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Further Reading

British Airships

Royal Naval Air Service

As the first business of the Royal Flying Corps was to help the army, so the first business of the Royal Naval Air Service was to help the navy. But this business of helping the navy was a much more difficult and complicated business than the other. To help the army from fixed aerodromes behind the line of battle was a dangerous and gallant affair, but it was not difficult. In the ease of its solution the military problem was child's play compared with the naval problem. How was the navy to be helped ?

As early as 1912 a policy for the employment of the Naval Wing of the Royal Flying Corps was laid before the Board of Admiralty by Captain Murray Sueter. In this statement the duties of naval aircraft were laid down ; the two first to be mentioned were: ' (1) ' Distance reconnaissance work with the fleet at ' sea. (2) Reconnaissance work off the enemy coast, ' working from detached cruisers or special aero' plane ships.' The policy is clear and sound ; but a world of ingenuity and toil was involved in those two short phrases-' with the fleet at sea', and 'working from detached cruisers'. Aircraft must work from a base ; when they had to work with the army on land all that was needed was to set up some huts in certain meadows in France. For aerial work with the fleet at sea the necessary preparations were much more expensive and elaborate. Seagoing vessels had to be constructed or adapted to carry seaplanes or aeroplanes and to serve as a floating and travelling aerodrome.

The seaplane itself, in the early days of the war, was very far from perfect efficiency. It could not rise from a troubled sea, nor alight on it, without disaster. Accidents to seaplanes were so numerous, in these early days, that senior naval officers were prejudiced against the seaplane, and, for the most part, had no great faith in the value of the help that was offered by the Royal Naval Air Service.

The Commander-in-Chief of the Grand Fleet well knew the value to the fleet of aerial observation, but the means were not to hand. The airship experiment had broken down. Such airships as were available in the early part of the war had not the necessary power and range. To build a vessel which should be able to carry seaplanes or aeroplanes for work with the fleet was not a simple matter. Such a vessel would be an encumbrance unless it could keep station with the Grand Fleet or with the Battle Cruiser Squadron, that is, unless it could steam up to thirty knots for a period of many hours together. Further, a stationary ship at sea is exposed ^:o attack by submarines, so that it was desirable, if not necessary, that the flying machines should be able to take the air and return to their base without stopping the ship.

This consideration led, at a later period of the war, to the use by the navy of aeroplanes flown from specially constructed decks. But this was a matter of time and experiment. As early as December 1911 Commander Samson had succeeded in flying off the deck of H.M.S. Africa, and when the war broke out the Hermes, which had formerly served as headquarters for the Royal Naval Air Service, was fitted with a launching-deck for aeroplanes.

The Hermes was sunk in the third month of the war; thereafter the Ark Royal, the Campania, the Vindex, the Manxman, the Furious, the Pegasus, and the Nairana were each of them successively fitted with a launching-deck. But launching proved easier than alighting. It may seem to be a simple thing for an aeroplane to overtake a ship that is being driven into the wind, and to alight quietly on its afterdeck. But immediately behind such a ship there is always a strong up-current of air. This upcurrent - the bump that the albatross sits on - is what makes the difficulty and danger of the attempt. An aeroplane which resists it by diving through it will almost certainly crash on the deck beyond.

The business of landing an aeroplane on the ship from which it had been launched was not accomplished until the 2nd of August 1917, when Flight Commander E. H. Dunning succeeded, at Scapa Flow, in landing a Sopwith Pup on the forecastle deck of the Furious, while she was under way. Five days later, when he was repeating this performance, his machine rolled over into the sea, and he was drowned. His work was not lost ; the Furious was fitted thereafter with a special landingdeck aft, and it was by naval aeroplanes flown from the deck of the Furious that one of the large Zeppelin sheds at Tondcrn^was destroyed on the 19th of July 1918.

The next ships in the succession were the Vindictive, the Argus (which was the first ship to be fitted with a flush deck), the Eagle, and the new Hermes, which last two ships were unfinished at the time of the armistice. In this matter of aerial work for the navy the whole period of the war was a period of experiment rather than achievement. The conditions of experiment were hard enough, when all the shipyards and factories of the country were working at full pressure in the effort to make good our heavy losses in merchant shipping. Yet experiment continued, and progress was made.

Three new forms of aircraft - the kite balloon, the small improvised airship called the submarine scout, and last, though not least, the flying boat - were all invented or brought into use by the Naval Air Service during the course of the war.

Kite Balloons

For stationary aerial observation the means employed in England, before the war, were the captive spherical balloon and the man-lifting kite. Many successful experiments with the man-lifting kite, or groups of kites, had been carried out, especially by Major B. F. S. Baden-Powell, during the closing years of the nineteenth century. But both the balloon and the kite had serious faults. The kite cannot be efficiently operated in a wind of less than twenty miles an hour, and the spherical balloon cannot be operated in a wind of more than twenty miles an hour. The balloon except in the lightest of breezes, and the kite at all times, give a very unsteady platform for observation, so that field-glasses are difficult to use.

The merits of both kite and balloon were combined and the faults of both were remedied in the kite balloon. The attachment of a kite to the upper hemisphere of an ordinary spherical balloon, on the cable side, to prevent the balloon from rotating in a wind, had been proposed by a private inventor as early as 1885, but nothing came of it.

The kite balloon which was used in the war was invented in 1894 by Major von Parseval, the German airship designer, and Captain von Sigsfeld. This balloon is sausage shaped ; the cable is attached to the forward portion; the rear end carries an air-rudder, and is weighted down by the car, or basket. Extending outwards at right angles on both sides of the rear portion of the balloon is a wind-sail which does the office of a kite and assists in preventing the rudder end of the balloon from being too much depressed by the weight of the car. The balloon is divided into two segments; the forward segment is filled with gas, the rear segment is kept full of air through a circular entrance attached, facing the wind, to the under surface of the balloon. But the steadying of the balloon is mainly achieved by the air-rudder, which is another inflated sausage, curved round the under side of the rear end of the balloon, and automatically filled with air through a valve at its forward end. The kite balloon is the ugliest thing that man has ever seen when he looks up at the sky, but it serves its purpose.

Before the war, kite balloons, often called 'Drachen' balloons, had been a German secret. The French and Belgians had obtained drawings of them, and at the outbreak of war had some few ready for use. Moreover, the French were at work on their 'Cacquot' balloon, an improvement on the 'Drachen' in that it made use of a new and more convenient stabilizing device. Where the 'Drachen' had used a long and clumsy string of parachute streamers attached to the tail, the ' Cacquot' achieved the same result by means of stabilizing fins attached to the balloon itself.

In October 1914 Wing Commander Maitland was sent to Belgium in command of a captive balloon detachment, to carry out aerial spotting for the guns of monitors working off the coast between Nieuport and Coxyde. His two balloons, which were spherical, proved to be useless in a strong wind. In January 1915 he made acquaintance with a 'Drachen' balloon which the Belgians were using in the neighbourhood of Alveringheim. He. was allowed to inspect this balloon and to take measurements and photographs.

General Birdwood, who had been sent by Lord Kitchener to the Dardanelles to report on the possibilities of a landing, and Admiral de Robeck, who was in command of the naval forces there, telegraphed to the War Office and the Admiralty that a man-lifting kite or a captive balloon would be of great use to the navy for spotting long-range fire and detecting concealed batteries. The Admiralty at once appropriated a tramp steamer, S.S. Manica, which was lying at Manchester, fitted her with a rough and ready apparatus, and on the 27th of March dispatched her with a kite-balloon section under Flight Commander J. D. Mackworth to the Dardanelles. This was the first kite balloon used by us in the war, and, it is believed, the first kite-balloon ship fitted out by any navy. The observation work done from the Manica was good and useful, especially during the earlier phase of the operations, and the difficulties encountered suggested many improvements in the balloon and in the ship. Orders were given for six balloon ships to be fitted out.

Admiral Beatty in August 1915, recommended that the work of aerial observation for the fleet should be done by kite balloons, towed by vessels accompanying the Battle Cruiser Squadron, and some trials were made which demonstrated the value of this suggestion. But here again very elaborate experiments were necessary before authorizing any large programme of construction, and in the meantime production on a considerable scale had become difficult, for the kite balloon, which was first manufactured in this country to the order of the navy, was already in great demand by the army for use on the western front.

As early as April 1915 the Army Council had asked the Admiralty to supply kite balloons for aerial observation with the expeditionary force in France, and by August of that year five kite-balloon sections had gone overseas and were doing invaluable work on the western front. At this point the kite-balloon sections working with the army were taken over by the War Office, but the Admiralty continued to provide the necessary material and equipment. Great Britain was involved in the greatest land war she had ever known, and the navy, with all the wealth of its inventive resources, stood by to help the army.

The British method of erecting an airship is different from the German in that they build the rings in a horizontal position and attach thereto a portion of the horizontal girders in a vertical position. The structure is then handled by means of block and falls, with a slip noose, so that it can be transferred from a vertical to a horizontal position.

Rigid airship design and construction was started in Great Britain about 1909, and the first ship underwent so many changes and "improvements" that after it was filled with gas and launched on 22 May 1911, the "May-fly," as it was popularly called, did not fly - it was too heavy. The first non-German rigid dirigible met with a disastrous accident upon leaving its shed 24 September 1911 a few months after its completion. It had been building for over two years at Barrow-in-Furness, by Vickers, Ltd., and was designed to embody the best features of Continental construction. It was the largest dirigible constructed to date, having a gas capacity of 700,000 cubic feet. It was over 500 feet in length, forty-eight feet in diameter, and had a lifting capacity of twenty-one tons. It was driven by two Wolseley engines each of 200-horsepower. The airship was designed for a capacity of twenty-two passengers and crew, and cost the British government over $200,000 at the time of its completion and launching. The rigid framework contains seventeen independent gas chambers, which together formed a cylinder with tapering ends. The accident which destroyed the Mayfly was caused by the failure of the central part of the frame, and deflation of a single compartment due to an accident caused by leaving the shed in a cross wind.

