12 March 1999

ATOPPING CHOICE INDEED

Simple implements for a

simple task. Yet pasture

toppers come in many

shapes and sizes.

Andy Moore examines

the variations

FROM mowing set-aside to trimming roadside verges, pasture toppers are often called upon to do more than simply slash weeds and stemmy grass on productive swards.

Happily, all but the lightest models are built strong enough to cope, though only the heaviest build and most robust drive-line will cope with neglected rough ground and encounters with the occasional rock or two.

For such a simple implement with a simple task, manufacturers manage to produce a remarkable diversity of formats. These amount to:

&#8226 Front or rear-mounted in-line.

l Rear-mounted with fixed or adjustable partial offset.

&#8226 Rear-mounted fully offset.

&#8226 Trailed in-line.

&#8226 Trailed fully offset.

Because of their simplicity and low cost, the rear-mounted in-line topper is most popular. But offset designs make it easier to mow tight to boundaries, while a front-mounted or fully offset machine is the only way of guaranteeing a clean cut by avoiding tractor wheelings through uncut grass.

Plenty of choice

In all categories, there is plenty of choice when it comes to matching working widths to available tractor power, as well as tractor size and weight, for that matter, which can be important as far as stability is concerned when working on hilly uplands.

Working widths for tractor-mounted toppers intended for pasture work are typically 1.8m to 2.7m (6ft to 9ft), though operators looking for higher work rates are catered for by companies such as Wessex, Port Agric, Suire and Major with machines 3.6m (12ft) wide and more, as well as the Votex range, which extends to 6.15m (20ft). Transporting these examples involves either folding wing sections or, as a lower cost solution, end tow or linkage kits.

Variations on the drive front come down largely to using belts or shafts to transmit power from the main gearbox to the cutting rotors. Teagle, Suire, Bomford and Wessex are among those that prefer the simple, shock-absorbing qualities of belt drive.

Others, among them Browns, Spearhead, Port Agric and Zaga, support the positive power transmission of shaft drive which ensures blade-tip speed is maintained in all conditions. Suire and Wessex hedge their bets by producing both belt and shaft-driven toppers.

Overload protection is typically by shear bolt, though larger machines often have the option of a slip clutch; rubber couplings help protect shafts and gearbox from shocks.

Where field surfaces are other than billiard table smooth, a toppers ability to follow ground contours is another consideration. Manufacturers commonly use chains or cables to suspend the mower deck when lifted from the ground, as, when in work, this allows free movement over undulations.

On Opico, McConnel and Bomford toppers, rigid steel headstock braces are preferred, with castor wheels regulating the cutting height. On other machines this is altered by pin and hole settings for the side skids.

Fitting two blades a rotor is typical (the free-swinging type can help limit damage from impacts with stones and other debris), though Zaga and Suire are among makers offering three or four blades a rotor where a finer finish is required.

Bomford and Spearhead toppers can be fitted with baffles on the underside of the cutting deck which ensures mown material is cut short and spread. Spearhead also produces a heavy roller and harrow tine assembly for its 3000-4W rotary cutter, so topping, rolling and harrowing can be carried out in one pass.

Good for trimming

Though most pasture toppers are operated in-line behind the tractor, some offset can be useful for trimming close to field fences, walls and hedges. Where adjustable or duplicate mountings are used, implements can be moved back to an in-line position for transport.

On Votex, Kverneland, Browns and Teagle toppers, clamp-type mountings allow the headstock assembly to be slid along a bar, giving some degree of flexibility over the amount of offset used. On Suire mowers, duplicate linkage arm mountings are included on the headstock, while Port Agric goes to the extent of providing a hydraulic mechanism on its 2.74m (9ft) Cutlass.

Keeping tractor wheelings out of unmown grass means using a front-mounted topper (Spearhead offers this option) or a fully offset rear-mounted or trailed machine.

The mounted machines – such as those produced by Suire, Major and Kverneland – are of similar layout, using a substantial arm to position the cutting deck to the right-hand side of the tractor. For simplicity, mechanical latching and manual folding to the transport position is common, though hydraulic fold can also be had in most cases.

But in-line trailed toppers provide the ultimate in working width for farmers and contractors with big cutting capacity in mind.

Wessex, Spearhead, Major and McConnel produce such machines in widths of 3.8m to 6m (12ft 6in to 20ft) and more, mostly equipped with three shaft-driven rotors each carrying two or three free-swinging blades.

Hydraulic folding for transport is a must on such equipment, while power requirements are from 80hp plus. &#42

TOPPER SUPPLIERS

Archie Kidd 01380-828123

AWS Farm Machinery (Zaga) 01844-281421

Bomford Turner 01789-773383

Browns Agricultural 01525-375157

COP Engineering 01283-585240

Kellfab 01524-736375

Kverneland 01380-722361

Major Equipment 01524-850501

McConnel 01584-873131

Mike Wilks (Conor) 01394-460518

Opico 01778-421111

Port Agric 01892-783424

Spearhead 01386-556748

Suire 01844-278542

Teagle 01872-560592

Twose of Tiverton 01884-253691

Votex 01432-274361

Watterson 01648-32251

Wessex 01420-478111