry. In May a fire broke out in the Zeppelin facility, which destroyed most of the remaining parts. The rest of the parts and materials were soon scrapped, with almost no trace of the German "giants of the air" remaining by the end of the year.

Non-German Zeppelin-type airships

Picture - U.S. Navy Zeppelin ZRS-5 "USS Macon" over Moffett Field in 1933

Airships using the Zeppelin construction method are sometimes referred to as zeppelins even if they had no connection with the Zeppelin business. Several airships of this kind were built in the USA and Britain in the 1920s and 1930s, mostly imitating original Zeppelin designs derived from crashed or captured German World War I airships.

The British R33 and R34, for example, were near identical copies of the German L-33, which crashed virtually intact in Essex on 24 September 1916. Despite being almost three years out of date by the time they were launched in 1919, these sister ships were two of the most successful in British service. On 2 July 1919, R34 began the first return crossing of the Atlantic by aircraft. She landed at Mineola, Long Island on 6 July 1919 after 108 hours in the air. The return crossing commenced on 8 July because of concerns about mooring the ship in the open, and took 75 hours. Their success led to proposals for a fleet of airships to link far-flung British colonies, but unfortunately post-war economic conditions resulted in most airships being scrapped and trained personnel dispersed, until design and construction of the R-100 and R-101 commenced in 1925, see Imperial Airship Scheme.

Another example was the first American-built rigid dirigible ZR-1 USS Shenandoah, launched in September, 1923, while the USS Los Angeles (ZR-3) was still under construction. The ship was christened on 20 August in Lakehurst, New Jersey and was the first to be inflated with helium, which was still so rare at the time that Shenandoah contained most of the world's reserves. When Los Angeles was delivered, she was at first filled with helium borrowed from ZR-1. Other airships were the USS Akron (ZRS-4) and the USS Macon (ZRS-5).

Cultural influences

Picture - Cepelinai is a Lithuanian national dish named after Zeppelin

The history of Zeppelins is of particular interest to stamp collectors. Many nations issued high-denomination Zeppelin stamps, intended for franking of Zeppelin mail. Among the rarest of Zeppelin covers are those carried during the fateful flight of the Hindenburg.

Zeppelins have been an inspiration to music, cinematography and literature. In 1934, the calypsonian Attila the Hun recorded "Graf Zeppelin," commemorating the airship's visit to Trinidad while on its way from Rio de Janeiro to Chicago for the World Fair. Hard rock band Led Zeppelin named themselves after the Zeppelin; the cover art of their first album is the picture of the Hindenburg on fire. In cinematography, Zeppelins have been depicted several times, including Hell's Angels (US, 1930); Zeppelin (UK, 1971) about a German-English soldier (Michael York) and a German scientist (Elke Sommer) participating in a German Zeppelin mission in World War I; Darling Lili (US, 1970); The Hindenburg (US, 1975) a disaster film of the ill-fated last trip of LZ 129; and a short appearance in the films The Assassination Bureau (UK 1968), Indiana Jones and the Last Crusade (US, 1989), The Rocketeer (US, 1991), Sky Captain and the World of Tomorrow (US, 2004), A Very Long Engagement (France, 2004), Flyboys (USA, 2006), Perfect Creature (New Zealand, 2007) and on Television: Fringe (US, 2008)..

Modern era

Since the 1990s Zeppelin Luftschifftechnik, a daughter enterprise of the Zeppelin conglomerate that built the original German Zeppelins, has been developing Zeppelin "New Technology" (NT) airships. These vessels are semi-rigids and not strictly zeppelins because their shape is based partly on internal pressure, partly on a frame.

The Airship Ventures company recently re-introduced zeppelin passenger travel to California with one of these Zeppelin NT airships.

Buoyancy compensator (aviation)
Lane hydrogen producer
List of Zeppelins
List of airships of the United States Navy
Schutte-Lanz
Zeppelin Museum Friedrichshafen
Airship hangar

de Syon, Guillaume (2001). Zeppelin!: Germany and the Airship, 1900-1939. Johns Hopkins University Press. ISBN 0801867347
Dooley, Sean C., The Development of Material-Adapted Structural Form - Part II: Appendices. THxˆSE NO 2986 (2004), x‰cole Polytechnique Fédérale de Lausanne
Eckener, Hugo. 1938. Count Zeppelin: The Man and His Work, translated by Leigh Fanell, London - Massie Publishing Company, Ltd. - (ASIN: B00085KPWK) (online extract pages 155-157, 210-211)
Lehmann, Ernst A.; Mingos, Howard. The Zeppelins. The Development of the Airship, with the Story of the Zepplins [sic] Air Raids in the World War. Chapter VI THE NORTH SEA PATROL - THE ZEPPELINS AT JUTLAND (online chapter)
Smith, Peter J. C. (1991). Zeppelins over Lancashire. Neil Richardson. ISBN 1852160667

