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Aviation History
1920
1920 - 1173.PDF
NOVEMBER II, 1920 with non-rigid airships moored to the type of mooring-mast introduced by Air-Commodore Masternian, an experimental mooring tower for. rigid airships was developed by Vickers, Ltd., in collaboration with the Air Ministry, and used at one of the airship stations for a comprehensive series of mooring tests with " R.24 " one of the early British rigid airships of the " R.23 " class. During these tests the ship lay out continuously for several weeks, during which it was subjected to gusts of wind blowing up to 50 m.p.h., phenomenally heavy rainfali, snow storms, and every extreme of the British weather. The behaviour of the airships demonstrated con- clusively the practicability of this system of mooring, and it was found that only 6 men at a time were needed to look after the mooring of the ship. Designs are now being prepared for a mooring tower specially arranged for use with passenger-carrying airships. The revolving head of the mast will be provided with a powerful hauling winch for hauling-in the mooring head of the ship to the automatic coupling apparatus and shock absorbing buffer which will enable the airship to be coupled up without difficulty even in winds up to 70 to 80 m.p.h. A passenger lift is provided within the mast-structure. Pipe mains for the supply of hydrogen, petrol and water to the airship also run up to the head of the tower, and so enable gas, fuel, and ballast to be supplied to the vessel in preparation for her next voyage with the least possible delay. Airship Bases It should not be forgotten that the present-day safety and regularity of steamship services is largely due to the develop- ment of safe ports and harbours, and to the lighting and charting of the coasts. This required many years and the expenditure of millions of pounds. Before regular world-wide air communications are prac- ticable, it will be essential to provide an equivalent equipment of landing stations night signalling and a reliable and elaborately-organised meteorological intelligence service. Eight main bases, with the same number of intermediate calling stations, would serve for airship services linking up Europe to North and South America, Egypt, South Africa, India, and Australia, and from these main bases smaller airships or aeroplanes would enable communication by air between all the chief centres of population in the world. Each of the main bases would be provided with a number of sheds and mooring towers according to the number of airships in service, and the intermediate stations with mooring tower? only. Both main and intermediate bases would be provided with hydrogen generating plant and storage for petrol and oil. The wireless equipment would be such as to enable an airship en voyage to be in constant communication with the nearest base. The Need for Trained Pilots Whilst we now have in this country airships which would be suitable for the running of experimental mail-carrying services, and the designing and constructional facilities which would enable us to build the larger type of airship required for regular passenger-carrying services, we still lack experience in the flying and handling of airships under the conditions appertaining to commercial services. The necessary experience and training can only be obtained by regular and constant flying, and it is strongly recommended that the airships that are at present available should be kept in constant service by the Air Ministry for this object. It would be desirable to put up several mooring masts of the simplest type necessary for training purposes in order that the pilots may become familiar with their use before having to undertake the command of an airship that will require to be used on the regular commercial services. The Germans have a great advantage in this respect, as many of the Zeppelin pilots who were employed on the passenger airships before the war have now made some thousands of flights. It takes at least two years'regular flying to train an airship pilot; not so much in the actual flying of the airship, but in the landing and handling. Will the Cost be Reasonable ? Fairly reliable estimates of the running costs of airships can be made; but allowances for depreciation and mainten- ance in particular are at present a matter of surmise as these can only be ascertained by trial on a commercial scale over a period of years. On the authority of Air-Commodore Maitland, the Director of the Airship Service, who has all the service records at his disposal, the probable costs for a regular service of airships between England and India to cany 4 tons of cargo and 100 passengers each way per week would be about 25. gd. per ton-mile, giving passenger rates about 50 per cent, higher than the present first class steamship rates, and mails at 6d. per ounce. , .^. - An approximate estimate has been prepared of the possible limits of the cost of carriage by airship, taking on the one hand the most favourable conditions that might be expected with a fully established service working on a favourable route with the best possible weather conditions, and such a demand that the service would be operated at full capacity all the year round ; and on the other hand taking the mott unfavourable conditions as regards cost and running con- ditions. The service investigated was on a basis of a regular two trips each way per week between places requiring, a non-stop flight of 3,000 miles, which would be operated by airships of the 4,000,000 cubic feet capacity type previously described. _ Taking the speed as averaging 60 miles per hour for the voyage, the time taken would be 50 hours, so that each ship could easily make two voyages per week. Thus two ships in service would make the required two trips each way per week. A third ship is held in reserve to enable each ship to be laid up periodically in turn for complete overhaul. If the two trips each way were kept up 52 weeks in the year, each of the three ships would have to do an average of between 3,400 and 3,500 hours flying and on this the cost of mainten ance is based. Allowing an ample allowance for the weight of petrel and oil and other non-useful loads, this size of airship woul be able to carry a full load of 24 tons of passengers, maiiJ or light freight. Accommodation is provided for 10c passengers who would be allowed a total weight of 300 lbs. p head, thus leaving further carrying capacity for about 10 to of mails and special freight. At each terminal aerodrome it would be necessary to have two housing sheds, a mooring mast equipment, hydrogen supply plant, workshops, and facilities for repairs, wireless and meteorological station, not forgetting a good allowance of spare parts. Without entering into details of the estimates—which are based on present-day prices—-the following figures which indicate the conclusions arrived at may be given :— Capital Required £ For 3 airships and flying equipment .. . . 1,500,000 For sheds, mooring masts, and other equip- ment for two aerodromes .. .. 1,300,000 Giving a total of . . .. .. 2,800,000 Or say, with working capital, a round figure of 3,000,000 Allowing for paying interest at 15 per cent, on this capital, this would mean an annual charge of .. .. .. .. 450,000 Depreciation and Obsolescence In the absence of actual experience of the deterioration of airships when constantly operated week-in and week-out in all kinds of weather, all the year round, it is difficult to decide what working life should be allowed to determine the rate at which their value should be written off. This is an item that is frequently discreetly relegated to the background. The probable life is variously estimated at from three to five years, so that the charge on this account would be from £300,000 to £500,000 per annum, and for sheds and ground equipment, say, £100,000 per annum, a total of from £400,000 to £600,000. Repairs and Maintenance Owing to the wear and tear of constant service, it is probable that the outer covers would require replacement about every six months, and the gasbags every two years, whilst the engines should have a life of at least two years. There will also of course be the cost of maintenance of the sheds and other aerodrome equipment. These items are estimated at from £100,000 to £300,000 per annum. Establishment Expenses Pay of officers and crews Salaries and wages of establishment and aerodrome staffs .. 35,000 150,000 Total 185,000 or say between £150,000 to £200,000. Insurance In the absence of any accumulated statistics of risk, it is impossible to say what rates would require to be paid for insurance of the airships against total loss or serious damage, and whilst it is thought the risks of total loss of an airship will eventually be very small, in the early stages of operation, there is always the possibility of a mishap. Therefore in the early stages the rate will be high, and may amount to 33 per cent, per annum on the total airship value. The insurance for three ships would thus be as a maximum say TI75
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