Íæż½ã½ã

Over the last five years, one Oxfordshire grower has made the most of a Versatile 550DT for frontline power. Its performance and low running costs have led to a second Versatile joining the fleet. Geoff Ashcroft reports.

For the last 20 years, north Oxfordshire grower David Morrell has focussed his attention on minimising soil compaction. Over the years, dual-wheeled articulated tractors have given rise to rubber-tracked horsepower for a blend of higher productivity and reduced ground pressure.

Mr Morrell explains: "Our cultivations and drilling regime was then 100% autumn focused. And we still operate with a sense of urgency to get all our crops established, whether contracting, contract farming or working our own land."

The business is proud of the sub-7psi ground pressure that it exerts on the land, and as a result, soils across the business are in rude health with impressive worm populations.

"If you can see where your tractor has been, then it is too heavy," he says. "We specify 36 inch tracks and spread the weight."

Morrells Farming operates an eclectic mix of power. The current fleet comprises a pair of Versatile Delta Track models for primary front-line power. These include a five-year old 550DT and an 18 month old 610DT, which have clocked up nearly 3,000 hours and 1,000 hours respectively.

These are backed up by a 12 year old, 5,500-hour Case IH 535 Quadtrac, though now seldom used, while a Challenger 55 and a 40 year old articulated John Deere 8640 are maintained for secondary operations. "The 8640 pulls a cultivator and rolls," he says. "With its dual Michelin tyres reduced to 6psi, you cannot see where it has been. The rolls will then cover and firm any surface marking that might be left by the Deere."

"Over the years, we have had a wide variety of power," explains Mr Morrell. "But nothing we have had has come close to the hill-climbing capabilities of the 550DT. It has the best mix of power and performance for our business. Its owning and operating costs are impressively low and it has needed little more than regular servicing over the last five years."

His comments are supported by years of experience running many Quadtracs, though changes in local dealerships prompted a look at the wider market to consider all the rubber tracked options available. "Our STX535 has been the best Quadtrac owned, and it is still on-farm, but only as a back-up," he says. "It has barely turned a track in the last five years since we bought the Versatile 550DT from JPM Agricultural."

By contrast, he says a previous STX600 was the most fuel efficient of all, but the cost of servicing and maintenance soon became excessive. "We had been well-looked after, but there comes a point when downtime and running costs take their toll and you have to look elsewhere."

Prior to settling on the Versatile, the farm carried out its own trials and proved that on its heavy Oxfordshire clays and rolling banks, the Versatile 550DT got its power down far better than anything else the farm had experienced.

"So far, tractor reliability has been impressive and the back-up from JPM has been better than expected considering it is not a local dealer," he says.

The ex-demo 550DT arrived with 300 hours on the clock and had its standard 30 inch tracks swapped for wider 36 inch belts. The farm also chose a softer compound track to help with ride comfort and grip and these are still on the tractor.

One of the keys to its performance, he says, is the tractor's 60:40 weight distribution, without the need for extra ballast. This is helped by saddle-tank fuel storage on the front half of the chassis and a drawbar that has its pull-point immediately behind the centre pivot pin.

"It is important to keep weight on the front tracks, because if they start to spin, particularly climbing a bank, the rear tracks then have nothing to bite in to," he adds. "And if the pull-point is further back, traction will suffer on a slope for those seeking weight transfer.

"The 550DT will pull down to 1,400rpm under full load and it just keeps on lugging," he says. "It does not give up or rush into a slow downshift loosing momentum, so forward speeds are far more consistent with a drop in rpm minimising any track slip. And with mid-rollers that oscillate fore/aft and left/right, each track is kept in constant contact with the ground, so the grip is phenomenal."

Comparing tractors, Mr Morrell says: "They have all got their good and bad points - you have to find something that works best for your own requirements and I believe we have that. We have seen that the Delta Track will go where others cannot keep up."

And it is a point not lost on operator Gordon Whittingham, who spends about 500 hours per year in the cab covering about 2,000ha of cultivation and drilling. Key implements include an 8.5m Gregoire Besson disc/12-leg subsoiler combination and an 8m Horsch Sprinter drill with seed cart.

Mr Whittingham says: "I had my reservations when we first considered a Versatile. My preference was for one of the more obvious brands when tried on flat ground, but I have been really surprised by the tractor's performance, particularly on sloping fields.

"You have to look past the badge and consider how it performs as a complete package," he adds. "I moved from an STX600 to the 550DT and I would not want to go back. Though the lack of cab suspension compared to the STX initially came as a shock."

Fortunately, the Delta Track's offset, oscillating mid-rollers provided an interim level of comfort before the rear of the cab was cushioned using an after-market AgCab suspension system. With twin airbags, dampers and an anti-roll bar, this proved a fraction of the cost of a factory-fitted system. "Comfort is now great, though the extra movement has numbed the autosteering," he says. "I am well insulated against changes in ride quality, though I can still feel high drawbar loads through the seat."

He has high praise for the spacious cab and its visibility over the rear to the drawbar, but says the air conditioning does struggle to keep up on hot days. It is a scenario slightly mitigated by having a cooled leather seat.

The key to the 550DT's success has been a combination of sympathetic operation and regular inspections. "We keep the same operator on the same seat," says Mr Morrell. "But like all rubber tracked machines, the operator needs an understanding and an appreciation of what can go wrong when shifting gear under full power."

Cab

Cab space is generous, but air conditioning is said to struggle on hot summer days.

"Travel speeds are limited to 30kph to manage heat build-up when moving around local roads, though regular inspection of tracks, rollers, and track alignment is essential," he says. "With 3,000 hours rapidly approaching, its running gear is all original."

Improvements though, are a continuous process. The Category 4 drawbars have been a weak point over the years and a custom Category 5 item - now a factory option - was supplied.

Trailed implements have been modified to suit and use a corresponding coupling with a snug-fitting ball socket to remove free play that can impact on operator comfort and reliability. "We have not broken a drawbar since swapping to 70mm pins," adds Mr Morrell. "And we have never been stopped in-season with the 550DT. Though, winter repairs have included a gearbox oil seal and a replacement alternator."

He says that tractor brakes have been a weak point and are cause for regular inspection. Mr Whittingham explains: "The 550DT has just two dry disc brakes - one ahead of each differential, though the 610DT has three dry disc brakes, with the rear axle getting a brake inboard each of the rear drive rollers. We have since added air brakes to both Versatile tractors and our trailed implements, so on-road safety is assured."

Versatile uses a 12 volt starting system and, with three batteries located in front of the cooling pack plus an auto-reverse cooling fan, operating temperatures have seen battery life doubled compared to past experiences.

Mr Whittingham adds: "While the saddle tank fuel storage is slow to fill for the last 25% of volume, it is a design that keeps fuel cool, unlike a large rear tank that can suffer with heat-soak. We have not had any mid-day drop-off in power with the Delta Track from warm diesel."

Fuel use comparisons

Verdict

Downsides are few, once you get past the basic and perhaps rudimentary aesthetics of Delta Tracks, says Mr Morrell. "It is a very simple and robust power unit and based on its performance, we figured that the 610DT would be a natural extension to our fleet when replacing an STX600, but we are still ironing out a few issues that seem to apply to any engine with AdBlue and cooled EGR.

"It might have more power, but due to Cummins having to authorise all engine servicing and repairs, it means waiting times can be frustrating," adds Mr Morrell. "A non-EGR power unit, such as FPT's C16 Euro 6 compliant Hi-eSCR engine, would solve these challenges."