Recent Technical Developments

Recent Technical Developments July, 1931 AIRCRAFT ENGINEERING 181 Vickers Showrooms—A New Noise Measuring Device— Carburising in Electric Furnaces Vickers Show Rooms A New Company purpos e of the test a standard engine selected by th e Air Ministry was installed in the Bristol N May 28 Vickers, Ltd., opened show rooms Messrs. Gibbons Brothers, Limited, Dibdale typ e 109 machine, a large single-engined biplane of a t Vickers House, Broadway, Westminster, Works , Dudley, in conjunction with Messrs. Wild- 50 ft. span and designed to carry a maximum all-up in order that customers may be able to Barfield Electric furnaces, Ltd., Elecfurn Works, weight of 9,000 lb. inspect examples of th e many branches of th e firm's Nort h Road, Holloway, London, N.7, have acquired Th e machine was stationed a t Famborough and manufactures, without the necessity of leaving from Messrs. Rudge-Whitworth, Ltd., Birmingham, throughou t the test was flown by Royal Air Force London. as from February 1, the sole manufacturing and pilots nominated by the Air Ministry. As a check selling rights of the Carburising Compound When it is remembered that the Vickers organi­ on the possible replacement of components the "Eternite. " sation comprises more than twenty companies with engine was scaled by officials of the Aeronautical I n connection with the above, and also the their works spread over the British Isles in more Inspectio n Directorate in numerous places. acquisition of the manufacturing and selling rights than eighteen towns, it will be realised what an advantage it must be to a prospective customer to of Hevi Duty Electric type mechanically-operated Th e aircraft was delivered to the Royal Aircraft be able to visit one central show room. furnaces (under agreement with the Hevi Duty Establishmen t on September 12, 1930, and flying The exhibits themselves range from a 75 mm. Electric Co., Milwaukee, U.S.A.), Messrs. Gibbons wa s carried out daily on all possible occasions in mobile anti-aircraft gun with a maximum vertical Brothers, Ltd., and Messrs. Wild-Barfield Electric periods • varyin g from to two to twelve hours. range of 30,300 ft., to a complete set of steel-shafted Furnaces, Ltd., are forming a new Company under Throughou t the test, apart from taking off and golf clubs. th e title of G.W.B. Electric Furnaces, Ltd. landing , the machine was flown at a constant throttl e setting giving 90 m.p.h. and 1,850 r.p.m., Many items manufactured are, of course, too unde r which conditions the power output of the large to exhibit, and of these beautifully-made Case-hardenin g in an Electric Furnace engine was approximately 350 b.h.p. models are shown. A large portion of a Vickers A new method of carburising has been introduced, "Viklebeest " is exhibited, comprising the front Thre e hundred hours flying time was completed in America by The Hevi Dut y Electric Co., whose' half of the fuselage, complete with engine and lower in March this year, and during this time the only Europea n patent rights are controlled by Wild- wings, to which are attached other products of seals broken were on a magneto after 232 hours, in Barfield Electric Furnaces, Ltd., and G.W.B. Vickers Ltd. , such a s th e Vickers-Berthier observers' orde r to replace a defective automatic timing Electri c Furnaces, Ltd., respectively. gun, Scarff ring gun mounting and Constantinesco coupling and to replace a set of valve-rocker gear Th e charge to be treated is loaded in a basket, synchronising gear. an d details due to a broken tie rod. an d although no special attempt is made to keep Under the wings, bombs and bomb racks of Throughou t the test the engine ran smoothly th e components of the charge from touching each various sizes are fitted, while a 1,610 lb. Whitehead an d well, both when cruising and at full throttle. other, they should be so placed to allow the circu­ torpedo, fitted with an eight-cylinder radial engine, Standar d Shell aviation petrol, without the addition lation of the carburising medium to take place is slung in its correct place between the under­ of dope or benzol, and a standard grade of Shell throughou t the charge. In this way maximum carriage legs. minera l oil were used exclusively, the average fuel uniformity in penetration and structure is obtained. Other types of aircraft, such as the Supermarine consumptio n working out at 20·6 gallons per hour, Th e loaded basket sits inside a heat-resisting alloy. 5.6, are shown in the model form. an d the oil consumption at 6·9 pints per hour. retor t inside the furnace chamber. In place of a Thi s fuel consumption may be regarded as excep­ basket , plates suspended on a vertical rod can be Stri p Steel Construction tionall y low, especially as the condition of the used for bevel and other gears and camshafts cylinders and valves a t the end of the test gave no The Bristol Aeroplane Company send an inter­ suspended inside the retort, which is fitted with a indicatio n of injury from running on too weak esting booklet, entitled "Bristol Steel Aircraft special cover making a sealed working chamber. a mixture. Construction," in which the question of weight/ A motor-operated paddle fan incorporated in the cover circulates the carburising gases throughout strength ratio of various materials—such as spruce, A