1 November 1996

Self-propelled tackle well

worth cost, say growers…

TAILOR-MADE, self-propelled harvesters have taken to the potato fields this year.

In Yorkshire, grower and contractor Peter Teasdale has been putting his bespoke two-row Riecam-based machine through its paces, while in Essex father and son team Jim and Charles Padfield have been harvesting with a three-row machine specially commissioned from Dutch manufacturer Amac.

Self-propelled harvesters, the growers believe, offer sufficient advantages to justify the extra cost over trailed machines. They list greater output from larger separation and cleaning systems, easier manoeuvrability in tight fields, and better traction in difficult conditions.

Peter Teasdale lifts between 400ha and 570ha (1000 and 1400 acres) of potatoes a year, half his own, half as a contractor, and wanted a high capacity self-propelled harvester incorporating the latest cleaning technology used on trailed machines.

His 1700mm (67in) two-row harvester is based on a Riecam chassis which he bought complete with engine, hydrostatic transmission and hydraulic drive systems, together with a topper, diabolos, lifting share and first web from Belgian manufacturer AVR.

He then added a double haulm roller assembly, a rubber covered main web and Nicholson roller cleaning system, a widened and re-configured "up-and-over" elevator from a Grimme Allrounder harvester, then a star roller cleaning section and four-man picking table.

A bunker-type elevator, with sufficient holding capacity to allow continuous lifting while trailers are changed over, completes the specification.

"We work on a great variety of soils from sands to clays and of course harvesting conditions change from season to season," says Mr Teasdale. "I wanted a machine which would cope whatever the situation, so it incorporates the latest thinking on separation and cleaning, with hydraulic drive to all elements and lots of adjustments for fine-tuning."

A Dahlman roller separation table was planned originally but discarded in favour of a more sophisticated transverse roller design from Norfolk-based Nicholson Farm Machinery.

"It is an expensive unit but more versatile," explains Peter Teasdale. "The angle, speed and spacing of the rollers can be adjusted, as well as the speed of the overhead flapper rotor. You can also alter how many rollers you have contra-rotating so, all in all, there are a lot of options for regulating the aggressiveness and flow of potatoes across the system."

Rubber covering for the main web is designed to minimise any bruising risk as the crop comes over the twin haulm extraction rollers, the curve of the up-and-over elevator has been reprofiled for increased capacity, and the 3t-4t capacity bunker floor lowers automatically as crop builds up during trailer change-overs.

The end section of the elevator itself has four pivots for maximum flexibility in placing the crop gently into a trailer.

"Our usual system is to windrow ahead of the harvester to get maximum output at a sensible working speed," says Peter Teasdale. "In one field this year, in good going, the spot work rate was between 100 and 120t/hour."

Jim and Charles Padfields principal need was for a harvester that would lift their 2.75m (108in) three-row beds – a system which reduces the amount of crop exposed to soil compacted during bed forming and separation work by limiting wheelings from 25% to just 17% of the cropped area. Two-row beds are planted every 25m (82ft), providing tramlines for spraying and irrigation equipment on standard wheel track settings.

"Moving from two-row to three-row lifting with no reduction in forward speed gives you a 50% increase in work rate but with fewer headland turns the overall improvement is probably nearer 60 to 70% overall," says Charles Padfield.

The harvester is conventional in terms of lifting, separation and cleaning equipment, apart from having hydraulic spacing adjustment of the two diabolos so that it can lift the two-row tramline beds as well as the rest of the crop.

There are three 2300mm (90in) wide web sections, plus two separate haulm extraction rollers, together with an axial roller cleaning/separation system.

Hydraulic drives are used throughout to allow the speed of each element to be fine-tuned in respect of ground speed and soil conditions; the cart elevator is reversible so that crop can be windrowed during trailer change-overs.

Each separation section is formed from three web conveyors rather than one full-width or two wide webs, so that 10mm rods can still be used to keep tuber bruising to a minimum.

"We have been stuck with lifting two rows of potatoes for years when harvesting capacity for other crops has moved ahead," says Charles Padfield. "The three-row bed system should not only give us better yields but more efficient lifting as well."

Peter Teasdales Riecam-based self-propelled potato harvester has hydrostatic all-wheel drive with up to four wheels across the back to spread the load.

Lifting three rows grown in a 2.75m (108in) bed, the Amac harvester has large rear wheels tucked underneath the 2.3m (7ft 6in) wide separation and cleaning elements. A reversible elevator allows windrowing during trailer change-overs.

Peter Teasdale: "I wanted a high capacity self-propelled harvester with the latest separation and cleaning technology."

Charles Padfield: Self-propelled harvesting of potatoes in three rather than two rows has to be the way to go.

