Ballast for optimum tractive performance
Authors: Harrison, H.P.
Description: Since the introduction of pneumatic tires for farm tractors, the amount of ballast to be added has been a concern of many farmers. They seem to be aware that there is an optimum amount for maximum tractive efficiency. The question has been complicated somewhat in recent years by tractor manufacturers offering a greater number of tire options. Ex tension personnel, who attempt to pro vide assistance, also have difficulty when the soil conditions and/or tire sizes have not fallen within their practical experience. The predicament is agravated by the continual introduction of new and larger tractors and tires. Though the effect of ballast and tire size on the drawbar horse power (DBHP) is known, it is a qualitative rather than a quantitative cognition. Because this is a problem in teaching, an attempt was made to develop a model that would relate the pertinent variables and provide a means to determine the optimum values of ballast and possibly tire size as well. If a simple expression could be found, it may be of interest to farmers and extension personnel. Reece (5) has proposed a method for estimating tractor performance in the field. It can be used to obtain the optimum combination of ballast and tire size by making a series of approximations through suitable substitution. As a simpler method was de sired, a different approach was chosen. Essentially it was to develop a mechanics for the power lost by the tractor wheels and then to determine the magnitude of the pertinent variables when the loss is minimum. The mechanics has the following form:
Keywords: ballast for optimum tractive performance
Citation: Harrison, H.P. 1970. BALLAST FOR OPTIMUM TRACTIVE PERFORMANCE. Canadian Agricultural Engineering 12(1):12-13.
Start page number: 12
End page number: 13