t the end of the 300 hours, the aeroplane was th e charge. duralumin, elektron, and various classes of steel— hande d over to the R.A.E. Experimental Flying are discussed and tabulated. The reasons for the Th e furnace and charge are brought up to heat Departmen t for Certificate of Airworthiness trials, adoption by this firm of steel strip construction wit h the fan running; which gives a rapid and an d was the n flown back t o Bristol, where th e engine are clearly explained and the problem of spar uniform rise t o th e carburising temperatur e of about wa s removed for calibration prior to stripping and design gone into. Thereafter the typ e of construc­ 940 deg. C , depending upon the type of steel used detailed examination. tion adopte d and methods of assembly are described. an d the kind of case structure required. The Th e calibration tests on th e Froude Dynamometer This is done in a historical manner so tha t th e reader carbona l is then introduced into the hot retort by revealed tha t the engine had maintained its power learns how and why the present-day methods have mean s of a drip-feed attachment mounted on the outpu t exceptionally well, the full-throttle power been evolved. The booklet is very fully illustrated retor t cover. a t normal r.p.m. being within 2 per cent of that with informative photographs and graphs. On entering the retort, the carbonal, which is developed by the engine prior to the 300 hours' mad e up of a vegetable base, very rich in hydro­ flight test. carbons, is forced outward against the hot walls by A Simple Method of Measuring Noise Finally , the seals were removed and the engine th e centrifugal action of the circulating fan, where wa s stripped for inspection under A.I.D. supervi­ London noises were measured some eighteen i t is immediately cracked up into hydrocarbon sion. It was found to be in very satisfactory con­ months ago by Dr. A. II. Davis, of the National gases, which circulate through the charge, thus dition, with the minimum of wear on the major Physical Laboratory, Teddington, by a novel exposing it to a very active carburising agent. component s and a marked freedom from gumming method which is surprisingly simple. He described Th e forced circulation assures fresh uniform gas u p of piston rings. his procedure on June 19, during a discussion on being brought to the work continuously. "Audition " held by the Physical Society of Carburising proceeds very rapidly, a penetration London, in which various British and Continental of from 12 t o 15 thousandth s of a n inch a t 930 deg. C. Shor t Floats for Canada authorities took part. A tuning fork having a takin g place per hour. After the carburising cycle pitch in the third octave above the middle "C " General Aircraft Builders, Ltd., of Montreal, is complete, the retort is lifted out of the furnace on the piano was struck in a standard manner and hav e come to an arrangement with Short Bros., b y an overhead gear, and cooled in th e air, while a placed to the ear. Observation was then made of Ltd. , of Rochester, whereby Short floats will bo second loaded retort is placed in the furnace. the time which elapsed before the loudness of the manufacture d in Canada. General Aircraft Builders I n some cases the carburised work is quenched fork fell to the loudness of the observed noise or, hav e specialised in the production of metal floats from the carburising temperature or a little under, alternatively, until the sound of the fork was no of standardised pattern suitable for all types of air­ thi s being accomplished by removing the cover and longer audible in the presence of the noise. On craft and have a practical knowledge of Canadian handlin g the charge direct t o the quench by means this scale,' sounds become painful at about 120 conditions. The floats will be made a t the G.A.B. of the basket containing the charge. decibels above the threshold of hearing, where factory at Ville le Salle. each decibel is th e least change of loudness percep­ A n Engine Flight Endurance Test tible to the ear. In descending order of loudness Italia n World Flight Dr. Davis placed the noises of acro-engines (110 Following upon th e series of 100 hour s full-throttle I t is understood tha t preparations are being made decibels), pneumatic drills (90), busy traffic (70), benc h tests carried out on the geared F-type side streets in London (50), rustling leaves (30), b y the Italian Air Force for a flight round the world. Bristol Jupiter engines, the Bristol Aeroplane suburban quiet (20), an d silence (0). The loudness Th e all-metal Savoia S. 55, M. type seaplane, Company, Ltd., decided to submit one of their of ordinary conversation was about 50 decibels described on anothe r page, will be used, the greater standar d 490 b.h.p. Jupiter XI. F. engines to an above threshold. This simple method has been enduranc e resulting from the lighter structure extende d endurance flight test, in order to demon­ found to give results consistent with those obtained makin g the crossing from the Azores to Bermuda strat e the reliability, smoot h running, an d economy with much more elaborate apparatus. of these engines under flight conditions. For the possible. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Aircraft Engineering and Aerospace Technology Emerald Publishing

