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With the grain harvest under way, there will be a fleet of tractors and trailers moving tons of grain from fields all across Ireland to the local co-ops and merchants.
For those farmers with trailers that may not have moved in some time and want to keep within the letter of the law, we are going to give a brief overview of what to check.
This is to make sure they are within the revised standards for agricultural vehicles last updated 1 January 2016 by the Road Safety Authority (RSA). These were brought in to give farmers a guide as to what weight they can carry with the trailers they have and for the capacities of potential new purchases.
The most important things to check are is the trailer safe and is it legal? The RSA also give advice in their communications that alterations can be made to existing trailers. This applies to farmers who want to bring their older trailers into line with the most recent RSA guidelines.
Generally trailers are fitted with one, two or in some instances three axles. These are normally sprung or bogie axles towed with an eye-type coupling or in some instances a ball and spoon, more on that later.
Single axle trailers with a rigid drawbar have a weight limit of 13 tonnes – 10t on the axle and 3t on the drawbar.
Tandem axle trailers have a few more options with regards to weight limits. If the axles have no suspension or a bogie system, a centre-to-centre distance of less than 1.3 metres, and the trailer is towed with an eye-type coupling, the limit is 19t.
This is 8t per axle and 3t on the drawbar. This total limit increases 1t to 20t when a ball and spoon type coupling is used.
The ball and spoon is as the name suggests an 80mm steel ball in place of the traditional “hook” of a pick-up hitch.
The spoon part fitted to the trailer sits snuggly over it with a clasp to keep it from becoming detached during work. An extra 1t is allowed on the drawbar with this type of coupling across all trailers, something worth considering if updating or changing your trailer.
On the subject of trailer eyes, check for wear, cracks and damage before you hook up to the tractor. A lot of stress and strain is put through this relatively small but very important part of the trailer.
If the trailer has a flexible suspension such as springs or air the load per axle increases 1t to 9t per axle and 3t on the drawbar.
Again, as already mentioned, when a ball and spoon type coupling is used this allows for an extra 1t on the drawbar bringing the total weight limit to 22t for a tandem axle trailer with flexible suspension. This is a very popular type of trailer amongst Irish farmers for moving grain.
If a farmer wants to increase this limit even more, he can do so by adding wider tyres – that is those of a width greater than 500mm. Irrespective of width, these must be in road legal condition.
So if four 500mm or wider tyres are fitted to a trailer being towed on an eye-type coupling the limit is 23t, 10t per axle and 3t on the drawbar. Again, fitting the ball and spoon coupling allows another 1t to be added to the drawbar load bringing this up to 24t.
Wider tyres
The other added advantage of using wider tyres is reduced damage to the farmer’s most important asset, the soil. In a wet year this can also mean the difference between getting stuck and getting out of a field. If a farmer specifies his trailer with a wider spacing between the axles of 1.8 metres or greater, this does not affect the weight limit of the trailer.
Requirement are a flexible suspension, such as springs or air, and a steering axle. Steering axles have their benefits. The point at which the trailer turns from is moved closer to the tractor thus making getting in and out of tight gateways a little easier. The trailer “follows” the tractor more closely and less scuffing occurs as a result.
In order to increase efficiency and reduce the number of trips, some farmers are opting for triaxle trailers.
Most mainstream trailer manufacturers now offer this option as demand for them is increasing in line with the tractor sizes across tillage farms in Ireland.
Added to this it means fewer trips to the co-op or merchant in a given day.
A triaxle trailer without any suspension being pulled with an eye-type coupling has a weight limit of 24t, 7t per axle and 3t on the drawbar.
Again, as already mentioned, add in the ball and spoon coupling and this increases to 25t.
When flexible suspension is added this increases to 27t with 8t per axle permissible and 3t on the drawbar, 28t when the 80mm ball and spoon is added.
When six 500mm or wider tyres are added to this suspended trailer, the weight limit increases to 30t on a standard eye-type coupling. This is split with 9t per axle and 3t on the drawbar, 31t on the ball and spoon.
Lastly, this limit increases to 33t for a triaxle trailer with one stipulation, the rearmost and foremost axles must be steering. This is split 10t per axle and 3t on the drawbar and 10t per axle and 4t on the drawbar on a ball and spoon coupling maxing out at 34t.
Trailers are getting bigger and tractors are getting faster with speeds of 50km/h now the norm. Some manufacturer’s tractors are capable of going in excess of this.
Shorter weather windows often push man and machine to their limit, both of which have their own dangers.
According to the RSA, the revised braking requirements apply to more than just trailers. Slurry tankers, fertiliser spreaders, grain chaser bins etc. all fall into this group.
To stop these trailers, the tractors towing them need to have the braking efficiency to match.
Shorter weather windows often push man and machine to their limit
Braking efficiency, expressed as a percentage, represents the amount of braking force needed to safely slow or stop a vehicle in relation to its design vehicle gross weight (DVGW).
Trailers with a speed rating of up to 40km/h and a DVGW of more than 5,000kg need a braking efficiency of 25% while those operating up to 50km/h must have a minimum braking efficiency 45%. Trailers manufactured after 1 January 2016 must have some sort of breakaway fitted.
Detached
Either air-brakes fitted with load sensing to match the braking effort or a breakaway brake to automatically stop the trailer should it become detached from the tractor.
There are a lot of these types of trailer in the country that can have this system retro fitted which are not designed for exceeding 40km/h. This can be a chain or wire rope attached to the tractor that engages the brakes on all wheels in the unfortunate event that the trailer becomes unhitched from the tractor.
Parking brake
In addition to this a parking brake must also be fitted. Retro-fit kits are now available that incorporate the parking brake and breakaway in one which are relatively straight forward to install.
Another point worth mentioning on brakes is only trailers with wider hubs of 420X180mm are permitted to exceed 40km/h.
New trailers must have auto slack adjusters fitted and older trailers with manual slack adjusters should be checked for wear.
Trailers that are designed to be towed at speeds in excess of 40km/h must be equipped with service, breakaway and parking brakes.
In addition to this, trailers manufactured after 1 January 2016 must be equipped with air brakes including load sensing.
Any trailer designed to be towed at speeds in excess of 60 km/h must also have ABS.
There are lots of options available but just a couple of key points to remember. Tyres should be in road-legal condition with no serious nicks, cuts or bulges that might cause a blow-out.
The last thing you want when the pressure is on is a punctured tyre on your grain trailer holding up the combine.
Tyre pressures should be checked regularly and adhere to manufacturer’s recommendations, generally found on the sidewall of the tyre.
As already mentioned and worth considering in soft ground conditions, wider tyres will spread the weight of the load over a wider footprint and reduce soil compaction. Plus, tyres greater than 500mm in width are allowed to carry 1t extra per axle.
Lights and reflective strips
Put simply, the trailers’ lights must be in working condition. They’re needed as much for your safety as those driving behind you.
Indicator lights, brake lights, tail lights and number plate lights are required under the new rules.
Side lights or marker lamps are compulsory on the right hand side of the trailer. Reflective side markings are necessary on the sides for all trailers travelling under or over 40km/h.
These should cover 80% of the trailer. On the rear, a red reflective strip across the width of the trailer is required.
SHARING OPTIONS: