Economies of scale – Dammann-trac DT3500H S4 – Summer ’19 edition
With a tank capacity of 12,000 litres and six-wheel drive, J Wharton Agriculture’s purchase of the UK’s first Dammann-trac six-wheeled self-propelled sprayer has put the firm in the big league of crop care.
Words and images by Geoff Ashcroft
Headline stats can be impressive. Take the Dammann-trac DT3500H S4 – three axles, six-wheel drive, 9.5m long, a 12,000-litre spray tank and a 25t maximum permissible weight – the proportions of the first of its kind, now earning its keep in the UK, almost dwarf its 36m boom.
For its owner, J Wharton Agriculture based at Rossville Farm, Swaby in the heart of the Lincolnshire Wolds, it’s all about the economies of scale. The 2,400ha Wolds-based farming business spans 70 miles from one end to the other, and aligning logistics with weather can pile on the pressure.
“It’s not all about using full capacity all of the time,” explains farms manager Simon King. “But when the going is good, we want to make the most of spray windows. And now we can cover some ground with this, and that’s when economies of scale start to pay off.”
Indeed it can. Applying at 100-litres/ha, the Dammann’s 12,000 litre tank delivers 120ha of coverage per fill – that’s nudging 300 acres in ‘old money’. And on a good day, J Wharton Agriculture has comfortably covered 360ha/day from just three fill-ups, and the farm has its eye on much more output as the season progresses.
Even at 200 litres/ha for pre-emergence, the bowser-sized spray tank can still cover 60ha of ground between fills.
“On liquid fertiliser, we’re still hitting 24ha per load,” he says. “The great thing about such a large tank is the enormous productivity potential it offers when the going is good – and the going doesn’t need to be any better underfoot than it was with our previous self-propelled sprayer.”
Ground conditions have been helped in recent years by the adoption of permanent tramlines, following the farm’s shift towards one-pass establishment and a 12/36m controlled traffic farming regime.
“We have the benefit of spreading 25t over three axles, and with six-wheel drive, we’ve actually increased our performance on steeper banks, compared with our old sprayer,” says Simon.
Powered by a 313hp MTU engine and driving all six wheels via a twin-range hydrostatic transmission, the DT3500H S4 packs a 380-litre fuel tank – enough for a 22-hour stint, says the farm, while a 50km/hr travel speed and all-round suspension boosts operator comfort.
In terms of manoeuvrability, sprayer operator Chris Traves says the Dammann is mightily impressive.
“With steering on the first and third axles, the sprayer turns very well when you consider its overall length,” says Chris. “And in-field, it rides superbly. It also packs plenty of power and shows no signs of giving up on either power or traction, particularly on a steep slope.”
Chris also has high praise for the sprayer’s revised cab, which is exclusive to Dammann and supplied by German cabin maker Dieteg. And with a generous sliding door and wide steps, access and exit is impressive.
“There’s not a cab like it on the market,” says Chris. “For leg-room, operator comfort and somewhere to put your bag, it’s fantastic and is easily a match for the comfort we enjoyed with the previous Rogator.
The 36m two-piece boom is managed by Dammann’s own boom levelling system, called Distance Control Dammann (DCD). At 36m, it uses six ultrasonic sensors, with two on each outer boom sections, to allow one to be mounted on the break-back.
DCD uses machine hydraulics and pneumatics to control the boom. In operation, it relies on six sensors working in combination with an angle sensor, while a gyroscope records yaw forces when dealing with curves. Effectively a VG-type boom, the Dammann-trac offers positive and negative boom movement from its rear mast folding points.
Section control amounts to 18, two-metre sections, run via a Müller system and linked into a Trimble auto-steering system with a signal supplied by RTK Farming’s network. LED spray pattern lighting automatically illuminates as boom sections are switched on, turning off as sections stop spraying.
Popular nozzle choices include 04 flat fan variable pressure nozzles, IDK air inclusion 03s and a liquid fertiliser nozzle.
“There’s no doubt that our productivity will increase as we settle into six-wheeled sprayer ownership,” says Simon King, who accepts that adopting any new process involved a period of familiarisation that is often needed to make the most of a machine’s strengths while managing its weaknesses.
“But we’ve quickly learned that tank capacity is key,” he adds. “And going back to a more conventional self-propelled sprayer would probably feel like we’re reaching for a knapsack sprayer.”