bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Geared Marine Oil Engine
Authors: Bradbury C. H. 
Published: October 2007

Although it is now more than ten years since the first geared oil engine installation put to sea, no country other than Germany has made any serious attempt to exploit this method of propulsion. The success of Germany's geared ships has, however, completely proved the reliability of this type of drive, and has exploded the once prevalent belief that mechanical reduction gearing would not withstand the uneven torque of the oil engine. The author first gives a brief historical survey of the geared oil engine ships at present in service, beginning with the original vessels of the Havelland class and finishing with Germany's “pocket” battleship Deutschland. The advantages of incorporating reduction gearing are then dealt with, the author maintaining that the disadvantage of added weight due to the inclusion of gears is more than compensated for by the advantages resulting from smaller engines running at higher speed. The types of drive in common use, namely, the rigid and the “Vulcan” types, are then described, together with the method of obtaining synchronized starting and reversing. It is pointed out that, although torsional vibration problems disappear to a large extent with the “Vulcan” drive, they are of extreme importance in the case of rigid drives. A complete analysis of the question is therefore made at the end of the paper, and expressions are obtained from which may be calculated the natural frequencies of the normal types of installation. A worked example is included to show the application of these expressions.
Liverpool and the Atlantic Ferry
Authors: Austin J. 
Published: October 2007

Liverpool shipowners have played prominent parts in the long struggles for supremacy on the North Atlantic between the more notable steamship companies, such as the Cunard, White Star, Collins, Inman, Guion, Hamburg-Amerika, and Norddeutscher Lloyd Lines, and associated with their names are those of the celebrated engineers and shipbuilders who were responsible for building the transatlantic mail steamers. An historical account is given of the evolution of the mail service from its commencement in the year 1710 to the present day, and includes the British Government Post Office Packet service commenced in 1710 by the sailing packet brig Royal Anne, the inauguration in 1816 by the Black Ball Company of the first regular sailing packet line, the commencement of the Atlantic Ferry in 1840 by the Cunard Line, and the evolution of the mail steamer to its present size, as represented by the liner No. 534 now building. This period covers the development from wood to iron, and iron to steel, for the construction of hulls, the change from sail to steam, from paddles to single, twin, triple, and quadruple screw propellers, from simple to compound, triple-, and quadruple-expansion reciprocating engines, the development of the Parsons direct and single- and double-reduction geared turbines, the change from tank boilers to low- and high-pressure water-tube boilers, and the evolution of passenger accommodation to its present standard. A few observations are made on the navigation and propulsion of modern liners. Tables show the record passages of Atlantic liners and dimensions of the present-day big ships. The state-rooms, lounges, ballrooms, cinema theatres, swimming baths, sports decks, and dining saloons in the modern liner are briefly described. The author thinks it is improbable that the Atlantic steam ferry will be supplanted by an air ferry, and he gives an account of the competition with foreign lines which receive subsidies for shipbuilding and operation, and explains the reasons for building No. 534, and the part which Liverpool and the Atlantic Ferry might play in the future development of the United States of America and the Dominion of Canada.
The Embrittlement of Low-Carbon Steel
Authors: Lea F. C. , Arnold R. N. 
Published: October 2007

The paper deals with those changes in the mechanical properties of steel having a low carbon content, which occur as a result of quenching from temperatures up to 900 deg. C. Attention is directed mainly to brittleness, especially to that resulting from ageing at atmospheric temperature, which the authors term “age embrittlement.” The range of temperature in which this occurs appears to include those temperatures used in the carburizing treatment of steel as well as lower temperatures. It is suggested that case-hardened steels should be subjected to a final tempering treatment after quenching to avoid the possibility of core brittleness. Theories are briefly discussed, but at present no direct explanation of the phenomenon is forthcoming, as X-ray and microscopic examination reveal no abnormalities in the age-embrittled steel. Ageing at 100 deg. C., after quenching, shows distinct age hardening, but this is found to be dissociated from age embrittlement.
High-Pressure Plant for Experimental Hydrogenation Processes
Authors: Barber A. T. , Taylor A. H. 
Published: October 2007

The paper gives an account of some of the mechanical difficulties experienced in the development and operation of experimental plant for the hydrogenation of coal and tar for the production of motor spirit. Particulars of the various stages of progress are given, from small autoclaves up to a continuous plant capable of producing up to 300 gallons of spirit per day. The pressure plant is operated at 3,000 to 6,000 lb. per sq. in., and at temperatures up to 950 deg. F. Hydrogen produces complete disintegration of the structure of mild steel under the higher temperature conditions. The use of special alloy steels reduces the liability to hydrogen attack, giving longer working life and allowing higher working pressures, but satisfactory service can best be obtained by insulating the pressure-resisting walls from the heating medium so as to avoid heating the metal beyond 200 deg. F. Various methods of making suitable joints for high-pressure pipes and cylinders are described, and the results of microscopic examination of sections of cylinders are given in Appendixes.
Heat Insulation as Applied to Buildings and Structures
Authors: Allcut E. A. 
Published: October 2007

