The Iron Age 1945-03-01: Vol 155 Iss 9

AGE March 1945 VAN DEVENTER President and Editorial BAUR Editorial WINTERS JACK HIGHT ALBIN JOHN ANTHONY BARMASEL DAVIS LLOYD Pittsburgh 428 Park Bidg. with 1134 Bidg. MOFFETT DONALD BROWNE Ma- HARDY Washington ns, are Notional Press Bidg. LLOYD write Cleveland 1016 Guardian Bidg. BRAMS erglas 7310 Woodward Ave. OSGOOD MURDOCK San Francisco 1355 Market St. Correspondents ROBERT EXHIBIT DEAN Buffalo Buffalo, March Boston 13-15. HUGH SHARP Milwaukee SANDERSON Ont. REWIND RAYMOND KAY Les Angeles JOHN McCUNE Birmingham ROY EDMONDS Louls JAMES DOUGLAS Seattle lable in: are apt lose perception improvement things with which are daily closely associated. But the way appreciate change people, products methods return them after absence ten twenty years. have just had experience this kind, having been carted away week ago the hospital where this being written. The reason: Double pneumonia and pleurisy. Just about twenty years ago, the day, had similar experience except that was merely one-lunger, without the pleurisy. Also was twenty years younger than now. those days, however, before sulfa and penicillin were known, the betting was 50-50 whether you would taken home ambu- lance undertaker’s wagon. remember very distinctly earliest experience with the pneumo- coccus bug and there has certainly been improvement the methods handling him since then. this stage the game, then, was seeing pink elephants instead writing editorials. But maybe from the reader’s standpoint that retrogression rather than progress. However, remove the personal coefficient, must tell you about the lady patient next door who paid friendly visit. hospitals are very friendly and democratic institutions, she came without introduction and indeed without knocking the door. She was very interesting and told that she was years old, had had pneumonia and was going home next day. asked her how she caught pneumonia and she said she got from shoveling snow. Imagine anyone years old getting away with pneumonia years ago! have heard about many other remarkable medical and surgical improvements, too, since have been here. Evidently, there have been great advances the techniques saving and lengthening life during the past two decades. seems not have been confined any one nation but has taken place even the Axis countries. the same token, during this same twenty-year period there has been equally widespread improvement the techniques taking life and shortening through war. Any one knows who reads The Iron Age. Having had time think about most anything that came hand during the past week, thought how nice would could confine all our improvements doing good people. Then started thinking how that could brought about. afraid you will have give few more days that one. 3 ‘ ¥ ¥ q q i Assistants | > q 38—THE IRON AGE, March 1945 This yard Inland Hi-Steel the right, saved $23,000 the first year. INLAND HI-STEEL SAVES $23,000 Facts and figures prove advantages using Inland Hi-Steel The records maintained Maumee Col- lieries show that when Inland Hi-Steel replaced castings these important advan- tages were gained: (1) The first cost was 40% lower. (2) Maintenance was cut half. (3) Weights were decreased much 32%. (4) Capacities went average 51.6%. The cost logic behind the use Inland Hi-Steel was summed Maumee official when said, estimate that our yard Inland Hi-Steel bucket saves three tenths cent yard over the bucket previously used. one year this yard bucket moved 7,671,000 yards overburden total saving $23,000.” Scores products and processes for war where light weight and high strength are needed. and peace are utilizing the corrosion-resist- ant, abrasion-resistant, high-strength and light weight characteristics Inland Hi- Steel. Write you would like further information. Inland Steel Company, South Dear- born Street, Chicago Sales Of- fices: Cincinnati, Detroit, Indianapolis, Kansas City, Milwaukee, New York, St. Louis, St. Paul. February all crea: the News Hitler has instituted new military decoration rank the highest German edal for bravery. the golden oakleaves with swords and diamonds the Whereas American steel makers are disdainful steel recuperators means heating blast furnace blast continuous cycle, German producers report use resulting considerable saving power consumption and smaller eat losses. efficiencies are expected combining the steel recuperator with the turbine the prime mover for blowers. Captured Republic Thunderbolts, with German markings, have been used for the strafing American troops. The Messerschmitt 262 Schwalbe (Swallow), the German's most "squirt" aircraft, being encountered very large formations, but they pick fight. Probably large numbers Luftwaffe pilots are training these new aircraft the hope that Germany can regain mastery the air when better weather comes. The other German "Squirt" job, the Messerschmitt 163B Komet, true rocket burns liquid oxygen, hydrogen peroxide and calcium permanganate, and has observed speeds excess 600 miles per hr. They climb speeds ft. per min. Men unusual physical stamina are required fly these greater number Komets appear their danger bomber formations serious. Great Britain must increase its exports five times the present figure rder redeem debts incurred during the war, according Brand, representative the Chancellor the Exchequer and the British Treasury. the United States alone, England has spent over billions while Canada dollar earnings there have been spent and additional Canadian dollars were selling back Canada-sterling investments amounting 700,000,000 dollars. WPB Requirements Committee last week agreed restrict allot- nts 104 per cent estimated supply and agreed that there would not any military allotments before the half year ends order stave the threatened disruption CMP operations. The danger CMP breaking down and letting the steel situation rocket into same "inflation" did when PRP and the priorities system fell apart, was the allotment 114.6 per cent estimated supply the first and the granting WPB tickets for additional 870,000 tons steel first two weeks January. Postwar plans magnesium and aluminum are being aired before the Senate Business Committee this week. reported that Reynolds