bluuebunny/crossref_metadata_2025 huggingface dataset:
The Strength of Thin Plates in Compression
Authors: von Kármán Theodor , Sechler Ernest E. , Donnell L. H.
Published: April 2023

The stability of thin plates has been investigated by many authors. However, in aeronautical structures, thin metal sheets are often used beyond the stability limits, and the load which can be carried by the structure is determined by the ultimate strength in compression. A recent series of experiments by the Bureau of Standards showed the ultimate load to be independent of width and length of the plate and approximately proportional to the square of the thickness. In the present paper an approximate theoretical analysis of this problem is developed, by which the “effective width” and the ultimate strength can be found. The result of this analysis shows the ultimate strength of a plate to be proportional to the square roots of the modulus of elasticity and the yield point of the material, and to the square of the thickness. This result gives a good check with the experiments mentioned.
Flow of Steels at Elevated Temperatures
Authors: Coffin F. P. , Swisher T. H.
Published: April 2023

Flow tests of steels at elevated temperatures, as carried on in the Research Laboratory of the General Electric Company, are described. The object of these tests is to predict the ability of materials to maintain dimensions under stress at operating temperatures for long periods of time. Various methods of testing are used. Some are for the purpose of obtaining a mass of information in the shortest possible time; here the rate of flow is measured for a series of successively reduced stresses at each of several successively increased temperatures. Others are designed to furnish more fundamental information regarding the nature of flow; here new specimens are subjected to constant stress at a constant temperature. A third is the constant-extension test where the stress is varied with time to maintain a constant total elongation (elastic plus plastic).
A New Type of Dynamic-Balancing Machine
Authors: Thearle Ernest L.
Published: April 2023

In this paper is described a novel type of dynamic-balancing machine developed for production balancing. The machine employs an automatic compensating device, making it possible for an unskilled operator to obtain accurate readings of amount and position of unbalance correction with great rapidity. The theory underlying the action of the machine is given and the characteristics of the automatic balancing head are investigated. The method of operating the machine is explained and data on the accuracy of balance obtainable are included.
The Use of Models in Vibration Research
Authors: Den Hartog J. P.
Published: April 2023

In this paper the theory of dynamic similarity as applied to vibration problems in mechanical engineering is discussed, and a number of specific examples are given.
Distribution of Pressure Concentrated on a Small Surface
Authors: Sadowsky Michael A.
Published: April 2023

In this paper the author discusses mathematically problems concerning the pressures and deformations that arise when a very rigid die or punch is pressed against a comparatively elastic material, and also in the case where column footings rest on an elastic soil foundation. The author considers (1) the case where the axial section of the die is given and the resulting distribution of pressure along the curved contact surface is required; and (2) where the distribution of pressure over the contact surface is prescribed and the proper curvature of the surface to give such a distribution of pressure is required. Solutions of each of these cases are given for two types of die; namely, when the die is a body of revolution, and when it has a rectangular cross-section the dimension of which perpendicular to the plane of the figure is either very large or very small.
Stresses in Railroad Track
Authors: Timoshenko S. , Langer B. F.
Published: April 2023

With the constant tendency in railroad practice to increase the axle loading and the speed of locomotives, the problem of stresses produced in rails by moving loads becomes more and more important. In a study recently made by engineers of the Westinghouse Electric and Manufacturing Company, principally in connection with the study of the tracking characteristics of electric locomotives, there has been developed a method for experimental determination, not only of vertical but also of lateral forces produced on the rails by a moving locomotive, and it is shown that these lateral forces produce in rails very high stresses. In this paper the authors briefly discuss the theory which has been used as a guide in this experimental research work, and describe some recent experiments in the laboratory and in the field.
Comparative Performance of a Large Boiler Using Oil and Natural-Gas Fuels
Authors: Philo F. G.
Published: April 2023

Tests were made with utmost care by well-trained and experienced observers, and the data presented are comparable in accuracy with carefully conducted tests burning coal. The boiler tested was a Babcock & Wilcox cross-drum, straight-tube type with interdeck superheater. The furnace was completely inclosed by Bailey-type water-cooled walls. The Babcock & Wilcox air heater was of tubular construction. Peabody combination oil and gas burners were used. The highest rate of output at which the boiler was tested was 450,751 lb. of steam per hour, which represented operation of the 3416-hp. boiler at 413.2 per cent of rating. Efficiency-capacity characteristics are straight lines between 100 per cent and 400 per cent rating. Efficiency with oil fuel is approximately 4 per cent higher than with gas due to higher “hydrogen losses” with gas fuel. Superheated-steam temperatures are considerably higher when burning gas than when burning oil fuel, due jointly to lower water-wall heat absorption and larger flue-gas volume while burning gas fuel. Maximum heat liberation was 27,300 B.t.u. per cu. ft. of furnace volume, although it is felt heat-liberation rates as high as 60,000 B.t.u. per cu. ft. might be satisfactorily maintained in this furnace.
High-Pressure Boiler and Turbine Operation at Northeast Station
Authors: Keeth J. A.
Published: April 2023

This paper describes the installation and major problems that came up during 2½ years’ operation of the high-pressure equipment at the Northeast Station of the Kansas City Power & Light Company. Reheater equipment is discussed, together with the experimental work involved in raising the steam temperature to the desired point, and incidentally obtaining a type of construction that would withstand the high furnace temperatures and give reasonable life. The effect of the reheater troubles on the use obtained from the equipment is also covered.