This, however, did not deter them from continuing the development with ultimate success. In 1917 a ship of Class 23 was launched - a cylindrical affair with pointed ends and external keel, following the lines of the early Zeppelin, the power units being suspended beneath the keel and the propellers direct-driven. The three propellers were in line and consequently in each other's slip stream. A fighting airplane was successfully carried and released from this ship, though no successful return to the airship was reported.

In December, 1916, the German airship L-33 was shot down at Colchester, England, which showed stream line construction and suspended nacelles of the Schuette-Lanz type. From this and later captures the airship known as R-33 and R-34 was evolved. Also the British have adopted the Zeppelin method of combining the forward power units with the commander's nacelle. The balonnets are at present made either of silk or cotton fabric, covered with gold-beater's skin.

It was in the R-34 type that the Trans-Atlantic trip of 1919 was made, reaching Mineola, Long Island, after 108 hours in the air. The return trip was made in 75 hours.

These craft were always known by the numbers which they bear. It must be admitted that the method was extremely confusing, but the original intention was to designate each airship owned by the Navy by a successive number. The original airship, the rigid Mayfly, was known as No. 1, the Willows airship No. 2, and so on. These numbers were allocated regardless of type and as each airship was ordered, consequently some of these ships, for example the Forlaninis, never existed. That did not matter, however, and these numbers were not utilized for ships which actually were commissioned. On thetransfer of the army airships, four of these, the Beta, Gamma, Delta and Eta, were given their numbers as they were taken over, together with two ships of the Epsilon class which were ordered from Messrs. Rolls Royce, but never completed. In this way it will be seen that numbers 1 to 22 are accounted for.

In 1915 it was decided to build a large number of small ships for anti-submarine patrol, which were called S.S.'s or Submarine Scouts. It was felt that it would only make confusion worse confounded if these ships bore the original system of successive numbering and were mixed up with those of later classes which it was known would be produced as soon as the designs were completed. Each of these ships was accordingly numbered in its own class, S.S., S.S.P., S.S. Zero, Coastal, C Star and North Sea, from 1 onwards as they were completed.

In the case of the rigids, however, for some occult reason the old system of numbering was persisted in. The letter R is prefixed before the number to show that the ship is a rigid. Hence we have No. 1 a rigid, the second rigid constructed is No. 9, or R 9, and the third becomes R 23. From this number onwards all were rigids and were numbered in sequence as they are ordered, with the exception of the last on the list, which was a ship in a class of itself. This ship the authorities, in their wisdom, have called R 80 - why, nobody knows.

No airships of the larger types, suitable for distant reconnaissance with the fleet, were in the service of Great Britain during the Great War. The building and manoeuvring of airships is not a pastime within the reach of a private purse. The British Government had taken advantage of the enterprise and rivalry of private makers of aeroplanes, whom it wisely permitted to run the risks and show the way. No such policy was possible in the manufacture of airships, which was essentially a Government business. There was therefore, it is perhaps not fanciful to say, something agreeable to the German temper, and disagreeable to the English temper, in the airship as a weapon of war. The Germans put an absolute trust in their Government.

The German navy was a powerful and splendid growth, fostered by the Government. But it was a forced growth, and the failure of the German operations at sea, regarded broadly, must be credited not to the British navy, but to the whole body of British seamen, naval and civilian. The British navy was at its appointed stations ; the temper of a seafaring people, self-reliant, resourceful, and indomitable, was everywhere, and shone like a phosphorescence over thousands of unregarded acts of sacrifice.

Airships chiefly concerned the Royal Navy. The question was not whether the Admiralty were willing to take up experimental work with a newfangled invention, but whether they could afford to neglect a weapon of uncertain value, which might prove to be a determining factor in war. The Admiralty responded in September 1912, when the naval airship section, which had been disbanded earlier in the year, was reconstituted.

In July 1913 Mr. Winston Churchill, the then First Lord of the Admiralty, who regularly gave his strong support to naval aeronautics, approved of the construction of two rigid airships and six non-rigid airships. Treasury sanction was obtained for this program. The rigid airships were to be built by Messrs. Vickers at Barrow-in-Furness. Of the six non-rigids, three were to be of the Parseval type, and three of the Forlanini type. One of the Parsevals was to be built in Germany, and two by Messrs. Vickers, who had succeeded in obtaining a licence for the construction of this type of ship ; one of the Forlaninis was to be built in Italy, and two by Messrs. Armstrong Whitworth. When the war broke out, the Parseval airship completing in Germany was confiscated by the German Government; and the Forlanini airship, under process of construction in Italy, was retained by the Italian Government. The building of one of the rigid airships had just begun, and work on it was for a time abandoned.