The insulating materials and conditions described in the paper are those relating to such temperatures as are likely to be met with in heating, cooling, ventilating, or refrigerating practice. The symbols and nomenclature used are those adopted by the Committee on Heat Transmission of the National Research Council (U.S.A.). The first section describes respectively, the hot-plate and hot-box methods of testing, the former being the more suitable for materials which are comparatively homogeneous, and the latter for walls or other built-up sections. Illustrations are given of the hot-plate apparatus at the University of Toronto, on which much of the experimental work was performed. It is frequently impossible to compare tabulated values of heat conductivity because of differences in test conditions, and accordingly in the second section the effects of ( a) mean temperature and temperature coefficient, ( b) differences of temperature on the hot and cold sides, ( c) superficial pressure, ( d) surface resistance, and ( e) time effect, are considered in detail and an attempt is made to indicate their relative values. A table of characteristic conductivities is given at the end of the paper. The third section deals in a similar manner with the effects of differences in the materials themselves or in their application. These include the influence of: (1) size and thickness of samples, (2) laminated structure, (3) density of fibrous and cast materials, (4) air spaces in materials or structures, (5) moisture, and (6) infiltration of air or gases. The objective in all cases is to obtain the greatest insulating value per unit of cost, and this is not always favourable to the use of material having the lowest conductivity. Structural strength and resistance to fire, moisture, and vermin are frequently important factors. The paper concludes with some statistics concerning the production and consumption of insulating materials in Canada.
The Yield of Steel Wire under Stresses of Very Small Duration
Authors: Mason William 
Published: October 2007

A steel wire 53 feet long was suspended vertically from a fixed point. Near its lower end a stop was soldered to the wire; a tup, sliding on the wire, was allowed to fall on to the stop from appropriate heights. Waves of tensile stress were thus sent up the wire and reflected at the fixed top. Extensions were measured on certain gauge lengths at the top of the wire. The form of the wave front was inferred from these measurements and from the corresponding distances travelled by the stop; the stresses were calculated from the extensions. The impacts of the tup on the stop were repeated after heat treatment, at a normalizing temperature, of the middle part of a 4-inch gauge length. The static yield being 16·3 tons per sq. in., a yield was found with a wave rising from 3·4 to 28·7 tons per sq. in. in 1·25 × 10−4second and falling again to 3·4 tons per sq. in. after a further 0·45 × 10−4second. Yields above the static yield but lower than the yield just mentioned were found with waves of less intensity but of longer duration. A limiting “higher” yield stress for indefinitely small duration of the stress is inferred. This limiting stress for the wire as normalized was about 30 tons per sq. in., the maximum stress in static tension being 24·8 tons per sq. in. The results are discussed with reference to the “higher” and “lower” yield stresses.
Machine Tool Tests and Alignments
Authors: Schlesinger Georg 
Published: October 2007

Limits and tolerances are the basis of all machine manufacture. Fourteen European countries adopted the system known as the ISA (International Federation of National Standards Associations) in December 1936; the system covers all grades of finish from the finest roller bearings to rough agricultural machines. Certain fixed principles of measurement must be observed, both in the manufacture of new machines and in the repair of old ones; for instance, extremely fine boring and grinding machines and jig borers are now obtainable and can be used equally for the manufacture of a new motor car or for the overhauling of an old one. Before a satisfactory basis for the establishment of correct limits for the manufacture of, say, drilling machines, lathes, and milling machines, the deformations set up during the cutting operations must be known. These deformations must therefore be measured during actual cutting. The measuring apparatus as applied to lathes, drilling machines, and milling machines, though varying greatly in individual cases, can be adapted to this research, which furnishes information on the admissible variations in deformation—which is of use during inspection—and on the forces and bending and twisting moments—which is of use to the designer. These records furnish manufacturers with the information required for organizing the sequence of operations when building machines to work with any desired precision. The “balance sheets” of various machines, giving the relationships of the forces, speeds, feeds, section of chip, power required, and efficiency, are of great value both to manufacturer and user.
The Combustion Process in the Compression-Ignition Engine
Authors: Drinkwater J. W. , Egerton A. C. 
Published: October 2007

