17 August 2001

Bigger units mean age of self-propelled has come

It now seems mandatory for

potato harvester

manufacturers to have a self-

propelled machine in their

portfolio. Some would say it

reflects the prosperity of the

potato industry – others

that it is a route to higher

output. Andy Collings

reports on the launch of

Grimmes two row machine

SELF-PROPELLED potato harvesters continue to make an increasing impact in the UK.

Only a handful of years ago most considered such a concept too futuristic to seriously contemplate, but with there now being fewer growers harvesting larger acreages, its age appears to have dawned.

Enter the Grimme SF 1700 GBS, a two-row self-propelled harvester which the company claims meets the needs of growers whether they major in earlies, second earlies, main crop or a combination of the three.

Its concept brings together the harvesting system used in the Grimme trailed GBS 1700 and the self-propelled technology employed by the SF 170-60, which was introduced last year. But Grimme is keen to show that this is much more than a converted trailed machine.

For starters, the operator sits directly above the intake zone where depth and forward speed can be precisely controlled. Having power on board means the speed and setting of hydraulically-driven components can be individually adjusted on-the-move to meet changes in harvesting conditions. And then there is the all-important traction, which many would have given a lot for in last years atrocious lifting conditions.

"It all adds up to a machine which can work effectively in conditions that would keep a conventional trailed machine in the barn," says Michael Alsop, Grimme UK managing director.

"Rising costs of production and the need for timely harvest management to suit market requirements should add weight to the argument for self-propelled units."

The SF 1700 GBS may not be the sexiest machine that ever was. Indeed, at two-thirds of a cricket pitch long with all the style of a wardrobe on wheels, Grimme has clearly struggled on the fashion front.

But what it can do in the field matters more and it is clearly a functional machine. Power comes from a 280hp Mercedes engine which is contained in its own modular casing along with the oil pumps it drives, control valves and radiators.

A totally hydrostatic machine, forward speed is infinitely variable as one would expect. But its wheel assembly merits greater interest. The right-hand rear wheel is a standard 460/85 traction wheel, but space does not allow such a large diameter wheel to be fitted on the left-hand side. A smaller one can be fitted, but Grimme believes many buyers will opt for a rubber track unit which can increase traction and reduce ground loading significantly. Bearing in mind that 80% of the machines 19t weight is on the back axle, it could be a good choice.

Front steering wheels – narrow and large to provide maximum ground contact yet still fit between rows – are also powered.

Both the rear and front track widths can be adjusted, while the rear axle can steer 7í to compensate for crabbing on slopes.

For the all-important harvesting system, the SF 1700 starts the process with a front-mounted haulm topper. After lifting, potatoes are passed on to an intake web and then to the first main web, where Grimme offers its Cascade "wavy" web as an option.

The crop then passes over the first separator unit – either an RS roller unit or the firms Multi-sep – before being elevated on to the top layer and over a second separation area, normally another Multi-sep unit which can have its rollers driven in a contra-rotation fashion or all in the same direction. The gap between the rollers can also be adjusted.

The crop then moves on to the picking web, where up to four pickers can be employed, and then on to the discharge elevator.

Grimme would appear to have built as many on-the-move adjustments as there are components, but the operator – sitting in an air-conditioned Claas-sourced cab – can view a screen linked to an on-board computer that informs him just how the machines components have been set. A nice touch is the ability to move the cab forwards by 1m to obtain a better view of the crop intake.

TV cameras set to view key parts of the machine convey pictures back to a second screen so crop movement can be monitored throughout their time within the harvester.

While the SF 1700 GBS is undoubtedly a sophisticated harvester, Grimme has its sights set on even greater things. "We are striving to achieve a harvester capable of lifting all types of potato crops in all types of conditions by equipping it with easily made adjustments that can accommodate these demands," says Mr Alsop. &#42

SF 1700 GBS

&#8226 Harvesting system Twin separation units.

&#8226 Power 280hp Mercedes Benz.

&#8226 Transmission Hydrostatic.

&#8226 Transport dimensions 4m high, 3.3m wide.

&#8226 Price About £174,000.