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A novel computer simulation program entitled TORAN™ has been developed by the Spicer Clutch Division of Dana Corporation. TORAN™ has been developed for use as an engineering tool for quick and interactive, yet a complete torsional analysis of heavy duty truck drivetrains. This will allow the design and application engineers to examine and predict the behavior of these drivetrains throughout practical ranges of frequencies and torques. TORAN™ is more than just another modification of similar existing programs. The Program, which includes a database of confidential data furnished by drivetrain component and OEM manufacturers and algorithms proprietary to the Spicer Clutch Division. The algorithm accommodates some substantial nonlinearities, such as clutch damper hysteresis and universal joint disturbances. Also included are several new modeling features describing geometrical configuration of axles, torsional properties of tires, etc.

TORQUE converters have many advantages for industrial and commercial vehicles. Some of those listed by the author are: 1. Smooth acceleration. 2. Engine need not be declutched when it is unloaded or idling. 3. More horsepower delivered at low output speeds and during acceleration, compared with conventional transmissions. 4. Operator mistakes of improper gear selection and missing of shifts are reduced to a minimum. 5. Load held to power source at all times. 6. Damping out of engine torsional vibration. 7. Increased life for drive train beyond transmission. 8. Cushioning of shock loads during starting and shifting, and of sudden increases in load.

Torsional rubber heavy vehicle suspensions have been used for over 60 years. The historical background makes an interesting engineering case study. A new simplified updated redesign of the system has been accomplished. It retains the long-life, relatively soft spring rate and roll stability advantages of the original design. Reduced adhesion stresses and a simplified vehicle leveling system are new advantages. Vehicle comparison testing with other suspension systems indicates significant improvement in ride comfort, stability and vibration reduction. Future designs will likely use new more sophisticated compression springs operating in combination with the torsional springs to further improve the ride.

THE troubles that are experienced when the conventional type of spring suspension is used in commercial vehicles could be eliminated, the author claims, by using the torsion-bar type of suspension. The torsion bar, he says, offers such advantages as weight reduction, reduction of unsprung weight, improvements in riding, stability, and steering.

The authors enumerate some of the questions that are involved and, after outlining a previous paper on the subject of plows, analyze these questions in part by the aid of diagrams and applied mathematics. Comparative draft data are presented in tabular form and commented upon, as well as comparative hitch-length data. Tractor reactions are explained and discussed in some detail in a similar manner, special attention being given to the reactions on a slope and up-hill. The reactions on cross-furrow slopes are considered, comparisons being made between two tractors that were reported upon in the University of Nebraska tests. The factors involving tractor stability and resistance against overturn are analyzed. The authors state that the analysis presents a definite method of attack for the more correct solution of the proper hitching-point, as well as being a study relating to lug design.

A tract comprising several acres of “tamarack” swamp, drained with tile the previous fall and cleared of stumpage the following spring, was utilized to obtain accurate information regarding the tractor and the plowing equipment required for the heavy operations of first breaking of the peat soil, which was from 5 to 7 ft. deep. The paper describes the equipment used, gives details of the procedure and presents the data that were obtained. Three different types of tractor and two types of plow, the latter having either a marsh or a breaker bottom and equipped both with and without a furrow pusher were used. Specifications of the tractors and the plows are given and commented upon, graphs and tabulations of the results being presented also. Power requirements on timbered peat and on grass marsh are compared and the efficiency of the plowing equipment is discussed.

The author describes a system of automotive transportation for intra-city hauling and the moving of merchandise between railroad terminals that has enabled the company he represents to serve the city of St. Louis and the railroad terminals there with a high degree of efficiency through the utilization of tractor and semi-trailer units and a thorough supervision of their movements. The units are described and illustrated, and the conditions governing their usage are set forth. The salient features of the paper include discussions of the necessity for adequate terminals, off-track versus on-track railroad depots, the volume of tonnage, tractor and semi-trailer operation and methods of procedure and control, weight and protection of loads, haulage distance, economy and a specific statement of the principal advantages gained through the use of automotive equipment of the type described.

THE author believes a more thorough understanding of the functions and use of drawbar implements is necessary. The tractor is incidental to agriculture. The implements used with tractors do the actual work and the tractor is a means to that end. Many tractors are sold on the quality of work done by the implements, and not because of their own work. Many a tractor is condemned because the implement combination is not correct. The amount of draft of plows must be thoroughly understood. Good plowing requires considerably more power than poor plowing, although done at the same depth and width. Turning the same number of square inches of furrow section will in one case require from 20 to 30 per cent more power than in another.

Whatever may be the conclusion of business men and engineers as to the fuel problem, dealing with it from the point of view of the engineer as a service man nothing further is needed than that the problem is before us. The paper deals with engine troubles that have been found to demand the greatest amount of attention from farmers. Tractors are not built for or operated by engineers. No quantity production is likely to be attained for some time to come with anything but the commonest forms of cylinder and other features. This judgment is based entirely on the limitations in upkeep knowledge of the average user. The four-cylinder tractor engine seems to be rapidly becoming standard, due to its simplicity and the familiarity of most farmers with this type. Consideration is given, topic by topic, to important parts of the tractor engine and the relation of fuel to difficulties discussed.

THIS paper outlines the advantages and disadvantages of present-day hydraulic systems. Included in the discussion are: the blocked return line system for single-acting cylinders, the blocked pump inlet, and the basic open-center-valve system. More advanced designs mentioned are: open-center-valve systems with cylinders in series and with parallel cylinders, close-centered valve systems with pressure regulator, and the central hydraulic and accumulator systems. The author points out that the advantages and disadvantages of each system depend to a great extent upon the design in which it is used.

The paper treats of the service, commercial and technical aspects of the subject in turn. The author calls attention to the fact that there can be no such thing as free service, because the customer pays in the end, and gives a specific definition of service. He argues that the engineering departments should urge upon merchandising departments intelligent distribution through dealers, the stocking of an adequate supply of parts and the maintaining of a well qualified mechanical force for the purpose of making engineering development work in the form of farm power automotive apparatus effective. There is a great need for a suitable system of training mechanics for tractor service work, and there should be a definite plan to assure that men making repairs and adjustments in the field are well qualified.

To test tractors for results valuable to the user, the reliability, durability, power, economy and utility should be determined. Standard tests measuring tractor utility and reliability are impossible practically and durability tests would be an extensive project, but tractor and engine-power tests and tests of the amount of fuel required for doing a unit of work can easily be made. The University of Nebraska tests described were for belt and drawbar horsepower and miscellaneous testing for special cases. The four brake-horsepower tests adopted are stated. Tractor operating conditions are then reviewed. The drawbar horsepower tests include a 10-hr. test at the rated load of the tractor, with the governor set as in the first brake-horsepower test, and a series of short runs with the load increased for each until the engine is overloaded or the drive wheel slips excessively, to determine the maximum engine horsepower.