British Rigid Airship No. 1 was started in 1909. During the construction great consideration was given to the various auxiliary gear required by the ship and to the problems included in the handling and mooring as well as the actual flying of the ship. The thoroughness and accuracy with which this auxiliary work was developed is most remarkable in the light of later experience. Before the first flight was made the ship was moored by the bow to a mast with her cars resting on the water. The ship was broken amidships in Sept. ign as the result of a mistake in handling while she was being returned to her shed after one of the trials of-handling before flight. Comparison of the details and estimated performance of this ship with the contemporary Zeppelins shows that she was a remarkably good first design and that had it not been decided to abandon rigid-airship construction the British development of these ships would almost certainly have become at least equal to that of Germany. British Rigid Airship R9, by Vickers, stopped at the beginning of the World War, was restarted in July 1915 and made her first flight in Nov. 1916. She made a rather remarkable passage to Howden through a snowstorm over the Pennine range. Being somewhat inadequate in buoyancy, she was used for instruction and ultimately for mooring experiments. She was followed by four ships of R23 class, built by Vickers, Beardmore and Armstrong, and again by R27 and R2Q, which were remarkable for the absence of the keel which had existed in all previous rigid airships and had been looked upon as constituting the real strength of the ship to resist bending and shearing forces. This keel subsequently reappeared in German Zeppelins and in the ships built in England, but then merely as a means of distributing to the main frames the weights of petrol tanks, etc., arranged along it. Two wooden ships, R31 and R32, were built by Short to a design closely similar to that of the Schiitte-Lanz type. They were considerably faster than contemporary ships. Subsequent to the R33 class the British R36 and R37 were constructed to a generally similar design, of somewhat greater capacity and much improved detail. R80, designed and constructed by Vickers, embodied several entirely new features, but her size was so restricted by the dimensions of the construction shed that her performance was seriously handicapped. R38 made radical changes in features of design, and a clear and definite departure from German methods. The United States had contracted for its purchase. It was to be used, as it was generally understood, for an experimental service from New York to San Francisco and for that purpose masts and intermediate stations were being prepared. R38, while on the final test flight before delivery on August 24 ig2r, caught fire and fell owing to structural weakness, and many lives were lost. At the beginning of the war England had three small non-rigids, also one Parseval and one Astra [by another account, at the outbreak of hostilities Great Britain had only seven airships, all of the non-rigid type]. Four had been taken over by the Admiralty on 13 December 1913, and of the remaining three, No.2 was the model on which all the S.S. (submarine scout) class of vessel have since been based; No. 3 was an Astra-Torres of trefoil section with internal rigging, and No. 4 was a Parseval bought from Germany. It was the irony of fate that this particular vessel should have been used to patrol the Channel on the night of August 5 and 6, 1914, following up the declaration of war with that country. The various classes of British airships were gradually developed from the beginning of 1915, when the interest in airships was revived by Lord Fisher's decision that they might be made to form an important defence against the submarine. It became necessary at the beginning of 1915 to develop the very small non-rigid airship as rapidly as possible as an antisubmarine protection. Extreme simplicity was essential in order to allow of rapid production by firms having no previous experience. The S.S., Coastal and N.S. classes were all designed and built at the R.N. Airship Station, Kingsnorth. They constituted a very interesting development from the small supply of ships and experience available at the beginning of the war. A considerable number of British non-rigid airships were built and supplied to the French, Italian, Russian and American services, and one Italian semi-rigid was supplied to England for experiment.

S.S. (Submarine Scout)

