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Aviation History
1920
1920 - 0733.PDF
JULY 8, 1920 suitable for either airships or large aeroplanes. The cylindershave 6 valves each, three inlet and three exhaust, operated from a single camshaft through push rods and rockers. Thecamshaft is enclosed in the crankcase, and is driven by a train of gears. With six cylinders, 180 by 210 mm., and runningat a speed of 1,400 r.p.m., the engine develops 425 h.p. The Sunbeam "Sikh." 12-cyl. 800-900 h.p. is alarger version of the engine previously described, having twelve cylinders disposed in Vee formation, at an angle of60 degrees. The cylinders again are separate, and any one cylinder may be easily removed without affecting the timingof the engine. As in the vertical type there are six overhead valves per cylinder, and these are operated by push rods androckers from a single central camshaft, which is housed in the crankcase within the Vee and driven by gearwheel directfrom the crankshaft. A feature of the design is the accessi- bility of the cam gear, it being only necessary to remove thecover at the timing end to enable the camshaft to be drawn out clear of the engine. The power is 850 h.p,, at a speed of1,400 r.p.m., at which engine speed the propeller speed is 920 r.p.m. The weight of the " Sikh " complete, but withoutwater, fuel or oil, is 1,952 lbs. Louis Breguet. (STAND 26)Paris. THIS firm has not been able to complete in time for the Showthe new giant Breguet " Leviathan " which is now in course of construction at the works of this French firm. Themachine, of which a scale model will be exhibited at the Show, has been designed to utilise the Breguet-Bugatti power unitexhibited at the Paris Aero Show. This power unit, it will be remembered, consists of two double Breguet-Bugattiengines placed end to end, and one slightly higher than the other. Each engine consists of two banks of eight cylindersplaced vertically and side by side. This arrangement has The Zeitlin Engine Co. (STAND 61a) » • '222, Strand, W.C. 2. No aero show is counted complete without at least oneunorthodox engine design. This year's is provided by the variable-stroke Zeitlin engine.The chief characteristic of the engine is that the four strokes of the working cycle are each arranged to be of differentlength so as to get nearer the ideal cycle for aero work and greatly simplify the engine. Bore, 135 mm. ; working stroke,181 mm. long; exhaust stroke, 203-5 mm.; induction stroke, 226 mm.; compression, 203-5 mm. The inductionstroke is divided in the two distinct stages, viz., the entry of fresh air through the exhaust valve, followed by the period ofvaporised mixture admitted through large ports during a period of over 88 degs. of rotation (as against the usual 40 degs),The extra supply of air in the induction stroke is sufficient to give full power at high altitudes. At ground level and lowaltitudes, by very simple means, which are under the com- plete control of the pilot, part of the top layer of air is rejectedbefore compression. The amount of air rejected is varied in accordance with altitude. Weight per brake h.p. is less than 2 lb.It is also impossible for this engine to back-fire. MM* two running. There is thus, it is claimed, little likelihood ofa forced landing en route. If this proves to be borne out in practice a great step forward has been made in commercial,aviation, since the forced landing is one of the greatest dangers of a long journey, especially in thick weather.The accompanying diagram shows the general arrangement of the fuselage of the " Leviathan," from which some ideamay be formed of the magnitude of the machine. We would, however, advise our readers to visit the Breguet stand andthere inspect the model of the machine, as this will give a much better representation than can a small diagram. Behindthe engine room, it will be seen, is a large passenger cabin with • DIAGRAM OF THE BREGUET "LEVIATHAN": A, propeller shaft; B, engines; C, clutch; D, radiator; E, oil tank; F, petrol tank; G, turbo-compresser; H, attachment of lower plane; I, passengers' cabin; J, pilot's cockpit; K, wireless cabin; L, water-tight bulkhead; M, adjustable fin; N, fixed fin; O, fixed fins some distance out from centre line; P, rudder; Q, adjustable tail plane; S, elevator; T, tail skid been made use of to accommodate the propeller shaft, whichruns between the two banks of cylinders. A series of auto- matic clutches ensure that in case of a breakdown the faultyengine is automatically thrown out of gear, and the only consequence, as far as flying the aeroplane is concerned, isthe loss of one-fourth the power until the engine can be repaired. In the " Leviathan " provision has been made fordoing repairs during the journey, as the engine-house is of ample proportions, allowing a mechanic to get at eitherengine and clean sparking plugs, adjust tappet rods, or effect any other minor repairs or adjustments that may berequired. It is therefore claimed that the " Leviathan" will be the equal of the airship in reliability, since it will flycomfortably with three engines running, and will only need to lose a comparatively small amount of altitude with only seating accommodation for about twenty passengers. Behindand slightly above, the cabin is the pilot's cockpit, over which is a small streamline housing with windows. Behind thepilot and under the same roof, so to speak, is the wireless cabin, for of course the " Leviathan " will be provided with thismodern adjunct to air travel. From a constructional point of view the " Leviathan "is of interest as being of the all-metal type. The weight of the machine empty is to be 5,500 lbs., and when full load iscarried the weight will be in the neighbourhood of 5 tons. The load can, of course, be made up of a large quantity of fueland a crew of three only, or of a smaller amount of fuel and a larger number of passengers, according to the purpose forwhich the machine is to be used. The span is 85 ft. 9 in., and the wing area is 1,500 sq. ft. THE AIR MINISTRY SECTION THE Air Ministry exhibit in the gallery at Olympia has beenspecially arranged at the request of the Joint Exhibition Committee in order that the public may realise that side ofaeronautical organisation and development which is under- taken by the State as co-partners with the manufacturingand transport sides of the industry. The exhibit, organised by the Controller-General of CivilAviation (Controller of Information), is divided into six main sections :—Aeronautical Inspection, Research, and Supply, Com- munications (Signals, Navigation and Wireless).i Meteorology. National Physical Laboratory, Medical, and Airships. The recruiting and training branches of the R.A.F. willalso be represented. In the Communications exhibit, a complete model airroute of the London-Paris Air Mail route will be shown. There is also a model of the London Terminal Aerodrome atCroydon, illustrating the general " lay out " and the various buildings and offices of a modern air station. Signalling appliances, navigation instruments and landinglights, etc., maps and air charts, clothing, devices used for medical tests of pilots and sections arranged by the Airshipbranch, the National Physical Laboratory and the Meteoro- logical Section go to make up one of the most interestingexhibits ever got together. 733 'i\ , -./
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