A general operating history of the turbine is given, dealing in considerable detail with the turbine-blade deposits. Discussion of this phase of the troubles brings out the various changes that have been made in boiler feedwater in an effort to find a relationship between boiler-water concentration and turbine-scale formation. The method used for turbine-scale removal is given.

Only minor troubles were experienced with boilers, high-pressure superheater, and auxiliaries. The effect of continued operation on boiler efficiency has been covered graphically, and the operating performance of the high-pressure equipment as well as the whole station for a typical month has been given showing the heat consumption of the two pressure turbines, the load distribution, and the net result for the station. Considerable detail is given concerning the utility factor of the entire installation and the effect the various individual parts have had on this factor.
Coordination of Research and Engineering With Production and Sales
Authors: Bausch Carl L.
Published: April 2023

This paper is largely an exposition of the organization of the Bausch & Lomb Optical Company, Rochester, New York, in so far as it affects the function of research and engineering. This company went through a thorough reorganization several years ago and was fortunate in being of sufficient size to justify a distinct research and engineering division, and still small enough to make it possible to tie the functioning of these departments to that of the other departments without becoming involved in too much machinery and red tape. The company employs about 3000 people and has a research and engineering force of about 100. It manufactures a very large variety of small-quantity-production items, although there are a few items that are manufactured on what might be considered a quantity-production basis. It has, naturally, tried to minimize the amount of development work on articles that are expected to be sold in small quantities; still experience shows that quantity can have no great influence on the thoroughness with which the development work must be done, the company being often forced by circumstances to spend large amounts on work which will never result in large production.

The head of the Research and Engineering Department reports directly to the general manager and assumes full responsibility for all expenditures for development work. A yardstick has been set up by which accomplishments can be measured. This yardstick is the relationship between money spent on development work and the value of new business created, which consists of the amount of work of a regular production nature placed in the plant for manufacture, plus all special customers’ orders requiring engineering-department design and follow-up. Figures are shown of this ratio for different classes of product.

Although the Research and Engineering Department assumes full responsibility for development work, sales and production are very definitely tied into the picture and must assume part of the responsibility when manufacture is finally started. Effective means are used to bring this condition about.
Belt Drives With Cast-Iron Pulleys and Paper Pulleys
Authors: Norman C. A. , Moffat G. N.
Published: April 2023

This paper gives data on transmission efficiency of various types of belts on cast-iron and paper pulleys and goes thoroughly into the transmissive power of oak-tanned and rubber belts on such pulleys with varying contact angle, a subject of importance in view of the prevalence of short-center drives with large transmission ratio. It is found that commonly used formulas for the effect of contact angle on transmissive power are not dependable for all combinations of belts and pulleys.
Oxygen Machine Cutting in Great Britain
Authors: Bainbridge C. G.
Published: April 2023

Cutting of metal by the oxygen flame has been practiced commercially for more than 25 years by means of hand-guided blowpipes. The hand cutter is largely used for scrap cutting and by concerns whose work involves the use or manipulation of steel plate, forgings, or sections. The work produced by the hand cutter is rough and inaccurate. The paper describes the use of the machine designed to hold the cutter rigidly and that propels the cutter by a simple feed motion at a uniform speed. Great progress has been made in the past 10 years in the development of these machines, and they now are considered as reliable, quick, and accurate shop tools. The paper describes the various machines and their uses, and gives instances of their application to difficult work, with the resulting reduction in costs.
Researches on Steels and Forgings for Greater Density, Machinability, and Durability
Authors: Cederleaf Fred W. , Sanders W. E.
Published: April 2023

In this paper the authors give details of a research carried out in an endeavor to find means of improving the machinability of gear blanks upset from bar steel, as well as the durability of the finished gears after heat treatment. The investigation shows that a steel of coarse grain upsets into a denser product than one of finer grain, and that this denser material is more readily machined, and with much less resultant tool wear. Specifications are given for the steel finally adopted and also details of its heat treatment, as well as figures from dynamometer tests which indicate a longer life for the wearing surfaces of the teeth on the gears made therefrom, and a marked decrease in pitting and granulation.
A Proposed Speed Characteristic for Oil Engines
Authors: Maleev V. L.
Published: April 2023