Recent Technical Developments

Aircraft Engineering and Aerospace Technology, Volume 3 (7): 1 – Jul 1, 1931

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Publisher
Emerald Publishing
Copyright
Copyright © Emerald Group Publishing Limited
ISSN
0002-2667
DOI
10.1108/eb029429
Publisher site
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Abstract

July, 1931 AIRCRAFT ENGINEERING 181 Vickers Showrooms—A New Noise Measuring Device— Carburising in Electric Furnaces Vickers Show Rooms A New Company purpos e of the test a standard engine selected by th e Air Ministry was installed in the Bristol N May 28 Vickers, Ltd., opened show rooms Messrs. Gibbons Brothers, Limited, Dibdale typ e 109 machine, a large single-engined biplane of a t Vickers House, Broadway, Westminster, Works , Dudley, in conjunction with Messrs. Wild- 50 ft. span and designed to carry a maximum all-up in order that customers may be able to Barfield Electric furnaces, Ltd., Elecfurn Works, weight of 9,000 lb. inspect examples of th e many branches of th e firm's Nort h Road, Holloway, London, N.7, have acquired Th e machine was stationed a t Famborough and manufactures, without the necessity of leaving from Messrs. Rudge-Whitworth, Ltd., Birmingham, throughou t the test was flown by Royal Air Force London. as from February 1, the sole manufacturing and pilots nominated by the Air Ministry. As a check selling rights of the Carburising Compound When it is remembered that the Vickers organi­ on the possible replacement of components the "Eternite. " sation comprises more than twenty companies with engine was scaled by officials of the Aeronautical I n connection with the above, and also the their works spread over the British Isles in more Inspectio n Directorate in numerous places. acquisition of the manufacturing and selling rights than eighteen towns, it will be realised what an advantage it must be to a prospective customer to of Hevi Duty Electric type mechanically-operated Th e aircraft was delivered to the Royal Aircraft be able to visit one central show room. furnaces (under agreement with the Hevi Duty Establishmen t on September 12, 1930, and flying The exhibits themselves range from a 75 mm. Electric Co., Milwaukee, U.S.A.), Messrs. Gibbons wa s carried out daily on all possible occasions in mobile anti-aircraft gun with a maximum vertical Brothers, Ltd., and Messrs. Wild-Barfield Electric periods • varyin g from to two to twelve hours. range of 30,300 ft., to a complete set of steel-shafted Furnaces, Ltd., are forming a new Company under Throughou t the test, apart from taking off and golf clubs. th e title of G.W.B. Electric Furnaces, Ltd. landing , the machine was flown at a constant throttl e setting giving 90 m.p.h. and 1,850 r.p.m., Many items manufactured are, of course, too unde r which conditions the power output of the large to exhibit, and of these beautifully-made Case-hardenin g in an Electric Furnace engine was approximately 350 b.h.p. models are shown. A large portion of a Vickers A new method of carburising has been introduced, "Viklebeest " is exhibited, comprising the front Thre e hundred hours flying time was completed in America by The Hevi Dut y Electric Co., whose' half of the fuselage, complete with engine and lower in March this year, and during this time the only Europea n patent rights are controlled by Wild- wings, to which are attached other products of seals broken were on a magneto after 232 hours, in Barfield Electric Furnaces, Ltd., and G.W.B. Vickers Ltd. , such a s th e Vickers-Berthier observers' orde r to replace a defective automatic timing Electri c Furnaces, Ltd., respectively. gun, Scarff ring gun mounting and Constantinesco coupling and to replace a set of valve-rocker gear Th e charge to be treated is loaded in a basket, synchronising gear. an d details due to a broken tie rod. an d although no special attempt is made to keep Under the wings, bombs and bomb racks of Throughou t the test the engine ran smoothly th e components of the charge from touching each various sizes are fitted, while a 1,610 lb. Whitehead an d well, both when cruising and at full throttle. other, they should be so placed to allow the circu­ torpedo, fitted with an eight-cylinder radial engine, Standar d Shell aviation petrol, without the addition lation of the carburising medium to take place is slung in its correct place between the under­ of dope or benzol, and a standard grade of Shell throughou t the charge. In this way maximum carriage legs. minera l oil were used exclusively, the average fuel uniformity in penetration and structure is obtained. Other types of aircraft, such as the Supermarine consumptio n working out at 20·6 gallons per hour, Th e loaded basket sits inside a heat-resisting alloy. 