The Iron Age 1929-07-25: Vol 124 Iss 4

AGE New York, July 25, 1929 ESTABLISHED 1855 VOL. 124, No. Universal Apprenticeship Essential Shortage Skilled Mechanics Overcome Long Common Duty Training Younger Generation Shirked HAROLD man who works the most important factor the in- dustrial world. abandoned factory, with crumbling walls, sagging roof, windows broken and doors off the hinges, excellent evidence that indus- try without men than useless. Up-to-date equipment, efficient accounting systems, strong financial foun- dation, advantageous location, loyal and satisfied customers —all these are futile without strong organization men who know their work. Manufacturers ness people have gradually come realize this important fact and are devoting more and more thought matters personnel. Business men who are confronted with more problems than they can take care have asked themselves why they should not train assistants help them with these problems. This thought naturally enough suggested efficient, will not present many problems the first place, and the second place will include great number men, even subordinate positions, who can solve their own prob- lems they reach the head the business. General Lack Interest TERN Apprenticeship Accordingly, there has ship the Oldest grown the last few Branch Ap- years very considerable prentice Training the Falk Shop Organized FALK* development personnel work industry. Employment departments have been set for careful and sometimes selection workers; the work and habits men are analyzed and recorded find for each one the task for which best fitted; shop committees have been appointed for safety, for the adjustment dis- putes, for improvement processes and for other pur- poses; insurance and pension features have been pro- vided; hospitals have been established; working condi- tions have been improved; training courses for young engineers, for salesmen, for foremen and for office work- ers, well other educational advantages, are avail- able many industries. curious fact that spite all this there general lack interest apprentice training among American business men. course, there are exceptions. Here and there may found organizations, especially among the railroads, the machinery building industry ‘ - J 203 — and the building trades, which thorough programs apprentice training have been arranged. However, the great majority our employers seem think that all necessary men can hired when needed, they not think about the matter all. Prevalent Opinion that Modern Mechanical Industry Requires Skill Some time ago spoke before group foundrymen the subject apprentice training. During the in- formal discussion that followed the talk, one the foun- dry operators stated that his plant was production basis and that all his castings were made molding ma- chines which were automatic and practically fool-proof. stated that modern machinery dispenses with skilled mechanics, that had need for them his plant and did not want any. This merely example the far OUNDRY Apprentices and Certain Machine Shop Ap- prentices Are Given Several Months’ Training Heat- Treating Shop, Not with the Idea Making Them Skilled Heat Treating Steel, but Teach Them Appreciate What May Done Changing Properties and Characteristics Steel too prevalent opinion that trained men are not required modern mechanical manufacturing. The following answer the argument from article which recently appeared well-known trade publication: “Managers automobile plants have been known say that they want nothing except men who can taught mechanical operation and are willing stay indefinitely. But where such managers obtain their superintendents, their foremen and inspectors? Who there show the mechanical operators what and how they are it? Mechanics are necessary pro- duction industries take care the maintenance machinery and set the first place. Skilled men the highest class are required plan and make the tools and fixtures that make production work possible. Only highly trained men can plan the routing work. the placing machines and the proper arrangement and correlation various departments.” may true that the proportion skilled mechanics required mass production smaller than the old- fashioned manufacturing methods, but the production in- 25, 1929, The Iron Age dustries have expanded much that the actual number mechanics required probably greater than ever before. Moreover, must not forgotten that there are important and extensive industries that not readily lend themselves mass production methods. For instance, not expect find any considerable number un- skilled men line assembly and machine operations the manufacture locomotives, passenger cars, boilers and turbines for public service corporations, furnaces, cars and rolls for the steel industry, printing presses, machinery for vessels, equipment for food and industries and water turbines. Such products will con- tinue for years built individual units rather than thousands along assembly line and, hence, those industries, the all around mechanic will continue hold his own. Shortage Apprentices the United States Magnus Alexander, president the National In- dustrial Conference Board, explained the situation excel- lently paper before the American Society Mechan- ical Engineers December, 1924. That some years past, but conditions have not changed materially since then. According investigations made his organiza- tion, about per cent the industrial workers the United States must replaced every year. Since the ordinary apprentice training course extends over period several years, per cent the total number skilled mechanics should constantly training apprentices order supply the required per cent every year. placed the number skilled mechanics the United States 4,500,000. Fifteen per cent this number would from 675,000 900,000 appren- tices. matter fact, only 144,000 apprentices were reported the United States the time his paper was presented. Accordingly, there was that time shortage over half million apprentices the country, indicat- ing pronounced shirking the duty training mechanics the part American business people general. Apprentice Training Not Financial Burden Apprentice training will not added financial bur- den