The author proposes a method of readily classifying oil engines as low, medium, high, or super-high speed, by means of a “speed characteristic” equal to the square of the revolutions per second multiplied by twice the stroke in feet. To show that it provides a consistent and practical means of classifying engines, he applies it to the data of some 84 modern engines covering a wide range of sizes, speeds, and powers.
Modern Oil-Lubrication Methods as Applied to Rolling-Mill Equipment
Authors: Merrill Joseph A. , May Edwin M.
Published: April 2023

The paper traces the improvement made in lubricant-application methods for rolling-mill machinery from earlier days to the present. The increase in size, speed, and capacity of rolling-mill machinery necessitated the use of heavier oils and of better methods of application. The modern heavy-oil circulating system is described, and common practice in the selection of oils for various types of equipment is indicated. Modern oil conditioning and application give maximum safety and protection against involuntary shutdowns and cut costs of lubrication as much as 80 per cent.
The SO4-CO3 Ratio for the Prevention of Sulphate Boiler Scale
Authors: Partridge Everett P. , Schroeder W. C. , Adams R. C.
Published: April 2023

The investigation described in this paper is a logical development of R. E. Hall’s well-known work. The authors felt that the true value of the SO4-CO3 ratio must be appreciably greater than the value calculated by Hall, and, as a result, a program of research at the University of Michigan was sponsored by The Detroit Edison Company to determine more accurately, if possible, the solubility relations of boiler waters. The work done on this project is described by the authors.
Developing a New Wood Product Through Research
Authors: Perry Thomas D.
Published: April 2023

Many appeals have been made before the Wood Industries Division for research, and several papers have been presented, particularly that of Dr. J. W. Lawrie, in October, 1930. The development of a new prefinished plywood flooring is covered in detail, beginning with the product selection and discussing competitive products of both solid wood and non-wood. Considerable attention is given to the principles of market analysis, although it is admitted that the present depression renders such investigation of less than usual value. Detailed consideration is given to product analysis, emphasizing the limitations and shortcomings of available wood floorings. This analysis is followed by the respective and corresponding steps required to overcome these shortcomings. Practical or applied research is the basis for all the solutions. Emphasis is placed on the strength and rigidity qualities of plywood as well as on the manifest advantages of prefinishing. Several unanticipated advantages appeared from time to time among the research steps. In conclusion it is pointed out that the development of this plywood flooring, from its inception to its acceptance by the market, has been accomplished in an unusually short time, and therefore offers encouragement to other woodworkers to do likewise in their field.
Improving Operation and Overall Economy of Diesel-Engine-Driven Generating Stations: These Conditions May Be Attained Through the Use of Selected Boiler Fuel Oils and More Intelligent Supervision
Authors: Stalnaker H. W.
Published: April 2023

The majority of Diesel plants are operating far below par, and if real economical operation is to be obtained, better supervision is necessary. The larger plants can afford to retain engineers capable of producing results. Small plants could engage supervising engineering companies on a percentage of the net savings. If boiler fuel oil could be proved to operate more economically, it should be used.
Semi-Luminous Flame Obtained With Heavy Domestic Fuel Oil in a Specially Designed Furnace
Authors: Mikeska P. L.
Published: April 2023

Some advantages of the semi-luminous flame for oil-burning furnaces are taken up in the early part of the paper. To assist in understanding some of the mechanics involved in obtaining the semi-luminous flame, the diagrammatic sketch, Fig. 2, labels a few of the happenings shown in Fig. 1. Fig. 2 shows four main branches, A, B, C, and D, coming off from the flame. Each of these branches has in it several blocks labeled with some of the factors involved. Branch A deals with oil atomization, primary air, and initial chemical reactions. Branch B deals with secondary combustion air, final chemical reactions, etc. Branch C explains the thermal setting for proper flame temperature. Branch D takes up the specially designed steel boiler made necessary to coordinate properly the many factors involved (such as proper size and correct proportion of the combustion chamber) to obtain the clean, quiet, efficient semi-luminous flame.
The Electric Molder and Its Efficiency
Authors: Vonnegut Anton
Published: April 2023

The great variety of molder work, involving different methods of operation and various types of cutter-head equipment to meet requirements in all branches of the woodworking industry, accounting for a wide range of expectations regarding molder performances, has caused the development of diversified points of view for appraising molder efficiency. This paper attempts to analyze basic molder design requirements, as determined by fundamental molder functions and principles of molder cutting actions, with the hope of developing a more general understanding of reasons and requirements for electric molder efficiency.
Plywood in the Aircraft Industry
Authors: Fitzpatrick James R.
Published: April 2023