Metal intends its postwar ingot capacity making offers for DPC plants now operated the Aluminum Co. pilot precision casting plant where cutting tools are cast from high speed scrap sponsored the Ford Motor Co. Camp Legion, Dearborn, Mich., has established part the vocational training program for disabled veterans accommodate students, who many cases could use only one arm, design were made the molds and wax injection machines. Since the handling metal molds occasioned strain, experiments the use lighter material the utilization general purpose thermosetting plastic the material. refinement the multiple mold consists replaceable inserts holding matrix portion the mold. More than 1,000,000 tank track shoes month will needed Ordnance The shoe has become one the most critical war items, 530 them needed every medium tank while tank production scheduled for overall increase per cent. 27, 1945 j | | : and Process Selection Metal selection for given end-product not always simple apparent. Production methods often are more importance than physical properties the metal its price. One excellent example this, herein, the substitution steel for magnesium the B-29 nose frame. This paper presented originally before OST product thinking con- ditioned manufacturing environments. tioning affects the selection mate- rials and processes much the same manner personal habits. Fabricators heavy steel, welders, stampers and press- formers, forgers and coiners metal think and compare product designs terms their own experiences. Each, however, has the same objective—to determine the most suitable construc- tion for the product piece. Each specialist could provide different answer. Often the manufacturing specialist can greatly assist those designers who conceive end-products. Too often this helpful relationship may un- encouraged. The progressive manu- the SAE facturing converter can often more helpful defining the material process than the material manufac- turer. This applies with lightweight materials and heavier materials alike. Often the material manufacturer’s representative lacks familiarity with latest conversion processes, convert- ing facilities, design ingenuity; his partiality determines the material se- lection. There market where each material and process rightfully be-- longs, more need for avoiding the pitfalls misapplication that penal- ize development. True, material se- lection not always simple appar- ent; much progress always made trial and error. may interest and help relate some practical experiences few comparative “case histories” 1G. views B-29 bomber nose frames. Left, welded steel frame; right, cast magnesium frame. STROTHMAN Industrial Engineering Consultant, Smith Corp., Milwaukee help define some “supremacy for low alloy steel and steel processes. developed for aircraft. See “Research the Lodestar Indus- trial Postwar Success,” Van De- venter. Printers’ Ink, Sept. 15, 1944. Recently unusually interesting case developed which substantiated the above contentions regarding the selection materials and processes,. and where steel was used successfully for the replacement magnesium the B-29 bomber nose frame (see Fig. 1), with weight really important. factor. Interesting, particularly be- cause such experience means debating with selection the lightest terial for application its foremost. market, aviation; and because substi- tution involves both materials and processes. Quite logically the air- plane designer conceived the original frame member constructed the lightest possible material, mag- nesium, and adopted the process casting because the great irregu- larity and shape and cross-section. Producing the frame casting most resourceful foundry organiza- tion proved major accomplishment. reported some 3000 5000 Ib. sand were required for each casting having finished weight only lb. The cost was further pen- alized the necessity for extensive use chills, together with large weighing many gates times the casting finished weight, effort control solidification and provide homogenous cast material. Rejections castings after X-ray ex- amination aroused such anxiety over delivery that the Mid-central District the Air Technical Service Com- mand began search for some alterna- tive solution. With characteristic thoroughness every consideration and volved the frame structure was Ser was use witl ° ° ° of ing for par sigr ligh stru fun Tab coul spec dal coul Wei imp and all acti atu sha] 40—THE IRON AGE, March 1945 ment. pen- many ht, and terial. over Com- lterna- in- was next approach. The frame struc- large the principle cross-sectional mem- bers ribs and each separately the Air Technicai Service Command. Why need the frame cast, and why need the material magnesium, all that was desired was equally strong lightweight structure? Why not use steel? Steel, such used for other more severely stressed landing gear structures? The Air Corps technicians, together with several members the Smith Corp., compared the ratios strength and weight, and modulus elasticity for steel and magnesium, with such encourag- ing reactions that the necessity for design study was quite ap- parent. The completed study the de- sign confirmed the original indi- cations, that the use steel was many ways preferable for this light-weight service, even com- parison with the lightest ma- terials, magnesium. Weight cal- culations revealed that the steel structure could slightly lighter weight than the magnesium structure and satisfy all the functional requirements (see Table I). finished structure identical shape, though differ- ent cross-section (see Fig. 2), could constructed that the specially formed and cut ellipsoi- dal glass and plastic transparencies could utilized together with the same method cover plate fastening. Weight, however, was but one the important factors; there was strength and stiffness still considered. With this structure designed re- sist the internal pressure the pres- surized cabin, was vital that the remain pressure tight under all service conditions, such impact landing when pierced enemy action, and with changes temper- ature and internal pressure. The ir- regular nature the ellipsoidal shape complicated the problem strength and stiffness deter- mination