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Safe Access Platforms for Tractors

by Lesley Day,  George Rechnitzer

January 2005

RIRDC Publication No 04/180 RIRDC Project No UMO-29A

Executive Summary
Introduction
Tractors account for approximately 15% of work related fatalities among those employed in agriculture in Australia, which is an average of 22 deaths per year. Historically, roll-over events have comprised the large majority of tractor fatalities. However, the proportion of deaths and serious injuries due to tractor roll-over events is likely to decrease as the retrofitting of tractor roll-over protective structures becomes more widespread.

Following roll-overs, run-over events comprise the next largest proportion of tractor fatalities.

Development and evaluation of appropriate interventions for tractor run-over death and injury has lagged behind that for roll-over events, possibly because run-over events are not homogenous and a range of interventions are likely to be required.

Mounting and dismounting a tractor has been identified as a common antecedent to tractor run-over events. In response to the apparent risks associated with mounting and dismounting older tractors, the Australian Centre for Agricultural Health and Safety produced a guidance note for the construction of safe access platforms for tractors, the design of which addresses a number of the factors found to be associated with run-over events. This guidance note has been used in Victoria by the Wellington and Colac Farm Safety Action Groups to retro-fit tractors with safe access platforms. We undertook an evaluation of the uptake and implementation of this initiative. The evaluation focussed on the operational aspects of the retro-fitted tractors, and the design aspects of the platforms themselves.

The project objectives were to:

The main outcomes are: Methods
A combination of qualitative methods and engineering-based inspections was used to (1) gather information from 10 farmers regarding benefits and dis-benefits of fitment and (2) assess the construction and fitment of the platforms. The farmers were recruited via the farm safety action group leaders. Data were collected on the participant’s property using a semi-structured interview protocol and an engineering based tractor inspection protocol. The features of the 10 access platforms were reviewed and an estimation made of the percentage reduction in potential damage achieved, where damage was defined as death or incapacitating injury. The average total cost per tractor was derived by converting the average farmer hours to a dollar term using standard wage costs and adding this to the material costs and engineer charges. Inspections were also conducted for comparison on seven new tractors readily available at farm machinery dealers.

Results
Participants and process
Participating farmers were generally very experienced. The terrain of the properties visited varied from flat to hilly, and the commodities produced reflected those typical of the two regions. The average age of the tractors fitted was 23.7 years (range 7-41 years). The two farm safety action groups utilised a different approach to platform fitment. Group A opted for a workshop approach involving an engineer and the farmers, which also provided the opportunity for discussion of other safety issues. Group B opted for fitment contracted to a local engineering workshop. The overall high quality construction of the retro-fitted platforms reflected the expertise of the engineers involved.

Cost
The average cost of fitment was $185 for Group A, with the average cost per tractor for this group recently increasing to $310 per tractor. The average cost for Group B was $446. With farmer time also taken into account, the average cost per tractor was $400 for Group A and $490 for Group B.

Operational considerations
All farmers identified improved safety as an advantage, and six of the ten farmers reported that the tractors were easier to get on and off. This was the aspect that most impressed the farmers who reported that they had not anticipated the extent to which access would be improved. Platform fitment had little effect on both the amount of time the tractors were used, or the tasks for which they were used. Few operational disadvantages were reported. When specifically asked, five farmers reported it could be tempting to carry passengers on the retro-fitted platforms. However, one of these farmers reported that this practice would occur regardless of platform fitment.

Design of retro-fitted platforms
The guidelines make recommendations with respect to step dimensions, positioning and materials, handrails, protection from the rear tyre and attachment of the platform. Step dimension recommendations overall were not closely followed, particularly with respect to step height and the step rise and tread depth on those tractors with more than one step. The positioning of the bottom step in relation to the outside edge of the rear wheel, a key criteria, was satisfactory for five tractors.

Adequate protection from the rear tyre, another key criteria, was provided on five tractors.