Further reading

Rich Archbold and Ken Marshall, Hindenburg, an Illustrated History, 1994 ISBN 0-446-51784-4
William F. Althoff, USS Los Angeles: The Navy's Venerable Airship and Aviation Technology , 2003, ISBN 1-57488-620-7
Peter Brooks, Zeppelin: Rigid Airships 1893-1940 , 2004, ISBN 0-85177-845-3
Manfred Griehl and Joachim Dressel, Zeppelin! The German Airship Story, 1990 ISBN 1-85409-045-3
Ces Mowthorpe, Battlebags: British Airships of the First World War, 1995 ISBN 0-905778-13-8
McPhee, John, The Deltoid Pumpkin Seed, 1992 ISBN 978-0374516352
Ian Castle, London 1914-17 - The Zeppelin Menace, ISBN 978-184603-245-5

Online

Airships.net - Illustrated history of passenger zeppelins
eZEP.de - The webportal for Zeppelin mail and airship memorabilia
Zeppelin Study Group - Research group for airship memorabilia and Zeppelin mail
Zeppelin Post Journal - Quarterly publication for Zeppelin mail and airship memorabilia
Zeppelin Luftschifftechnik GmbH - The original company, now developing the Zeppelin NT
Airshipventures.com - Bringing Zeppelin NT airships to the USA
zeppelintours.com - Zeppelin airship flights Needs Adobe Flash Player
Dark Autumn: The 1916 German Zeppelin Offensive
History of zeppelin development, Andrew Czernek (Omnivorous-GA), "Early Airship Design and Development", 9 May 2003
Diesel engines in zeppelins, Andrew Czernek (Omnivorous-GA), "Aircraft Propulsion," 11 June 2003

How the Zeppelin was destroyed Wednesday 6 September 1916 The Guardian
Zeppelin im Krieg University of Constance, online multimedia presentation in the Zeppelin-Museum Friedrichshafen (German)

Danish Post & Tele Museum Zeppelin articles

Iwersen, Malene (2006-08-01). "Fascination goes on". Post & Tele Museum, Denmark. http://www.ptt-museum.dk/en/online_magazine/latest_news/index.php?id=68. Retrieved 2009-05-29.
Iwersen, Malene (2006-01-01). "The Airship is Coming!". Post & Tele Museum, Denmark. http://www.ptt-museum.dk/en/online_magazine/latest_news/index.php?id=80. Retrieved 2009-05-29.
Gx¸ricke, Jan Hybertz (2006-01-01). "An Airborne Telegraph Station". Post & Tele Museum, Denmark. http://www.ptt-museum.dk/en/online_magazine/latest_news/index.php?id=82. Retrieved 2009-05-29.
Iwersen, Malene (2005-09-01). "There is Something in the Air". Post & Tele Museum, Denmark. http://www.ptt-museum.dk/en/online_magazine/latest_news/index.php?id=93. Retrieved 2009-05-29.
Steadman, Mark (2006-05-01). "The Goldbeater, the Cow and the Airship". Post & Tele Museum, Denmark. http://www.ptt-museum.dk/en/online_magazine/previous_articles/broadcasting/?id=74. Retrieved 2009-05-29.
"Zeppelin Exhibition". http://mini.ptt-museum.dk/zeppex/en/enFront.html. - An online exhibition about zeppelins by Post & Tele Museum, Denmark

Patents

U.S. Patent 0,621,195, "Navigable balloon". 14 March 1899. Ferdinand Graf Zeppelin.
US 1217657 , "Method of destroying aircraft", Filed 11 April 1916. Joseph A. Steinmetz
US 1449721 , "Light weight girder". Filed 28 June 1920. Karl Arnstein.
US 1474517 , "Airship". Filed 19 Aug 1922; Issued 20 November 1923. Julius Erhardt
US 1724009 , "Rigid airship with separate gas cells". Filed 27 November 1922; Issued August 1929. Hugo Eckener

More aircraft.

Source: WikiPedia