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The type of mobile equipment needed by utility companies in the performance of their services to the public are many and varied. The application is often so unique that it taxes the ability of a chassis which was basically designed as a highway carrier. Although these machines are common equipment in the utility business, they are unusual equipment in the motor truck business, and must be purchased with meticulous care and applied with good engineering knowledge and foresight. The end product is a machine designed by three engineers who never meet, the chassis engineer, the equipment engineer, and the engineer in charge of equipment at the utility company. The paper is prepared in dialogue form to characterize the brief exchange of information, to provide thought on vehicle selection, and to examine some of the problems usually encountered by motor truck and utility companies.

Filament wound glass-epoxy aerial booms are used as cantilever structural electrical insulators on mobile aerial manlifts. The effects of working loads, cycling, field wear and tear, environment, and electrical requirements must be considered in the design to assure units of long useful life. Filament wound glass-epoxy booms with oriented glass fibers are lightweight, extremely strong, corrosion resistant, and good electrical insulators, all of which are desirable for the application.

The mining industry of the United States moves about 7 billion tons of earth and rock per year. Much conventional earthmoving equipment is used in mining, particularly surface mining, but the special problems of the industry suggest that machines designed for mining would be better than machines designed for the construction industry in many applications. Underground mining now uses little automotive equipment. Systems of mining are reviewed to suggest to designers possible applications for new types of automotive equipment.

The unprecedented size of the Mangla Dam Project has lead to the selection, operation, and maintenance of the largest peacetime construction fleet ever assembled. Equipment selection was carefully made, native operators trained and modern production techniques practiced. Resultant mechanical problems were resolved and routine repairs were accomplished by an energetic maintenance program, thus satisfactory results have been achieved by combining American construction industry know-how with good construction machinery and vendor service.

Production cost analyses show a potential economic advantage for thegiant loaders on large jobs. This paper presents a cost comparison between the Model 475 tractor shovel, a smaller tractor shovel, and a swing shovel. Evolutionary events and designs leading to the creation of the 475 are presented and discussed. Design considerations and specific features of this unit are pointed out. Some of these are: loader linkage design, hollow boom construction, split hydraulic system, and a hydraulic power assist for operator controls. Prototype testing and changes are discussed and explained.

Large helicopters are being used for many types of construction work in the United States. Some of the helicopters that are used for this work and their operational problems are described in detail. Examples of jobs done for the air conditioning companies, electric utilities, ski lifts, and structural steel contractors are given. With proper planning and design and with much larger helicopters coming on the market soon, a tremendous increase in construction by helicopter will take place.

A brief description of the representation of physical systems as idealized systems and the computation of natural frequencies is given. Using an example of an engine and power shift transmission system, it is shown that a simplified analysis can be made with small effect on the computed natural frequencies. The prevention of torsional vibrations with a power shift transmission, and the prevention of gear rattle in conventional transmissions, is discussed.

This paper presents an analysis of axle weight data collected during the performance testing of the Broken Bridge dynamic electronic highway scale. Test results are analyzed by comparing the in-motion axle weights as measured by the Broken Bridge scale with the corresponding static values for an instrumented two-axle test vehicle and for a sample of trucks diverted from an Interstate highway. Analysis of the two-axle test truck data shows that the actual loads applied to the highway surface by the wheels of a moving vehicle vary above and below the static equivalents in a manner that is typical for a specific location and range of speeds. For a random selection of different types of trucks, the variation of dynamic from static axle weight is further affected by axle position (front, second, third, and so forth) and spacing.

A full-scale test procedure was developed utilizing the Mack differential power divider for the evaluation of gear lubricants. Test results indicate the superiority of MIL-L-2105B gear lubricants for heavy-duty rear axle carrier lubrication.

Considerable progress is being made toward the development of a standardized agricultural PTO driveline whereby the latter would be part of the tractor and could readily be attached to any implement by means of a quick disconnect. However, in order to establish a standardized design for an agricultural PTO driveline which would be universally acceptable, it must be made to suit all application requirements. This paper analyzes the interrelationship between the design of the driveline and its proposed application. The basic design is discussed in terms of the universal joint and center member. Application considerations are discussed with regard to driveline geometry, load cycle, and maximum torque.

A coordinated line of transmission, rear axles and hydraulic lifts for agricultural tractors in the 31 to 66 horsepower range is described and illustrated with reference to design criteria.

The technical evolution of the new Minneapolis-Moline G1000 tractor from the market analysis, preliminary design stages through the final design and testing stages is presented. The modification of an existing engine is described, with respect to the various engine parts. Technical features of the tractor, such as side rails, clutch, transmission, front end, PTO, and hydraulics are also discussed. Finally, the testing and evaluation of the unit are described.

This paper describes the design features of a new series of large agricultural tractors in the 90–120 PTO horsepower range. Basic design objectives are presented and a description given of the important aspects of chassis layout, powerplant and transmission design, and operator comfort and convenience features. Specific attention is given to the new implement control systems developed.

Hydrostatic drives for garden tractors enable the user to enjoy the many advantages he finds in automobile automatic and power systems, namely, no mechanical clutch, infinite speed range, dynamic braking, and similar conveniences. This paper describes the outstanding features of these drives and portends their use as portable hydraulic horsepower for PTO operation of units such as generators, air compressors, and a wide range of implements.

To meet the military hydraulic system requirements for construction equipment, the Engineer Research and Development Laboratories has initiated a hydraulic program to develop minimum standards of system and component acceptance through the media of performance specifications. The program will also establish a standardization of system types and of component mounting and port configuration. Such standardization, including hoses, tubing, and couplings, is intended to simplify maintenance and logistical support of hydraulic systems.

Analyses and tests were made on various kinds of mobile equipment comparing open and closed center systems. The work cycle and maximum horsepower were kept equal in the comparison of these systems. The closed center system surpassed the open center in both cycle time and efficiency of operation. New concepts of the closed center system evolved from this work. These concepts included: controlled acceleration and deceleration, selective maximum volume control to prevent overspeeding, and a means of lowering the circuit pressure when the valves are in neutral. Gains with the integration of the hydrostatic transmission and the closed center hydraulic system are also demonstrated.

The hydraulic industry, in order to meet the upward trend in size and mechanization of mobile type vehicles, has continued to provide increased horsepower per cubic inch of installed space in both pumps and motors and new control devices, such as pilot operated, solenoid or hydraulically operated and electro-hydraulic servo valves. These features, which are required for the optimum transfer and control of power to do useful work, are discussed in this article.

A simplified, linear analysis is made of the lateral motions of a tractor-trailer combination consisting of a tractor, semitrailer, and full trailer, and traveling at a constant forward speed. Equations of motion are derived for the combined vehicle, and solutions of the resulting equations are obtained and discussed in terms of the steady-state and transient response to steering control. Results of exploratory calculations are presented to indicate the manner in which the dynamic lateral response is influenced by various vehicle design parameters.

This paper is meant to illustrate the effects of improved material and design technology when applied to the problem of a new engine design. The S-7D and S-8D engines (7.25 and 8.25 hp, respectively) represent the use of fewer parts than those of an existing Wisconsin engine of similar horsepower rating while retaining the typical heavy duty Wisconsin ruggedness.

A recently developed three directional (3 D) optical square establishes three mutually perpendicular lines-of-sight in one instrument setting. Since no realignment or rotation is required once it is aligned to a target, a substantial savings in time and cost is realized in tool erection and routine checking. The instrument and its application at The Boeing Company is discussed in this paper.