Recommended material for the steps had been used for all steps on five of the tractors, and the bottom step of an additional three tractors. Non-slip nosing and contrast edging were absent from most of the tractors.

Handrail recommendations were generally well met. The placement of the upright portion of the front hand rail could have been improved on four tractors. The space between the front handrail and the platform was filled in with mesh on six tractors.

Recommendations for the attachment and bracing of the access platforms, underframe clearance , and access to service points were well met. Attachment of the handrails was adequate with the exception of one tractor, where it appeared that the front handrail had been welded onto the roll-over protective structure frame, potentially compromising the structural integrity of the frame. The possibility of access on the opposite side had been removed as recommended in three of the tractors. Access had unquestionably been improved on each tractor, compared with that available prior to fitment. The estimated reduction in potential death and serious injury ranged from 30-40% to 90-95%. Eight tractors achieved a reduction greater than 75%.

Comparison with new tractors
Six of the seven new tractors inspected were cabined tractors. Step height, rise and tread depth dimensions were unsatisfactory on all the new tractors. The positioning of the bottom step in relation to the outside edge of the rear wheel was satisfactory on four of the seven tractors. All the new tractors used non-slip materials for the steps, however, on most tractors this did not extend to the outer edges of the steps, increasing the risk of slipping particularly with higher step heights. A common observation on the new cabined tractors was the awkwardness of exiting forwards, as step placement and dimensions encouraged placing the foot diagonally across the step.

None of the new tractors had a handrail which fully defined the front of the access path, although this path was partly defined by the handrail on four tractors. The front handrail met the recommended diameter requirement on one new tractor. All cabined tractors had handrails on the inside of the door which provided a rear handrail for access.

There was no guarding of the rear tyre on the un-cabined tractor, and very little guarding of the rear tyre, either from the mudguard or the door, on the cabined tractors.

Discussion

Overview
This initial implementation of safe tractor access platform retro-fitment has proved to be relatively successful.

The step/platform factors associated with decreasing the risk of a fall include the step height and dimensions, handrails, non-slip materials, and lips on step edges. Step dimensions, lip edges, and handrails generally met the specifications. Greater attention to non-slip materials for steps and step nosing, and to step height, would further enhance platform performance.

The step/platform factors associated with decreasing the risk of a run-over should the operator fall from a moving tractor include the positioning of the outer edge of the bottom step, and the guarding of the rear wheel. The key criteria for positioning the bottom was met by only half the tractors.

Further, the rear wheel was adequately guarded on only half of the tractors. Closer attention to these two specifications would have increased the estimated potential damage reduction of some retrofitted tractors.

Any possibility of increased passenger carriage as a result of the retro-fitted platforms may be at least partially offset by the probable decrease in run-over risk, should a passenger fall from a platform or steps which meets the key criteria of extending level with the outer edge of the rear wheel.

Reduction of the risk of falling and of the risk of a run-over in the event of a fall are two strategies for the reduction of run-over events. Since ineffective park brakes also play a role in run-over events, regular testing and maintenance of the park brake is an advisable adjunct to platform fitment.

Further, technical advances increase automatic protection for tractor operators from run-over events would also contribute to future reductions as the tractor park is replaced with newer models.

The retro-fitted tractors performed at about the same level or better than the new tractors on step height and dimensions, rear tyre guarding, extension of bottom step to outer edge of the rear wheel, and front handrails which defined the access path. The impact of the dis-benefits of access design on the new tractors may be tempered by other features and systems which reduce the risk of a run-over, if these are adequately maintained.

Implications
This strategy has the potential to significantly reduce the risk of tractor run-over events if adherence to the key criteria can be achieved, to also reduce the physical work demand of frequent mounting and dismounting tractors. Platform retro-fitment could be considered to be current best practice in the management of tractor run-over risk, and mechanisms for promoting, encouraging and facilitating uptake may need to be considered by the relevant organizations. This study has implications also for the design of new tractors.

Recommendations