Although plywood is used for nearly all parts of airplanes, its most general use is in wing construction. It is used for wing covering, leading edges, spar webs, gusset plates, cover plates, nose pieces, and tail pieces. The author in this paper tells of joining methods, results from use of plywood in shear, and takes up typical examples of its use in airplane construction.
Design and Development of Seaplanes for Transatlantic Service
Authors: Rumpler E.
Published: April 2023

The author takes up in succession the various problems involved in the design and construction of a multi-engined airplane capable of making a transoceanic non-stop flight of 5000 miles and carrying a pay load of 21 tons. Among the topics dealt with are: Location of engines and propellers; influence of load distribution on weight of wing structure; aerodynamical researches of the Göttingen laboratory on a model of the author’s plane; hydrodynamical starting tests in tank at the Hamburg Shipbuilding Research Institute; influence of various factors on size of pay load; maximum power outputs from oversize engines at various altitudes; necessity of greatly increased airplane speeds; etc.
Some Aspects of the Seaplane: With Special Respect to Its Development in Germany
Authors: Schuettel Frederick P.
Published: April 2023

After a brief historical résumé, the author deals, respectively, with the efficiency of the seaplane, constructional features, design of floats and boats, engine arrangement, beam load, seaworthiness, service questions, official requirements to be met, etc. Many tables, charts, and illustrations are included.
Vibrations of Railway Bridges
Authors: Goodier J. N.
Published: April 2023

The paper contains a discussion of the nature of the approximately resonant vibrations of bridges due to the pulsating forces generated by unbalanced drivers, the influence of the motion of the train, and possible action of the springs; a group of proposed approximate formulas for predicting the natural frequencies of bridges, whether unloaded or supporting trains; a description of the methods of measuring natural frequencies; a list of the sources of damping; a theoretical demonstration of the effects of a small amount of distributed damping in restraining the forced vibration, and an appendix in which the frequency formulas are derived.
Flow of Gases at a Rate Exceeding the Acoustic Velocity
Authors: Tietjens O. G.
Published: April 2023

This paper deals with the flow of gases at high velocities, that is, at velocities exceeding the velocity of sound in the gas under the existing conditions of temperature and pressure. The discussion starts with the development of the fundamental equations of flow and shows why the acoustic velocity assumes such critical importance. In particular, the flow of gas through a De Laval nozzle is considered, the natural assumption of adiabatic flow being made. The so-called compression shock is discussed and the conditions under which these shocks occur, their connection with the acoustic velocity, and their effect on the flow through the nozzle, are pointed out.
Forced Vibrations With Combined Coulomb and Viscous Friction
Authors: Den Hartog J. P.
Published: April 2023

Steady-state vibrations of mechanical systems damped by a combination of dry and viscous friction occur quite frequently, but until very recently no method for their calculation existed. A very satisfactory approximation was presented by L. S. Jacobsen before the A.S.M.E. in June, 1930. In the present paper the author gives the exact solution of the problem, together with a number of test results.
Strength of Materials Subjected to Shear at High Temperatures
Authors: Everett Franklin L.
Published: April 2023

This paper treats of an experimental program which is basically fundamental in the study of creep. Uniformly pure shear is produced in a thin tubular specimen submitted to twist, whereas the usual method employs a solid bar in tension. This torsion form of test permits of greater accuracy in the measurement of creep and provides the simplest stress condition, besides offering other decided advantages.

Since this work in twist represents virtually a pioneer attack, it has been necessary to develop practically from the beginning each phase of the investigation. The type of specimen, apparatus for the creep tests, including the measuring instruments, and experimental technique are described.

The experiments have been of three kinds: (1) Room-temperature tests were first made to determine the usual physical properties in torsion and in tension; (2) at various temperatures short-duration tests were made to learn the effect of different rates of loading, the modulus of elasticity in shear, and the ultimate strength in shear; (3) at 400 deg. cent. and 500 deg. cent. several creep tests in shear of relatively long duration were conducted. An accelerated method of making creep tests has been devised. In addition several special problems were investigated such as a study of the increase of the yield point by creep and the restoration of the original yield point by annealing, the effect of vibrations which included a continuous record of creep, and the effect of temperature fluctuations.
Strength of Thin Cylindrical Shells Under External Pressure
Authors: Saunders Harold E. , Windenburg Dwight F.
Published: April 2023