upon the manufacturer, carefully established and the quota apprentices correct. has been shown experience that the work apprentices done well enough carry not only the labor cost but all indirect charges caused apprenticeship administration and supervision well. However, apprenticeship longer paying enterprise the quota apprentices too high. For this reason the present conditions are unfair those few manufacturers who train apprentices. They find that very considerable portion the apprentice graduates leave soon completed. This proportion sometimes high per cent. Accord- ingly these companies are forced maintain double the correct quota apprentices order supply their own requirements skilled men. Industry Needs Universal Apprenticeship There are reasons other than the unfairness the present methods why apprenticeship should extended every industrial district and practically every manu- facturer. Industry’s need for trained men will not satisfied until this done. Although certain manufac- turers now train many more apprentices than they them- selves utterly impossible for them train all that are required, even they were willing so. The shortage half apprentices the country which was pointed out Mr. Alexander cannot made until apprenticeship becomes universal. Apprentice- ship should made community responsibility every manufacturing district. Employers each district should Machinist Apprentices the Falk Plant Are Required Spend Several Months the Erecting Shop Learn How the Various Parts That They Have Made Are Set Together and Also Become Impressed with the Necessity for Accurate Work associate themselves for the purpose supplying together the number skilled mechanics required the district. How universal apprenticeship achieved an- other matter. Apprenticeship will not grow itself. comparatively easy point out the need for and extremely difficult devise way bringing about. However, intensification efforts already begun will long way. Promotion Interested Employers Employers who are training apprentices can accom- plish much. Economists, engineers, employment experts, Federal and State agencies, educational authorities—all these can preach the need apprenticeship manu- facturer and will pay little attention them. But when another manufacturer, one his own class, one who confronted the same problems tells him that apprenticeship necessary and that has made success it, the skeptical manufacturer becomes interested. Therefore, manufacturers who employ apprentices will well call the attention their associates constantly the advantages apprentice training: The strong corps young mechanics who will effective for years come; stable organization, sympathetic with the poli- cies the employer; group young men from whom Corporation Apprentices Have Association That Sponsors Entertainments and Athletic Events. meeting depicted shows part the association organizing for annual picnic The Iron Age, July 25, 1929— 205 utives and officials may selected, and bility force mechanics who are not only skilled their but thoroughly acquainted with products addition. Milwaukee branch the National Metal Trades Association much been accomplished this direction hip. standardized supervision and procedure and program promotion 1ey have doubled the number apprentices the district the last years. Trade kill contests, banquets for apprentices and for foremen and inte and contact with the schools have played important part this work. Wide Publicity Essential addition, the development apprentice training atly assisted gen ral and constant publicity. should directed only toward business men, but toward the general public, associations various nds, civic and, especially, school teachers and authorities. has frequently been pointed out that program apprentice training will successful that pon the approval the community. this matter publicity, the trade and business papers have performed excellent ser- vice and doubt will continue so. Helpful Activity Trade and Manufacturing Associations Much can expected from the manufacturing and trade associations, which have also contributed great deal the development apprenticeship. The officers and professional managers these associations have, rule, shown more foresight and appreciation the ad- vantages apprenticeship than have the members them- This was expected. The individual member association more less absorbed the activities his own plant and business. seldom position ern him directly. the other hand, officers and managers associa- can the entire industry that they serve, and investigations frequently disclose the existence that must solved the industry whole, they may not oppress any individual member any_appreciable extent. For instance, every employer who member association may hire salesmen and foremen needs them and think nothing it. How- ever, the manager the association understands that members are merely taking these salesmen and foremen from each other, creating high turnover and increasing the cost doing business for all. number associations have appointed training directors and have made considerable appropriations for their work. The directors visit the members, help them organizing apprentice training programs and make efforts interest those who have not begun the work. Associations have also made discussion apprenticeship problems part their regular meetings, have booklets and circular letters the subject and have given the movement the support their boards directors. addition, certain associations have made careful study the problems apprenticeship and have pre- pared solutions for their membership when possible. Thus, they have arranged and published courses work for various trades, standard forms for contracts, certificates and records, have established bureaus information, have made calculations the needs their membership for mechanics and have worked out theoretical minimum quotas apprentices. Unfortunately, such work has seldom been fully appreciated and sometimes has not even had the full approval all members. Worthy Activity for Wealthy Foundation The suggestion has been made that apprenticeship would excellent field activity for one the wealthy foundations. The mere fact that such institu- tion took the