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Road test methods are described by means of which the total drag force, the air drag force, the tire drag force, and other drag components of a truck can be measured. The road tests consist of coastdown experiments over a wide speed range at several loads. Independent measurements of tire drag force and air drag force demonstrate that these road data are essentially correct. Examples of results of the road test method are shown for a few large transport trucks.

Many technological advances have taken place during the past decade which have enhanced the status of fuels and lubricants for construction equipment. Standardization and simplification of recommendations have been accelerated. These contributions have helped us to gain economy and reliability of operation. Petroleum product suppliers, construction equipment manufacturers, and the users of both products have contributed to these advances. Above all, the cooperative effort of the producer and consumer members within the framework of professional organizations has had a stimulating effect. This paper discusses the current status of fuels and lubricants for construction equipment; equipment descriptions, fuels, lubricants, and problem areas are presented.

Power shift transmissions used in off-highway agricultural and construction tractors are subjected to rugged duty and the planetary type using needle bearings has proved its reliability when good design practices are followed. This pa per reviews the types of bearings, design data, and applications, and provides the formulas used in calculating speeds, loads, and shaft slopes in planet gears. Discussion of the subject matter by representatives of other companies in the industry conclude the paper.

Freight loss and damage claims of class I railroads exceed $100,000 annually. A major portion of annual loss is believed to result, directly and indirectly, from impacts to which freight cars are subjected in the classification yard and in slack action effects on the road. Paper deals with the possibility of reducing problem by providing special cushioning for end-to-end impacts.

Discussion of specific procedures for the design and manufacture of spiral bevel and hypoid gears for heavy-duty axles. A more refined approach to design is being sought, and to facilitate a general understanding, certain terms need clarification. The paper is concerned with two major areas: highway trucks and buses and a wide variety of off-highway vehicles such as trucks, scrapers, payloaders, and bulldozers.

Truck Frame Siderail Design The recent development of high strength steels for truck frame usage has led to a refinement of the section proportions of conventional channel siderail designs. To enable the frame designer to fully utilize the availability of high strength steels, to reduce the weight of truck frames and increase their durability, new design criteria must be established. This paper highlights the basic design alternatives from which the frame designer can design improved frame assemblies utilizing high strength steels.

Differences of opinion regarding optimum filtration and reservoir design practice of hydraulic systems are presented by 13 authors in diverse industries. These differences exist since the precise function of the filter or reservoir will vary according to its specific adaptation. A discussion of various type filtering systems, as well as detailed information pertaining to specific applications, is presented. Basically, conclusions to be drawn depend upon an individual's needs, experience, and judgment.

The history of earthmoving equipment is covered, and the basic motions and operations performed by these machines is explained so that the reader will also understand how they perform. Three general classes of earthmoving machinery are discussed: the power shovel, the scraper, and bulldozers and endloaders. These machines perform the same job in the same basic manner as the shovel.

To provide the engine with the appropriate charging, cranking and ignition systems requires a proper understanding of the electrical equipment. The purpose of this paper is to describe the function of these systems, pointing out the design features that are required to give proper electrical performance and to provide adequate life in the varying environmental conditions. Present designs will be reviewed along with the forward thinking which engine builders should be considering for future applications on farm, construction, and industrial equipment.

We pay for all fuel supplied to an engine, but in most cases get back only 33% of investment in the form of brake horsepower. The remaining 67% appears as heat in the engine jacket water, heat in the exhaust gas, and radiated heat. This paper deals with the energies coming out of the engine; where they come from, their intensities, and their disposal or recovery. Graphs show trends of output energies as influenced by engine load, speed, and atmospheric conditions. Properly designed cooling systems and their installations are covered in the text and shown in illustrations.

Remote hydrostatic power, reciprocal and rotary, offers advantages to farm implement and industrial equipment designers where distance, multiplicity of drives, complexity of motion, or control of speed and (or) direction or rotation present problems. The most efficient system is gained by using individual motors selected for each drive. However, in interest of cost, a universal motor having three speed ranges and a standardized mounting is suggested. The need for test codes, reliability factors, and standard tractor hydraulic systems is obvious. The universal motor also requires a standard, and recommendations are made for the development of these requirements.