The scope of existing formulas for the design of cylindrical tubes and vessels under external pressure, especially with regard to the determination of empirical constants and coefficients by systematic and comprehensive experimental data, is rather limited. The introduction and expansion of industrial processes, involving the treatment of materials under a vacuum, or within double-walled chambers whose jackets are filled with steam under high pressure, has, in conjunction with reduction in operating costs by the use of large units, resulted in the building of cylindrical vessels of great size, in the design of which engineers have had to be guided largely by what little past experience they could muster. The dimensions and proportions of these units fall far beyond the scope of any previous experiments. With fabrication costs so high and with satisfactory performance in service so important an item, the use of inadequate formulas can hardly be justified. Engineers called upon to execute these designs very rightly feel that they must have at their command workable scientific formulas, based upon logical application of accepted theories and capable of establishing proportions which will result in proper distribution and economy of material. It was because of the lack of adequate design formulas of this kind that the A.S.M.E. Special Research Committee on the Strength of Vessels Under External Pressure was organized. This paper represents the first attempt of the committee to meet the needs of designer and engineer. It is being published in advance of completion of research work on this project, to fill urgent needs in the profession and to bring forth suggestions, comment, and criticism from those interested in this work.
Action of Slags on Firebrick and Boiler Furnace Settings
Authors: Klinefelter T. A. , Rexford E. P.
Published: April 2023

The results contained in this paper were obtained in an investigation conducted by the Columbus branch of the U. S. Bureau of Standards for the A.S.M.E. Special Research Committee on Boiler Furnace Refractories. The paper presents a rational discussion of the action of coal ash upon boiler-furnace refractory walls and shows the consistency of results from the authors’ laboratory slag tests with firebrick under actual service conditions in boiler furnaces.
Nitriding Analyses—Their Physical Properties and Adaptability
Authors: Sergeson R. S. , Clark M. M.
Published: April 2023

In this paper the authors give the range of analyses of the present chrome-aluminum-molybdenum nitriding steels. The physical properties of these analyses are given in detail both in regard to tensile and impact values. Some data on fatigue tests have been added. Mention is made as to the proper quenching temperatures and there is a suggestion as to the amount of stock to be removed for elimination of decarburized surface obtained previous to machining. Many applications which are operating highly successfully are given.
Machining Properties of Some Cold-Drawn Steels
Authors: Boston O. W.
Published: April 2023

This paper gives the results of a series of machining tests on 13 cold-drawn screw-stock steels and 2 cold-drawn stainless steels. Machinability values for standardized conditions are given for each steel as follows: The force required to remove a chip by a planer tool; the energy required to remove a chip by a single-tooth milling cutter; the torque and thrust developed by a ¾ in. diameter drill; the penetration of a ¼ in. diameter drill under a constant feeding load. An attempt is made to correlate the results of these various machining tests with the Brinell, Rockwell, and scleroscope hardness values, as well as the analysis and structure of each bar. Values representing the power required to cut 1 cu. in. of metal per minute under specific standardized conditions are given for planing, milling, and drilling the various steels.
Haynes Stellite Cutting Tools
Authors: Becker W. A. , Gordon E. E. , Wissler W. A.
Published: April 2023

This paper describes briefly the physical properties of Haynes Stellite and gives the more important details of several types of machining operations on which it is being successfully used. Its most important property is red hardness. Measurements of hardness were made by an improved method up to 1100 deg. cent. The resulting data show that the cobalt-chromium-tungsten alloy is harder than high-speed steel at temperatures above 500 deg. cent. This is believed to account for its superior cutting quality.

When used for milling, three typical jobs on cast iron show 87, 100, and 27 per cent increased production, respectively, on high-speed steel. On boring cylinder blocks the increase was 64 per cent. Turning operations in cast iron show 33, 35, and 60 per cent increase in production, and on steel, 123 and 93 per cent.

In general, Stellite bits and blades can be used economically on all operations on cast iron, semi-steel, malleable iron, bronze or similar metals, and on mild steel if the section is heavy and the tools are rigidly supported. It has not been successful on automatic or semi-automatic machines for cutting steel.
Experiments on the Flow of Air Through Engine Valves
Authors: Dennison E. S. , Kuchler T. C. , Smith D. W.
Published: April 2023

The resistance of air flow through poppet valves has been tested experimentally by the authors. The experiments which they carried out and describe include flow in both inlet and exhaust directions, and the ranges of valve opening and of pressure head extend to or beyond the limits which normally may be utilized in practice. Individual valves were tested variously mounted, and pairs of valves were tested as grouped in an actual design.

The experiments have been extended in an effort to improve the flow characteristics of the poppet valve by modification of its shape and that of the valve approaches.
Light Metal-Alloy Pistons and Rods in High-Speed Industrial Engines
Authors: Isidin Benedict J.
Published: April 2023

