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TESTS simulating actual dynamic loading that a seat belt might receive during a crash of a motor vehicle are discussed in this paper. Design criterion was set as 20-g deceleration uniformly applied for 50 millisec. Development and design of the test sled, body block, frame, quick-release mechanism, and in particular the oil buffer are discussed. According to the author this dynamic test machine is the most valid test for predicting failure of seat belts.

THIS paper presents observations of 25,000 hr of testing on five free-piston engines. Endurance test investigations were made especially on the operation of free-piston-engine air compressors and gasifiers. As a result of the data obtained, basic parts of these engines were redesigned for better performance, power, economy, and reliability.

USE of residual fuels in medium- and highspeed diesel engines is discussed here. The objective is to improve overall economy of operation by using less costly residual fuels to get satisfactory performance. Problems resulting from use of these residual fuels are discussed in light of economic effect on short-term performance of 4-stroke and 2-stroke diesel engines. Two types of 2-fuel systems, the diesel fuel selector system and the diesel fuel blender system, have been developed for utilizing residual fuels in medium-speed engines.

HUMAN perception thresholds to motions and the various characteristics of motions in six degrees of freedom are presented. Experiments made to establish these thresholds for disturbances of the duration or frequency that might arise from highway geometry—durations in the range of from one second to several hundred seconds—are described. Applications of motion sensitivity criteria in the design of vertical and horizontal highway curves and transitions are developed, with examples from company proving grounds in Arizona and Michigan. The resulting geometric features of the high-speed road systems differ in several important respects from conventional highway practice and previous automotive test-track designs.

THE problem of crash protection for ground-vehicle occupants relates not only to the general public but involves the Armed Forces inasmuch as there is a tremendous loss of man power to the defense effort from motor vehicle accident injuries. Evidence for the need of safety devices in ground vehicles in order to improve their crash-protection characteristics is recommended. Specifications for lap belts and lap belt installations are described, and the use of these belts in priority vehicles to evaluate their effectiveness is recommended. The three fundamental harness configurations are briefly discussed.

THE FIREBIRD II represents an interpretation of future trends in powerplant and chassis design. It was conceived as a high-speed, turbine-powered vehicle to carry its four passengers comfortably for long distances on smooth highways. The chassis and suspension provide a smooth level ride, the brakes give adequate stopping power, and the hydraulic system furnishes the means for powering accessories for convenient and easy car control.

THE GT-304 Whirlflre engine, incorporating fuel-saving regeneration, has been built to overcome shortcomings of earlier vehicular gas-turbine models. The overall power package was given prime consideration. Attention was focused on design and location of each component to achieve a compact, well-integrated assembly. These basic design considerations and preliminary operating experience are the subject of this paper.

IN the first part of this paper, Mr. Halgren discusses modified 4-square testing of gears in relation to service performance, field tests, and other accelerated laboratory test methods. It contains a short description and photographs of nine different designs of modified 4-square gear testing machines now in use. Description of machines includes comments on mounting rigidity, mass-elastic system, load application, measurement and control, shut-off devices, and lubrication. Mr. Wulpi discusses single-tooth fatigue testing which is used to measure the bending strength of gear teeth. One tooth at a time is tested in the manner of a cantilever beam. By successive testing, many teeth of the same gear may be tested, and endurance limits obtained if desired. Results of these tests show that it is possible to determine clearly the effect of various metallurgical factors, such as material, heat-treatment, or surface-finishing treatment upon the bending-fatigue strength of gear teeth.

APPLICATION of nuclear energy for civilian automotive uses has possibilities, these authors say. Nuclear power for automotive applications, they feel, is technically feasible now where size and weight are not prime considerations; where size and weight are major parameters, discoveries of new materials for construction of nuclear-power reactors must be made. New materials are needed for reactor fuels, heat extractants, neutron reflectors, reactor construction materials, controls, and radiation shields which must have unique nuclear properties in addition to conventional engineering properties. This paper presents nuclear automotive propulsion devices in terms of technologies now available. The necessary radiation-shielding mass and weight requirements are presented for an ideal point-source nuclear-heat-power engine.

APPLICATIONS of nuclear energy in automotive manufacture have been made principally in the field of radioactivity. These are grouped under the following categories: radiography, nondestructive testing, gaging and control, tracer techniques, and static neutralizers. Radioactivity techniques are being used in foundry operations to check stock and metal levels in cupolas and distribution of element additives. In steel operations, these techniques are being used to check assimilation of ore-concentrate fines and thickness of rolled sheet steel. Other applications include measurement of pipe and wall thickness in pressure lines and engines, and inspection of castings and welds for internal faults. Radioactive techniques for improving processes, quality, and materials have potentially universal application. Greater industrial access to reactors will permit broader study and speed the development of new applications of radio-activity in industry.

THIS paper utilizes the proposed formula for “the strength of gear teeth” developed by the Gear Rating Coordinating Committee of the American Gear Manufacturers Association to answer the question “What do calculated gear stresses mean?” It is shown that meaningful gear-stress calculations use a formula developed upon a good basic theoretical foundation and used within the limitations of validity. The basic formula must be adjusted by measurable modifying factors evaluating load, accuracy, and materials. These modifying factors depend upon data secured by field experience and laboratory tests. It can be concluded that gedr testing and theoretical analysis are complementary functions necessary for accurately calculating the stress in gear teeth.