study apprenticeship give great impetus the movement. The development apprentice training far has been due almost exclusively the efforts the various agencies that have been described and, undoubtedly, they will achieve still greater results. more people can attracted these activities and can made take interest them, much greater extension the move- ment during the next few years may expected. Other and better plans may come the minds those who apply themselves the study universal appren- ticeship, problem that must solved. Germans Study Energy Losses Heroult Furnaces articles have appeared the German technical paper, Archiv fiir das Eisenhiittenwesen, discussing energy losses Heroult electric furnaces. The first article discussed losses 7-ton furnace with particular reference heat accumulation processes. Wark was the author. With the intention determin- distribution the energy losses between the transformer, the current leads, the cooling water, the furnace body and the gases, was found that time charging, the quality the scrap and the con- lition the furnace walls particular, have influence the heat losses the furnace. The flow heat through the furnace walls was investigated, and was ascertained that the the accumulated heat decreased during the melting period, the heat the walls was insufficient make for that vhich was radiated externally Wark, losses 15-ton furnace with particular the roof were discussed. En- lance sheets were prepared for the life one roof from the data obtained during four melts, using cold charges. These showed clearly the dependence the heat losses the wear the roof. regards the ability the roof material absorb heat, the results which were obtained confirmed those recorded with the 7-ton furnace, referred above. The thermal balance sheets melts made with liquid charges showed that the energy supplied was almost entirely used the formation the slag and making the radiation losses. abstracts were made the Iron and Steel Institute and the National Federation Iron and Steel Manufacturers London, England. “The Expansion Tantalum” the title research paper No. the United States Bureau reprint from the bureau’s Journal Research and the author Peter Hidnert. contains pages and illustrated with charts. eference the wear 25, 1929, The Iron Age oundry Uses Hot-Blast Cupolas Marked Savings Fuel and Time—Borings Made into Briquettes for Charge— Mixing Ladle Used FRED PRENTISS* adopting improved production, materials-hand- ling and other methods, and providing better arranged foundries and more efficient equipment, the automotive industry has played important part the last few years the development the foundry industry. These changes have resulted the reduction hand labor minimum, better working conditions for the men, lower production costs and improvement the quality the product. When new foundry built make motor car cast- ings, the builder attempts improve the last one and thus assure further increase efficiency and reduc- tion the cost making castings. The latest foundry built for the manufacture motor car castings the gray iron unit the Oakland Motor Car Co., Pontiac, Mich. Its numerous interesting features lay- out, arrangement, handling and other equipment, foundry practice, elimination hand and hard labor make outstanding plant the foundry field. Well lighted and well ventilated buildings make working conditions excellent. Preheated Blast Used for Two Cupolas From production standpoint one the most inter- esting features the use hot-blast cupolas, the blast two the four cupolas being preheated the com- *Resident editor, Cleveland. the a ~ >. bustion gases from the cupola, resulting greater output and saving fuel. This the first automobile foundry use the hot-blast method with its cupolas, although the Griffin Wheel Co. has been using hot-blast cupolas for some time. new method handling the cupola charging ma- terial and making the charges designed im- provement over methods employed other modern pro- duction foundries which have largely eliminated hand labor the charging cupolas. One the interesting features this part the foundry that cast iron borings are made into briquettes for the cupolas. The equipment for handling the borings and the briquettes themselves all part the cupola materials-handling system, working conjunction with the equipment for handling pig iron and scrap. Methods provided for delivering castings and sand from the shake-out the basement, removing them im- nediately from the foundry floor and keeping the foundry largely free from the heat, smoke and gases that come from the molds and castings, are recent developments which tend improve working conditions the Built for making practically all castings for the Oak- land and Pontiac cars, the foundry has rated melting capacity 450 tons day. The buildings are arranged for convenience handling material and castings, the whole plant being laid out avoid counterflow work. \ Cupola Charging Floor. Charges are brought the cupola charger from the ground floor through the shafts shown The Iron Age, July 25, — coming from one side feed the plant. Two these are for sand and two for fuel and metal. fifth track serves conyeniently located service build- ing, running along dock the side that building for delivering flasks, wire, machinery and miscellaneous sup- plies the maintenance department, stock room and wire room. Finished castings, leaving the cleaning department, move the adjoining shipping department and from the loading dock the side that department are carried truck the adjoining motor building. Service yards ample size are provided between the foundry buildings. All four cupolas have shells, lined down about in. Gases combustion are drawn from the hot-blast cupola into gas chamber through openings ft. below the charging door, suction fan using suction. The gas, mainly carbon monoxide, delivered the combustion chamber one blast heater that serves the Cold air for the eupola blast delivered the cupola blowers into the blast heater and, after preheating the burning the cupola gases, enters deg. Fahr. That temperature closely maintained all times. The volume preheated air entering each cupola controlled Bacharach indicator and recorder. Blast for the four