The 'Blimp' or 'S.S.' - v- type of coastal airship was evolved in response to the demand for a vessel which could be turned out quickly and in quantities. The year 1915 saw the first building of small S.S. airships, and they repaid their cost many times over. On the 28th of February 1915 Admiral Fisher sent for Commander E. A. D. Masterman and Wing Commander N. F. Usborne, and told them that he wanted some small, fairly fast airships to operate against the German submarines, and that he wanted them at once. There was no time for experiment or the elaboration of new designs; speed in production was essential, and speed could not be attained except by the adaptation of existing types and the use of standard parts. The navy was seen at its best when it has to rise to an unforeseen occasion ; within three weeks the first of the now famous S.S.'s was ready for service. For the design of this airship it is as difficult to apportion credit among the small band of naval officers who had a hand in it as it is to divide the praise for the first flying machine between the brotherhood of the Wrights. The idea seems to have been struck out during a conversation in the mess at Farnborough at which there were present the late Wing Commander N. F. Usborne, Flight Lieutenant T. R. Cave-BrowneCave, and Mr. F. M. Green of the Royal Aircraft Factory. In the result the body, or fuselage, of a B.E. 2 c aeroplane was slung on to the envelope of a Willows airship, and the job was done. The original model consisted of an aeroplane body with super-imposed more or less stream-lined envelope. This first S. S. ship was constructed by suspending a B.E. airplane, stripped of its wings and tail, under a suitable small envelope. The trials of the first ship were made in less than twenty days from the time the instructions to proceed were received. The first flights were so satisfactory that the Admiralty gave instructions that the production of those ships was to proceed at once. This was followed by S S. Zero, a vessel of 70,000 cubic feet capacity, with a blunt-nosed envelope 145 feet in length, and a main diameter of 29 feet. The longest flight of one of these vessels was just under 51 hours. The S.S. class of airship differed very slightly from the original ship in certain respects which had been found desirable on the first trial. A few cars of the pusher type which generally resembled the nacelle of a Maurice Farman, were constructed by a private firm, but although they relieved the pilot of the propeller slip-stream, they did not prove as satisfactory as the older B.E. type. For the first 30 ships aeroplane bodies were used as cars, but later special cars far more suitable for patrol work were adopted. Engines of about 90 H.P. were used and a crew of three carried. Some 150 ships of the S.S. classes were built, but at the end of the war it had been decided to adopt a slightly larger ship with twin engines and a crew of five as being more suitable for the longer patrols which became necessary. The success of this airship was as great as its design was simple. It fairly fulfilled the main requirements-to remain aloft for eight hours in all ordinary kinds of weather, with a speed of from forty to fifty miles an hour, and carrying a load which should include a wireless telegraphy installation for the purposes of report and a hundred and sixty pounds' weight of bombs for more immediate use. The first twenty-five of these ships to be produced were fitted with the 70 horse-power Renault engine. With a speed of between 35 and 40 miles an hour, the 'Blimp' had a cruising capacity of about ten hours; it was fitted with wireless set, camera, machine-gun, and bombs, and for submarine spotting and patrol work generally it proved invaluable, though owing to low engine power and comparatively small size, its uses were restricted to reasonably fair weather. Variations and improvements of the design followed in steady succession, providing greater endurance, and more comfortable cars for the crew. In 1917 the S. S. Twin made its appearance, its length was 164 feet, main diameter about 32 feet, cubic capacity 100,000 feet, the car carried a crew of three, and this class of airship has been found so eminently satisfactory that no more of the pn vious S. S. models will be built. The motive power is supplied by twin engines, two 75 h.p. Hawks. By the time the last year of the War came, Britain led the world in the design of non-rigid and semi-rigid dirigibles. The ' S.S.' or 'Blimp' had been improved to a speed of 50 miles an hour, carrying a crew of three, and one of them had reached a height of 10,000 feet.

Coastal class

Later in 1915 a larger type - the Coastal class - having greater speed and taking a crew of five, was built. It soon became necessary to construct a ship of larger size and capable of lifting a greater load and of longer endurance than the small S.S. airships. The C.1 or coastal type, used an Astra-Torres envelope and a car made from two Avro fuselages with the tails cut off. An envelope of the "Astra" type was obtained from a ship which had been built before the war as a Belgian millionaire's air yacht. For these the Astra system of rigging was adopted in order to reduce to a minimum the necessary height of the sheds. The Coastal type has a capacity of 200,000 cubic feet. A suitable car to take four men was constructed and rigged below it. This again proved a satisfactory preliminary experiment and was the beginning of the Coastal type. The envelope had to be re-designed, but the modifications made to the car were comparatively small. Thirty-five of these ships were built during the war. Airships of this type did most of the long distance patrols during the last two years, and were largely employed in convoying ships from beyond the Scilly Isles up the Channel. The Coastal class of ship was modified in January 1918 to the type known as C* (Coastal Star), which had again a better shaped envelope and slightly better crew accommodation in the car. Ten of an improved (C*) class were built during the war. These ships later carried a crew of five and had an endurance of 12 hours at a full speed of 51 knots. The motive power is provided by a 110 h. p. Berliot forward, and a 260 h.p. Fiat aft.