THIS paper presents the results of tests conducted during 1955 on more than 1200 vehicles selected from the general traffic. It compares past and present levels of brake performance and shows that since 1949 improvements in the brake performance of most vehicle types have been small. Current levels of brake performance are indicated with respect to vehicle type, gross weight, vehicle capacity, and axle load. The paper also indicates the ability of different types of vehicles to comply with current Uniform Vehicle Code specifications for brake performance.

SINCE 1954 the CIMTC Subcommittee has been engaged in a program to meet military requirements through industry's production of construction equipment which can give satisfactory cold weather performance down to temperatures of −65 F. Individual contracts for three crawler tractors and one motor grader were negotiated by ERDL for these projects, and their performance is discussed. Industry participation was subsequently expanded to include engineering tests in the cold weather conditions of the Mesabi Iron Range. This joint report of the Winterization Sub-committee of the CIMTC and ERDL Winterization Section consists of separate papers by various members and consultants of this Sub-committee and ERDL personnel.

THIS paper deals with cavitation pitting where vacuum bubbles exist. Experiments are described which attempt to correct this condition where plating of liners varied in composition and thickness. It was concluded that a nickel-chrome plating has very good resistance to cavitation-pitting attack. Investigation of cylinder-wall vibration was made to find out about the cause of cavitation. Minimum liner wall vibration results with use of a 2-piece heavy wall liner and a piston with 20% less clearance. Endurance tests prove that on these pitting has been eliminated.

IT has been found that by means of magnetostrictive cavitation testing, it is possible to duplicate the conditions that lead to deterioration of the water side of diesel-engine cylinder liners. In order to obtain accurate results it is necessary that conditions of temperature and pressure present in the water system be duplicated on the laboratory facility. It has been shown that increasing water pressure will definitely inhibit the erosive action of cavitation. Changes in operating temperatures will have less predictable results. The use of a chromate-type corrosion inhibitor is effective in decreasing cavitation within concentration limits of 1000 to 2000 ppm. Soluble-oil water treatments are also effective in concentrations between ½ and 2%. Boron-nitrate type of corrosion inhibitors are ineffective in combating cavitation.

THE “Orion” gas-generator turbocompound engine consists of a supercharged, regenerative aircooled, 2-stroke-cycle opposed-piston diesel engine driving two centrifugal compressors. One of these compressors is for combustion air with fine air filtration, while the other is for cylinder cooling with much less filtration. The gas-generator engine has a bore of 4¼-in. diameter and a stroke of 5⅞ in. × 2. The engine turns at 2340 rpm, and the combustion air compressor turns at 37,000 rpm while the cooling air compressor turns 17,000 rpm. The cylinder is cooled with air at nearly the supercharge level and at an equivalent temperature because this air later does work on the turbine. The cooling airflow is about 3½ times the combustion airflow. These two airstreams join in a plenum chamber downstream from the engine, and the mixture temperature is about 500 F. This hot gas stream then goes to the power turbine, which is mechanically free of the gas generator.

STYLING the Continental Mark II with a very low silhouette without sacrificing leg room, seating comfort, and driver visibility was accomplished by using a specially designed frame and a 3-joint driveline. These two features are the basic engineering innovations which make possible the Continental's distinctive classic styling. As a result of this structural analysis, Ford has produced an automobile that, according to the author, has technical advancements that are of value to the consumer.

EQUATIONS relating to noise outside a turbulent jet to the turbulent velocities inside the jet have been derived making use of Lighthill's suggestion that the actual flow field can be simulated with a stationary field of quadrupoles. Hot-wire anemometer techniques were applied to a 3V½-in. air jet to measure the turbulent structure of the mixing region. These measurements and the previously derived equations were used to estimate some of the characteristics of the sound field. The estimated characteristics were found to be in good agreement with the experimentally measured sound field of a full-scale turbojet engine.

THIS paper is an elementary nonmathematical discussion of the essential thermal processes of gas turbines with emphasis on turbine types suitable for use in vehicles. A brief history is followed by discussion of the limitations imposed by strength of materials. The effects of pressure ratio, compressor and turbine efficiency, turbine inlet temperature, and atmospheric temperature upon output and thermal efficiency, are discussed., The effects of regeneration upon thermal efficiency at full and part load, with particular emphasis upon the latter, are discussed, and the regenerator is stated to be essential to obtain acceptable fuel mileage in vehicle use. The probable performance parameters of a vehicle turbine of about 200 rated hp are explored.

THE main emphasis is on the testing of tires for use on high-performance cars, and both indoor and road testing techniques are described. The importance of insuring freedom from “traction wave” or “tread ripple” is stressed. As the difficulties of road evaluation are greater with high-speed tires, machine testing-methods have been extensively developed and correlated with service performance. These preliminary tests give a good indication of the tire's capabilities before road tests are planned. The subsequent evaluation of tread life, casing strength, and handling characteristics is illustrated on suitable stretches of Continental roads. Proving methods for world's land speed record tires and high-speed aircraft tires are included as examples of cases in which almost complete reliance must be placed on indoor testing.