Vineyard Harvest Tub Modification

Task
Cutting, lifting, carrying and dumping of grapes during manual harvest in vineyards. Job cycle for cutting and handling one tub of grapes varies from 1-3 minutes. After cutting the grapes and filling the tub, the lifting, carrying and dumping phase lasts approximately 10 seconds.

Problem
During the hand harvesting of wine grapes, a rectangular tub is used for loading and carrying the fruit. As the worker cuts clusters of grapes, he/she uses the non-dominant hand to drop them into the tub. Periodically, the worker will slide the tub to the next vine, or lift and carry it to a new position in which to continue harvesting. This is typically done with the foot until the tub gets too heavy to slide in this manner. When the tub is full (mean weight = 57 lbs./ 26 kg.), the worker stoops, grips, lifts, carries, and dumps the tub into a large gondola.

This occurs up to 20 times per hour, and often involves lifting the full tub above the head and walking or running to the gondola. Ergonomics risk factors include static flexion of the trunk and extension of the neck during the cutting phase (typically 1-3 minutes), high force applied with the foot to slide and with the hands to lift the tub, awkward postures of the spine, wrist, shoulder and knees, and upper extremity, and contact stresses on the hands during the cutting and tub handling phases of the job cycle.

Intervention
A smaller and lighter tub with add-on grips was introduced. The width and height was slightly decreased compared to the previous tub. The smaller tub weighs an average of 46 (vs. 57) pounds with a full load of grapes. Distance between the center of gravity of the tub and the worker is slightly reduced with the smaller tub, decreasing the moment arm as well as the weight. The rounded grips reduce contact stresses on the hands, especially when the tub is held overhead.

Cost
$13 per tub

Quantitative Evaluation of Intervention

Ergonomic Measure
Without Handles
With Handles
NIOSH Lifting Index
5.2
2.4
Mean Ground Sliding Force
19 lbs
13 lbs
Mean weight full tub
57 lbs
46 lbs
Dimensions
25” x 16” x 8”
24” x 14” x 8”

Evaluation of Intervention

  • Pros
  • Load on the back and knees is reduced
  • Lower tub weight and smooth bottom allowed less force to slide the tub on the ground
  • Pressure on hands reduced because of rounded grips
  • Study showed pain symptoms reported by workers were significantly reduced compared with original tub
  • Cons
  • Lifting rate may be slightly increased
  • Productivity may be slightly decreased.

Semi-Quantitative Evaluation of Intervention

  • Reduction of Identified Risk Factor
  • No New Risk Factors Introduced
  • Productivity not Reduced
  • Low Cost
  • Total
  • 4/5
  • 4/5
  • 4/5
  • 4/5
  • 16/20

Other Possible Interventions

  • Further modifications of handles to reduce awkward wrist postures during lifting and carrying
  • Light-weight wheels to help with the sideways movement on the ground
  • Developing a lifting machine to raise the tub and dump it into the gondola (in progress)

Acknowledgements
This project was funded by NIOSH and was carried out by the University of California Agricultural Ergonomics Research Center. Further information is available from the AERC website [ag-ergo.ucdavis.edu] and in the CDC/NIOSH Publication, “Simple Solutions” [DHHS Publication No. 2001-111].