The speed of oil and gasoline internal-combustion engines has been brought into a higher range following the availability of improved materials and the necessity of obtaining increased power output without sacrificing space and weight. This often makes it necessary to reconsider some points of design and to adopt better grades of material to solve the problems of higher heat stresses and increase in dynamic bearing loads. Therefore the piston is sometimes cast of steel in thinner section and the cylinder liner is made thinner and is cast of steel to reduce thermal stresses. Connecting rods are made of special alloy steels and can withstand higher stresses than are allowed in plain carbon steel. As a satisfactory means of reducing the weight, the author discusses the use of aluminum, allowing heavier sections, preserving the rigidity, and removing any thermal difficulties encountered in the piston.
Lubrication Research Activities: Fifth Report of A.S.M.E. Special Research Committee on Lubrication
Authors: Flowers Alan E. , Buckingham Earle , Alford L. P. , Bradford L. J. , Dickinson H. C. , Hersey M. D. , Howarth H. A. S. , Karelitz G. B. , Kingsbury Albert , Norton A. E.
Published: April 2023

A new general program for experimental work and publications recently formulated by the Committee is outlined in this report, and is followed by a brief statement of results already accomplished. Particular attention has been given to the coordination of data obtained by various investigators on viscosity under high pressure, to the study of pressure distribution in the oil film as applied to both thrust bearings and journal bearings, and to the development of methods for measuring oiliness. From experiments on the flow of liquids through very fine glass and platinum capillaries, it appears that the ordinary laws of viscosity may safely be relied upon down to a film thickness at least as small as one-millionth of an inch. The report concludes with a brief review of recent European investigations.
Development in Gaseous Fuels and a New Singeing Application
Authors: Van Note R. S.
Published: April 2023

Liquefied petroleum gases are finding an application in various process-heating work. In the textile industry butane is available as fuel for singeing, calendering, gas tenter-frame heating, and yarn-singeing operations. New cloth-singeing equipment has recently been developed and is discussed in the paper.
Use of the Butted Seam by Textile Manufacturers
Authors: Washburn John M.
Published: April 2023

Increasing use is being made of the butted seam by textile manufacturers, and this paper defines and illustrates the butted seam, describes many of its inherent properties, and outlines some of the advantages to be gained by its use in the finishing of woolens and worsteds, cottons, silks, and rayons.
Airplane Servicing From the Operator’s Point of View
Authors: Marshall Richard C.
Published: April 2023

The necessity for periodic overhauls of equipment and the large financial outlay necessary to do this work properly form one of the operator’s greatest problems. The author tells why centrally located shops equipped to do this work at lowest possible prices constitute the answer to the problem. This is an able and well-informed paper on airplane servicing, drawn from actual experience, and should be helpful to airplane operators.
Some Fundamental Economics of Aircraft Operation
Authors: Upson R. H.
Published: April 2023

The paper is intended as a sequel to the author’s paper entitled, “The Airship for Long-Haul Heavy-Traffic Service,” presented at the annual meeting of the American Society of Mechanical Engineers in 1922. In that paper the airship was considered mainly as an ocean-going vessel, the principal comparison being made with ocean steamships. Various design problems were also discussed and the desirability of certain improvements pointed out. The situation needs reviewing on account of the sensational bid for transoceanic service that has subsequently been made by the airplane and the fact that many of the improvements indicated as desirable in the previous paper have now been demonstrated in experimental form. Hence, this paper is devoted principally to the consideration of the relative economic fields of airships and airplanes, the attempt being made to deal primarily with fundamental characteristics rather than with current performance records.
Air-Transport Management
Authors: Tomlinson D. W.
Published: April 2023

Problems which must be solved by a manager of air-transport lines are discussed in this paper. The operating department of the T.A.T.-Maddux Air Lines is divided into two groups: (1) flight and (2) engineering. The first corresponds to the operating department of a railroad, and the second takes care of inspection, maintenance, and general overhauling of equipment. There are many essentials to a well-organized air-transport company. Weather conditions must be studied and reported, radio is a necessity, and the flying force must be chosen for its keen sense of observation as well as for skill in flying. The author describes the duties of each class into which the force is divided and tells how the work is carried on with greatest success and reliability.
Stresses and Deflections in Flat Circular Plates With Central Holes
Authors: Wahl A. M. , Lobo G.
Published: April 2023

Simplified formulas are derived for calculating maximum stress and maximum deflection of flat circular plates having central holes. Eight different loading and edge conditions are considered. These formulas are presented in a usable form for the practical designer. Approximate solutions are given for purposes of checking the formulas. Using the principle of superposition, a simple method of superimposing fundamental cases is developed for calculating cases other than those considered in the paper. Experimental determinations of stress and deflection for certain cases indicate that the formulas are sufficiently accurate for practical work where the edge conditions are determinate. For indeterminate edge conditions, as for example so-called built-in edges, the tests indicate that, while there is good agreement in the case of stress, the measured deflection is considerably greater than the theoretical.
Power Application to Oscillating Axles
Authors: Madlé Alain
Published: April 2023

In this paper a type of axle is described in which the load is not carried by the wheel center but is suspended at the end of an arm which is permitted to swing like a pendulum about the wheel center. This mechanism is called a differential drive, and its application to motor-driven vehicles is described. The forces acting in the mechanism and the conditions necessary for an equilibrium of forces are worked out mathematically, and a comparison is given of starting motor trucks by two systems: first, when equipped with an oscillating axle with differential drive, and second, with the usual method of drive.