cupolas supplied through one feed line three Root blowers, two driven constant- speed and one variable-speed motor. low pres- sure used the hot-blast cupolas, the full capacity the three blowers not required. For this reason the volume air regulated the use one variable- speed motor. two cupolas. Measure the Improvement Performance Melting capacity the cupolas has been materially increased the use the hot blast. The output each hot-blast cupola tons hour, compared with tons hour the cold-blast cupolas with the same linings. Coke consumption has been reduced one ton for tons iron melted, compared with ratio 208—July 25, 1929, The Iron Age the cold-blast cupola. The sulphur content iron melted the hot-blast cupola considerably lower than that made the cold-blast cupola. Another advantage claimed for the hot-blast method that preserves the furnace linings. For making iron for all kinds castings the cupola charge 4000 which approximately per cent malleable pig iron, per cent nickel-chrome iron, per cent cast scrap and the remainder steel scrap. Cyl- inder blocks and heads are made hard iron. Iron for flywheels and clutch plates present softened the addition ferrosilicon the ladle. With the completion all the molding units, both hard and soft iron will made, the latter used for the smaller parts. These will include transmission housings, intake and exhaust ANDLING Equipment Weighing Room, the Stockyard Be- ing the Left, Outside the Build- ing. Weighed ma- terial charging buckets they are pushed along the rollers The briquette hopper shown top 4 > 4 IFT Truck Picks Charging Bucket Cone Head Shaft Extending Through Center Bucket, and Carries Slot the Truck Frame manifolds, clutch plate housings and miscellaneous small castings. Metal from the four cupola spouts will flow into 4-ton mixing ladle, installed shortly, secure more uniform metal. This ladle, the tilting type mounted electric truck, will deliver the iron the Sprague hot-metal carrier now This has ladle which metal taken the pouring bays, where Four short, horizontal conveyors carry metal from the stockyard through openings the side wall the weighing room, the side the cupola building, which the charges are made up. One conveyor handles Bin the Weigh- Core AYOUT the Foundry Departments, Showing How Iron and Cores Move from Either Side the Molding and Pour- ing Floors. Thence the castings proceed toward the right, the outside cooling the cleaning room Cooling Skip Hoist Yard Runway HARGING Bucket Setting ceive Its Charge Coke the Hopper Above (Right) The Iron Age, July 25, OO cast scrap and two pig iron. Pig iron crane, equipped with lifting magnet, and each conveyor the metal drops into weighing hop- i-ton capacity. weighing hopper for each conveyor and ett The metal dropped from the weigh- a-charging bucket 4000-lb. capacity set conveyor located floor level. This conveyor extends along the side wall the weighing room, directly neath the hoppers. The bucket pty charging pecially designed electric lift truck under and, after the charge received from the bucket pushed forward the roller that moves the beneath the second second portion its charge, and are placed the scrap, waste scrap, ttes, two charging truck the loaded bucket the end roller conveyor and sets beneath hoisting haft that connects with the cupola charging floor above. Borings are brought open-top cars from the motor plant the stockyard and unloaded with the stockyard which the scrap into two bins, each 50-ton single belt conveyor carries the rap from bins Southwark briquetting machine which they are made into cylindrical briquettes in. diameter and in. long, weighing about lb. each. The ttes are discharged into elevator which carries ign horizontal conveyor above the weighing room. this they fall into two orage bins located ar briquettes are bins weigh hopper the discharged into located line with the other hoppers 1 in malkine nn + share making the charges. Col limestone are dumped from hopper-bottom cars into the hopper automatic skip hoist, which ww} Gears and bureaus the United States / arge use gears: the Bureau Ordnance, torpedo. tubes, and the Bureau Engineering, the power supply and all auxiliaries, and hoisting engines. Both bureaus phosphor the former = { | « = } a 25, 1929, The Iron Age delivers the fuel and limestone end the into storage bin the weighing room. This bin, having capacity for four carloads coke and one limestone, divided into five sections, the center section being for limestone and the others for coke. Coke and limestone are dis- charged from the bin through hopper into charging bucket—800 1000 capacity—set scale. The discharge gate each bin section can operated inde- pendently. The bucket with its charge coke and lime- stone, lb. the latter per ton metal, taken the charging truck the hoisting shaft. Coke breeze and fine coke pass through screen that leads storage tank. feature the coke-charging equipment thesdesign the charging buckets. have steel shaft through the upper end which, extending slightly above the top the bucket, cone- ype button which used for handling the bucket. The charging truck designed operate the bucket picks the bucket the button. The cupola charging machine which elevates the bucket the charging floor also lifts the bucket gripping the button end the shaft. The buckets are in. high and in. diameter, and have dump bottoms, the elevating shaft oval form, providing room for two buckets, loaded bucket can pass and empty bucket down the same time. The cupola charg- ing machine sets the bucket into the cupola, flanges the bucket sides resting wishbone the Then the bucket dumped from the bottom. cupola. This charging machine differs from those used some foundries that not provided with operating cab. Instead, operated control switch the side the cupola, and only one man required charge two cupolas. controls the movements the bucket and charging simply stepping from one switch the other. second article will follow, describing the- molding, pouring and cleaning Wireless Antennae Phosphor Bronze gun mountings, the latter auxiliary engines and equipment. And both specify gears which show best possibilities civilian practice; they desire that such products standardized. the two pictures, which