This paper deals with the problems of designing tractors to be sold all over the world while at the same time minimizing the variables in order to obtain the economies of mass production. The physical, psychological, and legal requirements and difficulties are dealt with and a summary of the maze of European road and safety regulations is included as an Appendix. The author concludes that since these regulations are inescapable, it is in the interests of the industry to support every effort at rationalizing the requirements among the different countries.

The new 706 and 806 farm tractor series are described, including their appearance, operation, and engine specifications. A new clutch facing pad material is used - a sintered material used in high temperature aircraft brakes. The hydraulic system has three subdivisions: the front pump system, the rear pump system, and the independent power take-off.

This paper describes the construction of a clean room within an existing facility. The description of the details shows that areas capable of close environmental control can be developed from commercial construction materials readily available. Controls for such an area may also be relatively simple and routine, but must be regularly scheduled. Thus, at realistic costs, a facility may be constructed that will be more than adequate for supercritical inspection, assembly, and test operations.

As increasing populations set demands for the abundant natural resources of the colder regions, the complex industrial machines of American Industry are expected to build the new railroads, roads, cities, mines, power sources, airports and factories, and operate these activities year round. This paper reviews the basic problems of “winterization” and the design practices, materials and components used with varying effectiveness in “winterizing” construction and associated equipment for use in moderate and extreme cold geographical areas. Several new charts are included which offer design temperature data for the northern United States, Canada, Alaska, Greenland, as well as average January isotherms around the earth. The authors are members of CIMTC Subcommittee XV, “Environment”.

Utility winches are reliable and durable pieces of equipment. Their installation on the truck chassis frame is not difficult to accomplish. However, as pure mechanical drives become more complex, the problem of proper location and configuration is intensified. In this connection, hydraulic motor drives offer improved flexibility and reduced installation problems at the sacrifice of some power loss. Although considerable progress has been made in the technical development and application of constant load utility winches and hydraulic drive installations, important advances are still to be realized, especially with regard to achieving higher efficiency and more compact design units.

The paper covers basic design factors, testing procedures, and application considerations for clutches used in motor trucks, farm tractors, construction equipment, and stationary power units. Clutches discussed include spring loaded dry, spring loaded wet, over-center dry, over-center wet, electromagnetic single plate dry, electro-magnetic multiple disc wet, and hydraulic multiple disc. Basic and theoretical aspects of clutch design are converted into practical information useful in designing and applying clutches of various types. Because the scope of the paper is broad, many formula derivations were omitted to permit presentation of as much practical material as possible.

This paper considers the various aspects of estimating the fatigue life of the structure of construction equipment under severe service loads, assuming that representative service load measurements are available and the fatigue characteristics of the structure in the form of a constant amplitude σ-N relation are known. This method is generally applicable to metal components subjected to a spectrum of load amplitudes; however, the details differ depending upon material, the method of fabrication, the load history, the number of load sources, and the nature of the loads. The paper emphasizes large vehicles made of structural steel and fabricated by welding. A scraper frame including the gooseneck, the draft tube, and the draft arms is considered as a typical structure. The basic approach to the problem is reviewed. A sample computation is included and the questions and uncertainties that arise in the estimation of fatigue life are discussed.

An appraisal of the advantages of integrating truck and bus maintenance in a vehicle fleet maintenance program is presented. Basically, reliability and cost are the major considerations in any fleet program. Evidence is presented indicating that generally bus maintenance shops are better equipped, have better trained mechanics, utilize an effective preventive maintenance program, and have an optimum balance between maintenance cost and road failure cost. Generally speaking, bus repair shops can be utilized to the mutual advantage of truck and bus operators by using spare capacity of bus shops and thus eliminating this responsibility from truck operators.

An eight speed, hydraulically controlled, stepped transmission was found to be the closest practical approach to the ideal for agricultural and industrial tractors. This paper describes the means used to obtain maximum reliability and operator acceptance. Proper spacing of speed ratios, automatic programing of modulated shift pressures, and close attention to minimizing torque loss during shifts were found to be of prime importance.