Infrared heat guns can be pointed at bearings around harvesters to determine whether or not the part needs monitoring or replacing prior to failure.
The dry finish to the 2014 season means many growers across the southern Australia are fast-approaching or already into harvest. Growers are reminded to conduct harvester operation checks and maintenance both in the lead-up to and during harvest to reduce the risk of fire.
Research conducted by the Kondinin Group shows that, on average, about 7 per cent of harvesters per year will start a fire. In these cases, 1 in 10 will cause significant damage to the machine or surrounding crop.
Kondinin Group general manager – research Ben White says many pre-harvest preventative checks tie into what growers already do on a regular harvester maintenance basis, such as checking belts and bearings for damage.
“From a mechanical perspective, growers don’t want breakdowns during harvest so they need to make sure bearings and belts are well-maintained with visual inspections before harvest,” he said.
“Growers should also be checking for any electrical issues before harvest, such as making sure wiring isn’t rubbing on anything or if there are any exposed electrics which need to be insulated.
“Oil seals should be inspected. A dripping line or weeping seal needs to be repaired prior to harvest, otherwise that could become a fire hazard.”
Mr White says the entire harvester should be inspected – including fronts – not just the engine, turbo and exhaust system.
“A lot of harvester fires are caused by bearing failure in the front,” he said. “Often people just worry about the engine and exhaust, which are important, but the front tends to be neglected because it’s detachable.”
Mr White also stressed the importance of having properly functioning fire extinguishers on harvesters.
“Growers need to make sure fire extinguishers are fully charged before harvest,” he said. “Most extinguishers have a charge indicator on them.
"If the extinguisher uses powder and has been used, even only a little, it needs to be professionally recharged because when the powder is released the release valve will not re-seal effectively.
“I would recommend growers have two fire extinguishers on their machine – one near the entry ladder and one near the engine bay.”
Some growers use materials such as exhaust insulation blankets and ceramic fibre on exhausts and turbo chargers to reduce fire risk. Mr White said this was a good way of reducing fire ignition sources, but growers needed to be careful with the impact such insulators could have on engine and turbo operation temperatures.
He emphasised the importance of harvester hygiene during harvest by conducting regular clean-outs.
In extreme cases, this could see a clean-out required every time the grain tank was emptied with a high-pressure air lance, working down from the top of the header to the bottom. Leaf blowers have also been successfully used on broad open areas of the machine by some growers.
“Bearings should also be monitored during harvest and the best way to do that is by checking their temperature,” Mr White said. “Infrared heat guns are relatively cheap these days and can be pointed at bearings around the machine.
"If there are elevated or increasing temperatures on a particular bearing, it might be one to monitor or replace prior to failure.”
Mr White says growers should be exercising particular caution when harvesting leafy pulse crops, as these were renowned for dust build-up.
“Don’t neglect the basics, like keeping a mobile fire fighting unit with ample water in the paddock that is being harvested,” he said.
There are also a number of pre-harvest measures that can be taken which are not mechanically-related.
“It is important to have a meeting with all harvest staff prior to harvest to talk about what happens if there is a fire so everyone knows what the process is, what UHF channel to use, what phone numbers they should have and what needs to happen should the harvester catch alight,” he said.
“If a harvester catches fire and it is practical to do so, operators should point it into the prevailing wind before getting out to fight the fire.”
While South Australia has the grain harvesting code of practice and grassland fire danger index, Mr White says these can be used as a useful benchmark guide for operators across all states because it takes temperature, wind speed and relative humidity into account. Other states have state-based or local government harvest bans.
Harvester fire reduction checklist
- Recognise the big four factors that contribute to fires: relative humidity, ambient temperature, wind and crop type and conditions. Stop harvest when the danger is extreme.
- Focus on service, maintenance and machine hygiene at harvest on the days more hazardous for fire. Follow systematic preparation and prevention procedures.
- Use every means possible to avoid the accumulation of flammable material on the manifold, turbocharger or the exhaust system. Be aware of side and tailwinds that can disrupt the radiator fan airblast that normally keeps the exhaust area clean.
- Be on the lookout for places where chafing can occur, i.e. fuel lines, battery cables, wiring looms, tyres, drive belts etc.
- Avoid overloading electrical circuits. Don’t replace a blown fuse with a higher amperage one. It is your only protection against wiring damage from shorts and overloading.
- Periodically check bearings around the harvester front and the machine. Use a hand-held digital heat-measuring gun for temperature diagnostics on bearings, brakes etc.
- Static will not start a fire but may contribute to dust accumulation. Drag chains, or better still drag cables, may help dissipate electrical charge but are not universally successful in all conditions. There are some machine mounted fire-suppression options on the market.
- If fitted, use the battery isolation switch when the harvester is parked. Use vermin deterrents in the cab and elsewhere, as vermin chew some types of electrical insulation.
- Observe the Grassland Fire Danger Index (GFDI) protocol on high fire risk days.
- Maintain two-way or mobile phone contact with base and others. Keep an eye out for hazards on machinery during the season.
*Taken from the Grains Research and Development Corporation’s Reducing Harvester Fire Risk: The Back Pocket Guide
Ben White, Kondinin Group, firstname.lastname@example.org
View Reducing harvester fire risk: The Back Pocket Guide
View the South Australian Grain Harvesting Code of Conduct and Grassland Fire Danger Index