were furnished the Phosphor Bronze Smelting Co., Philadelphia, gears that metal, hidden the winch and the gun mountings, not appear. But the wireless antennae shown are the same metal. bucket fixed hopper—to receive the until the charge made up. Charges the roller track which the charges are made up. Metals Used Airplane Making Increasing Volumes Chrome-Molybdenum, Nickel and High-Carbon Steels and Aluminum Alloys GEORGE HERRICK INCE the memorable flight heavier-than-air ma- chine Orville Wright Kitty Hawk, C., Dec. 17, 1903, not only the materials but the designs aircraft con- struction have been changed radically. The box-like craft bamboo, ash balsa wood and cloth, with ordinary steel wires for the flying and landing braces the wings, has rapidly developed into the modern craft rakish lines and metal con- struction. Each step progress has found metal com- ing into increasing importance, until the airplane has become the incentive the rather in- tensive development both steel and non-ferrous alloys, all competing for permanent and efficient place aircraft manu- facture. Almost the American end the airplane industry became real factor Tubes, Round, Square and This tubing, listed Army and Navy specifications No. 57- 180-1A, has analysis 0.20 0.30 per cent, Mn, 0.50 0.80 per cent, 0.045 per cent maximum and 0.050 per cent maximum. Its phys- ical properties are minimum strength 55,000 Ib. per sq. in. and yield point 36,000 far the greater number American builders today are using chrome-molybdenum steel tubing classified the Army and Navy specifications No. 57-180-2A and with standard analysis 0.25 0.35; Mn, 0.40 0.60; 0.04 max., 0.045 max., Cr, 0.80 1.10 and Mo, 0.15 0.25. This the seamless manufacture, stream- lined (ovate section) exterior positions, where air resistance Cam Various Sizes, Are All Used the Construction The round chrome-molyb- among our manufacturing Aircraft. The display tubes made the denum tubing used ranges terprises, and while Europe, the development the motor car, continues, course, builder airplanes, America the throes activity which approach- ing the mass production basis that characteristic. modern industries this country. estimated that about companies are construct- ing almost per cent all the airplanes produced this country the present time. these, about eight are leaders building the large, all-metal, passenger carrying types. the total output, probably about per cent the planes are fabric covered over alloy steel frames, with few alloy aluminum frames, leaving about per cent covered with aluminum alloy sheets. Magnesium still preferred some makers for certain parts. Aluminum foil still finds use cover the wocd frame, metal parts, protect them against rotting corrosion from contact with the textile covering, which has been treated with acetate “dope.” Chrome-Molybdenum Steel Most Used Except for certain builders who are using fuselage frames alloy the form structural Shapes tubing, steel tubing preferred. Those who have European experience cling medium-carbon seamless steel tube. was the ordi- nary seamless tube which succeeded the fuselage wood and still used many British and Continental builders. Summerill Tubing Co., Bridgeport, Pa. size from outside di- ameter and 0.028 in. wall thickness and 7/16-in. with 1/32-in. wall 2%-in. with wall. certain the large passenger carry- ing ships, tubing large 3%-in. with %-in. wall used, usually only for small section for axle for part the frame the landing gear. The smallest diameters tubing are used high- speed planes for forming the frame the tail and after section the fuselage, the larger diameters going into the main section and the undercarriage. Certain makers use limited amount square tubing for the frame around the cockpit, they claim that the square tube offers greater resistance squeezing, tending afford great protection the the cockpit the Streamline tubing goes into such parts the under- carriage and struts the wings, where motion through the air will attended with minimum eddies. These streamlined tubes are drawn all the required sizes and vary somewhat shape, may the accom- panying illustration sample stand the Summerill Tubing Co., Bridgeport, Pa. The quantity tubing used individual plane anges from 350 ft. small open cockpit, single place plane possibly 1000 ft. open cockpit two place plane, about 1400 ft. inclosed cockpit design, 1600 ft..or more large passenger carrying plane, such the “Patrician” recently built the Keystone Aircraft The Iron Age, July 25, Products for Aircraft, Consisting Bolts, Tie Rod Terminals, Turnbuckles, Shackles, Washers, Grom- mets, Thimbles, Pulleys, Ferrules, Clevis Pins, Are Produced the Aero Supply Mfg. Co., College Point, Its Subsidiary Companies, the Standard Automatic Products Corporation, Corry, Pa., Products Co., Dayton, Ohio and the National Corporation, Bristol, Pa., and much 3000 ft. large, 30-passenger ship, recently constructed the Fokker Aircraft Corporation America, Hasbrouck Heights, Makers tubing for aircraft, manufacturers other materials entering into airplane construction, apply rigid standards inspection. the plant the Aero Supply Mfg. Co., College Point, Y., promi- nently displayed the advice workmen, “Make Safe for the Flyers,” and the inspection department the Summerill Tubing Co., Bridgeport, Pa., large sign with the advice inspectors, “Above All Careful. Fly Yourself Some Day.” this latter mill, tubes travel through lots, usually consisting single order. When the swaged end, used for drawing the tubes through the dies, sawed off, each tube permanently numbered the end and after passing through the straightening machine goes inspector, who tests for hardness. marks the result sheet, which kept record together with the order the customer; and the event complaint the hardness indication well the analysis the steel used are available for each tube. When material for the Army Navy, the FEW Shapes the Welded Aluminum Tanks for Aircraft Fabricated the Paramount Welded Prod- Corporation, the foreground Aluminum ucts Brooklyn, are for honeycombing the interior 212—July 25, 1929, The Iron Age tubes are turned over for final inspection Govern- ment inspector, who marks each tube passed him with his own