that simple comparative analysis was the most practical ture was accordingly divided into compared for strength and stiff- ness (see Fig. and Table II). Formed pressed shapes high- strength low-alloy S.A.E. material with yield strength 135,000 Ib. per sq. in., nearly eight times the 17,000 Ib. per sq. in. yield strength for the cast material, was selected compensate for the four times greater unit weight the steel material. With this selection steel, the calculated strength index the greatest stressed upper struts rib members proved more than double that the cast magnesium, which was satisfactory even improve- ment. But the calculated stiffness ratio these same steel ribs proved only half that the cast magnesium ribs, and evaluation the stiffness factor became most important. Rib-By-Rib Analysis This comparative method sepa- » SS S Fig. 2—Cross-section comparison welded steel and cast magnesium bomber nose frames. rate rib analysis served primarily compare weight and indicate the possibilities for alternative con- struction that justified building actual steel nose frame the design suggested. This became the only suit- able procedure answer the indeter- minate questions and evaluating the composite stiffness the redesigned frame. approval was obtained for experimental frame construction embodying our specialty background experience press-forming and then TABLE comparisons alloy steel and cast magnesium frame. Description Weight, Lb. 14.95 6.56 4.30 Outer Ring............ 2.51 Lower Ribs............ 4.41 Gusset Total Weight Welded Press-Formed Steel Frame Shorter Bolt Weight Saving Fabricated Frame Combined Weight Frame Less Bolt Saving Weight Cast Magnesium Frame THE IRON AGE, March 2 | 1305 e ully nin Fig. tant. be- ting ma- most. bsti- and air- mag- regu- Jr Total Fig. 3—Separate press-formed pieces for steel B-29 bomber nose frame. assembling separate pieces weld- ing provide new simple construc- tion. Stamping and drawing the whole frame structure from single steel sheet was not considered because doing would seem more practi- cal than making automobile frame such method; nor did consider forging and machining the pieces, might have been first sug- gested individuals with only that type experience. Experimental testing the steel frame, complete with assembled trans- parencies proved most revealing. was found practical produce actual assembled steel frame com- parable weight estimated. the TABLE Strength, Stiffness and Weight Calculations B-29 Steel and Magnesium Nose Frame Sections Moment Section Inertia a Stiffness Yield Ultimate Strength Strength Stiffness Weight Index, Index, Ratio, Ratio, Per Cent Per Cent Per Cent Per Cent KEY: rib section for Magnesium; same for steel; Y.S. 17,000 Ib. per sq. in.; U.S. 30,000 Ib. per sq. In; 4340; Y.S. 135,000 Ib. per U.S. 150,000 Ib. per sq. See nose frame and key diagram for shape and location rib Per unit 42—THE IRON AGE, March 1945 specified pressure leakage and progressive pressure greater pressure was without leakage than had ble with the cast magnesium Even after leakage there was structural weakening, which fyr. ther indicated that even greater pressures were possible with minor increases weight provide the stiffness prevent leakage. This latter factor, together with the greater resistance frame cracking rupture and the fact that the repaired emergency were tional advantages favorable for Production and quality control were simplified with steel construction, re. claiming rejected frames was simple matter and the redesign proved most practical solution for important structure. lar instance were not such important factors. But since cost often major criterion, some comment this may interest. The cost the finished assembled nose piece steel construction comparable the latest reduced costs the finished assembled cast magnesium construc- tion. With comparable conditions the steel construction should prove more economical, especially since the ma- chine finishing operations are mate- rially reduced with accurate forming and assembling the mullion ribs (see Figs. and 5). The problem glazing was likewise reduced because the transparencies could made and formed fit the gages for the ings. The rough weight the alloy steel material was less than one- quarter that the rough cast mag- nesium material, largely because gates and risers were re- quired, and which reflected cost sav- ings and savings critical material. Little new equipment was required for the steel construction, since the prin- cipaloperation simple press-forming and for which there was adequate equipment available, while the dies and fixtures were not costly. Thus capital expenditures also proved ma- terially less for steel than for the cast magnesium construction and cost factors well were favorable for steel. summarize, the findings for the B-29 bomber nose frame redesign and the considerations welded press- formed alloy steel compared with cast magnesium construction are: (1) Weight equal for welded press-formed alloy (2) Steel construction stronger. weight Section Section Area, Factor asse In. for stee nose 1.660 0.390 5,440,000 100 100 100 100 0.406 0.106 2,640,000 216 136 102 1.660 0.390 5,440,000 100 100 100 100 0.499 0.111 3,080,000 255 142 126 1.000 0.268 1,700,000 100 100 100 0,229 0.095 2,050,000 282 177 120 1.400 0.153 975,000 100 100 100 100 0.408 0.035 800,000 181 114 123 1,000 1,000 100 100 100 100 0.299 0.250 197 126 126 rred; Cases fur. Safe but This the king the were Te- for ticu- ‘tant shed the nore (3) stiff enough for the func- tional service. (4) Steel construction less easily damaged. (5) field repairable and shop reclaimable. (6) Also steel construction simpler, quicker produce. Landing Gear Members Another group equally interest- cases that comparing the use different fabricating processes, but the same material, such welded press-formed steel and forged bolted steel constructions. These cases are not spectacular controversial the case just re- viewed, cases between different ma- using either the same dif- ferent manufacturing processes. The aircraft industry has greatly simulated constructive redesign de- presenting opportuni- ties where weight savings and greater strength safety are great