23 August 1996

Tailored trailers more & more in vogue

By Peter Hill

TRAILER buyers are either becoming fussier or more discerning in what they want from their purchases. Either way, root crop trailers are rarely "standard builds" any more, but more often have bespoke specifications to meet individual needs.

The basic configuration of a low, long body enabling a full payload to be carried without piling beet or potatoes too deeply remains the principle design requirement. But little else is taken as standard.

The low sides of a root crop trailer already go some way to reducing bruising damage by allowing harvester operators to lower the cart elevator as far into the trailer as possible.

This is further facilitated by hinged or sliding upper panels. Most manufacturers offer the former.

Only Marstons Salop range, however, can be had with sliding upper panels, and these take up nearer half the trailer body depth. Two versions are available (both using a hydraulic ram and cable lift/lower mechanism) – side only or side and front combined to minimise the risk of elevator/trailer collisions.

High tipping dumper-type trailers are popular for carting sugar beet because of their piling ability but compromise on volume and are less suitable for other applications.

Several manufacturers – following Armstrong & Holmes lead – produce "hybrid" models with conventional bodies mounted on a subframe that can be raised to increase the discharge height – by between 0.9m and 1m (35.4in and 39.4in) in most cases.

Mechanical up-and-over or hydraulically operated tailgates provide faster turnarounds and save operators the potentially risky release of a conventional door which is under considerable pressure.

Being able to lift the tailgate clear helps avoid root impacts but also allows load discharge – into a reception hopper, for example – to be regulated more effectively.

A generous number of roping hooks is the least trailer buyers can expect, and with food hygiene regulations becoming more prominent, being able to easily sheet a trailer load of potatoes, carrots or onions is taking on new significance.

Commercial vehicle-type powered sheeting systems, comprising a roller that takes a canvas tarpaulin across the body (from Ken Wootton, for example) are expensive but are quick and safe – the job can be done at ground level instead of on top of the load.

Radial trailer tyres are increasingly being recognised for their harder wearing, improved flotation and puncture resistance qualities, and are particularly favoured on high-speed trailers.

Strong axles, wheels and chassis, together with effective brakes, are essential characteristics of trailers that will be operated by faster tractors to cope with the additional stress loads imposed.

Smooth progress

Effective springing smooths progress both in the field and on the road, and some growers are now looking to air suspension to more effectively cushion more delicate crops from bumps that tend to settle loads and can result in pressure bruising.

Manufacturers will usually be fairly flexible about the size and form of front panel grilles which give tractor drivers an essential view into the trailer body, and similarly with ladders which need to provide safe and secure access.

Lights – including flashing beacons where appropriate – need to be reliable, bright and in a housing that protects them from damage (and dirt) to make road travel as safe as possible. Prominent "Slow Vehicle" signs also help.

Sliding upper panels on Marstons Salop range ease trailer loading.