The grain harvest unit is assumed to be harvesting a field located 20 km from a grain storage. Reasonable combine efficiency will require two operators on infield hauling units and two truck drivers hauling with tractor-trailer trucks to the grain storage. Total crew required is then 1 (combine) + 2 (grain wagons) + 2 (truck drivers) = 5.

To achieve reasonable cotton harvester efficiency, the unit will require the following crew: 1 (harvester) + 2 (side-dump wagons) + 1 (operator for module builder) = 4. As compared with the grain operation, the crew size is reduced from five to four by disconnecting the field operations from the highway hauling. Remember, the cotton module is covered and left in roadside storage to be hauled later. Infield hauling is not delayed when a truck is not present to receive the seed cotton. Another key difference between the grain and cotton systems is that the highway hauling is done by the gin, not the farmer/producer.

A sugarcane harvesting unit is defined as 5 harvesters, 8 tractors pulling 3 wagons each for a total of 24 wagons, and 1 operator at the ramp for a total crew of 14. If the field is only 3.5 km from the sugar mill, the over-the-road hauling will require eight tractor-trailer trucks each hauling two bins. If haul distance is 15 km, then 15-18 trucks are required. At 40 km, it requires 25-28 trucks to keep the harvest unit moving.

Capacity for a harvest unit with good harvest management is given in Table 7.8. There are many production situations where the average capacity for an entire day’s operation will be only half the capacity shown in Table 7.8. As a reference point, the cost is also shown. These cost numbers are constantly changing, thus they should not be used out of context.

Hauling

Truck tractors used for over-the-road hauling are a mature technology. (There are over

250,0 trucking companies in the United States, and truck manufacturers work continuously

to improve the performance of their trucks and capture a greater share of this market.) Costs to operate the truck tractor are well defined.

It is interesting to compare the cost per dry t for the three systems. For this analysis, the cost to operate the truck is assumed to be $450/day. Labor cost for the driver is included; however, fuel cost is not included.

If a truck averages three loads of 20% moisture content grain per day, and the load size is 22.5 t, the hauling cost is

3 loads/day x 22.5 t/load x (1 — 0.2) = 54 dry t/day

If a truck (module hauler) averages four loads of cotton per day and the module is 7.2 t at 20% moisture content, the hauling cost is

4 loads/day x 7.2 t/load x (1 — 0.2) = 23 dry t/day

The truck on which the module hauler is mounted is basically the same machine (same engine, drive train, running gear) as the truck tractor used for grain hauling; thus, it is appro­priate to compare the hauling cost using the same per day truck cost.

If a truck averages 10 loads of sugarcane per day and the total load (two bins) is 24.5 t at 80% moisture content, the hauling cost is

10 loads/day x 24.5 t/load x (1 — 0.8) = 49 dry t/day

$450 day
49 dry mton. day

These results are summarized in Table 7.9 . Using the grain hauling as a reference, cotton is 2.3 times more expensive, and the sugarcane is 1.1 times more expensive. Unlike the harvest costs shown in Table 7.8. the hauling costs can be directly compared. Truck owner­ship and operating cost ($/day) for short-haul operations is approximately the same no matter what the truck is hauling.