His Majesty's Airship No. 1 was designed and built by Vickers, Sons and Maxim at their works in Barrow-in-Furness, Lancashire, England, as an aerial scout airship for the Royal Navy. It was the first British rigid airship to be built, and was constructed in a direct attempt to compete with the German airship programme. Often referred to as "Mayfly", a nickname given to it by the lower deck (i.e. the non-commissioned component of a naval ship's crew), in public records it is designated 'HMA Hermione' because the naval contingent at Barrow were attached to HMS Hermione, a cruiser moored locally preparing to act as its tender.[1]
When it was moved from its shed in Cavendish Dock to conduct full trials on 24 September 1911 it broke in two before it could attempt its first flight as a result of being subject to strong winds .[2] Although Mayfly never flew, its brief career provided valuable training and experimental data for British airship crews and designers.[3]
Background
In July 1908 CaptainReginald Bacon, the Royal Navy's Director of Naval Ordnance, recommended that the Navy should acquire an airship that would compete with the success of the early German rigid airships built by CountFerdinand von Zeppelin.[4] The British Government agreed that a sum of £35,000 (£4.6 million today) "should be allocated to the Admiralty for the building of a dirigible balloon",[3] and in March 1909 the armament firm of Vickers, Sons and Maxim advised that they could construct the ship for £28,000 (£3.7 million today), not including the goldbeater's skin gas bags and outer cover, for which the Admiralty was required to provide contractors, and that they would erect a constructional shed at their own expense in return for a 10-year monopoly on airship construction, similar to the submarine agreement they already had with the Crown. The contract was awarded to Vickers on 7 May 1909, with design responsibility divided between Lieutenant N.F. Usborne at the Admiralty and C.G. Robertson of Vickers; however, the 10-year monopoly clause was refused.[3][4]
Design
Mayfly was intended to be an aerial scout, and was similar in design to contemporary Zeppelins, but with some major differences. At 512ft (156m) length and 46ft (14m) in diameter, it was 66ft (20m) longer than the contemporary LZ6 and had a 50% larger volume, giving a correspondingly greater lift. His Majesty's Airship No. 1 was more commonly known as the "Mayfly", or simply referred to as "No. 1."[5] In official records HMA No. 1 is often referred to by the name of the tender in which the crew was quartered, HMS Hermione, or the "Hermione Airship".[6] The name Mayfly originated as a nickname originated by the sailors assigned to it. HMA No. 1 was essentially an experimental design and was therefore to be built as cheaply as possible.[7]
Zeppelins of the time had a useful load of around 10,000lb (4,500kg) and were capable of flying at 37mph (60km/h).[8] The Vickers design was intended to be moorable on water, carry wireless equipment, be capable of 40kn (46mph; 74km/h) for 24 hours, have a ceiling of 1,500ft (460m), and carry a crew of 20 in comfort. The mooring was to be to a mooring mast, a practice that the British were the first to adopt as standard, and Mayfly was the first rigid airship to be fitted with the mooring equipment in the nose of the ship.[3]
Before construction began an experimental section was constructed. This used a variety of construction techniques: one end used hollow timber spars, the centre frame used a combination of timber and aluminium, while the other end used aluminium only. Although wood proved the most satisfactory, the Admiralty preferred metal.[9] In late 1909 duralumin became available, and it was decided to use this new alloy, which would allow a considerable weight saving while also forming a stronger structure.[10] The use of Duralumin preceded its use by Zeppelin by four years.[9] Development of HMA No. 1 involved essentially inventing the technology necessary and considerable experimentation in materials and manufacturing techniques was required before the final manufacturing processes were decided upon.