5.6, are shown in the model form. an d the oil consumption at 6·9 pints per hour. retor t inside the furnace chamber. In place of a Thi s fuel consumption may be regarded as excep­ basket , plates suspended on a vertical rod can be Stri p Steel Construction tionall y low, especially as the condition of the used for bevel and other gears and camshafts cylinders and valves a t the end of the test gave no The Bristol Aeroplane Company send an inter­ suspended inside the retort, which is fitted with a indicatio n of injury from running on too weak esting booklet, entitled "Bristol Steel Aircraft special cover making a sealed working chamber. a mixture. Construction," in which the question of weight/ A motor-operated paddle fan incorporated in the cover circulates the carburising gases throughout strength ratio of various materials—such as spruce, A t the end of the 300 hours, the aeroplane was th e charge. duralumin, elektron, and various classes of steel— hande d over to the R.A.E. Experimental Flying are discussed and tabulated. The reasons for the Th e furnace and charge are brought up to heat Departmen t for Certificate of Airworthiness trials, adoption by this firm of steel strip construction wit h the fan running; which gives a rapid and an d was the n flown back t o Bristol, where th e engine are clearly explained and the problem of spar uniform rise t o th e carburising temperatur e of about wa s removed for calibration prior to stripping and design gone into. Thereafter the typ e of construc­ 940 deg. C , depending upon the type of steel used detailed examination. tion adopte d and methods of assembly are described. an d the kind of case structure required. The Th e calibration tests on th e Froude Dynamometer This is done in a historical manner so tha t th e reader carbona l is then introduced into the hot retort by revealed tha t the engine had maintained its power learns how and why the present-day methods have mean s of a drip-feed attachment mounted on the outpu t exceptionally well, the full-throttle power been evolved. The booklet is very fully illustrated retor t cover. a t normal r.p.m. being within 2 per cent of that with informative photographs and graphs. On entering the retort, the carbonal, which is developed by the engine prior to the 300 hours' mad e up of a vegetable base, very rich in hydro­ flight test. carbons, is forced outward against the hot walls by A Simple Method of Measuring Noise Finally , the seals were removed and the engine th e centrifugal action of the circulating fan, where wa s stripped for inspection under A.I.D. supervi­ London noises were measured some eighteen i t is immediately cracked up into hydrocarbon sion. It was found to be in very satisfactory con­ months ago by Dr. A. II. Davis, of the National gases, which circulate through the charge, thus dition, with the minimum of wear on the major Physical Laboratory, Teddington, by a novel exposing it to a very active carburising agent. component s and a marked freedom from gumming method which is surprisingly simple. He described Th e forced circulation assures fresh uniform gas u p of piston rings. his procedure on June 19, during a discussion on being brought to the work continuously. "Audition " held by the Physical Society of Carburising proceeds very rapidly, a penetration London, in which various British and Continental of from 12 t o 15 thousandth s of a n inch a t 930 deg. C. Shor t Floats for Canada authorities took part. A tuning fork having a takin g place per hour. After the carburising cycle pitch in the third octave above the middle "C " General Aircraft Builders, Ltd., of Montreal, is complete, the retort is lifted out of the furnace on the piano was struck in a standard manner and hav e come to an arrangement with Short Bros., b y an overhead gear, and cooled in th e air, while a placed to the ear. Observation was then made of Ltd. , of Rochester, whereby Short floats will bo second loaded retort is placed in the furnace. the time which elapsed before the loudness of the manufacture d in Canada. General Aircraft Builders I n some cases the carburised work is quenched fork fell to the loudness of the observed noise or, hav e specialised in the production of metal floats from the carburising temperature or a little under, alternatively, until the sound of the fork was no of standardised pattern suitable for all types of air­ thi s being accomplished by removing the cover and longer audible in the presence of the noise. On craft and have a practical knowledge of Canadian handlin g the charge direct t o the quench by means this scale,' sounds become painful at about 120 conditions. The floats will be made a t the G.A.B. of the basket containing the charge. decibels above the threshold of hearing, where factory at Ville le Salle. each decibel is th e least change of loudness percep­ A n Engine Flight Endurance Test tible to the ear. In descending order of loudness Italia n World Flight Dr. Davis placed the noises of acro-engines (110 Following upon th e series of 100 hour s full-throttle I t is understood tha t preparations are being made decibels), pneumatic drills (90), busy traffic (70), benc h tests carried out on the geared F-type side streets in London (50), rustling leaves (30), b y the Italian Air Force for a flight round the world. Bristol Jupiter engines, the Bristol Aeroplane suburban quiet (20), an d silence (0). The loudness Th e all-metal Savoia S. 55, M. type seaplane, Company, Ltd., decided to submit one of their of ordinary conversation was about 50 decibels described on anothe r page, will be used, the greater standar d 490 b.h.p. Jupiter XI. F. engines to an above threshold. This simple method has been enduranc e resulting from the lighter structure extende d endurance flight test, in order to demon­ found to give results consistent with those obtained makin g the crossing from the Azores to Bermuda strat e the reliability, smoot h running, an d economy with much more elaborate apparatus. of these engines under flight conditions. For the possible.

Journal

Aircraft Engineering and Aerospace TechnologyEmerald Publishing

Published: Jul 1, 1931

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