By means of the differential drive it is claimed that torque can be applied momentarily to the wheel without turning it, and that an elastic connection is provided between the power line and the wheel which cushions torsional impacts. Whenever there are changes in the running conditions of the vehicle, fluctuations of energy between the wheel assembly and the vehicle body take place. The reaction forces of these fluctuations provide an increased pressure against the ground, an additional accelerating force, and a greater retarding force.
The State of Stress in Full Heads of Pressure Vessels
Authors: Coates W. M.
Published: April 2023

After a brief survey of the significant experiments upon which a comparison with the theory developed is to be based and a statement of the problem, the author derives expressions for stresses and displacements at any point of a thin-walled pressure vessel. Assuming that the shell offers no resistance to bending, an analysis is made considering it as a membrane. A study of the resulting equations indicates that in the neighborhood of the junction of head and cylinder, bending couples result, so that the plates may not be considered as membranes, at least in this locality. This leads to a consideration of the local effects of the reactions set up at the junction, the head and cylinder being considered as surfaces capable of carrying bending stresses with loads which are uniformly distributed edge shearing forces and bending couples. The resultant effect at any point is obtained by superposition. An illustrative example is given.
Further Research on Helical Springs of Round and Square Wire
Authors: Wahl A. M.
Published: April 2023

A method of calculating the stress in helical springs of square or rectangular wire is proposed. The method is to use an approximate formula, based on St. Venant’s results for torsion of rectangular wire, and multiply by a correction factor based on the spring index. The method is quantitatively checked by strain measurements both on semi-coils of actual square-wire springs and on complete springs loaded in compression. It is suggested that this new formula replace those commonly given in handbooks, which may lead to considerable error in certain cases.

Deflection measurements between coils of helical round-wire tension springs made from the same bar but having spring indices varying from 2.7 to 9.5 indicate that the ordinary helical-spring formula for round wire gives results quite close to the actual deflection.

A simple approximate formula, based on St. Venant’s results, for deflection of rectangular-bar springs is proposed to replace those ordinarily used and commonly given in handbooks. These ordinary deflection formulas may also lead to considerable error in certain cases.
The Hayes Process Low-Temperature Carbonization Plant at Moundsville, W. Va.
Authors: McQuade J. D.
Published: April 2023

Low-temperature carbonization was adopted at Moundsville so that the large percentage of slack and screenings could be converted into a merchantable fuel and sold at a profit, clearing the way for the prepared coal at a price that would enable it to enter the open market and justify the continued operation of the mine. The process adopted had to meet the requirements of being operated over long periods and be free from carbon formation when working high-volatile bituminous coal; the retorts must be of a design to allow of easy repair with a minimum of time and labor; the process must be automatic; it must yield tar and gas as by-products; the investment must be so low as to yield an operating profit. Operating costs and returns have been such that the unit will be expanded for a much larger output.
A Review of Calorimetric Measurements on Thermal Properties of Saturated Water and Steam
Authors: Fiock Ernest F.
Published: April 2023

This review has been prepared to assemble the data which are now available on the calorimetric determinations of the thermal properties of saturated water and steam, and to reduce them to a uniform basis for comparison. After a careful analysis of the reports which have appeared in the literature, an attempt is made to point out some possible causes for the variation among the recorded results. Wherever it seemed desirable a thermodynamic interpretation of the experiments is given, and in a number of cases the data have been recalculated. By these means the agreement among the various determinations has been improved in several instances.

It is hoped that this assembly of results presented on a uniform basis may serve as an aid to future International Steam Table Conferences in the choice of base values and tolerances for the International Skeleton Tables.

By means of deviation charts the experimental values for the heat content or enthalpy of the saturated liquid and for the latent heat are exhibited and compared. The agreement is in general quite gratifying.

Several modern steam tables are compared graphically with one another and with the Bureau of Standards experimental results on the thermal properties of the saturated liquid and vapor. A marked improvement in the tables is evident with the increase in scope and the reliability of the basic experimental data.
Flow Characteristics of Some Lead Cable Sheath at Temperatures Above Atmospheric
Authors: Clark C. L. , Upthegrove C.
Published: April 2023

This paper gives results of an investigation on three types of lead cable sheath differing only in the antimony content, which was, respectively, 0.06, 0.6, and 1.2 per cent.

At room temperature all three compositions elongated at more or less fixed rates with loads as low as 245 lb. per sq. in. The results would indicate that a similar behavior would be obtained with still lower loads and that the behavior of lead at 70 deg. fahr. should be similar to that of plain carbon steel at a temperature above its equicohesive range.