impor- tance. Klein, Douglas Air- design consultant, evaluates wight savings the value gold, $35 per oz.; and mentions $10 per currently and commercially With the range evalua- Welding assembly fixture for steel B-29 bomber frame members. ° ° DESCRIPTION C-47 LANDING GEAR TRUSS (one required) Combined strength, wt. B-24 MAIN LANDING GEAR FORK (two required) tion liberal most any amount se- lected warrants reasonable redesign efforts. *“Fundamental Airplane Design,” Klein, Transactions, Vol. 52, No. 12. The several selected plane landing gear redesign cases welded press-formed alloy steel con- struction offered many advantages over forged and bolted alloy steel con- struction. According Jerome Hunsaker, National Advisory Com- mittee for Aeronautics, the size TABLE Weight and Strength Comparisons Several Plane Landing Gear Structures Rough material Finished structure Strength Rough material Finished structure Combined strength, wt. B-29 MAIN LANDING GEAR TRUNNION (two required) Rough material Finished structure 186 80.8 100% 125% +25 100% 189% +89 436 355 710 256 229 157 Original Smith Differential, Design, Lb. Design, Lb. Per Cent planes will strictly limited the economies larger landing field, en- gines, including propellers, and land- ing gear, and the latter especially serious for land planes. Therefore, these landing gear cases may more important revealing design de- velopment trend for such critically stressed members. redesigning the truss the C-47 landing gear the Douglas cargo plane for welded press-formed alloy steel, considerable weight was saved and difficult production prob- lem circumvented (see Fig. 6). Two THE IRON AGE, March 1945—43 ming ribs ° 5—Welded steel center joint construc- tion B-29 bomber nose frame, inside and outside views. ° ° ° Welded press-formed steel truss construction C-47 cargo plane landing gear. ° steel truss cargo plane landing gear. ° large, long and thin alloy steel forg. ings were selected initially the most suitable construction for the principal truss members (see Fig. 7), This forged design might have proved the final one except for number problems that arose during produc. tion. Large drop hammer facilities for forging these members were ited. was not practicable duce these forgings with less than in. thick web, which required ducing the in. web thickness pensive milling. Because.of the size and shape, forging die breakage and developed with the result that deliveries were milling machine facilities for web- milling were also limited, which meant new equipment tying machines that could better utilized. The welded design, produced assembling simple press-formed steel strut members the overcame all these difficulties. The necessity for machine work was re- duced minimum forming the pieces essentially size and rately assembling pieces welding fixtures. Increases production did not require expensive new equip- ment while the breakage dies was avoided substituting press-forming for forging. press-formed type strut similar design could easily made larger and stronger without ficulties, which difficulties with the forging process would have increased. Savings critical alloy rough terial were not only important from shortage standpoint, but from the savings possible the cost ma- terials. Table III shows these rough weight savings amount 106 per truss, per cent; while the fin- ished weight savings were lb., per cent. summarize, this truss changing from the forging bolted construction press-formed and welded ber (1) streng (2) equipn (3) duced (4) liable jection (5) proces (6) steel The landin alloy the terial some Fig, tough sulted finish impor the machi the 4 4 4 the the ities pro- pro- size and that web- lized. steel alloy, the accu- iction was ‘ming ily the rom the rough per and The welded construction, results num- advantages: (1) Reduced weight with adequate strength. (2) New forging and machine tool equipment unnecessary. (3) Machining operations duced that delivery was expedited. (4) Delivery controllable and re- liable through avoidance scrap re- jections and die breakage. processes more economical. (6) Materially less critical alloy steel required. The evolution the B-24 bomber landing gear half-fork likewise in- teresting that several low alloy steel forgings, together with bent alloy steel tube combination, were re- placed two press-formed halves the same type low-alloy steel ma- terial, upper sleeve, axle and some lugs, all assembled welding form composite structure (see and 9). Some savings tough weight alloy materials re- sulted, together with improvements with but slight increase weight (see Table III). The important factor was the elimination the need for additional forging and machine equipment effect half-fork the time required. Espe- tially interesting the assembly the finished machined axle with the half-fork welding and which prac- ° ° ° RIGHT and bolted steel tube main half-fork construc- tion B-24 bomber landing gear. ° ° ABOVE, LEFT Welded press-formed steel con- struction B-24 landing gear. ° ° ° BELOW press-formed steel trunnion con- struction B-29 landing gear. THE IRON AGE, March 1945—45 ee a tice contributes economy. Axles both seamless tube and centrifugal castings have been used with only slight advantage weight tolerance favoring the former. redesigning for the welding and press-forming processes practical and economical construction obtained, and one proved evolution. the time initially designing the B-29 main landing gear and The same construction opportunity not practical with the forged trun- nion design, although might have been incorporated. This design in- genuity combining members that they function single unit too often overlooked during the design conception. The trunnion story good one, because illustrates utilizing the constructive help available. The welding press-formed members steel trunnion B-29 bomber landing gear. where members greatest practical strength were desired, the designer selected forged alloy steel and bolted type trunnion. Before this original design was adopted for pro- duction, the general problem was pre- sented for redesign -consideration, where analysis showed that press- formed low-alloy welded steel struc- ture would better serve the purposes (see Fig. and 11). Not only was the finished weight each two cent, but the rough alloy material saving was 450 per trunnion, per cent. The substitution welding for bolting assembly accounted for much this weight reduction, be- cause greater strength and stiff- ness the integrally combined welded trunnion and tube members. 