Combining slash bundling with in-woods grinding operations

Using the predicted model for the bundler and holding all other variables constant pile class 2
and pile class 6 resulted in the longest predicted cycle time of 2.04 minutes (Table 4; Table 5).
Pile class 3 yielded the smallest predicted cycle time of 1.60 minutes. The difference in predicted
cycle time between piles is linked with grappling, which consumes the largest portion of a total
bundling cycle. Processor piled materials are generally aligned parallel which is preferable for
the bundler because of the reduced need for grappling, but larger size materials are harder to
grapple and don’t bundle as well resulting in poor bundle integrity. When loaders pile material
they tend to rake the slash into heaping piles with lots of air space and poor material alignment,
which is negligible considering the machine’s compacting force, especially when smaller size
materials are bundled.
Table 4: Predicted delay-free average cycle time and production rate.
Bundler Loader Hook-lift truck
Cycle time Prod. Rate Cycle time Prod. Rate Cycle time Prod. Rate
(min) (BDT¹/PMH²) (min) (BDT/PMH) (min) (BDT/PMH)
Unit A 1.72 8.23 0.46 41.22 34.28 11.49
Unit B 1.93 7.30 0.44 42.77 42.83 9.20
Unit C 1.61 8.77 0.43 43.33 22.37 17.61
Overall 1.76 8.04 0.44 42.32 35.43 11.12
¹BDT: bone dry ton
²PMH: productive machine hour
Table 5: Bundling productivity predicted using regression equations based on slash Pile
Classifications.
Pile Class¹ # Bundles Avg. time (min/bundle) Tons/PMH # Bundles/PMH
1 70 1.66 8.7 36
2 31 2.04 7.1 29
3 5 1.60 9.0 37
4 148 1.75 8.2 34
5 40 1.73 8.4 35
6 6 2.04 7.1 29
¹ Refer to Figure 1 or Table 3
Average predicted delay-free cycle time for the loader to pick up a bundle, and place it in a bin
took 0.44 minutes or 26 seconds (Table 4). It took an average of 21 cycles or 9 minutes to fill an
entire bin with bundles which had an average weight of 6.6 BDT, meaning the loader could
produce and astounding 42.32 BDT/PMH. The compacting element in a loading cycle was the
most time consuming part of the loading process due to the time used to carefully stack and
maximize the number of bundles inside the bin. Traveling took the least amount of time (0.01
minutes, 3.1%) because the bundles were properly roadside decked minimizing the operators
need of travel.