Increasing antimony content does not result in a decrease in the rate of flow at the lower temperatures, but in a lowered resistance to creep.

At a temperature of 80 to 120 deg. cent. the higher antimony content results in a decrease in the rate of creep, while the lower antimony results in a comparatively high rate of creep.
The Heat-Balance Test as a Means of Obtaining Evaporative Efficiencies of Steam-Generating Equipment
Authors: Cross B. J.
Published: April 2023

The efficiency of any energy-converting apparatus is determined by a division of the energy output by the energy input. In the case of boiler and furnace this is attained by weighing the coal or other fuel and weighing the water evaporated. The paper attempts to show that the efficiency as determined by the heat-balance method should have equal value with an efficiency as obtained by the test of weighing the coal and water.
The Purpose and Characteristics of the Air-Flow Mechanism of a Boiler Meter
Authors: Lauffer W. G.
Published: April 2023

Stack loss in a modern steam-generating station is assumed to be a controllable item effected by the installation and use of combustion guides. The paper reveals the probability of error in such an assumption. The airflow mechanism of a well-known boiler meter, the proper operation and calibration of which have probably not been understood, is given a detailed study in this report, and the result is described as resulting in an indicator of combustion efficiency that is reliable within close limits.
Cleaning, Distribution, and Uses of Blast-Furnace Gas
Authors: Haven William A. , Thorne C. B.
Published: April 2023

In this paper the authors discuss blast-furnace operation and show the relationship between blast-furnace operation and the amount and quality of blast-furnace gas produced. A comparison is given between methods and costs of gas cleaning, the distributive equipment and cost of distribution, application for various purposes, and the profit that can be expected from blast-furnace gas as a by-product.
Use of Economic Manufacturing Quantities: Obstacles Encountered in Introducing Mathematical Formulas for Economic Manufacturing Quantities—Lot Sizes
Authors: Kent Robert W.
Published: April 2023

For the sake of establishing better manufacturing procedure, the author points out methods for determining how much to manufacture of a particular item or part at one time or in one lot. He discusses what is meant by economic manufacturing quantities, the aid toward increasing profits that comes from use of proper formulas, and states that minimum economic manufacturing cost can be obtained only through application of the principles made use of in developing a proper formula to fit each specific case.
Management of Service Departments—Budgeting and Wage Incentives Applied to a Large Organization
Authors: Ferguson William B. , Blair Tom H.
Published: April 2023

The organization and the management of the service departments in a large plant with over 6000 employees doing a great variety of unstandardized work of fluctuating volume and spread over an area of 140 acres present many difficult and complicated problems in comparison with similar problems in the usual manufacturing establishment. After the productive or operative departments in the Newport News plant had been reorganized and modern methods of planning, scheduling, production control, cost control, and wage-incentive plans had been put into effect over a period of about five years, it then became possible to undertake further improvements in the staff and service departments with respect to better organization and the training of executives and employees, and the measuring in some way, directly or indirectly, of the value of the service rendered or the output of these service departments; and finally the applying of bonus plans or other wage-incentive schemes to reward the employees in these service departments, with over 700 men and women, for improved efficiency. The methods described are the result of preceding study and preliminary work for over a year and represent the simplest forms of wage incentive that seemed practicable to apply to a large plant of this character. The first service department was put on a bonus system in April, 1928, and there resulted a net saving during the first 15 months (that is, about four months after the last service department was put on a bonus system) of about $175,000 for the whole plant. The simple methods used have created great interest on the part of heads of departments and employees. The main feature is that an opportunity has been and can be offered to all employees in all service departments for increasing their earnings in proportion to their results and thereby increasing the net earnings of the company to a much greater degree than has probably ever been appreciated.
Designing for Safety in Materials Handling
Authors: Hucke R. H.
Published: April 2023

The author covers the special handling of large cases for shipment. The equipment designed to meet the operating conditions is described, and also the features of safety and speed in handling materials. Every conveyor before installation must pass the inspection of the works engineer, and after installation the system is checked over to see that proper guards and switches are supplied.
Turning With Shallow Cuts at High Speeds
Authors: French H. J. , Digges T. G.
Published: April 2023

In this paper a method is described for testing lathe tools under shallow cuts and fine feeds. The relations are determined between the cutting speed, feed, depth of cut, and tool life for carbon and high-speed tool steels. Comparisons are made of tools of different forms and of tool life when cutting dry and with water or lard oil. Heat treatment and chemical composition of the tools are also studied, including in the case of high-speed tool steels, the effects of cobalt, nickel, molybdenum, arsenic, antimony, phosphorus, sulphur, copper, tin, aluminum, titanium, and tantalum. The results obtained under shallow cuts and fine feeds with these steels are compared with those obtained under heavy duty.