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Until approximately 50 years ago horses and manpower were considered the best means for earthmoving. Progress from this point came in the late 1930s as off-highway trucks began to replace on-highway trucks. The development of engines with more horsepower moved the industry ahead. Today earthmoving is made more complex for we must consider not only the advances in earthmoving equipment, but also if equal advances hav been made in auxiliary equipment and manpower to allow maximum efficiency.

An overview of the Iowa State Coal Project is presented. Draglines and scrapers are compared for energy efficiency in stripping coal. Survey results on scrapers are presented which show diverse production and cost relationships indicating that many factors other than size of machine, haul distance, and grade are important.

Contaminants that find their way into the lubrication system of a mechanism can have significant adverse effects on the useful life of the antifriction bearings in the application. This paper provides a discussion of the more common types of solid and liquid lubricant contaminants and the possible sources from which they originate, plus the different modes of premature bearing damage that can result. Some case histories of applications plagued with contaminated lubrication problems and the resulting difficulties encountered with bearing performance are also reviewed. These views are primarily limited to past experience with tapered roller bearings manufactured from case hardened materials.

The paper provides details of dynamometer, track, fleet, and leased car tests sponsored or conducted during the period 1963-1974. The data show an average improvement of 4.4% in fuel consumption results from the proper dispersion of 1% weight molybdenum disulfide (MoS2) in the engine oil.

“Maintenance Management Programs” for aircraft and their engines have changed in the past 5 years. The maintenance programs have expanded from the hard time limits and on-condition sampling techniques of the 1960s to include condition monitoring (fly to malfunction). The Boeing 747 and Douglas DC-10 went into service using an on-condition maintenance program. The next generation of aircraft will in all probability go into service with a complete “Maintenance Management Program.” The cornerstone of any maintenance/reliability program is an effective information collection, analysis and dissemination system. The collection of information from the many and varied sources has its problems. All too frequently the data is too little, too late, wrong format, inaccurate or incomprehensible. This paper will review the systems United Airlines uses, or is developing to gather and distribute the information required to support aircraft and engine “Maintenance Management Program.”

Comparisons are presented between the last U.S. SST design and results of recent progress on an advanced supersonic transport design. The results are shown of changing from a double-delta 2.7 Mach configuration to a modified arrow-wing 2.2 Mach design. Information is presented covering increased range, lower operating cost, reduced technical risk, and noise levels that meet anticipated requirements of society. The main emphasis in this paper is on an aerodynamic lift-to-drag ratio of 10 and how this high level of aerodynamic cruise efficiency can be substantiated for a tailored design.

Dragfoiler II, an effective and practical add-on aerodynamic drag reducing system for tractor-trailers, has been developed. Wind tunnel tests with 1/16- and 1/7-scale tractor-trailer models were used to determine empirical design guidelines for the Dragfoiler II's side elevation and planform shapes. Optimum designs for various combinations of tractor roof height and length, trailer height, and tractor-to-trailer gap length gave zero-yaw drag reductions between 30 and 35%. At a yaw angle of 10°, the percentage drag reductions were about half those at 0°. Off-design performance and the effects of trailer side-edge geometry were investigated. Several full-scale Dragfoiler II's are currently undergoing proving ground and commercial fleet evaluation tests.

A field test was conducted to study the feasibility of monitoring trace lead in shipments of unleaded gasoline by means of an X-ray fluorescence continuous low lead analyzer. Batches of unleaded gasoline were blended at the refinery and transported to distant terminals by tankers and by pipeline. The low lead analyzer was used to continuously monitor the lead content of the unleaded gasoline as it left the refinery and was received at the terminals. Field data of good precision were in agreement with the accepted ASTM D-3237 atomic absorption method. The standard deviation of the X-ray method is ±0.0029 g Pb/gal and the test repeatability is ±0.008 g Pb/gal. X-ray fluorescence appears to be the best practical method available to determine the average level of lead contamination in large volumes of unleaded gasoline in the field with accuracy and precision.

Various systems were developed for deleading contaminated unleaded gasoline. As shown in both laboratory and pilot plant studies, the most promising systems consisted of passing gasoline through a fixed bed of carbon or silica gel impregnated with cupric chloride. The carbon system was most effective for removal of tetraethyl lead; the silica gel system was preferred for removal of the equilibrated mix of tetraethyl and tetramethyl leads. The effect of various parameters on deleading activity is discussed. The deleading process was demonstrated to be feasible on a service station scale.

