Get your trailer in gear for the silage harvest

The new road rules regarding the use of agricultural vehicles came into force last year. When carrying out routine maintenance for work this season, a once-over on the trailer is advised, looking at it from two perspectives. Number one, is it road legal? Number two, is everything working as it should?

AXLES

A trailer fitted with a bogie axle, is not considered to have flexible suspension under the new road regulations. Even though it is a bogie with one hinge point, it can carry 8t per axle with an allowance of 3t on the drawbar.

A flexible suspension system with springs or air-fitted, allows for 9t per axle, with 3t on the drawbar. If adding 500mm flotation tyres or greater, allow for 10t weight per axle. Fitting a ball and spoon coupling system can increase the drawbar weight by 1t.

All axles should be inspected before use this season. Wear and tear on bumpy roads can lead to damage. Springs should be looked at for visual cracks, and the axle itself for splaying and stress fractures. It should be noted that only trailers with wider commercial brake hubs which are 420X180mm are permitted for use at speeds over 40 km/h. This will give a greater braking surface area in the hub. New-build trailers must have auto slack adjusters.

However, if in place, manual slack adjusters will suffice on trailers manufactured before January 2016. Slack adjustors need to be in working order and examined.

Manual adjustment should be carried out if the braking effort has decreased. Trailers operating at speeds of 50 km/h need a 45% braking efficiency

Tyres

As stated earlier, trailers with flotation tyres over 500mm, are allowed to carry 1t extra per axle. Regardless of the width of the tyre, they need to be in road-legal condition. A visual inspection for bulges on the tyre wall should be carried out. Also tyre rimming out can occur where the trailer has been operated at low pressures.

Tyre pressures need to be checked before use, to prolong tyre life, reduce fuel consumption and to protect the silage fields. The mentioned factors can lead to a blowout on the road. Any bare tread wire is a red flag, and they tyre should be replaced. The trailer studs should be tightened, with all or missing studs replaced. Replacement studs should be of the recommended strength, for the axle and trailer weight.

COUPLING

The point is critical on the trailer. Most drawbars are permitted to carry a weight of 3t. The tractor hook and trailer eye need to be very carefully inspected. Constant work will wear the bottom of the hook and the drawbar eye. Worn hooks and eyes must be replaced. Welding should be carried out by a certified professional to ensure there are no issues. A ball and spoon connection is also an option. Again these systems will wear and need grease to lengthen the working life.

BREAKAWAY SYSTEMS

The breakaway system on the trailer has to be fitted and working. The legislation states for a silage trailer to be used at under 40km/h, fitting a secondary coupling system such as a chain or wire rope will suffice, ideally fitted to the bottom of the tractor hitch and welded to the trailer drawbar. An automatic breakaway system will have to be fitted to some trailers for use over 40km/h. This device may be a hydraulic valve connected via a cable to the tractor, electronic breakaway device, manual connection to handbrake, or air brakes with red-line breakaway pipe. All new trailers manufactured after January 2016 will require air brakes as standard for use over 40km/h. An automatic breakaway device is required for all trailers manufactured after 1 January 2016. All trailers must have a parking brake with 16% braking efficiency. This must to be fitted or repaired on all trailers regardless of speed category.

LIGHTS AND REFLECTORS

The trailer’s existing lights must be in working order and located correctly. Under the new rules, reflective side markings on the trailer are required for both over and under 40km/h. On an 18ft trailer, it costs around €36 plus VAT. The trailer must also be fitted with a marker lamp on the right-hand side if, when coupled to an agricultural tractor, the overall length of the combination is more than 10m. The marker lamps must be fitted at least 25cm from the ground and not more than 3m from the front of the trailer. When carrying out alterations to lights, it is a good opportunity to inspect for any potential damage, and fit neat junction boxes. Illuminated number plates are also a requirement under the revised road regulations. Reflective side markings are required on 80% of the trailer.

On the rear of the trailer a single red reflective strip is required. Speed discs are only required on trailers operating at 50km/h. All new trailers will come with this as standard.