[11] The hull was made up of 40 twelve-sided transverse frames spaced 12.5ft (3.8m) apart: some of which were cross-braced by wires, dividing the structure into 17 bays of irregular length, varying from 12.5ft to 37.5ft (3.8m to 11.4m). The frames were connected by 12 longitudinal girders and a triangular section keel below the main structure.[12] The hull shape was based on work by the American aerodynamicist Albert Zahm, and its head resistance was claimed to be 40% of that of contemporary Zeppelins. A fully streamlined shape had been proposed, but was rejected by the Admiralty as being too difficult to construct. It was not until 1918 that a truly streamlined airship, the R80, was designed.[13]
Experiments were also carried out to determine the most suitable material for the outer cover, resulting in the choice of a treated silk. The covering of the upper half was additionally treated to reduce heat absorption by adding aluminium powder to the coating. This resulted in the underside being primrose yellow and the top aluminium coloured.[14]
The design of the control surfaces, based on a design by Short Brothers and adopted after experiments by the National Physical Laboratory, consisted of quadruple rudders and triple elevators attached to the trailing edges of the cruciform tail surfaces, supplemented by forward mounted triplane elevators and small triple rudders behind the aft gondola.[11]
The two gondolas were constructed of mahogany using the Consuta process to make them watertight so that the craft could be operated off water.[15] Each contained a Wolseley 160 hp water-cooled V-8 piston engine, that in the front gondola drove a pair of 11ft 10in (3.61m) diameter four-bladed propellers mounted on outriggers and geared to rotate at half engine speed. The rear engine drove a single 15ft (4.6m) two-bladed propeller mounted at the rear of the gondola. Equipment to recover water from the exhaust gases was fitted to replace the weight of fuel as it was consumed and so avoid the necessity to vent lifting gas.[16][17] Considerable mistakes were made due to inexperience, Admiralty requirements, and in devices such as water recovery systems for engine exhaust.[18]
Construction and trials
The construction shed which also doubled as a hangar, was designed by Vickers and built from the wall of Cavendish Dock at their "Naval Construction Yard" in Barrow, out to piles driven into the basin floor. It contained a float on which construction of the airship took place and which could be taken out of the shed together with the airship. Beginning in 1909, the work was due to be completed in August that year and the ship delivered two months later, but in June trouble occurred with driving the piles into the floor of the dock. Consequently, the shed was not completed until June 1910, at which point the actual construction of HMA No. 1 could begin. A screen was erected in the dock together with a newly designed 38ft (12m)-high floating mooring mast that was capable of withstanding a steady pull of 80tons (81tonnes). A large safety margin had been allowed; the maximum load the ship would exert on the mast was calculated to be approximately 4tons (4tonnes) in a wind of 80mph (130km/h).[3]
In preparation for the completion of Mayfly, crew training commenced on 25 February 1910, covering important skills such as working the rubber fabric (carried out at Messrs Short Brothers works, Battersea, London), instructions in petrol engines at Vickers works, and instruction in signals, aeronautics and meteorology.[3]
"Two crews were used to look after the ship whilst out, as the work was new. They lived on board the airship and suffered no discomfort at all although no provision had been made for cooking or smoking on board. At night the temperature of the living space was a little above that of the outside air, but as the ship proved quite free from draughts in the keel and the cabin, it was anticipated that with suitable clothing, no trouble would be experienced from the cold."