N.S.1 North Sea

In 1916 the first ship of the North Sea type was flown. Sixteen of these ships were built. A ship larger again than the Coastal was found to be required for extended cruising in the North Sea and for work with the Fleet, and the N.S. ship was designed. This class was intended to work with the fleet and had an endurance of some 24 hours at 50 knots. The N.S. 1, or North Sea type, in use at the end of the war, had an endurance, on occasion, of from two to three days. The North Sea type was designed to act as a scout with the fleet, or to carry out patrols of 20 hours. Its envelope has a cubic capacity of 360,000 feet, and the normal crew is 10 men, but the car will carry 20. Since the signing of the armistice, one of these vessels has made a record voyage for a non-rigid airship of 61 hours 21 minutes, and is understood to have been surpassed on two occasions only by Zeppelins. This class are 262 feet in length, main diameter 55 feet, and they are fitted with two 275 h. p. Eagle or two 260 h. p. Fiat engines. It was owing to the incapacity-apparent or real- of the British military or naval designers to produce a satisfactory rigid airship that the 'N.S.' airship was evolved. The first of this type was produced in 1916, and on her trials she was voted an unqualified success, in consequence of which the building of several more was pushed on. The envelope, was made on the Astra-Torres principle of three lobes, giving a trefoil section. The ship carried four fins, to three of which the elevator and rudder flaps were attached. She marks a distinct departure from the earlier classes; her machinery is in a unit quite separate from the main car, which latter only carries the crew and navigating party. The characteristic of these ships, more particularly the N.S. class, was that the petrol tanks and all other weights possible were carried direct on the envelope. In the N.S. class the car was separate from the power unit and the weight distributed over the length of the ship. This gave important advantages over all earlier non-rigids where the loads had been concentrated in the car. The gasoline carried by this ship amounted, under certain circumstances, to about three tons, and the distribution of this load constituted a very interesting problem. In the first ship it was carried in a number of tanks attached to either side of the top lobe at a convenient distance above the top ridges. Access to tanks was obtained through the gun tube, which passes up through the centre of the ship, and then down a ladder way to a walking way along the top ridges. It was not, however, considered desirable that a man should have to be sent on top of the ship every time it was desired to turn on an additional gasoline tank, and arrangements were made to lead wires from the power unit round the surface of the envelope to each individual tank. This method operated satisfactorily, but difficulty was experienced with the hose conveying the gasoline from the tanks to the car. The weight involved in the whole installation was also considerable. An alternative scheme was therefore designed and installed in the next ship. This provided large 90-gal. gasoline tanks drawn up through the under surface of the envelope and suspended from the two top ridges by independent internal rigging generally similar to the main rigging. It is an interesting point that in the first few ships these tanks were made totally of fabric lined with a special gasoline-resisting dope. Experiments on these tanks had been proceeding for a considerable time, and one tank had contained gasoline for over twelve months without serious loss of fuel or any apparent damage to the dope. It was found, however, after these tanks had been in use in several ships that an alteration in the constituents in the gasoline had included something which gradually softened the dope and caused cracking and leakage. As it was probable that further alterations in the gasoline might be made as the war proceeded, it was decided to be desirable to substitute aluminum tanks for these fabric ones, and metal tanks were, therefore, substituted in all later ships. The long coveredin car was built up of a light steel tubular framework 25 feet in length. The forward portion was covered with duralumin sheeting, an aluminium alloy which, unlike aluminium itself, is not affected by the action of sea air and water, and the remainder with fabric laced to the framework. Windows and port-holes were provided to give light to the crew, and the controls and navigating instruments were placed forward, with the sleeping accommodation aft. The engines were mounted in a power unit structure, separate from the car and connected by wooden gangways supported by wire cables. A complete electrical installation of two dynamos and batteries for lights, signalling lamps, wireless, telephones, etc., was carried, and the motive power consisted of either two 250 horse-power Rolls-Royce engines or two 240 horse-power Fiat engines. The principal dimensions of this type are length 262 feet, horizontal diameter 56 feet 9 inches, vertical diameter 69 feet 3 inches. The gross lift is 24,300 lbs. and the disposable lift without crew, petrol, oil, and ballast 8,500 lbs. The normal crew carried for patrol work was ten officers and men. This type holds the record of 101 hours continuous flight on patrol duty.

R 9

In the matter of rigid design it was not until 1913 that the British Admiralty got over the fact that the 'Mayfly' would not, and decided on a further attempt at the construction of a rigid dirigible. The contract for this was signed in March of 1914; work was suspended in the following February and begun again in July, 1915, but it was not until January of 1917 that the ship was finished, while her trails were not completed until March of 1917, when she was taken over by the Admiralty. The details of the construction and trial of this vessel, known as ' No. 9,' go to show that she did not quite fill the contract requirements in respect of disposable lift until a number of alterations had been made. The contract specified that a speed of at least 45 miles per hour was to be attained at full engine power, while a minimum disposable lift of 5 tons was to be available for movable weights, and the airship was to be capable of rising to a height of 2,000 feet. Driven by four Wolseley Maybach engines of 180 horse-power each, the lift of the vessel was not sufficient, so it was decided to remove the two engines in the after car and replace them by a single engine of 250 horsepower. With this the vessel reached the contract speed of 45 miles per hour with a cruising radius of 18 hours, equivalent to 800 miles when the engines were running at full speed. The vessel served admirably as a training airship, for, by the time she was completed, the No. 23 class of rigid airship had come to being, and thus No. 9 was already out of date.

R 23

Three of the 23 class were completed by the end of 1917; it was stipulated that they should be built with a speed of at least 55 miles per hour, a minimum disposable lift of 8 tons, and a capability of rising at an average rate of not less than 1,000 feet per minute to a height of 3,000 feet. The motive power consisted of four 250 horse-power Rolls-Royce engines, one in each of the forward and after cars and two in a centre car. Four-bladed propellers were used throughout the ship. A 23X type followed on the 23 class, but by the time two ships had been completed, this was practically obsolete.

R 31

The No. 31 class followed the 23X; it was built on Schutte-Lanz lines, 615 feet in length, 66 feet diameter, and a million and a half cubic feet capacity. The hull was similar to the later types of Zeppelin in shape, with a tapering stern and a bluff, rounded bow. Five cars each carrying a 250 horse-power Rolls-Royce engine, driving a single fixed propeller, were fitted, and on her trials R.31 performed well, especially in the matter of speed. But the experiment of constructing in wood in the Schutte-Lanz way adopted with this vessel resulted in failure eventually, and the type was abandoned.