The object of the work, which was carried out in the University Engineering Laboratory, Oxford, was to investigate the combustion process in a compression-ignition engine by determining the extent of the chemical reactions of the fuel and air at various stages during the compression and expansion strokes. The results of the tests are illustrated by several curves showing the percentage volumes of the constituent gases in the engine cylinder at different points in the cycle. Various inferences are drawn concerning the combustion in this type of engine. Attempts were made to determine the concentration of aldehydes in the gases, but the tests showed that the amount was less than anticipated. Oxides of nitrogen were detected, and considered to have an influence upon cylinder wall corrosion. It is suggested that there is scope for further work using the sampling method for investigating combustion problems in engines under running conditions.
The Measurement of the Thickness of Metal Walls from One Surface Only, by an Electrical Method
Authors: Thornton B. M. , Thornton W. M. 
Published: October 2007

There is a definite need in the engineering industry for an instrument which will determine accurately the thickness of a metal wall from one side only, and which is portable, robust, independent of external power supply, and easy to operate. The instrument described in the paper fulfils all these conditions. The method is essentially that of comparing the resistance of a metal wall under test with that of a similarly shaped wall of the same material, of which the thickness is known. Current, usually under 10 amp., is supplied by a 6- or 12-volt battery to two current contacts held against the wall and usually spaced 2 or 3 inches apart. The current in the circuit is adjusted by varying the rheostat or the number of cells of the small car-battery employed, until the very small potential drop indicated by the deflexion of a galvanometer connected to two potential contacts reaches a predetermined fixed value. From a calibration curve the thickness of the wall corresponding to the current registered by the ammeter is determined. The contacts are made on the plates whose thickness is to be measured by means of Evershed and Vignoles spring-controlled rotating points that were originally designed for a four-point method of working. The flexible leads from these, sometimes 100 but usually 30 feet long, are rubber-covered, and are connected to the circuit in the box by plugs and sockets. These are removed for transport and carried in a separate box. The instrument was originally designed for measuring the thickness of boiler tubes, and examples are given showing that its accuracy in this respect is within a few thousandths of an inch. It was found in practice that the instrument could be used to measure the thickness of mild steel plates up to 1·25 inches and of iron castings, up to 3 inches, with the same order of accuracy. It is also used for the measurement of engine cylinder walls to detect core shift. Examples of these are given in the paper. One notable case was that of the examination of a bank of superheater tubes in a boiler that had given much trouble due to the use of an unsuitable chain-grate stoker. Thinned tubes were at once detected and on being cut out the thicknesses indicated by the instrument were confirmed. Examples are given of the regular use of the instrument in determining the thickness of boiler and superheater tubes, ships' hull plates, tank wagons, and various iron castings that were accessible from one side only.
Roller Crushers
Authors: Miller W. T. W. , Badger G. 
Published: October 2007

The paper describes roller crushers used for the reduction of ore, stone, coal, or chemical preparations of similar densities. Single-roll breakers developed originally for the crushing of coal, have been applied for the reduction of semi-hard slippery materials such as phosphate, gypsum, shale, and certain limestones. Two-roller crushers are the most numerous class and their growth from the early Cornish type to the modern high-speed rolls of great size and capacity is illustrated. Three-roller mills have not proved very successful in this particular field of service. Two examples are described and their defects explained. Four-roller machines have proved useful for the crushing of coal and some of the chemical products. Six-roller crushers are not very common. Two examples are shown and reasons are given for their restricted application. Two special types of roller crushers are also discussed, namely Taylor's three-stage coal breaker and the “Simplex” machine comprising two rollers and an intervening rotary disk. The factors which influence the performance of the rolls are examined in detail and a formula for obtaining their capacity is given. The correlation of the angle of nip and the feed size, and their effect on the diameter of smooth rolls, is emphasized. A time factor diagram is given to show the reason why rolls of large diameter can be run with advantage at the higher circumferential speeds. Figures covering normal power consumption are specified.
Cylinder Bore Wear
Authors: Taub Alex 
Published: October 2007

The author has been responsible for the design of engines for a motor car in which the life of the cylinder bore over a period of ten years and a total of eight million engines is 12,000 miles per 0·001 inch wear. The factors contributing to this result are as follows: (1) thermostatically controlled cooling for water at a minimum temperature of 145 deg. F., preferably 160 deg. F.; (2) crankcase ventilation to eliminate the effects of blow-by in the oil sump; (3) adequate oil supply to cylinder bores; (4) complete control of the lubricant at the piston rings, not at the source of supply of the oil; (5) control of gas blow-by at the rings; (6) leanest possible mixture ratios for general operating conditions; (7) close attention to the type of fuel used to ensure that it is properly vaporized; (8) a uniform hot metal temperature; and (9) an accurate spark advance mechanism. All these factors are discussed by the author in detail, special attention being paid to the testing of piston rings in the laboratory, the correct use of thermostats, and crankcase scavenging.
Some Principles of Modern Methods of Water Treatment for Steam Raising
Authors: Hamer P. 
Published: October 2007