The Admiralty's officer responsible for the design of HMA No. 1, Lieutenant N.F. Usborne, was selected as captain.[19]
The finished Mayfly was the largest airship yet constructed.[citation needed]
Static trials
Static trials inside the shed began on 13 February 1911. The motors were run and controls operated, but outdoor trials could not be carried out until the weather moderated.[20]
On Monday 22 May 1911 Mayfly was removed from the shed for handling and mooring trials. It was towed stern first from its very narrow shed, then gradually swung out of Cavendish Dock and attached to a mooring mast mounted on a pontoon. While moored, nine officers remained on board (having quarters in the keel and telephone communication between the cars) to conduct engine trials, but these were cut short due to radiator problems. On the following day it was subjected to winds of 45mph (72km/h), and during the two nights it was out of the shed, searchlights were trained on it so that its movement could be observed. Mayfly showed no signs of rising, and it was discovered from calculations that the removal of fixtures weighing some three tons would be necessary to enable it to become airborne.[3] It was decided to return it to the shed, where with all ballast, fuel and some equipment removed it floated for approximately five hours with both gondolas around 3ft (0.91m) out of the water. During this time the engineers were able to perform trim trials.[3] It was obvious that drastic modifications to reduce weight must be made if HMA No. 1 was ever to fly.[21]
The most drastic of the modifications was the removal of the external keel which resulted in both weakening and distorting the airship's framework.[22] Hartley Pratt, a draughtsman working in another department at Vickers, calculated that this would be disastrous, but his warnings were ignored. Pratt subsequently left the company, but was re-hired to lead the design of the next British airship, the No. 9r which was ordered from Vickers in 1913.[23] Other changes included deleting the forward elevators and the water recovery apparatus. The positions of the gondolas was also reversed, the heavier forward gondola being moved to the aft position.[21] Also removed were the cabin and accommodations for the crew while in port.[21] So extreme were the attempts to reduce weight that holes were drilled in engine control levers.[24] The changes resulted in the Mayfly having a disposable lift of 3.21 tons.[25] With the massive alterations Captain Murray Suter under pressure from the Admiralty solicitor was forced to provisionally accept No. 1 with the provision that she be flown.[26]
Final outing
Mayfly emerging from its floating shed on 24 September 1911HMA No.1 after breaking its back
While under cover, an improved system was devised for removing Mayfly from the shed. This consisted of a series of electric winches that could gently ease it out, even in windy conditions, and on 24 September 1911 it was decided to move Mayfly from the hangar for full testing. Just as the nose cleared the hangar door, a gust caused the ship to roll virtually onto its beam ends. It eventually righted, but as it was being swung round so that the nose would point back out to the dock, there were cracking sounds amidships and it broke in two. At that point the centre started to rise, and the crew in the aft gondola dived overboard causing the stern to rise. Subsequent damage was caused by a bracing cable on the top of the hull, which held fast causing several frames to be severely damaged as the hull was moved by the wind.[26] There were no fatalities, and the wreck was returned to the shed the same day.[27]
A court of inquiry's conclusion was that no-one could be attributed the blame for the incident, and that it would be reasonable to support the story that the squall was to blame.[27] It was of such a force that later ships would have also been severely damaged if they had encountered it under the same circumstances.[3] Commander Masterman is reported as stating unofficially that, "Mayfly was pulled in half by the handling party when someone forgot to release the lines that tethered the bows of the ship."[28] Furthermore, in an article entitled Twenty-One Years of Airship Progress Lt.Col. W. Lockwood Marsh wrote: "This accident, though the ship was undoubtedly weak, was directly due to a mistake in handling, one of the parties on a hawser continuing to haul in without noticing that the after car had fouled a buoy."[29]
Aftermath
Captain Sueter proposed that No. 1 be repaired and used for mooring experiments.[27] He also proposed the building of two more airships to keep intact the design and manufacturing capability.[27]
Reginald Bacon had left the Navy in 1909 and "Jackie" Fisher, who was an advocate of airship development was no longer First Sea Lord. Winston Churchill, who became the First Lord of the Admiralty on 24 October 1911 was generally dismissive of airships, favouring the development of heavier-than-air aircraft. As a result, no attempt was made to repair the Mayfly and it was left to rot in its shed.[3]