ASTM Committee D-2 has undertaken a program to develop a laboratory test which correlates with low-temperature engine oil pumpability in field service. As the first step in this program, pumpability data were obtained using thirteen ASTM Pumpability Reference Oils in seven full-scale engines. The engines and oils were chosen to be representative of a wide range of commercial practice. Borderline pumping conditions, as defined by the ASTM Task Force, were determined for each oil-engine combination investigated. The mode of pumping failure in the engines and the times required to lubricate the rocker arms were also obtained. The results indicate that substantial differences in pumpability exist among both engines and oils. Possible reasons for these differences are suggested, based on engine oil pump inlet system characteristics and the viscometric properties of the oils.

This paper deals with the development and evaluation of a mathematical model for a 4-stroke, single-cylinder, spark ignition engine. This paper has two parts. The first part describes the development of the mathematical model and the computer program. The assumptions that were made in the model are also described. The instruments that were developed for the evaluation of the model are included in the second part, which also contains the evaluation of the results obtained from the model. The simulation results are found to agree well with the experimental data.

A three-phase program was conducted by the Army in order to obtain basic data required for the development of a new arctic engine oil (OEA) specification to replace the obsolete MIL-L-10295 sub-zero engine oil specification (OES). The first phase of the program involved the development and initial testing of improved arctic engine oils formulated using synthetic hydrocarbon or ester base stock materials. The second phase of the program involved field-testing of the improved oils, and the third phase covered definition of the performance requirements necessary for the new specification, MIL-L-46167 (OEA). This paper covers the initial testing, development of the improved arctic engine oils, discussion relating to mixed fleet military field test experience with the new lubricants, and laboratory testing of these new oils in standard oil test engines as well as in a specific military high-output diesel engine.

A series of stable colloid lubricant additives have been evaluated for their influence on vehicle fuel economy through modification of engine friction. The SAE J-1082 procedure was used to determine fuel consumption in tests conducted in a seven vehicle fleet exercise which showed encouraging improvements in fuel economy, especially in the SAE Urban cycle. In addition, an extended dynamometer test was conducted on the most promising colloid additive system. After 100 hours of test at 55 mph (road-load), fuel consumption was reduced by approximately 2% and engine friction was inferred to have been reduced by more than 10%. Engine oils treated with these stable colloid additives hold the promise of effecting important fuel savings over the total existing vehicle population within a minimum time frame.

Intake silencing on small engines can be used to improve power output as well as reduce sound levels. The parameters involved are intricate and only partially understood. Two approaches to silencing and power retention are outlined in this paper.

There are basically three types of carburetors commonly used on small gasoline engines. The correct selection of the basic carburetor type depends on the end use of the engine-carburetor package. Since the initial selection of carburetor type is often made in the design stage of the package, a basic approach to carburetor type selection is presented. The areas of current engineering emphasis are improved performance and lower manufacturing costs. These are now possible due to recent methods of carburetor construction.

A High Energy C.D. Ignition system has been developed that is capable of operating surface gap spark plugs with excellent results. Surface gap spark plugs have existed in various forms for many years, and ignition systems of various forms have been developed, attempting to fire them, using both Inductive Discharge and Capacitive Discharge types of ignition. It has been shown that an Inductive Discharge spark with its low peak spark current and slow voltage risetime will not operate a surface gap spark plug. A high energy C.D. spark, with its rapid release of power and fast voltage risetime is necessary to keep a surface gap plug clean for extended periods. The first application for this ignition system has been on snowmobile engines.

This paper discusses an over-the-road fuel economy test procedure developed to show a true reflection of fuel consumption for the everyday road user. It explains the parameters for the test, the preparation involved, the test procedures, and an analysis of the tests.

A logging attachment for felling and bunching full trees has been developed and is now being utilized for mechanized harvesting. The attachment allows an operator full control to sever, position, and lay trees into desired bunches so they can be easily skidded out of the forest for loading and transport. Many requirements must be considered to develop such an attachment. It must efficiently sever various types and sizes of trees. It must also effectively handle these varying tree diameters, heights, and weights. The attachment must withstand accumulations of ice and debris. The structure must withstand rough usage in typical harvesting conditions which expose it to snow, mud, rocks, undergrowth, and stumps.

This paper is an attempt to pull together, under the concept of “total environment”, some concerns and philosophies associated with such subjects as product application, product maintenance, human, ecological, economic and legal considerations. It is intended to emphasize the need for real understanding of these subjects, to stimulate the thinking of engineers, manufacturers and end users, and to demonstrate the effect their performance can have on many aspects of our society.

Logging safety is discussed in terms of recognition of hazards and their elimination. The conclusions drawn from NIOSH study of logging safety is that the creation of work practice regulations and the encapsulation of the operator on a machine will reduce logging accidents. Standards that apply to forestry equipment design are listed and examples of how one company is approaching the problem of providing a machine which will satisfy the safety requirements are detailed.