12 November 1999


FROM Beaconsfield Farm on the Great Tew Estate, Chipping Norton in Oxon, agricultural contracting firm A&R Parker has recently raised its game, stepping up the horsepower for cultivation duties with the switch from an 18-year-old 260hp John Deere 8640 artic, up to the most powerful production tractor currently available in the UK – a 425hp John Deere 9400.

"We have a lot of steep banks to work on and this is where the 8640 was struggling to keep up a decent pace pulling a set of 4.3m Besson discs with an integrated press," says the firms Richard Surtees who has put about 200 hours on the big Deere since it joined the fleet in July. "When forward speed drops off, the quality of discing reduces too. Maintaining a constant speed is essential."

And with 425hp on tap – rising to 455hp as engine speed drops back to 1900rpm – Mr Surtees can easily achieve the desired forward speed needed when discing. The firm also uses the 9400 with a Vaderstad drill and there are plans to add either subsoiling tines to the Besson discs or perhaps a 10-furrow reversible plough, for next season.

"We first looked at re-powering the 8640, then considered importing a 350hp Deere 8870 from the States until the opportunity to acquire a second-hand 9400 came along," he says. "We bought much more horsepower than we initially wanted."

Clearly pleased with extra horsepower now available, Mr Surtees reckons a wider set of discs could perhaps make more use of the tractors available grunt.

"Most of the time, were in 8th gear at about 1800rpm, which gives a generous forward speed of 11kph for any task," he says. When discing, this equates to an output of about 60ha/day (150 acres), which is almost twice that achieved using the lesser powered 8640.

"The 9400 just doesnt struggle – theres masses of torque available and the tractor gives you a feeling of confidence that theres always plenty in reserve."

Such a horsepower reserve has proved invaluable this season. With catchy weather and 810ha (2000 acres) of contract farming to cultivate and drill, A&R Parker has been glad of some spare tractor capacity.

"When you know youve got to press on a little, the 9400 allows us to catch up on a few missed days," he says. "Though itll slurp its way through about 800 litres of diesel a day."

A&R Parkers 9400 differs only slightly from the model Deere plans to bring into the UK next year – it has a 12-speed powershift transmission. Like the John Deere 8000-series, the 9400 uses the Command Arm control console, making driving the tractor a finger-tip operation.

"If it had the manual box, then we probably wouldnt have added the 9400 to the fleet," he says. "Its a smooth and simple gearbox and makes manoeuvring the tractor in corners of fields and around obstacles, very easy. And compared to the 8640, the cab is much roomier, quieter and a lot more comfortable."

Mr Surtees says wheelslip is about 1-2% unless field conditions become sticky and he is looking to remove another tonne of ballast to make the tractors 17-tonne operating weight tread even lighter for top work. Shod on 710/70 R38 dual wheels running at about 7psi, Mr Surtees reckons wheelings are virtually unnoticeable.

"For its size and weight, it is remarkably agile," he says. &#42

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