Front loaders fitted to tractors with programmable hydraulic controls
This SIM advises inspectors about the safety requirements for front end (or fore end) loaders fitted on agricultural tractors and a potential hazard when they are fitted to tractors with programmable hydraulic functions.
The control systems on certain makes/models of tractor may permit the loader to function without the operator of the tractor at the controls. This could allow the operator or other people to enter an area to the front or side of the tractor where they could be at risk of being struck by the loader.
FOD inspectors who encounter deficiencies in the implementation of the control measures should consider taking the appropriate action detailed in this guidance.
Front end loaders are commonplace in agriculture. They consist of detachable lifting arms for materials handling designed to be mounted on a frame secured to the front of a tractor. A variety of attachments can be mounted on the loader to enable it to handle a range of goods or materials such as pallets, bales, grain, manure etc. The loader is powered by the tractor’s own hydraulic system. Operation of the loader and attachment is controlled by the tractor driver seated at the normal driving position.
Some agricultural tractors feature a programmable hydraulic system - commonly called a headland sequencing function - normally used to allow the tractor to carry out several hydraulic operations when moving complex machines in and out of work positions.
The sector is aware that front end loaders may be fitted to tractors that have programmable hydraulic controls. For example in one case it was found that:
- the loader could be operated through a secondary mid-mounted hydraulic valve block using an on-board joystick control which could be programmed via a touch screen.
- This allowed the loader to be programmed to automatically carry out an action, or series of actions, with a single touch on the joystick.
- In this case it was possible to have up to three functions (lift, tilt and auxiliary) operating sequentially for up to 30 seconds each after a single initial activation of the joystick. It did not require continual operator presence to do this (i.e. it was not of the “hold-to-run” type).
This increases the risks from uncontrolled operation and meant that the operator could potentially leave the operating position (the driver’s seat) and enter the danger area around the loader whilst it was operating. Other people in the vicinity of the loader could also be at risk.
Any loader that operates through the tractor on-board auxiliary spool valves and has programmable hydraulics is potentially affected. This could include loaders that are supplied both as original equipment with the tractor and also as loaders purchased separately as after-market accessories. Users may have purchased hydraulic accessories that permit the loader to be connected to the spool valves offering the programmable function. Loaders and tractors that do not have programmable functions are not affected so no action is required for these machines. The Sector is unable to provide a definitive list of which makes/models may be affected.
Loaders that operate in the manner described above do not meet the 'hold-to-run' function required by the Machinery Directive 2006/42/EC and specified in the harmonised standard BS EN12525:2000+A2:2010 'Agricultural machinery – Front loaders – safety'. Programmable sequences (such as repetitive loading functions) that still require 'hold-to-run' control are acceptable.
Action taken by the sector
The Sector has approached the AEA (Agricultural Engineers Association), as the UK manufacturers’ and importers’ representative, to raise this issue with relevant AEA members who include most of the major tractor and loader manufacturers.
HSE has advised AEA to instruct their members;
- to review their products to ascertain whether this problem exists or can potentially occur;
- to identify whether a technical or software solution is possible;
- where a problem or potential problem exists, take action to notify their supply network and customers of the action they need to take to address the issue;
- for new equipment where the tractor and loader are supplied together to ensure that it is not possible to programme the loader functions unless they operate via hold-to-run controls;
- to ensure the tractor operator manuals include a warning that loaders should not be operated through the programmable hydraulics and instructions or indication of how this can be achieved;
- to ensure front loader operator instruction manuals include a similar warning and reference to the tractor manual.
Action by inspectors
Inspectors are asked to note this information and to raise the issue with duty holders at relevant inspections, investigations or complaints where they encounter tractor- mounted front end loaders.
- Risk assessments for the use of the tractor/loader combinations may need to be revised to include the potential hazard and risks described in this SIM.
- Operators may need to receive further instructions and information about the hazards/risks and precautions to take. For example, on a farm premises with several different tractors duty holders should make arrangements to ensure that the front end loader is not used on tractors that feature programmable hydraulic controls unless they feature “hold-to-run” controls for the loader as described above.
- Dutyholders found to be using equipment where operation is possible without the hold-to-run control should contact their supplier to ascertain if their make/model of tractor/loader can be modified to address this potential safety issue.
- Where the supplier has failed to take the action outlined above enforcement action may be appropriate. Inspectors should follow the guidance on the product safety pages of the HSE intranet website.
The benchmark is nil or negligible where the loader controls are hold-to-run. Where the controls can be programmed there is a remote possibility that the operator could enter the danger zone and a substantial risk gap is indicated by the EMM.
For further advice please contact Agriculture Waste and Recycling Sector – Safety team, Worcester.
BS EN12525:2000+A2:2010 'Agricultural machinery – Front loaders – safety'.