46—THE IRON AGE, March 1945 assistance the specialist manufac- turer with practical knowledge designing and constructing special structures should more encour- aged. Too many initially designed parts lack design consultation that management could have easily pro- vided. addition product design all these cases involve problems fabri- cation. How weld the selected alloy steel, heat-treat, straighten, finish, well how press-form have each considered. Welding these high strength low-alloy ma- terials, though not difficult, requires proper welding combined with knowledge preheat- ing and controlled cedures. The separate pieces are more easily formed after annealing and often welded after heat-treatment, instead before heat-treatment might first proposed. the determina- tion when weld especially important and which factor may even affect the selection material. Very often welding after heat-treat- ment, and then only stress-relieving the welded joints below the draw temperature for the alloy material, objectionable distortion and straight- ening may avoided. combining such type fabrica- tion experience knowledge with de- sign conception simplifies fabrication. may even provide means for mak- ing some redesign either practical more economical, both. the case the C-47 cargo plane truss each press-formed half, after assembling and welding the fastening pads feet, were separately held shape rod tack welded these feet. After accurately assembling the two halves together assem- bly fixture, the finished structure re- but minor straightening. the same rangy structure had heat-treated after welding the fabri- cation would have been more difficult and costly. The advantages this same procedure solution even more apparent the fabrication the B-29 bomber nose frame. Partiality for one material pro- cess may influence selection, but still should not alter recognition the design facts. Kettering, dur- ing address, cited the argument that would see use airplane before all-aluminum auto- mobile. believe this argument was based faith engineers and their understanding that each material process has its proper application. Furthermore, that with ingenious de- sign low-alloy steel provides many favorable characteristics that should awaken new interest steel. How- ever, the probability for practical se- lection any one type material best satisfy functionally defined de- sign problems for most auto, plane, other structures beyond engi- neer’s conception. Some the competitive practices marketing premium-priced ma- terials should serve lesson for the steel industry. Their selection often follows reconsideration and conception design, and which excellent procedure for displacing any material. Steel purveyors generally have been tonnage-minded and less constructive, but they should seriously consider adopting the rede sign approach. Yesterday’s selections may more secure than the call the next progressive purveyor. the whi ope can pos con ard rail rail pla and bui pos eac ead ght ally ven eat- ring raw rial, de- tion. nak- case each hape mple \fter ding sem- abri- this even dur- iment auto- was their ation. de- many How- se- rial engi- actices for lection any minded should lections call Lincolnweld Automatic Welder Shows Operating Economies CONOMY effected the use the fabrication hatch covers for cargo ships, welding costs have been cut half compared with manual methods. Details the equipment are announced for the first time. the latest equipment for auto- matic welding one the chief reasons why the use this method becoming widespread. One fabricator, for example, has re- duced the welding cost hatch cover sections for cargo ships per cent compared previous manual welding and has eliminated straight- ening operations that were formerly required. The covers are fabricated new type submerged melt automatic welding known Lincolnweld, de- velopment the Lincoln Electric Co., Cleveland. The automatic welding installation the Youngstown Steel Car Co., Niles, Ohio, Fig. consists standard Lincolnweld head, flux hop- per and controls mounted motor driven carriage which runs tra- vel beam ft. long. The beam can manually raised lowered means screws, one each end the beam. The ft. truck which the work mounted hand operated and designed that can later motor driven for rapid positioning the work. The truck constructed framework stand- ard channels and angles supported railroad car wheels which run rails embedded the floor the plant. Thus the entire truck can moved under the welding travel beam drawn back clear the beam for loading and unloading the work. comprehensive view the complete set-up shown Fig. The beam and work handling equipment was built the Youngstown Steel Car Co. The hatch cover bases are com- standard channels automati- cally fillet welded both sides each channel base plate (see sketch, 2). The work ° ° TAYLOR Vice-President, Lincoln Electric Co., Cleveland tioned two V-shaped yokes, one each end the welding truck plat- form effect flat position. The welding head then positioned over the seam, Fig. and the car- riage automatically travels along the beam. granular flux deposited ahead the welding are shield the molten weld metal. After weld- ing the unfused flux removed vacuum suction unit and screened for reuse. Welding speed for this fillet weld- ing operation the rate in. per min., using 5/32 in. diameter wire electrode. Wire consumed per foot weld averages 0.09 lb. with 0.10 Ib. flux per foot. The second automatic welding operation consists butt welding the Mechanical Properties Lincolnweld Automatic Welds Yield Strength, Material Lb./Sq. In. Low carbon steel such Armco iron 36,000 Medium carbon steel ship plate High carbon (0.40) steel (Gear steel) 64,000 *Pressure vessel steel plate 55,000 Stress relieved 1200 deg. Ductility Per Cent Elongation In. Tensile Strength, Lb./Sq. In. 53,000 ,000 87,000 74,000 THE IRON AGE, March view Lincolnweld automatic arc welding installation used fabricating ship hatch covers. AUTOMATIC BUTT WELD COVER PLATE, CHANNEL ° ° LEFT 2—Cross-section hatch cover construction showing lo- cation automatically deposited fillet and butt welds. AUTOMATIC FILLET WELDS-BOTH SIDES CHANNEL BASE PLATE BELOW 3—Close-up Lincolnweld metallic arc unit opera- tion postioned fillet weld for ship hatch cover section. 