11 February 2000

Following the correct track

A fertiliser spreader running

on tracks may be an unusual

format but for one

Notts-based contractor

business such a system is now

a reality. Andy Moore reports

NOTTS-based C&B Hinchley Contracting cannot get enough of tracks – three Caterpillar Challengers, a tracked chaser bin and now a tracked fertiliser spreader.

The brain child of company manager Philip Walmsley, the machine was developed last November when he considered better use could be made of an existing Caterpillar VFS50 track unit used on a Ken Wootton chaser bin.

"At £25,000, the tracked chaser bin represents a vast amount of unused investment if it only works two months a year during the combining season," explains Mr Walmsley. "Putting the track unit under the fertiliser spreader will help distribute this cost throughout the year – and also help keep one of our Challengers out of the shed."

Designed as a de-mount unit, the fertiliser spreader unit is a seven-year-old KRM Bredal B4 trailed machine which was separated from its original wheeled chassis.

The 5t hopper and spreading equipment was attached to a purpose-built sub-frame, and mounted to the track unit via four quick-coupling lorry container latches.

"Providing the same axle width as the old wheeled chassis, the unit proved a good match for the spreader, despite the 63cm wide tracks protruding 15cm either side of the Challengers tracks," he says.

Attachment currently takes about an hour and requires the spreader to be lowered by crane on to the track but there are plans to build four support stands to make the task simpler.

Other adaptions

To cater for the extra height provided by the subframe, the machine has been equipped with an additional hopper inspection platform and a flight of steps, while the existing bag lifting crane at the front was mounted on a support stand. Other adaptations include a longer drive shaft to power the twin spreading discs and the addition of side panels that can be removed to provide access for greasing.

"The entire job took two of us about three weeks to complete and cost about £1000 for the spreader to be shot-blasted and re-sprayed, while the steel costs came to almost £200," says Mr Walmsley.

In operation, he believes his 212hp Challenger 35 is well suited to work with the tracked spreader – high horsepower and tracks which provide a similar level of low ground pressure as the spreader.

"The track unit exerts a high rolling resistance when laden with a full 5t hopper, but our Challenger pulls it effortlessly with only about 2% wheelslip," he says. "An equivalent horsepower wheeled tractor would struggle to pull the spreader and wheelslip would be unacceptable."

To reduce the incidence of scalping, Mr Walmsley may consider fitting the spreader with track lift rams which will serve to raise the front half of each pivoting track during headland turns.

Ground pressure for each of the 62cm wide tracks is calculated at about 8.2psi under a full load, comparing with up to 20psi when the spreader was used with the 620/75 R26 wheeled axle.

Best selling point

This reduction in ground pressure, Mr Walmsley believes, will be the combinations best selling point, providing the ability to apply top dressings on wet ground over a longer period in the season with minimal damage to the seed-bed or crop.

Spreading on rough ploughed land, he claims, will increase field performance by up to 30%, due to faster forward speeds and higher spreading accuracy.

In addition, less soil compaction and wheelings are said to cut out the need for flat lifting and benefit subsequent machinery operations after harvest – for example baling and ploughing.

Spreading to 24m, first top dressings for this year are planned to start at the end of February with compounds being applied to winter wheat. Final top dressings for mature crop will either be carried out using a liquid application system, or a tractor mounted machine in favour of higher ground clearances – an area where the tracked spreader is restricted.

Mr Walmsley intends to use the tracked fertiliser spreader on a total of about 1000acres, travelling if necessary up to 40 miles with the machine transported on a low loader trailer towed by a Fastrac. &#42

Treading lightly….The tracked fertiliser spreader comprises a KRM Bredal B4 machine mounted on a pair of Caterpillar VFS50 tracks; ground pressure for each spreader track is 8.2psi. Philip Walmsley (inset), farms manager of C&B Hinchley Contracting, says the tracked combination will be able to apply top dressings on wet ground over a longer period in the season with minimal damage to the seed-bed or crop.