die, which, the case the Navy anchor, the initials U.S.N. and the inspector’s own initials sign. Covering the Fuselage Aluminum and its alloys are being increasingly used construction. While sizes and gages sheets are far from being standard they are usually Nos. gage, but mostly Nos. gage, corrugated. The corrugating varies with the builder. general, sheets are used wing construction, gas tanks, ship cabins, bottom lining, cowling, instrument boards, fusel- age covering and incidental fittings such battery boxes. seaplanes, hull frames and sheathing, decking and pontoons are often made strong alloy sheets. difficult estimate the average amount aluminum entering into airplane, but noteworthy that 1928 the aluminum used aircraft increased about 250 per cent over the quantity consumed the preceding year. airplane production increased only about 150 per cent during that period, appears that the use aluminum has grown faster than the industry. the all-metal airplane, aluminum alloy sheets, usual- duralumin, 17-ST, Alclad sheets, are used almost exclusively. Kansas City, Mo., builder recently experi- mented with welding thin-gage black steel sheets, for covering the fuselage, but the results are understood have been less satisfactory than expected. Pure aluminum sheets are used almost entirely for fuel tanks, which sometimes occupy most the available space the fuselage and some cases are the wings. The welded tank preferred. Occasionally riveted duralumin Alclad tank will specified and few instances tanks have been made dairy tin plate. Some years ago copper tanks were rather widely used. Aluminum, alloy aluminum, sheets for tanks are usually Nos. 14, 16, and gages, depending upon the capacity the tanks, which range from few gal- lons those designed for the wings tail much 550 gal. single tank the larger air transports. with many other products entering into aircraft, tanks are far from standardized, each builder specifying the size and shape suitable the plane being con- structed. certain the larger craft, intended for long-distance flights, practically the entire interior, except the cockpit, will sometimes composed closely fitted tanks. much space they occupy that they are not only formed the shape the fuselage, but when neces- sary, pass controls and other wiring through, ARGE Capacity Alu- minum Tanks with the Baffle Plates Riveted Place and the Rivets Welded. This interior construction permits free flow fuel the mo- tors, but prevents sudden shifting the contents section pure aluminum tubing welded into the tank from side side, across corner. When the space through the tank for controls large the tank prac- tically built around hole. For oil tanks, number builders specify tubes welded across the tank, usually the ends, permit circulation air aid maintaining cool oil supply. Such tubing almost entirely pure aluminum, although the fittings tanks are sometimes aluminum alloy, which holds thread more satisfactorily than the pure metal. The accompanying illustrations show tanks various designs for aircraft fabricated the Paramount Welded Aluminum Products Co., 195 Morgan Avenue, Brooklyn, The cross section baffles all the larger tanks and most the small designs are stamped from aluminum sheets and riveted into the tank interior prevent sudden shifting gasoline one side, which might cause heavily loaded plane overturn. The baffle sections are constructed permit free flow fuel the motor any position. Black Sheet Stampings The industry uses small tonnage black steel sheets the manufacture miscellaneous fastenings and acces- sories. When stamped, otherwise fabricated for use exposed places, the usual requirement Army and Navy specification No. the analysis which 0.25 0.35 per cent; Mn, 0.40 0.60; 0.04 max.; 0.045 max., Cr, 0.80 1.10 and Mo, 0.15 0.25. Stampings places where strength and resistance corrosion are not important are usually Army and Navy specification No. 57-136-3 and have analysis 0.20 0.30, Mn, 0.50 0.80, 0.045 max. and 0.045 max. The finished stamping either quality sheets always coated, usually with cadmium, prevent corrosion. Steel Cord and Tie Rods for Bracing Wire and cord, the number tie rods used plane vary with size and design. biplane with two wings braced with the landing and flying braces requires considerably more wire cord tie rods exter- nally than monoplane. few years ago, builders most cases used wooden longerons, members for the fuselage, and these were braced with wire, which could adjusted the proper tension turnbuckles. This type construction still used, but chrome-molybdenum, high-carbon aluminum alloy tub- ing, rolled alloy aluminum shapes take the place the wooden longerons. Tinned No. No. gage steel wire, tie rods the exact length the section braced are used. Two active makers tie rods are the Stewart Hart- shorn Co., New York, and the MacWhyte Co., Kenosha, Wis. The rods range from 0.138 in., 6-40 thread 0.625 in. diameter, thread and have total ultimate strength 1000 24,700 lb. the streamline section, depending upon the size and from 1080 35,800 the thread section. They are made A.S.M.E. specifi- cations the smaller sizes and S.A.E. specifications the larger sizes. The Army and Navy specification for tie rods compares with the S.A.E. and requires 0.40 0.50 per cent, Mn, 0.50 0.80, 0.045 max. and 0.050 When used externally for landing braces these tie rods are streamlined. For tying the frame the fuselage square rod usually specified. All such rods are plated, usually with cadmium. Sizes used depend upon the capacity the plane, ordinary light commercial plane requiring about 5/16-in. and smaller rods, the larger sizes entering into the heavy transports and bombing planes for the Army and Navy. All such rods are subject careful inspection with other pro- ducts for aircraft, and the case the Stewart Hart- shorn Co., all rods are subjected proof test load equivalent per cent the specified breaking load. While many manufacturers use tie rods throughout their planes, others specify steel aircraft cord. this, three principal types are used, the so-called hard, 19-wire strand, composed galvanized, tinned wires stranded together, the so-called flexible cord, com- posed strands seven galvanized tinned wires, six