48—THE IRON AGE, March 1945 *9/32 in. steel cover plate the end channels (Fig. 2). this instance, the work flat positioned after man- ually welding backup bead the underside the joint with American Welding Society specification E-6012 shielded electrodes. The work then turned and automatically welded from the opposite side with 5/32 in. electrode which penetrates into the backup weld. Details Welder This development meet the need for more foolproof and easier ap- plied process has established its prac- ticability over period several years during which number the units have successfully welded va- BELOW 4—Carriage type Lincolnweld mounted overhead beam. riety been joint ° ° ° thro i fuse ther riety The equipment has been used welding all types joints, including butt, lap, and fillet, well corner. The process designed for use with direct current, utilizing bare metallic electrode which fed through granular flux deposited the joint welded. Sufficient flux applied completely blanket the arc and the molten metal; the un- fused flux then reclaimed for fur- ther use. Direct current offers many advan- tages over alternating current; such more simplified and positive con- trol; ability weld non-ferrous ma- terials; and better control electrode melting rate through the option either straight reverse polarity. Extremely high current densities are used. For example, in. di- ameter electrode may carry much 650 amp. compared with manual welding, this produces greater pene- tration and permits section weld metal with resulting saving cost and reduced warpage and distortion. Users report that the Lincolnweld less sensitive scale and moisture than conventional automatic methods. This eliminates plate cleaning prior weld- ing. extreme cases scale buffing with power wire wheel usually pro- Vides sufficient edge cleaning, whereas grinding and sandblasting might have been required formerly. The exceptional quality the produced Lincolnweld auto- matic welding indicated the ac- companying table. Further endorsement the new Lincolnweld process evidenced the fact that meets the welding codes, rules, regulations and specifica- tions sponsored the following: A.S.M.E. Power Boiler Code; A.P.I.- A.S.M.E. Unfired Pressure Vessel Code; Rules American Bureau Shipping; Lloyd’s Register Ship- ping Regulations; and the United States Maritime Commission. The particular advantages reported for Lincolnweld over existing proc- esses are follows: One type and grade flux, to- gether with one analysis elec- trode, can used with the same procedure for wide range steel analyses. For example, ingot iron and steels 0.40 per cent car- bon can welded with the same procedure. Thus, special joint preparations, changing flux, wire analysis and welding procedure are eliminated, which importance manufacturer using automatic welding. The equipment will take 7/32 in. electrode without changes drive rolls, wire contacts con- trol. The control extremely sim- ple and quick acting, since there are vibrating relays nor electric devices. The electrode will feed either direction means the wire motor being controlled through special The automatic control box has current, arc voltage and travel speed rheostats one ABOVE 6—Roller for Lincolnweld tractor showing bev- elled rollers prepared butt joint work. ° ° ° LEFT 5—Lincolnweld unit the motor driven tractor type. compartment, and ammeter, voltmeter and two contactors for the operation the equipment the others. This gives the oper- ator quick control over voltage, current and speed when changing from one job another. The welding head normally used conjunction with specially built motor-generator type welding set 1200 amp. capacity. The current rheostat the automatic control box permits current range 300 1200 amp. The unit has two exciters, one for the automatic head control and one for the welder field excitation. The welder control box has provisions for easy wiring the automatic. Fig. shows the welding head, with flux hopper, wire reel and control mounted motor driven carriage. Fig. shows mounted the portable tractor unit. This has straight wire guide for butt welding. For square butt welding, pointer used for following irregular seams. For prepared joints, bevelled roller guides are provided for engaging the seam, Fig. The standard head changed from butt fillet welding matter only few minutes. making fillet welds the lower wire guide and flux tube are changed from straight curved, thus permitting the head and wire reel left its normal posi- tion. The wire fed deg. from horizontal which gives the maxi- mum effective throat for horizontal fillet welds. THE IRON AGE, March 1945—49 the J = the need ap- rac- { eral the $ 4 4 ‘3 UTURE probable available open pit ore and lack uniformity ore are topics bandied about conversationally eastern steel circles, but one which Colorado Fuel Iron Corp. already has tackled. Open pit mining about years ago when the pit be- came too deep allow access rail. For many years milling pit opera- tion was carried on, but eventually all remaining ore lay beneath 200-ft. limestone capping and full underground mining was necessary. Because the ore must hanled 370 Colo., cheap mining was urgent. Borrowing leaf from the old Pewabic Iron Mountain, Mich., and superintendent experienced block from Arizona’s porphyry cop- suitable block caving system, the cheapest kind underground mining, has solved the problem splendidly. In- 50—THE IRON AGE, March 1945 PEN pit the Sunrise, Wyo., iron ore mine. Messiter bedding and reclaiming sys- tem blend the ore and sintering plant handle the per cent fines may stand beacon the future other Output has in- creased per cent—attributed per cent sintering and per cent For discussion blending see John Meissner (Robins Conveyors, Inc., Chi- cago), “Blending Bulk Materials,” Blast Furnace and Raw Mate- rials Committee, Pittsburgh, April, 