Ergonomics in Agriculture: Critical Postures, Gestures, and Perceived Effort in Handling Foldable Roll-Over Protective Structures (ROPS) Fitted on Tractors. In: Bagnara S, Tartaglia R, Albolino S, Alexander T, Fujita Y, editors. Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018). Cham: Springer International Publishing; 2019. pp. 194-202. [DOI: 10.1007/978-3-319-96089-0_22]

Improving Tractor Safety: A Comparison between the Usability of a Conventional and Enhanced Rear-Mounted Foldable ROPS (FROPS)

Tractor rollover is the main cause of both fatal and non-fatal injuries in agriculture. The foldable rollover protective structure (FROPS) can help to prevent these injuries. However, in many cases, the FROPS is left in a folded-down position. Human factor and rear-mounted FROPS technical characteristics influence operators' behavior in roll-bar handling. To improve the FROPS's comfortable use, the prototype of an enhanced handling system was developed, and its usability was tested and compared with a conventional FROPS. Usability was assessed with 93 novice tractor users through an ad hoc questionnaire (investigating perceived effort, time demand, the posture adopted and satisfaction) and observations (investigating effectiveness and efficiency) during lowering and raising tasks. For both tasks, the participants perceived significantly less effort, less physical discomfort, a higher level of satisfaction and less time demand while operating the enhanced FROPS. Observations showed that the critical issues that emerged for the conventional FROPS were eliminated by adopting the developed and implemented handling system. The developed handling system showed itself to be usable and effective in making the FROPS easier and safer to be operated.

Energy Absorption in Actual Tractor Rollovers with Different Tire Configurations

In order to better understand the complexities of modern tractor rollover, this paper investigates the energy absorbed by a Roll-Over Protective Structure (ROPS) cab during controlled lateral rollover testing carried out on a modern narrow-track tractor with a silent-block suspended ROPS cab. To investigate how different tractor set-ups may influence ROPS and energy partitioning, tests were conducted with two different wheel configurations, wide (equivalent to normal ‘open field’ operation) and narrow (equivalent to ‘orchard/vineyard’ operation), and refer to both the width of the tires and the corresponding track. Dynamic load cells and displacement transducers located at the ROPS-ground impact points provided a direct measurement of the energy absorbed by the ROPS cab frame. A trilateration method was developed and mounted onboard to measure load cell trajectory with respect to the cab floor in real-time. The associated video record of each rollover event provided further information and opportunity to explain the acquired data. The narrow tire configuration consistently subjected the ROPS cab frame to more energy than the wide tire arrangement. To better evaluate the influence of the ROPS cab silent-blocks in lateral rollover, static and dynamic tests were performed. The results confirm that tires influence the energy partition significantly and that further understanding of silent-blocks’ dynamic performance is warranted.

Tractor Rollover Protection: Is the Incorrect Use of Foldable Rollover Protective Structures Due to Human or to Technical Issues?

OBJECTIVE

To identify the critical behaviors that may hinder the correct use of foldable rollover protective structures (FROPS) on tractors and to explore the influence of user factors and FROPS technical characteristics.

BACKGROUND

FROPS are effective in preventing fatal injuries in rollover accidents if they are in the upright position. However, many farmers leave FROPS folded down.

METHOD

Twenty farmers and sixteen models of tractors were involved in the study. Operators were observed while raising the FROPS, and the observed behaviors were correlated with user factors and FROPS technical features.

RESULTS

In the initial rotation of the FROPS, higher lowered roll-bar to ground distance and FROPS pivot-pin to ground distance required more awkward and unbalanced postures (p = .02 and p = .01, respectively). When rotating the FROPS in upright position, smaller stature of the participants and higher FROPS pivot-pin to ground distance were significantly correlated with using the tractor's rear 3-point lower links as a supporting surface (p = .01 and p = .02, respectively).

CONCLUSION

FROPS might be revised considering users' comfort in use and anthropometric variability, to improve reachability, avoid risky behaviors, and enhance FROPS operation.

APPLICATION

Technical solutions to enhance FROPS accessibility may be developed, particularly by providing safe surfaces to support operators and highlighting the grasping points. Further best practices and information on correct gestures to handle the FROPS should be included in the tractor manual.