Self-propelled tackle well

worth cost, say growers…

Is there a future for the self-propelled potato harvester?Peter Hill spoke to two growers who clearly think there is

TAILOR-MADE, self-propelled harvesters have taken to the potato fields this year.

In Yorkshire, grower and contractor Peter Teasdale has been putting his bespoke two-row Riecam-based machine through its paces, while in Essex father and son team Jim and Charles Padfield have been harvesting with a three-row machine specially commissioned from Dutch manufacturer Amac.

Self-propelled harvesters, the growers believe, offer sufficient advantages to justify the extra cost over trailed machines. They list greater output from larger separation and cleaning systems, easier manoeuvrability in tight fields, and better traction in difficult conditions.

Peter Teasdale lifts between 400ha and 570ha (1000 and 1400 acres) of potatoes a year, half his own, half as a contractor, and wanted a high capacity self-propelled harvester incorporating the latest cleaning technology used on trailed machines.

His 1700mm (67in) two-row harvester is based on a Riecam chassis which he bought complete with engine, hydrostatic transmission and hydraulic drive systems, together with a topper, diabolos, lifting share and first web from Belgian manufacturer AVR.

He then added a double haulm roller assembly, a rubber covered main web and Nicholson roller cleaning system, a widened and re-configured "up-and-over" elevator from a Grimme Allrounder harvester, then a star roller cleaning section and four-man picking table.

A bunker-type elevator, with sufficient holding capacity to allow continuous lifting while trailers are changed over, completes the specification.

"We work on a great variety of soils from sands to clays and of course harvesting conditions change from season to season," says Mr Teasdale. "I wanted a machine which would cope whatever the situation, so it incorporates the latest thinking on separation and cleaning, with hydraulic drive to all elements and lots of adjustments for fine-tuning."

A Dahlman roller separation table was planned originally but discarded in favour of a more sophisticated transverse roller design from Norfolk-based Nicholson Farm Machinery.

"It is an expensive unit but more versatile," explains Peter Teasdale. "The angle, speed and spacing of the rollers can be adjusted, as well as the speed of the overhead flapper rotor. You can also alter how many rollers you have contra-rotating so, all in all, there are a lot of options for regulating the aggressiveness and flow of potatoes across the system."

Rubber covering for the main web is designed to minimise any bruising risk as the crop comes over the twin haulm extraction rollers, the curve of the up-and-over elevator has been reprofiled for increased capacity, and the 3t-4t capacity bunker floor lowers automatically as crop builds up during trailer change-overs.

The end section of the elevator itself has four pivots for maximum flexibility in placing the crop gently into a trailer.

"Our usual system is to windrow ahead of the harvester to get maximum output at a sensible working speed," says Peter Teasdale. "In one field this year, in good going, the spot work rate was between 100 and 120t/hour."

Jim and Charles Padfields principal need was for a harvester that would lift their 2.75m (108in) three-row beds – a system which reduces the amount of crop exposed to soil compacted during bed forming and separation work by limiting wheelings from 25% to just 17% of the cropped area. Two-row beds are planted every 25m (82ft), providing tramlines for spraying and irrigation equipment on standard wheel track settings.

"Moving from two-row to three-row lifting with no reduction in forward speed gives you a 50% increase in work rate but with fewer headland turns the overall improvement is probably nearer 60 to 70% overall," says Charles Padfield.

The harvester is conventional in terms of lifting, separation and cleaning equipment, apart from having hydraulic spacing adjustment of the two diabolos so that it can lift the two-row tramline beds as well as the rest of the crop.

There are three 2300mm (90in) wide web sections, plus two separate haulm extraction rollers, together with an axial roller cleaning/separation system.

Hydraulic drives are used throughout to allow the speed of each element to be fine-tuned in respect of ground speed and soil conditions; the cart elevator is reversible so that crop can be windrowed during trailer change-overs.

Each separation section is formed from three web conveyors rather than one full-width or two wide webs, so that 10mm rods can still be used to keep tuber bruising to a minimum.

"We have been stuck with lifting two rows of potatoes for years when harvesting capacity for other crops has moved ahead," says Charles Padfield. "The three-row bed system should not only give us better yields but more efficient lifting as well."


Riecam-Teasdale two-row

Power unit 270hp Deutz engine powering hydrostatic transmission and hydraulic drives to crop handling systems.

Crop handling 1700mm full width share, web, two-roller haulm extractor, rubber covered web, transverse roller cleaner, up-and-over elevator, star roller cleaner, picking table, bunker elevator for adjustable floor height.


Amac three-row

Power unit 245hp DAF engine powering hydrostatic four-wheel drive transmission and hydraulic drives to crop handling systems. Hydraulic self-levelling.

Crop handling spacing adjustable diabolos for two- or three-row lifting, 2300mm full-width share, three web sections, contra-rotating axial roller cleaning/separation system, reversible cart elevator for windrowing.