1944. bedding—and variations pig iron have been brought materially into line. Where formerly there was 0.40 0.50 per cent variation silicon there now half that and the company able guarantee not over per cent insolubles. Uniform iron cuts melting time, the amount lime needed, and reduces bottom troubles. Following period which Indian Exhaustion open pif ore and wide variations ore analysis posed operating and economic problems the Colorado Fuel Iron Corp. These were solved cheap underground mining methods, ore bedding and sintering. tribes found greasy hematite ex- Block Caving cellent for war paint pigment, Sun- rise mine during the latter part the last century was scene gopher holing operations for copper occurring the limestone capping. The copper ore soon petered out, and after start- ing shovel operations exposed iron claims 1901. With the virtual end shovel operations year later, three compartment 18-ft. shaft was sunk 470 ft. Raises were put under the pit and milling operations were started which late 1939 accounted for per cent the mine’s annual production. date more than million tons ore have been extracted, but the remaining por- tion the body sufficiently large justify program nearing completion which may reach two million dollars cost. This includes new six- compartment 750-ft. steel and concrete lined shaft, 199-ft. headframe, and large power and hoist house. The remaining ore will partly extracted block caving, which started Sunrise 1931, but the largest tonnage will extracted sub-level caving. The block caving system extreme- simple and, with blocks running high 400 ft., extremely cheap. Ex- cessive dilution one the factors which bars for many mines, but the strong capping Sunrise, which breaks large, reduces this problem. order avoid excessive develop- ment costs for block caving system ore body must have considerable mass and rise considerable ver- tical height. The ore itself, course, must relatively uniform, readily, and sufficiently fine easily drawn through the chutes with little packing. Little timber quired fortunately for Sunrise, whos the whose nearest supply Oregon and Washington. Block caving limits se- lective mining, for the slope angle the caved ore must kept ap- proximately deg. prevent piping and raises must drawn schedule. Intermittent operation likewise obviously impractical. The technique utilized Sunrise’ involves main raises 15-ft. intervals along the haulage drift, driven from pony set over the haulage drift timber. George Rupp, “Block Caving the Sunrise Iron Mine, Wyoming,” Technical Publication 1069, Class Metal Mining, No. 107. Raises are ft. section and are driven deg. angle for ft. with vertical section ft. more. The tops these main raises are connected the grizzly drifts which are driven 25-ft. centers, parallel and least ft. above the haulage drifts. contended and Ore Blending that this departure from the usual right-angle easier and better ventilation, allows higher tonnage, and simpler. All grizzly drifts each block are joined supply raise driven from the main level. Grizzly rails are set 11% in. apart. From the grizzly level, 4-ft. finger raises are driven nearly ver- tically, each side the grizzly set, for distance almost ft. pro- vide direct outlet for caved and broken ore above the undercut level. These finger raises are untimbered. Tops the finger raises are con- driven centers without ° ° shown nearing completion, 199 high, one the tallest the country. New power and hoist house ground, also part the new two mil- lion dollar development program the mine ° ° ° CHARLES POST ° ° timber. -The undercut drifts are parallel the grizzly drifts, and are driven along the bottom the ore whenever possible. Sequence this development de- pends upon the character the ground. hard, solid ground, all undercut drifts may completed be- fore any blasting pillars between drifts attempted. heavy ground, main level drifts, supply raises and supply grizzly drifts are always driven, but main raises, grizzly drifts, finger raises and undercut drifts are opened only needed avoid weakening the ground and avoid excessive maintenance costs. Boundary raises are put the four corners each block within ft. the capping order es- tablish planes weakness. drifts, ft. and parallel the grizzly drifts, are driven from the boundary raises vertical intervals from ft. ft. from the cap- ping the undercut. The backs THE IRON AGE, March ing ron the aft ons 939 the ave tion rete DUMPING PRIMARY CRUSHING STATION preparation plant Pueblo. One two beds may stocked time, and likewise one two beds may reclaimed si- multaneously. ° ° these slice drifts are drilled with 7-ft. stoper holes and blasted from the top slice down, but are not cleaned out. shrinkage stope then run from the undercut level near the bot- tom the lower slice drift along the foot boundary the block. The pur- pose the slice drifts and boundary raises weaken the sides, pre- vent arching the caving progresses upward and form line weak- ness limiting lateral caving and cause the ore break fine enough handled through finger raises. Actual caving block initiated first drilling the pillars between the undercut drifts with jackhammer holes and the backs the drifts with stoper holes. Pillars are drilled and for the full width the block, start- ing the extremity the block and retreating toward the shaft. Blast- ing removes horizontal slice ore 14-ft. thick, and the back begins break and cave its own weight. The broken ore drops into the finger raises and down the grizzly position. Fine ore drops through the grizzlies into the main raise. Oversize lumps are either drilled and blasted broken with pneumatic pavement breakers pass through grizzlies. Care taken avoid dilution from adjacent mined out areas from the schist side walls restricting the open space between the solid back and broken ore the cave kept working upward. Additional strips ft. long are blasted and the ore drawn definite schedule keep 60-deg. angle broken ore the cave. flatter angle induces piping and dilu- tion from the overlying capping. Height ore being caved varies be- cause the irregular shape the de- posit, but has been much 400 ft. 52—THE IRON AGE, March 1945 COKE DUMPING STATION => Screen SECONDARY ~ crusher STATION above grizzly levels. The average between 200 and 300 After passing grizzlies and down the main raises, ore loaded from the main-level pony-set chutes into 120 cu. ft. 8-ton capacity side-dump mine cars are hauled eight ton trolley locomotives. the new shaft ore hoisted gross ton skips screening and picking equipment the headframe, thence three ore bins for loading. in., and in., any combination these sizes can shipped. waste rock bin also provided. double drum Nordberg hoist, with variable rope speed 1500 ft. per min., provides hoist capacity 4000 tons per hr. shift. For the cage, Ottumwa hoist, with set rope speed 800 ft. per min. provided. The prevailing ore Sunrise red, earthy hematite, somewhat similar Mesabi ore, with some black specular hematite, and minor amounts stalactitic forms hema- tite and soft ocherous limonite (prin- cipally the now flooded Chicago ore body). Source blast furnace prob- lems prior inauguration ore bedding, however, were inclusions thin, irregular streaks pinite, hydrous aluminum-potassium silicate. Typical analysis range (wet) shipments is: per cent Fe. per cent silica plus alumina, with aluminum varying from per cent. 0.05 0.065 phosphorus. 0.05 sulfur. 0.07 0.09 manganese. ORE LOADING SINTER 4 0.5 1.0 lime. 0.2 0.5 magnesia cent. per cent moisture. Approximately per cent the ore minus in. and per cent minus 100 mesh, which excellent for purposes block caving, but which makes necessary sintering the Pueblo plant. Upon arrival Pueblo’, each car ore pulled onto all-over car 1.00 1.25 For flowsheet Pueblo, see Harvey Linhardt, “Ore Preparation Plant the portant Role Defense Production Rec- dumper, with capacity 800 tons per hour. The car dumper operator either automatically manually con- trols the raising and tilting the car ore through angle 155 deg., discharging the ore onto metal con- veyor. the primary crushing sta- tion, ore passes 5-in. grizzly with crusher. The material then travels via belt conveyor the secondary crushing station, checked route weightometer. Material failing pass in., square, single Gyrex vibrating screen enters bin which feeds two Symons ton ore ont thr an the the i an tri RANSFER CAR LEGEND ORE SINTER crushers, each with capacity 400 tons per hour. Reduced minus in., ore belt conveyed the main ore screening station, passes auto- matic sampler, and enters large surge bin. The ore then discharged onto any one combination three sets single deck Gyrex vi- brating screens. Minus in. ore passing the screens belt conveyed and discharged through automatic double winged tripper into series seven concrete storage bins serving the sintering plant. Total capacity these bins 3000 tons. The coarse ore in. in.) Geary-Jennings type auto- matic sampler and and belt conveyed the ore bedding area. The conveyor terminates automatic double armed stacker tripper, which travels back and forth the length the bedding area dis- tributing the ore either side thin layers which eventually become piles triangular cross section. These “beds,” are approximately 600 ft. long, and, when full, comprise about 25,000 tons each. ore needed the blast fur- Naces, reclaimer, which there are two, removes it. triangular shaped harrow, corresponding the face the bed, tilted from support the base the reclaimer until its teeth contact the ore uniformly. For- ward motion the reclaimer gouges the teeth into ore, and the same time side-wise ft. reciprocating motion uniformly rakes the ore from the entire cross sectional face the bed. The ore thus removed drops plow conveyor, attached the bot- tom the reclaimer, which turn pulls the ore belt conveyor run- ning the length the pile. This con- veyor installed concrete trench insure cold weather operation. The trench conveyor then discharges onto main conveyor leading ccncrete car loading bin. The stacker and the two reclaimers are moved the desired positions for piling reclaiming shunting them onto transfer car located pit the far end the ore beds. One two beds may stocked time, and likewise one two beds may reclaimed simultaneously. present there are four but provision made for possible addition two more. The capacity the sys- tem for stocking ore the beds 450 net tons per hour; and for ore plus sinter 575 net tons per hour. The capacity the system for re- claiming from the piles 400 tons for each reclaimer, total 800 tons per hour. Fine ore, which has passed from the screening station storage bins then sintered. Extraction from the bins through continuous slot means automatic traveling four armed plow which has changeable speed both extraction and traverse. Discharged onto continuous belt the fine ore goes elevated surge bin, which turn feeds two revolving table feeders. The ore tables dis- charge onto belt carrying coke breeze from storage. (Coke breeze screened and crushed size before storage three 90-ton bins). Both ore and coke breeze table feeders (from the bins) are controlled re- mote control from the burner floor the sintering plant. Ore and coke breeze are joined, after discharge onto another belt, sinter fines rejected after sintering because size and this material travels elevated surge bin serving the sintering plant proper. The surge bin feeds through agitators two pug mills, where, with water added, the mixture pugged, then discharged belts lead- ing the distributing spouts for loading each the sintering ma- chines. Each the two Dwight-Lloyd sintering machines 102 ft. long, and composed 124 pallets with six 72-in. wide grates making each pallet. Coke breeze screened out the coke plant and blast furnaces used for fuel. Delivered railroad unloading track hopper, it: belt conveyed receiving hopper the coke preparation plant, ad- jacent the sintering plant. Here fed onto either one two 3/16-in. Gyrex vibrating screens. Oversize goes two hammer mills, having rated capacity tons per hr., con- nected circuit with the screens- Material passing the screens goes belt four storage bins whence it: joins the fine ore described machine pallets, loaded depth in., pass under combustion furnace fired with coke oven gas which ignites the coke breeze the surface the load. The pal- lets then pass over series suction chambers which suck the surface igni- tion through