Churchill later made the following statement in House of Commons on 26 March 1913: "Altogether, compared with other navies, the British aeroplane service has started very well... I have a less satisfactory account to give of airships. Naval airship developments were retarded by various causes. The mishap which destroyed the May-fly, or the Won't Fly, as it would be more accurate to call it, at Barrow, was a very serious set-back to the development of Admiralty policy in airships."[30] And on 31 March 1913 Sir Bolton Eyres-Monsell - who would himself later become First Lord of the Admiralty, made the following comment regarding the fate of Mayfly and the lack of British airships: "The 'May-fly' broke three years ago, and nothing further has been done. In non-rigid airships, Germany has seventeen, and against that we have two very inferior ones and two on order, but we are not doing anything in this respect."[31]
Despite never having flown, the brief career of Mayfly provided valuable technical experience for British airship designers.[3]
Specifications
Data from Airships Heritage Trust,[3]Flight International[4] (sources do not agree on all values; and as Mayfly never flew, performance figures are theoretical. Engine data from Lumsden[32])
General characteristics
Crew: 20
Length: 512ft 0in (156.06m)
Diameter: 46ft 0in (14.02m)
Volume: 660,000cuft (19,000m3)
Empty weight: 44,000lb (19,958kg)
Useful lift: 48,000lb (22,000kg)
Powerplant: 2 × Wolseley 160 hp (each driving 2 propellers), 147hp (110kW) each
Performance
Cruise speed: 42mph (68km/h, 36kn)
Range: 1,090mi (1,750km, 950nmi)
Endurance: 24 hours
Service ceiling: 1,500ft (460m)
Notes
↑ Jarret, P., (ed.) (2002) Pioneer Aircraft; Early Aviation before 1914. London: Putnam. ISBN0-85177-869-0, p. 41
A Zeppelin is a type of rigid airship named after the German inventor Ferdinand von Zeppelin who pioneered rigid airship development at the beginning of the 20th century. Zeppelin's notions were first formulated in 1874 and developed in detail in 1893. They were patented in Germany in 1895 and in the United States in 1899. After the outstanding success of the Zeppelin design, the word zeppelin came to be commonly used to refer to all forms of rigid airships. Zeppelins were first flown commercially in 1910 by Deutsche Luftschiffahrts-AG (DELAG), the world's first airline in revenue service. By mid-1914, DELAG had carried over 10,000 fare-paying passengers on over 1,500 flights. During World War I, the German military made extensive use of Zeppelins as bombers and as scouts. Numerous bombing raids on Britain resulted in over 500 deaths.
An airship is a type of aerostat or lighter-than-air aircraft that can navigate through the air flying under its own power. Aerostats use buoyancy from a lifting gas that is less dense than the surrounding air to achieve the lift needed to stay airborne.
The R.38 class of rigid airships was designed for Britain's Royal Navy during the final months of the First World War, intended for long-range patrol duties over the North Sea. Four similar airships were originally ordered by the Admiralty, but orders for three of these were cancelled after the armistice with Germany and R.38, the lead ship of the class, was sold to the United States Navy in October 1919 before completion.
His Majesty's Airship R100 was a privately designed and built British rigid airship made as part of a two-ship competition to develop a commercial airship service for use on British Empire routes as part of the Imperial Airship Scheme. The other airship, the R101, was built by the British Air Ministry, but both airships were funded by the Government.
R.36 was a British airship designed during World War I, but not completed until after the war. When she first flew in 1921, it was not in her originally intended role as a patrol aircraft for the Royal Navy, but as an airliner, the first airship to carry a civil registration (G-FAAF).
The R.33 class of British rigid airships were built for the Royal Naval Air Service during the First World War, but were not completed until after the end of hostilities, by which time the RNAS had become part of the Royal Air Force. The lead ship, R.33, served successfully for ten years and survived one of the most alarming and heroic incidents in airship history when she was torn from her mooring mast in a gale. She was called a "Pulham Pig" by the locals, as the blimps based there had been, and is immortalised in the village sign for Pulham St Mary. The only other airship in the class, R.34, became the first aircraft to make an east to west transatlantic flight in July 1919 and, with the return flight, made the first two-way crossing. It was decommissioned two years later, after being damaged during a storm. The crew nicknamed her "Tiny".
The R.80 was a British rigid airship, first flown on 19 July 1920, and was the first fully streamlined airship to be built in Britain. Originally a military project for the British Admiralty, it was completed for commercial passenger-carrying. R.80 proved too small for this role and after being used briefly to train the United States Navy personnel who were to crew the ZR-2 airship, R.80 was retired and eventually scrapped in 1925.
