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THE inherent simplicity of the gas turbine and its well-known success in aircraft applications is leading to its consideration for locomotive use. As a matter of fact, gas turbine locomotives have already found limited use by a few railroads throughout the world. The author discusses these applications and some of the lessons learned from them. He points out that, although the first gas turbine locomotive to be put in service was built in 1941 - the same year that the first commercial diesel locomotive was placed in service -the latter has forged rapidly ahead, so that today the railroads are about 75% dieselized. What, then, has held the gas turbine locomotive back? Mr. McGee points out that two of the most significant factors responsible are: 1. Metallurgical problems - the need for materials capable of withstanding the high temperatures encountered. 2. High fuel consumption.

USE of adhesives to join metal skins to low-density cores results in major weight, manufacturing time, and cost savings, according to the authors. They report here that such sandwich structures have been used in several projects, the most advanced being the B-61A Matador. To achieve a bonded joint between two aluminum sheets or between sheet and core, four generally similar steps are required. The sheet must be cleaned, coated with adhesive, force-dried to remove volatile materials, and finally cured under temperature and pressure. The authors conclude that production adhesive bonding of flat and contoured primary structures, with all its inherent advantages, is now available to the industry.

THE control of residual stresses in automotive cylinder blocks is discussed in this paper. According to the authors, this study was started because a small percentage of castings was being scrapped because of cooling cracks in the valve compartment wall. They discovered that the greatest single factor in inducing trapped stresses in castings is too great a difference in the cooling rates for different portions between 1400 F and 600 F. They also found out that residual tensile stresses can be eliminated in a particular section by keeping its cooling rate at least as fast as that of other significant sections. Moreover, it is possible to move trapped stresses from one section to another by overcooling. They have also developed a method that gives quantitative results that serve as good index values of the trapped stresses present even in complex castings.

INCREASING fuel prices and fuel taxes have forced engine builders to find ways to better engine specific fuel consumption in order to help operators survive the onslaught of increased operating costs. This paper explains how an improved combustion system has yielded up to 15% improvement in fuel consumption. This system was arrived at by analysis of those previous combustion systems which held most promise. The resulting direct-injection open combustion chamber is described here.

COMMERCIALLY available high-temperature brazing alloys, with examples of successful applications for each, are described here. Brazing alloys included are: Nicrobraz, Coast metals alloys, Mond Nickel alloys, Handy & Harman alloys, and Solabraze. Production brazed parts are shown, and details of brazed joints are explained with the aid of photomicrographs. Developments of new high-temperature sheet metal assemblies made possible by brazing techniques are discussed. Particular emphasis is given fabrication of high strength/weight ratio structures. An encouraging future for corrosion-resistant high-temperature brazing is predicted.

MOLECULAR weight or volatility has been found to be the most important factor in determining the extent to which a lubricant contributes to combustion-chamber deposits and octane requirement. Bright stock appears to be particularly harmful. Crude source (or variation in predominating hydrocarbon type) seems to have little effect. These authors report further that commercially practical mineral-base oils have been developed that show a significant advantage over previously known conventional lubricants in their ability to prevent these deposits and octane requirement increase when used with a conventional leaded fuel. Moreover, they say that SAE 5W-20 motor oils can be made that give a 4-5-octane advantage over conventional motor oils in preventing detonation. They point out, further, that, although progress has been made, even better lubricants and fuels are needed, in this respect.

A NEW procedure for explosion testing of aircraft equipment is such that the effects of mixture ratio, ignition location, and temperature are now reflected in the test results. The investigation of the effects of these items on flame suppression, which prompted adoption of the new test procedure, is described in this paper.

This paper presents one writer’s viewpoint on some of the many tractor design considerations that must be recognized when incorporating one of the following types of hitches: Front and rear integral hitch, towed implement hitch, and rear integral hitch.

THIS review of early developments in automotive equipment and its lubrication requirements was presented by Mr. Mougey upon the occasion of his retirement from General Motors. He covers such subjects as crankcase oil specifications, crankcase dilution and corrosion, oil consumption, break-in oils, e-p crankcase oils, hydraulic valve lifters, relation of oils to octane requirement increase in engines, and hypoid-gear rear-axle lubricants - discussing what progress has been made and what problems are still to be solved. He also pays tribute to a few of the many individuals who contributed to the progress that has been made in automotive lubrication. He points out that there are many other subjects on which progress has been made, but that he couldn’t cover them all in one short paper.

It is not the purpose of this report to dwell extensively on the physical properties of the subject material. But, rather with the steel defects that are a vital factor from the stand-point of efficiency and economy to both the producer and user of sheet steel. It is fitting therefore, that these factors be delt with extensively at this time.

AN analysis of jet engine noise as a function of jet engine design characteristics is presented in this paper along with some thoughts as to possible means for reducing the noise of jet transports for the future. The authors present a summary of (a) scale-model noise work, (b) full-scale jet engine noise measurements in test cells and free field, and (c) a discussion of information gleaned from comparisons of scale-model work with full-scale engine work. This paper received the Wright Brothers Medal for 1954.