Farm Ireland
Independent.ie

Wednesday 24 January 2018

As harvest progresses over the following weeks, on the back of exceptional temperatures, our tips will help you avoid disaster

fire hazards and combines – what you need to know

Derek Casey

Derek Casey

Our warm summer weather has accelerated the ripening of crops with the result that combines have been turning into the first fields of winter barley in southern counties over the past week.

This year's exceptional temperatures are throwing up a few unusual fire hazards for combines, so as the harvest progresses over the next few weeks, the following tips should help keep belts and pulleys on the move.

1. Preventing combine fires

Combines are massively expensive machines (see table 1), but unfortunately each year a number of combines can be destroyed by fires. When it comes to reducing the chance of having a combine go on fire, there are two key points to remember: prevention and preparation.

We all remember the "fire triangle" from our school days, which states you need three ingredients for a fire: fuel, heat and oxygen.

You can't really remove the heat (from the engine) and oxygen (from the environment) components from the equation, so to prevent combine fires you have to be extra careful to remove the fuel (grain and chaff) component. This is best done by keeping the machine clean.

It's a good idea to power wash to remove caked-on grease, oil and crop residue.

At the end of each day, blow chaff, leaves and other crop materials off the machine and remove any materials that have wrapped around bearings, belts and other moving parts. Specific areas to blow out around include:

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* The engine, especially the exhaust manifold, turbocharger, muffler and exhaust pipe

* Hydrostatic pump, motor, hydraulic lines and tubes

* Brake and transmission housings

* Electrical components

* Engine drives and all moving parts

* Batteries and battery cables

* Straw chopper drive gear compartments

It is possible to eliminate some heat sources from the combine. For example, exhaust surfaces, exposed electrical wiring, worn bearings, belts and chains can potentially generate enough heat to make dust and crop residue go on fire. Check these areas daily and make repairs if there are problems. Never park a hot combine in the shed. After a long day of harvesting, smouldering hot spots may be present in the combine. If those spots suddenly flare up, at least you won't lose the building.

We all hope it doesn't come to it, but in the event of a combine fire, you have to be prepared. Always keep at least one (and preferably two) fully charged and certified dry chemical fire extinguisher in the combine cab. In addition, mount a second fire extinguisher on the outside of the machine that can be reached from ground level. The second one can be a water charged extinguisher, but never use a water extinguisher on an oil fire. You should recharge any partially discharged extinguishers before the season starts.

2. Keep a regular routine

As the harvest has already started, the aim now should be a regular combine maintenance routine. Carrying out this routine in the morning rather than at night works best for a couple of reasons.

Firstly, you have good light for a clear look at the machines to find potential problems like worn bearings or cracked parts. Secondly, the combine will be cooler and easier to work around than it would be after a day in the fields.

Some operators argue that for certain jobs, for example greasing, the grease will travel more effectively in around warm bearings than cold ones. This is a fair point, but the main thing to remember is to get into the habit of doing all the vital checks at a given time in the day to help you remember them all.

3. Daily checks to do

The most important steps in maintenance are greasing all the nipples, checking the air filters for cleanliness and adjusting the chains for tightness. Every morning, you should grease all 10 and 25 hour nipples.

A good habit to get into is doing a couple of related jobs in one sequence. For example, when filling the machines with fuel, check both engine and hydraulic oil levels, and then check the radiators to see if they have sufficient water – critical during these long, hot days.

Stone traps do not necessarily need to be checked every day if the crop is generally clean, but in modern combines, access to the stone trap is simple, so it may be worth taking the 10 seconds needed to have a check.

The header is obviously a very important part of the combine and contains a lot of moving parts. Every day you need to look for any serious damage to the knives, skids or fingers.

The wobbler box should have had a full inspection in a pre-season maintenance programme at your local dealer or in your own garage.

A wobbler box working for around 200 hours per season will generally last for anything from eight to 10 years depending on the operator.

This is just a guide, so more or less use than 200 hours use each season will dictate the wobbler box lifetime.

4. Checks every two days

Every two days you should check the air filters for cleanliness, grease any 50-hour nipples, and check chain tensions – especially the feeder house chains.

The feeder house chains sit on pieces of timber that look similar to roof slats.

Over time, the chains can wear into these timbers with the result being the chains can slacken.

As well as monitoring the chains for slackness, the timbers themselves will need to be replaced periodically, so keep a close eye on them. Watch out for broken or bent chain reels on the intake as well.

5. Weekly checks

Duties that need to be performed only once a week include checking air pressure in the tyres and emptying the rock traps when combining trouble free crops.

Other common parts that tend to wear out over time include bearings, chains, belts, sprockets, sickle sections and injector lines. A good visual inspection is key.

A common misdiagnosis is replacing a belt when the pulley is the real problem. The new belt will only be an expensive and short-term solution and will be worn out in no time by a faulty pulley.

How do you know if a belt is slack? First of all, switch off the engine if you are doing any hand inspections. The rule of thumb is that you should only be able to get half a twist by hand on a belt that is properly tensioned.

If you can twist a belt 360 degrees around it needs to be tensioned to prevent excessive wearing and subsequent replacement cost.

6. Fill the van with tools and spares

A lot of contractors these days have service vans in which they carry all their tools and spare parts.

A number of grease guns, a wrench set and a socket set are three essentials. A generator/ welder combination is also useful to patch up small problems.

To minimise downtime in the field, parts that should be kept in stock include a full set of belts for the combine; a belt-tightener pulley; connector links, half links and chains; sickle sections and guards for the cutter bar; drive chains for the heads; and fingers for the header auger. Engine and hydraulic oil, assorted bearings, bolts and nuts, and a supply of welding rods are useful too.

Irish Independent