HSE publishes results of research into structural deterioration of ageing tractor safety cabs

HSE Press Release: E091:04 - 6 July 2004

Tractor safety cabs keep farmers safe, but greater care and preventative maintenance is needed to prolong the life of the tractor cab says a new report issued today by the Health and Safety Executive (HSE).

Carried out by the Silsoe Research Institute, the research looks at the effects on tractor safety cabs that have been in service for many years.

The potential risk of serious injury posed to agricultural tractor drivers by rollover incidents has been widely recognised for 40 years. To protect drivers, legislation was introduced in the UK requiring all new tractors sold after 1 September 1970 to be fitted with a rollover protective structure (ROPS) to prevent the operator from being crushed should the tractor overturn.

This requirement, and the later Agriculture (Tractor Cabs) Regulations 1974, has been outstandingly successful in terms of improving the standard of safety. In the decade before the Regulations came into force, annual deaths each year due to tractor rollovers were in double figures, typically in excess of 30 with a peak of over 50 deaths in 1966.

Since their introduction, the number of fatalities has fallen to low single figures. Last year's characteristic figure showed that there were just two deaths due to tractor rollover incidents. The deaths today generally occur with tractors that do not have a safety cab or roll bar fitted.

Given this, HSE wanted to determine whether safety cabs that had been in service for a number of years would be likely to still provide the intended degree of protection and commissioned the research with the Silsoe Research Institute. This involved a detailed survey of around 400 used tractors manufactured between 1970 and 1990.

Of the 400, seven tractors were subject to intense examinations including partial dismantling to assess their structural condition. Five of these tractors were then selected for a recognised structural testing procedure to determine if they were still capable of providing the intended degree of rollover protection.

This work demonstrated that:

• the extent of corrosion varied due to age, cab type, and use, maintenance and storage history;
• four cab structures passed the test, one failed;
• three of the five tested were short of mounting bolts or experienced bolt failure during testing.

The conclusions reached were:

• the integrity of tractor safety cabs is weakened by corrosion;
• this corrosion is accelerated by lack of care, including a lack of preventative maintenance;
• some safety cabs had been repaired: this is prohibited, i.e. the cabs would lose their 'Approved' status;
• some cabs had not been correctly re-installed following removal for vehicle maintenance.

In order to improve safety cab/ROPS longevity and, ultimately, the protection they provide to the driver in the event of a rollover incident, HSE advises tractor owners and operators that they should:

• regularly check the cab, and cab bracket mounting bolts will combine with moisture torque and condition, especially after instances of cab removal. Remember that most Q-cab mounting brackets bolt both to the cab and to the tractor chassis;
• rectify poor cab sealing and water leaks from doors, windows, roof hatches. Also be aware of the risk of water/moisture ingress that can result from roof drainage and air conditioning systems;
• keep the cab as clean as possible, especially the interior. Granular fertilisers, slurry or farmyard manure will combine with moisture and cause accelerated corrosion;
• remove mud and other moisture-retaining debris from external traps and ledges on the cab;
• if surface corrosion develops on the cab treat it sooner rather than later and remember it may be hidden by floor mats or cab cladding.

The full report entitled 'Structural deterioration of tractor safety cabs with age' RR251 is available on the HSE website at http://www.hse.gov.uk/research/rrhtm/index.htm

Notes to editors

1. The detailed research brief agreed with the Silsoe Research Institute set out the objectives of determining the prevalence, structural severity and practical implications of Tractor safety cab/ROPS structural deterioration with age in the UK.

2. A detailed survey of the nature and degree of cab deterioration present in about 400 used tractors manufactured between 1970 and 1990 was conducted at a series of major UK auctions.

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