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A large contractor expresses his feelings and some facts on the type of machinery the industry is producing today. The reliability, availability, and longevity are not being built into the present construction machine.

The quality of a product is as perceived by the user and includes the net effect of the quality of the original product and of available product support. Engineering objectives should include improvement of support capabilities, regardless of the exquisiteness of the design.

Earthmoving equipment manufacturers need to concentrate on machine service related problems which have been identified in the past ten years. These service problems are grouped into routine maintenance, design, safety equipment, component reliability, tires and export machine problems. Specific requirements are outlined and recommended design objectives are identified. The conclusion is equipment manufacturers need to concentrate on designing machines that reduce service and maintenance cost as well as provide simplicity of operation and maintenance while simplification for utilization in export markets is a common requirement.

An analytical model has been developed that provides a valuable addition to the tools available for practical exhaust system design. Correlation with experimental results has been improved by including the effects of such factors as temperature gradients, complex elements, higher order modes, and source impedance. The model can be used for specific design problems as well as general parameter studies to maximize exhaust system attenuation within a given volume.

A suspension seat has been developed for earthmoving and other off-highway vehicles, following specific guidelines established by the manufacturers of such vehicles. A wide range of adjustments is provided to properly position the operator relative to the various vehicle controls. Several new ideas are employed, such as a fore-aft slide with self-cleaning rollers, a mechanical suspension spring system which provides air spring characteristics, and a seat/suspension package which will meet the SAE recommended practice for seat belt attachment strength without the need for additional tether belts.

Prior to starting construction work in Japan, it recently has become necessary to predict the noise pollution level caused by construction equipment at the job site boundaries. This led to the development of a simple, inexpensive but relatively precise computer program and method for noise prediction. Input for the computer program requires measurement of the noise level of each machine used on the construction project. Accuracy of the method has been experimentally verified by actual field tests.

A presentation of present rail haulage practices in open pit mining. Description of car types, sizes, and their application for various haulage jobs, car construction practices and air braking data are presented. Loading and unloading methods for various car types are illustrated. Job matching the locomotive with an eye toward fuel economy, including a review of basic transportation formulas.

To evaluate the feasibility of an alternative to the costly construction and reclamation of haulage roads in surface coal mines, the Bureau of Mines contracted with the Dravo Corp., Denver, Colo., to conduct an engineering and economic evaluation of the haulage of coal out of the strip pit via conveyors running in culverts laid under the advancing spoil. The results of this study, which are presented in this paper, discuss the cost savings, plus the more subtle advantages and disadvantages of this novel haulage system in a number of alternative strip coal mine designs. The Bureau's plans for a demonstration of a prototype underspoil coal haulage system are also outlined.

A combination of hydrostatics and planetary gearing has proven to be a synergistic mating of two basic modes of power transmission in mobile applications. This paper reviews this combination, particularly as applied to track drives for the earthmoving and construction industries.

Efficiency characteristics are considered of simple control types (constant pressure and constant power) applied to a variable displacement pump as single unit or in connexion with a fixed displacement motor or a dummy actuator (having efficiency features of a transmission line). The most efficient way to implement a specific control is identified in terms of speed and displacement, while basic control parameters result from the optimization of maximum or mean efficiency. Some effects of controls on driving engine fuel consumption and sizing are also discussed. Computations are based on efficiency models devised by authors as approximation of a number (sometime large) of reference data, and carried out with an original Non-Linear Programming code (FALL77).

This paper describes the design and development of a new wheel loader which has replaced the 992B Wheel Loader. Included within the description, are the major features of the new machine and a unique approach to transporting the machine from factory to user.

An optimum scraper suspension system was developed as a result of determining the performance and related cost characteristics of several alternative systems. The optimized system consists of a pivoted axle assembly controlled by hydro-pneumatic springs, and a hydraulic control system with self-leveling and manual on-off features.

This paper discusses the development of batteries for electric vehicles, the performance goals for the batteries, and the strategy being followed in the U.S. to promote commercialization of electric vehicles. Supported by the government, intensive development of several near-term and advanced rechargeable batteries that are projected to meet performance and cost requirements for electric vehicles is underway. Of the potential near-term batteries, lead-acid, iron-nickel oxide, and zinc-nickel oxide are the most promising for use in vehicles with limited range and applications. Much better performance is expected from second generation batteries, which include lithium-aluminum/metal sulfides, zinc/chlorine, and sodium/sulfur batteries. Successful development of electric vehicles will help conserve the world's resources of petroleum by shifting the energy source to coal and nuclear.

Considerable insight into alternatives to petroleum as fuels for earthmoving and other off-highway vehicles can be gained from investigations related to highway vehicles. At the same time, off-highway equipment has the potential of greater flexibility in choice of fuels because of simpler fuel logistics. Uncertainties in both petroleum resources and alternative supplies are reviewed, and implications for the remainder of this century are highlighted. However, technology to make alcohols is well established and a multiplicity of resources is available. Thus, the technical benefits and problems of using alcohols as a petroleum extender or substitute are detailed.

A new high energy impact hammer incorporating a fluid tappet and a high velocity piston is described which offers improved productivity, safety and reliability in rock excavation, structure demolition and secondary boulder breaking. Two models of this hammer are discussed, the 411 with a blow energy of 6000 ft. lb. (685 kg.m.) and the 514 with 20,000 ft. lb. (2275 kg.m.). The attachment of these new tools to a wide range of excavators and special machines is shown. The process of impact breaking is analyzed and several examples of effective use of these hammers are presented.

This paper outlines some of the basic criteria used by the earthmoving vehicle designer to meet the specified cooling, deaeration and reliability of the radiator and oil coolers for heavy duty off-highway earthmoving vehicles.

Cooling system fan noise reduction can be best achieved by a combination of aerodynamic design and control of the fan environment. Design for minimum noise is a complex procedure that requires the optimization of fan geometry and fan environment, maximum efficiency at the operating point and the lowest possible blade tip speed. Good noise measurements are essential to research and development activities in fan noise reduction. Computer aided design techniques are required to optimize the fan.

A system is proposed for producing a mixture of hydrogen and methane for automotive fuel by steam reforming gasoline. These gaseous fuels are produced under the hood and only at the rate demanded by the engine. The energy of formation is obtained from waste heat. The results of a computer model of the system are given and a verifying experimental program described.

This paper describes results of the field accident performance of the VW Passive Restraint System (VWRA) installed in Rabbit vehicles operating on U.S. highways. The historical development of the VWRA as an outgrowth of VW's research and development programs is detailed for perspective. To act as a baseline, dynamic sled and full-scale barrier crash testing with instrumented surrogates using the VWRA are presented. The primary portion of the paper deals with collected and calculated data from VW's field investigations which have been in progress over the last two years. Parameters measured and presented are vehicle repair costs, VDI (Ref. 1), EBV (equivalent barrier velocity), OIS/AIS (Ref. 2), occupant contact points, and some collision data involving NHTSA-supplied crash recorders. Specific areas of interest are explored such as, frequency/severity of injury to knee-femur-complex, the head and the thorax.

Chrysler Corporation's Kokomo Casting Plant has just started volume production of the 225 CID (3.7L) 6-cylinder intake manifold as a die cast and welded assembly. The development of the die castings and welding of the 380 aluminum is discussed. The production welder and processing is also described.