APPENDIX C 

 Effect of Density on Daily Truck Trips 



The less dense the production of pouhry the greater the distance 

 trucks must cover to assenihle a given vohime. The density of production 

 coupled with the physical possibilities of truck performance establishes 

 those volumes which can he assembled within a time limit and the num- 

 ber of trips a truck can make per day. 



A first approximation to the relationship among density, volume, 

 truck miles, and truck trips is worked out in Figures C-1, C-2, and C-3 

 which show the six supply bands corresponding to the six firm sizes 

 under the three density assumptions of 1,000, 5,000 and 25,000 pounds 

 per square mile per year. The annual volume of each firm is divided by 

 the density level, which yields the supply area of the firm in square 

 miles. Using the assumption of a circular supply area surrounding each 

 plant, the radius of the supply area for each firm is determined, and the 

 circumference of each supply area drawn on Figure C-1, C-2. or C-3. 

 These supply areas must be visualized as a set of six superimposed con- 

 centric discs, each disc being a separate firm. The quantity of poultry in 

 each concentric supply area thus constructed remains the same for the 

 several density levels. But for different density levels the outer rim of 

 each area will be located at different radial distances from the center. 



Supply Band I is the supply area for Firm A. Supply Band II is 

 formed by the additional area needed to make up the whole supply area 

 for Firm B, To meet the area requirements of Firm C, Supply Band III 

 is added to the supply area of Firm B. The successively larger firms. 

 Firms D, E, and F, in turn require the addition of Supply Bands IV, V, 

 and VI. Thus, the supply bands are the additional parts of the super- 

 imposed supply areas as firms get larger. A supply band, such as Band 

 III, will have the same amount of poultry regardless of density level, but 

 for less dense production situations a supply band will be farther 

 from the center. In each supply band the impound point is located by 

 the procedure outlined in Appendix A. Impound point locations within 

 each liand are shown in Figures C-1, C-2, and C-3. 



The physical possibilities of 190-crate trucks reaching any given 

 distance, loading, and returning to the plant within a 10-hour day are 

 shown in Figure C on pages 49, 50 and 51. Possibilities for making one, 

 two, or three trips to any given distance are shown. These possibilities 

 are based in part on crew size, because average labor productivity per 

 hour increases up to the nine-man level (See Appendix D) ; in part on 

 the distance involved, because average truck speed varies with distance; 

 and in part on truck size. Figure C shows the maximum radial distances 

 that a 190-crate truck can reach with a three-man crew and with a ten- 

 man crew. Other crew sizes within this range will result in distances be- 

 tween these two limits. Similar distances for the 220-crate truck would 

 be shorter because of the added time required to load this larger truck. 



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