A rigid airship is a type of airship in which the envelope is supported by an internal framework rather than by being kept in shape by the pressure of the lifting gas within the envelope, as in blimps and semi-rigid airships. Rigid airships are often commonly called Zeppelins, though this technically refers only to airships built by the Luftschiffbau Zeppelin company.
The 23 class were rigid airships produced in the United Kingdom during the First World War. Development of the 23 class began in August 1915 when Vickers was asked to improve the 9r design by increasing its gas capacity by adding a bay and increasing the capacity of the bow and stern gas cells. The 23-class was designed by H.B. Pratt and Barnes Wallis of Vickers. Vickers built the first and last of the four ships. The other two were built by William Beardmore and Company and Armstrong-Whitworth. While the 23 class airships were never used in combat, the four ships provided many hours of valuable training and experimental data for British airship crews and designers. Although a total of 17 of these ships were contemplated at one time, only four were ever built. The 23 class was found to be significantly overweight, leading to its cancellation in favour of the more-refined R23X class.
HMA No. 9r was a rigid airship designed and built by Vickers at Walney Island just off Barrow-in-Furness, Cumbria. It was ordered in 1913 but did not fly until 27 November 1916 when it became the first British rigid airship to do so. It was dismantled in June 1918 after being flown for around 165 hours, mainly for experimental purposes.
The DN-1 was the United States Navy's first airship.
The ZeppelinLZ 1 was the first successful experimental rigid airship. It was first flown from a floating hangar on Lake Constance, near Friedrichshafen in southern Germany, on 2 July 1900. "LZ" stood for Luftschiff Zeppelin, or "Airship Zeppelin".
SSclass airships were simple, cheap and easily assembled small non-rigid airships or "blimps" that were developed as a matter of some urgency to counter the German U-boat threat to British shipping during World War I. A secondary purpose was to detect and destroy mines. The class proved to be versatile and effective, with a total of 158 being built in several versions.
A mooring mast, or mooring tower, is a structure designed to allow for the docking of an airship outside of an airship hangar or similar structure. More specifically, a mooring mast is a mast or tower that contains a fitting on its top that allows for the bow of the airship to attach its mooring line to the structure. When it is not necessary or convenient to put an airship into its hangar between flights, airships can be moored on the surface of land or water, in the air to one or more wires, or to a mooring mast. After their development mooring masts became the standard approach to mooring airships as considerable manhandling was avoided.
LZ 10 Schwaben was a German rigid airship built by Luftschiffbau Zeppelin in 1911 and operated by DELAG for passenger service. It is regarded as the first commercially successful passenger-carrying aircraft.
Neville Usborne was a British naval officer who played a prominent part in British military lighter-than-air aviation before the First World War. He was involved with the construction of the first British rigid airship HMA No. 1 and was killed in one of the first experiments in launching an aeroplane from an airship.
LZ 18 was the second Zeppelin airship to be bought by the Imperial German Navy. It caught fire and crashed with the loss of all aboard on 17 October 1913 before entering service.
The Zeppelin P Class was the first Zeppelin airship type to be produced in quantity after the outbreak of the First World War. Twenty-two of the type were built as well as twelve of a lengthened version, the Q Class. They were used for many of the airship bombing raids on the United Kingdom in 1915-16, for naval patrol work over the North Sea and Baltic and were also deployed on the eastern and south-eastern fronts.
The Zeppelin R Class was a type of rigid airship developed by Zeppelin Luftschiffbau in 1916 for use by the Imperial German Navy and the German Army for bombing and naval patrol work. Introduced in July 1916 at a time when British air defences were becoming increasingly capable, several were lost in the first months of operation, leading the Germans to reconsider their technical requirements and eventually to develop airships capable of bombing from a greater height. Most surviving examples were modified to meet these requirements, by reducing weight at the expense of performance. A total of 17 were built.
Zeppelin LZ 38 was Zeppelin P Class airship of the German Imperial Army. It was the first to bomb London, United Kingdom.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
