8 June 2001

Finding a way for the wide

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As implements get wider, so they become more difficult to

transport from field to field. Peter Hill explores how

manufacturers are tackling the problem

IT sounds a simple enough solution. If its too wide to go on the road, chop off the ends, put in hinges and fold it up.

For some simple cultivation tools that may, indeed, be the answer. But the bigger and more complicated the implements become, the more difficult that simple solution is to execute. Folding wing sections requires extra metal to provide hinges and reinforcement, and more components in the shape of hydraulics cylinders to move them.

All of which adds weight and expense. It can also create instability in wide implements that end up with wings towering above a centre section or a half-split frame above a backbone chassis.

There are alternatives, such as the disc cultivators on which gangs are rotated to a position in line with the chassis for transport rather than being raised hydraulically above it. That keeps the centre of gravity low and can eliminate the cost of hydraulic cylinders – although operators may choose hydraulic gang adjustment for ease of use.

The only disadvantage is that it tends to make an already lengthy implement longer, and once the gangs are aligned for transport they are less wieldy for turning off roads into narrow gateways.

Italian manufacturer Concept Machinery has a swivelling drawbar and transport wheels assembly for its Speed Till combination cultivator. Preparing the implement for transport takes no more effort than extending the telescopic drawbar and swinging it through 90 degrees.

The Swing Kit transport system is available for 3.5m and 4m models in the range. A ball-bearing swivel at the centre of the cultivators main frame carries the drawbar and two arms carrying the wheels.

In work, the drawbar is secured to pin connections on the front face of the cultivators folded-steel mainframe. To reposition for transport, these pins are withdrawn, allowing the tractor to pull forward to extend the drawbar.

With the tractor uncoupled, the drawbar is free to be moved by hand to the transport position where the tractor is coupled up again and reversed to engage the drawbar on to securing pins on the side of the cultivator. Moving the drawbar in this way also positions the support wheels ready to lift the cultivator clear of the ground.

Problems other than stability can arise when folding wings provide the only practical solution for reducing implement width. On Simbas Solo disc cultivator/subsoiler combination, for example, it was realised that, in transport configuration, the subsoiler tines would project to an unsociable degree.

So the hydraulic cylinders used to provide break-back protection are also used to draw in the tines to a safer position.

On a big seed drill, such as Kvernelands Accord MSC, there is the problem of ensuring that wide wing sections can be given enough flotation in work to follow contours while remaining secure during transport.

The solution for the MSC drill is to split the mid-mounted cultivator section down the middle so that it can fold up either side of the central seed hopper, and fix the two halves to subframes. These provide a central pivot in work but are arranged such that the cultivator frames are held securely when raised.

With a vast 12m cultivator or seed drill like the CO model produced by Horsch, the transport challenge is a real poser. Somehow, Horsch gets these implements to fold gull-wing fashion before rotating to a vertical position, then swinging in-line with the direction of travel.

A remarkable feat given the number of components that must be in the right place to function correctly in work without fouling each other as the implement goes through its concertina act.

With precision drills for maize and sugar beet, stacking has become the popular solution. Simple vertical wing folding has the disadvantage that, because seed boxes are not seed-tight when tipped on their sides, everything has to be empty before moving to a new field.

By mounting banks of seeding units on pivots, everything stays neatly upright on a stack-folding drill, with pivots ingeniously positioned on some wide beet drills so that the units on one wing section end up above those on the other.

End towing is a potentially cheaper alternative, for box-type seed drills as well as precision seeders and power harrows. Except that a certain amount of messing about is involved in dropping off the implement, repositioning the tractor and hitching up again.

Besides, as implements have become wider and heavier, so end towing has become increasingly unwieldy on the road, as well as expensive on implements such as wide precision seed drills because of the need for robust supporting frames as well as transport wheels and drawbars.

Hence the popularity – despite a significant cost penalty – of the hydraulically folding power harrow. At 4m, 5m and 6m, these implements are easily put together using two standard half-width harrows carried on a folding top frame. A central gearbox and lateral drive shafts completes the assembly.

This format enables users to change quickly between transport and work configuration, to carry the implement safely and within required width limits, and to gain easy access (with appropriate safety precautions) for changing tines.

Less popular, but a practical and more versatile solution nonetheless, is the low-loading trailer. This again involves a degree of effort dropping an implement on to the deck and hitching up to the trailer drawbar. And with low deck height and wheels positioned right at the back, these are not the most manoeuvrable of trailers.

But the investment they represent can at least be recouped moving any suitable implement or other items that need transporting.

Yorks-based Jones Engineering reckons its low-loader is more versatile – and more practical – than most thanks to a configuration that enables it to load low but travel like a conventional trailer.

To drop the steel deck to the floor, the rear chassis extension is lowered into position and locking pins holding the tandem axles in a position around two-thirds of the way from the front, are released. With the brakes on, the trailer is drawn forward until the wheels enter the chassis extension, which is then raised again, taking the wheels with it.

With the rear end of the deck now on the floor, the front end is lowered using the hydraulic drawbar, and ramps extracted (if needed) for side or front-end loading. &#42