strands around one, and the extra flexible, cord, composed strands tinned wires, six strands around one. The illustration cross sections cord manufactured the John Roebling’s Sons Co., Tren- ton, For the wing bracing biplanes, the usual practice, when cord used specify.19 strand, galvanized tinnedy which classified the Army specifications No. 48-21. some instances, makers use cotton center galvanized tinned cord, Army specification No. 48-14A and occasionally wire center, galvanized tinned cord, Army specification No. 48-22. special flexibility required the wire for this exterior bracing the wings. substantial footage required the flying wires are generally double while the landing braces are either single strands cord, two small-diameter pieces are used, that they may streamlined binding together with balsa wood between. When steel cord used, turn- buckles are required. These range from 4%-in. 9%-in. Fig. 19-wire Aircraft Strand Fig. (Wire Center) Aircraft Cord The Iron Age, July 25, | A pin-eye pin-eye, with strength 800 lb. the sizes 17,500 the larger size The ends the turnbuckles are steel S.A.E. ecificatior No. 2330, while the barrels are special Army and Navy specification No. 57-162. considerable length the heavier cord used interi for controls the rudder, elevators and usual steel cord for this purpose the 19, tinned, which extra flexible. The sizes used vary from in. diameter. While difficult estimate the amount wire used airplane, the total footage the various solid wires and cords will range from 250 300 ft. small design using steel cord for exterior bracing and 500 700 ft. and more large passenger carrying plane. Some builders monoplanes the exterior bracing the wings use chrome-molybdenum tubing from the fuselage the underside the wings and this streamlined covering with aluminum sheet. making these braces wide, builder claims increased lifting power for the nian While galvanized wire still used, the tendency decidedly toward increa with cadmium plating. sed use the tinned wire, and wire case other materials, the wire and cord used are subject numerous tests and are all manufactured either Army Navy specifica- the case wire and cord the two Government ranch till retain specifications which vary slightly instan addition the wire and cord required. for interior bracing the fuselage, and wing exterior bracing nose and tail and the controls, there mount insulated wire used ignition, winoe moderate the wiring for lights, grounding and antennae, and welding rods are used for chrome-molybdenum steel tubing rolled shapes Resistance Corrosion Factor Second only factor strength aircraft construction the ion. When aluminum used, further pro- not necessary, but aluminum alloy the 17-ST type subject corrosive action, which has been over- come certain extent the Alclad sheet. the case alloy steel, which exposed, protective coating must applied meet the Army and Navy test 100 hr. phere salt spray. tection an atmos Galvanizing sometimes used, but being succeeded many plants cadmium plating, tin coating and other processes. Recently chro- mium plating for exposed parts made aluminum alloy being considered manufacturers. All bolts, nuts, rivets and wing reinforcement mate- rials are either heat-treated aluminum alloy alloy steel. While nuts are ordinary steel, all bolts are made from nickel steel, according S.A.E. specification No. 2330, Army and Navy specification No. 1004-C, with analysis 0.25 0.35 per cent, Mn, 0.50 0.80 0.040 max., 0.050 max. and Ni, 3.25 3.75. All bolts are heat treated give minimum strength 125,000 lb. per sq. in. Products Bear Makers’ Marks Whenever the product permits, there growing use among manufacturers individual marking materials. While not general, number have adopted system marking bolts and similar small finished products with the official designation Army and Navy specifi- cations and certain manufacturers add their own sign letter. The Aero Supply Mfg. Co., College Point, manufacturer bolts and other small products, whose entire production goes aircraft builders, marks each bolt the head with the Army and Navy and letter, changed each year, that any time the bolt may identified made this producer certain year. the Army and Navy specifications have been re- vised considerably and are still subject minor revisions from year year, this identification enab!es the maker determine any time whether not the ques- tion was made the standard effective the year desig- nated the mark. From this becomes ments evident that, despite the require- lightness, strength and resistance corrosion for material entering into aircraft production, this new and growing industry offers source increasing con- sumption alloy steels. Non-ferrous meta aluminum and its alloys, are being will undoubtedly continue be, and the aircraft in- dustry tends reach basis quantity production comparable other great industries the country, the factor cost materials well quality will in- creasingly important, which should br! alloys steel into still greater use the builders aircraf especially extensively and Flash Welds Aircraft Tubing OINTS the forming the craft are commonly welded with flame used, and tubing eleton air- the being well fitted for the thin gages metal the intersections are such varying angles that hand work the most econumical method. some instances, however, plain butt joint must made between straight tubing, end fitting attached. Then resistance flash weld solution. Cases point are the struts the landing gear and the motor fitting the Ford tri-motored planes. The former illustrated, lying the lower jaws the welding machine. These welding jaws dies are lined with Elkonite, proprietary series alloys copper and tungsten The copper gives the electrical conductivity required pass the welding currents large amperage, and the ungsten hardens and raises the melting point resist wear and overheating. said that the dies shown are perfect shape after 600 welds had been made, whereas the materials formerly used required redressing after operations. logical supporting 25, 1929, The Iron Age Terminal Strut Immediately After Welding (upper dies removed) Obsolete and Inactive Patterns Determining How Long They Should Kept— Practices Leading Companies