R.33

Meanwhile, Germany had been pushing forward Zeppelin design and straining every nerve in the improvement of rigid dirigible construction, until L.33 was evolved; she was generally known as a "super Zeppelin", and on September 24th, 1916, six weeks after her launching, she was damaged by gun-fire in a raid over London, being eventually compelled to come to earth at Little Wigborough in Essex. The crew gave themselves up after having set fire to the ship, and though the fabric was totally destroyed, the structure of the hull remained intact, so that just as Germany was able to evolve the Gotha bomber from the HandleyPage delivered at Lille, British naval constructors were able to evolve the R.33 type of airship from the Zeppelin framework delivered at Little Wigborough. Two vessels, R.33 and R.34, were laid down for completion; three others were also put down for construction, but, while R.33 and R.34 were built almost entirely from the data gathered from the wrecked L.33, tne three later vessels embody more modern design, including a number of improvements, and more especially greater disposable lift. It has been commented that while the British authorities were building R.33 and R.34, Germany constructed 30 Zeppelins on 4 slips, for which reason it may be reckoned a matter for congratulation that the rigid airship did not decide the fate of the War. In all its main features the hull structure of R.33 and R.34 followed the design of the wrecked German Zeppelin airship L.33. The hull follows more nearly a true stream-line shape than in the previous ships constructed of duralumin, in which a greater proportion of the greater length was parallel-sided. The Germans adopted this new shape from the Schutte-Lanz design and have not departed from this practice. This consists of a short, parallel body with a long, rounded bow and a long tapering stem culminating in a point. The overall length of the ship is 643 feet with a diameter of 79 feet and an extreme height of 92 feet. The type of girders in this class has been much altered from those in previous ships. The hull is fitted with an internal triangular keel throughout practically the entire length. This forms the main corridor of the ship, and is fitted with a footway down the centre for its entire length. It contains water ballast and petrol tanks, bomb storage and crew accommodation, and the various control wires, petrol pipes, and electric leads are carried along the lower part. Throughout this internal corridor runs a bridge girder, from which the petrol and water ballast tanks are supported. These tanks are so arranged that they can be dropped clear of the ship. Amidships is the cabin space with sufficient room for a crew of twentyfive. Hammocks can be swung from the bridge girder. In accordance with the latest Zeppelin practice, monoplane rudders and elevators were fitted to the horizontal and vertical fins. The ship is supported in the air by nineteen gas bags, which give a total capacity of approximately two million cubic feet of gas. The gross lift works out at approximately tons, of which the total fixed weight is 33 tons, giving a disposable lift of 26J tons. The arrangement of cars was as follows: At the forward end the control car is slung, which contains all navigating instruments and the various controls. Adjoining this is the wireless cabin, which is also fitted for wireless telephony. Immediately aft of this is the forward power car containing one engine, which gives the appearance that the whole is one large car. Amidships are two wing cars, each containing a single engine. These are small and just accommodate the engines with sufficient room for mechanics to attend to them. Further aft is another larger car which contains an auxiliary control position and two engines. Five engines were installed in the ship; these are all of the same type and horsepower, namely, 250 horse-power Sunbeam. R.33 was constructed by Messrs Armstrong, Whitworth, Ltd.; while her sister ship R.34 was built by Messrs Beardmore on the Clyde.' Of the two vessels, R.34 appeared rather more airworthy than her sister ship; the lift of the ship justified the carrying of a greater quantity of fuel than had been provided for, and, as she was considered suitable for making a Transatlantic crossing, extra petrol tanks were fitted in the hull and a new type of outer cover was fitted with a view to her making the Atlantic crossing. She made a 21 hour cruise over the North of England and the South of Scotland at the end of May, 1919, and subsequently went for a longer cruise over Denmark, the Baltic, and the north coast of Germany, remaining in the air for 56 hours in spite of very bad weather conditions. Finally, July 2nd was selected as the starting date for the cross Atlantic flight; the vessel was commanded by Major G. H. Scott, A.F.C., with Captain G. S. Greenland as first officer, Second-Lieut. H. F. Luck as second officer, and Lieut. J. D. Shotter as engineer officer. There were also on board Brig.-Gen. E. P. Maitland, representing the Air Ministry, Major J. E. M. Pritchard, representing the Admiralty, and Lieut.-Col. W. H. Hemsley of the Army Aviation Department. In addition to eight tons of petrol, R.34 carried a total number of 30 persons from East Fortune to Long Island, N.Y. There being no shed in America capable of accommodating the airship, she had to be moored in the open for refilling with fuel and gas, and to make the return journey almost immediately. Brig.-Gen. Maitland's account of the flight, in itself a record as interesting as valuable, divides the outward journey into two main stages, the first from East Fortune to Trinity Bay, Newfoundland, a distance of 2,050 sea miles, and the second and more difficult stage to Mineola Field, Long Island, 1,080 sea miles. An easy journey was experienced until Newfoundland was reached, but then storms and electrical disturbances rendered it necessary to alter the course, in consequence of which petrol began to run short. Head winds rendered the shortage still more acute, and on Saturday, July 5th, a wireless signal was sent out asking for destroyers to stand by to tow. However, after an anxious night, R.34 landed safely at Mineola Field at 9.55 a.m. on July 6th, having accomplished the journey in 108 hours 12 minutes. She remained at Mineola until midnight of July 9th, when, although it had been intended that a start should be made by daylight for the benefit of New York spectators, an approaching storm caused preparations to be advanced for immediate departure. She set out at 5.57 a.m. by British summer time, and flew over New York in the full glare of hundreds of searchlights before heading out over the Atlantic. A following wind assisted the return voyage, and on July 13th, at 7.57 a.m., R.34 anchored at Pulham, Norfolk, having made the return journey in 75 hours 3 minutes, and proved the suitability of the dirigible for Transatlantic commercial work. R.80, launched on July 19th, 1920, afforded further proof, if this were needed. It is to be noted that nearly all the disasters to airships have been caused by launching and landing - the type is safe enough in the air, under its own power, but its bulk renders it unwieldy for ground handling. The German system of handling Zeppelins in and out of their sheds is, so far, the best devised: this consists of heavy trucks running on rails through the sheds and out at either end; on descending, the trucks are run out, and the airship is securely attached to them outside the shed; the trucks are then run back into the shed, taking the airship with them, and preventing any possibility of the wind driving the envelope against the side of the shed before it is safely housed; the reverse process is adopted in launching, which is thus rendered as simple as it is safe. Considerable surprise was expressed that so few of the R.38 crew escaped by parachute, and the question was raised whether they were wearing their harnesses. It should be remembered, however, that when the ship broke the two portions may have taken up such an angle that it was impossible for the majority of the crew to reach their parachute stations. As the airship fell into the water it sent out a flame of blazing petrol, which spread over a considerable stretch of water and formed what might almost be described as a barrage of fire, greatly interfering with any attempts at rescue of the unfortunate members of the crew. One extremely plucky attempt deserves to be mentioned. Charles Harrison Brown, of the U.S. Air Service, who was on holiday at Hull, put off to the wreckage in a tug. He jumped into the water, and, diving under the surface to avoid the flames, swam to the aft cockpit and around the fins, and found one body, which he got into a small boat. Undaunted by the R-38 failure in 1921, the United Kingdom built the R-100 and R-101 in 1929. They were both large airships (the R-101 was 131 feet in diameter and 777 feet in length). In 1930, the airship was assigned to take the Secretary of State for Air, Lord Thomson, to India. Lord Thomson had boasted to the press that the R-101 was "safe as a house, except for the millionth chance." The flight to India was meant to showcase the abilities of English airships. The airship launched in October 1930; it was heavily loaded. During the flight, the R-101 apparently lost hydrogen from one or more gas cells, the cause is not known. The airship lost lift due to the hydrogen leak and crashed outside of Beauvais, France (about forty miles northwest of Paris) during a rainstorm on October 5, 1930. By an unfortunate circumstance, calcium flares were in the control cab for use during flights across the English Channel. When the craft crashed, these flares were damaged. The exposed flares contacted water from rain and subsequently ignited. The burning flares ignited the hydrogen escaping from R-101's gas cells that ruptured on impact with the ground. The hydrogen exploded. The account does not specify if the explosion was a deflagration or a detonation; multiple flares burning are a strong ignitor so it is possible that a detonation occurred. One unharmed witness claimed to be only a few hundred yards away from the crash, therefore, a flash fire is the most likely combustion phenomenon. Only six people survived the crash; forty-eight people were killed. This event caused the United Kingdom to turn away from airships. The R-100 was scrapped and no further airship designs were pursued.