The paper describes some recent advances in knowledge of the physico-chemical principles on which the correct treatment of boiler feed water is based. Straub's work in America was confined mainly to the tannins, the use of which in boiler compounds is almost traditional. The effect of tannins in the boiler appears to be threefold: (1) the delay of the precipitation of calcium compounds by the action of heat or alkalies; (2) the reduction of the amount of deposit which may be due to a change in the crystal shape of calcium sulphate and calcium carbonate brought about by the presence of tannins; and (3) a marked effect in conjunction with alkali, in preventing corrosion by the formation of protective films. The principles laid down by R. E. Hall for the prevention of calcium sulphate scaling are restated. Recent work has led to a modification of the theory underlying Hall's recommendations, the significance of which is explained. A short description is given of Partridge's experiments on the growth of crystalline deposits on hot metal surfaces, but further work is necessary to explain why these deposits adhere to the metal. Recently published studies on the solubility of the calcium phosphate precipitated in the boiler, and the effects of sodium salts are described. Mention is also made of the formation of silicate scales and the use of sodium phosphate and caustic soda as preventatives. It is suggested that the work described in this paper emphasizes the fact that the prevention of scale in boilers is essentially a chemical problem, and that the success of the recommended methods of prevention depends on careful control at each stage of the feed water treatment.
Estimation of the Leakage through a Labyrinth Gland
Authors: Hodkinson B. 
Published: October 2007

The usual theory gives leakage per unit clearance area [Formula: see text] but this assumes that the successive pressure drops are all small, and further, ignores the fact that with decreasing back pressure the quantity flowing cannot go on increasing indefinitely, but reaches a maximum, and thenceforth any further decrease of back pressure pn has no effect. Its critical ratio to the initial pressure p0 is given in a diagram which also serves to give the progressive pressures along the gland. For calculating the leakage quantity a method is given, more accurate than the usual formula above. For the case where the kinetic energy of the fluid is not completely destroyed at each stage, the consequent increase of leakage can be assessed by a correction factor given by a formula made to agree with some test results, but based on the fundamental idea that the stream spreads out conically from the cylindrical surface at a small angle.
The Energy Balance Sheet of the Internal Combustion Engine
Authors: Lanchester F. W. 
Published: October 2007

The author has amplified and in some degree revised the treatment described in a series of articles published last year. He believes that the method is new. By presenting the energy balance sheet in the form of a triple account the quantities which cannot be directly determined appear as differences. For the original articles the author had to fall back on tests of an Otto cycle engine of his own design, dated 1895, but his attention has since been called to an admirable Ph.D. thesis by J. S. Clarke of Birmingham University, the data in which he has been able to use for this paper. It is unfortunate that the indicating of high-speed engines is not yet sufficiently precise to allow of the application of the author's treatment. The production of an indicator capable of giving reliable diagrams up to 2,000 or 3,000 r.p.m. is a matter of great importance.
The Elements of Pendulum Dampers
Authors: Zdanowich R. W. , Wilson T. S. 
Published: October 2007

The dynamics of a pendulum damper is treated in a more general way than hitherto, all known types being included. A new method of considering the effects of a pendulum damper when fixed at any point in an engine system is developed, showing that its action results in an alteration or displacement of the critical speeds at which the harmonic orders occur. A convenient method is outlined for arriving theoretically at the best design for a pendulum damper, whatever may be its location in the engine system. As a practical illustration, a brief account is given of experimental work which was undertaken to test the behaviour of a well-known engine when a certain pendulum damper was fitted to the flywheel. A further account of a similar application to a six-cylinder engine is also given. Special forms of pendulums, and a note on the estimation of angular amplitudes, are discussed in Appendix I, and a bibliography and a short list of the most important patent specifications relating to pendulum dampers are also included.
The Static and Fatigue Torsion Strengths of Various Steels with Circular, Square, and Rectangular Sections
Authors: Holley E. G. 
Published: October 2007

The paper records the results of a research into the comparative elastic and fatigue torsion strengths of bars of circular, square, and rectangular cross-sections. The static torsion tests reveal that in the case of square and rectangular sections the use of enlarged ends leads to discrepancies between the experimental and theoretical values of the elastic torsion strengths. The fatigue torsion tests disclose astonishing fatigue weaknesses in square and rectangular bars, the weaknesses being masked when the ends of the specimens are enlarged. The fatigue torsion strengths of square and rectangular bars are compared with the fatigue torsion strengths of circular shafts with keyways and it is emphasized that outstanding fatigue weakness may be associated with certain forms of stress distributions even when high stress concentrations are absent. Consideration is given to the value of the static properties of metals as safe criteria of fatigue strengths. In an appendix the problem of the raising of the elastic stress in a material when the distribution of stress is uneven is discussed.