Reviewed —Storage Charges Sometimes Levied HEN dispose the little used obsolete pattern constitutes one the difficult problems industry, and affects the small firm well the large one. The purpose here present methods current use different companies various fields industry, the hope that the information may helpful. The money expended for storing patterns evident from the amount storage space used. One firm has less than large warehouses filled with patterns; another has nine; others from one seven eight. Ingersoll-Rand Co. has, among eight large warehouses devoted solely pattern storage, one which 600 ft. long, ft. wide and three stories tall. Sessions Foundry Co. has three good-sized warehouses for storing patterns, one being large five-story building modern construc- tion. Sturtevant Co., which has manufactured fans, blowers, and allied products for nearly years, has ac- cumulated tremendous number patterns. Its line varied that may called upon furnish less than 1,000,000 different repair parts, many which are castings. present the company obliged carry nearly 100,000 different patterns. Several factors are considered before formulat- ing definite policy pertaining the retention pat- terns which are seldom used. One the value the pattern, measured terms its replacement cost, and the other the obligation the company the cus- tomer furnish repair parts castings which require that particular pattern. The ‘value pattern ordinarily should balanced against its cost storage. obsolete pattern might easily absorb, storage cost over given period time, more than its worth. Often more economical replace occasionally pattern which has been destroyed than invest thousands dollars storage facilities for patterns that are not being utilized. standard practice appears use the amortization the pattern account. From replies re- ceived from companies all over the country, different fields manufacture, the rate varies from per cent per cent year. wide difference opinion exists concerning the obligation company its customers the matter furnishing repair parts. interesting note that the Sturtevant Co. recently had returned it, for repair, fan that was sold 1865. The customer did not want new one. The Krementz Co., Newark, several years ago received for replacement 25-cent collar button its manufacture which had been con- tinual use for more than years. “Obsolete” ordinarily means having gone out use. However, when applied patterns, the word takes different aspect. which may classified report prepared the Policyholders’ Service Bureau, Manufactures, Metropolitan Life Insurance in 15 Stetes, from Massachusetts to Missouri and and Wisconsin Tennessee and Virginia, drawn upon, vbsolete one industry may not another. The type industry and the nature the product should the determining factors the interpretation the word “obsolete.” Manufacturers heaters, boilers and stoves fre- quently are called upon furnish new grate bars and analogous parts for units their manufacture which have been service for many years. The sides stove rarely require replacement. Therefore patterns for old grate bars would not classified obsolete, whereas those for the sides the same stove may con- sidered. The nature the product itself would govern the definition this instance. large stationary steam engine standard manu- facture may have life years service. Its initial cost runs into sizable figure. long the engine operation, parts for the engine which, be- cause wear otherwise, may ordinarily require re- placement should available the owner. The maker the engine cannot therefore consider the patterns for those parts obsolete, even though they may remaip used for long period time. the foundry, different situation exists. av- erage jobbing foundry usually has hand many patterns that belong its customers, and which obliged store accommodation. The foundry has little control over these, other than the knowledge from its own records their activity. The foundry not position judge the obsolescence the patterns question, but must guided entirely the owners’ wishes. Singer Mfg. Co. provides many metal patterns each part for mounting its molding machines. When class style machine superseded new model, all the obsolete metal patterns are destroyed, with the exception one set, which kept fill orders for spare parts over period years. this case, the pattern becomes obsolete when new model brought out supersede the machine using casting which required that particular pattern. Organizations Setting Standards Some effort has been made set definite method procedure standard several fields industry. this end number trade associations have set standard practice recommendations for the guidance their membership. The Ohio Foundries Association and the Newark Foundrymen’s Association have adopted “Uniform Trades Custom,” that patterns not use for six months shall subject storage charges. The Steel Founders Society has issued circular covering recommended trade customs, Section which reads follows: The foundry shall not expected provide stor- for patterns for which orders have been re- ceived during a period of two years. The “Standard Trade Customs” adopted the Mal- leable Iron Research Institute incorporates the same rul- ing under Item 15. The Machinery Builders Society, upon the recom- The Age, July 25, 1929—215 mendations made its Committee Obsolete and In- active Patterns, recently adopted the following stand- ards for its membership: All patterns, jigs and fixtures special for job, and not likely used again, should scrapped the end the guarantee period. All other patterns, jigs and fixtures that have not been used for period five years shall scrapped. The customer shall charged with the cost replacing any of the above that have been destroyed after the stated period, the customer being advised this fact receipt his order for repair The National Machine Tool Builders’ Association states that, with the progress machine tool design, the average life the design standard machines seems about seven years. Therefore, economic life the users’ hands counted ten years, the user the last machine produced the design would getting reasonable service could get repair part from the original pattern ten years after the las