The British also used nonrigid airships to patrol their coasts and rigid airships for convoy protection against German submarines. The British expression "blimp" came into use during World War I as a slang term for nonrigid airships. Its origin is unknown. Toward the end of World War I, the British began focusing on rigid airships and built the R34 and R38. The R34 made the first transatlantic roundtrip flight in July 1919, flying from East Fortune, Scotland, to Newfoundland, Canada, back to Mineola, New York, and returning to Pulham, England. It flew about 7,000 miles (11,200 kilometers) in 183 hours and 15 minutes. In January 1921, it was wrecked while landing at Howden, England. The R-38, built about the same time and some 25 percent larger than the R34, was also wrecked that year when its frame snapped and the hydrogen gas ignited. Forty-four of the 49 crewmembers perished. It was the worst aerial disaster to date. In 1909, the Admiralty decided to experiment with rigid airships, the outcome of this decision being Naval Airship No. 1 which showed by its failure to rise that it was not a simple matter to construct these vessels, and when lightened by alteration of construction, it broke in two in 1911. It was given out the following year that the prospects of using this type of airship were not sufficient to justify the great cost. The nation that was to be the main enemy in the greatest war of all time thought otherwise, and backed their opinion, continuing to construct and improve on the Zeppelin model, with the result that on many occasions, and notably in their dire need at the battle of Jutland Bank, they reaped the reward of their consistent policy of enterprise and at relatively infinitesimal cost.