8 January 1999

DVLA clears up crawler doubts

By Andy Collings

CONFUSION over the licensing designation for rubber tracked crawlers (FW Machinery 25 Dec) now appears to have been resolved.

The DVLA has ruled that such machines are tracklayers and, as such, require operators driving them on the road to hold a group &#42 driving licence.

Operators holding a full licence (group F) can drive tracklayers on the road with a provisional licence – the full licence allows this – but they must display L plates.

This is a situation which many may take issue with and most will wish to ensure they hold a group &#42 driving licence to be certain that they stay within the law. But where tests can be taken and what they will comprise has yet to be decided.

Further information is available from PC Mark Bryant of Halesworth Traffic Unit (01986-835353). &#42

Vicon LZ515 solo drill plugs a gap in the firms range and has a starting price of £13,150 with Suffolk coulters, £15,750 with disc coulters.

Vicons drill plugs gap

VICON has plugged a gap in its range of pneumatic drills with the introduction of the LZ515, a 4m (13ft) solo model with 32 rows at 125mm (5in) row spacings.

Slotting between the 4m power harrow mounted LZ505 and the 6m solo LZ520, the new drill can be fitted with either Suffolk coulters, or 330mm (1ft 1in) diameter concave disc coulters for work in difficult soil types.

Hopper capacity is 1310 litres – an extension provides a further 200 litres – with seed distribution by the companys Marksman metering system, while Vicons rot- ating beam coulter adjustment arr-angement maintains planting depth.

Electronic in cab controls operate the tramlining facility and automatic indexing of the gull wing folding bout markers, in addition to monitoring functions such as seed shaft rotation speed, hopper level and air pressure.

Standard specification also inc-ludes wheel track eradicators. &#42

Sprayer testing is vital

POORLY maintained sprayers will cost farmers money, insists crop protection company Hutchin-sons Machinery, which recommends operators have their machines professionally tested and registered with the AEA Sprayer Test Scheme.

"With the development of crop and produce assurance schemes, growers are under greater pressure to show pesticides are being applied efficiently through well maintained, regularly serviced and correctly calibrated spraying equipment," says Hutchinsons Barry Shearman.

"Many sprayer problems cannot be detected with the naked eye, so it is easy to believe a machine is work- ing correctly when it is not," he says.

Common faults discovered by the company when carrying out its SprayCheck service include worn jets and water and hydraulic leaks.

Faulty gauges, defective valves, boom defects and broken couplings have also been found, as have defective fittings and missing labels. &#42

Robot tractor boost

It doesnt exactly look futuristic but the Squire robot is packed with some of the latest computer aided guidance technology.

ROBOT tractors – the boffins call them Intelligent Agricultural Vehicles or IAVs – will be taking over some of the routine farming jobs in the next century, according to an Essex-based research team which is developing the computer systems which will control them.

The list of jobs the engineers say the robot vehicles will handle includes bale collection and handling boxes of fruit or vegetables in the field and loading them on a trailer. They could also drive over fields looking for weeds which need spot treatment with a herbicide spray, or deal with routine transport jobs such as bringing crops from the field and delivering feed to livestock. One of the guidance systems could also help to steer a combine or forage harvester.

At this stage, harvesting help is the most advanced part of the project, which is organised by engineers at the University of Essex and Writtle College. They have designed an IAV called the Squire which has two sensors on one side feeding signals to a computer. This accurately guides the vehicle beside a fence or the side of a building.

The guidance sensors can also follow the edges of a standing crop. Tests with wheat and tall grass have shown that the guidance system could be used to steer a harvester, says Victor Callaghan of the University of Essex, easing the load on the driver and allowing faster working speeds.

For general field work the robot would need different guidance technology. This would be based on an imaging system, with a convex mirror above the IAV to give a 360 deg view of the whole field while the computer records the position of static features at the edge of the field. The features could be trees, posts, gates or buildings, and they would help the computer to map the field boundary.

As the robot moves about the field collecting bales or boxes or looking for weed patches to spray, the guidance system constantly checks its position with the boundary features. This would enable the vehicle to position itself with sufficient accuracy for most purposes, the research team believes, but the addition of GPS will also be considered. &#42

Standard specification for Claas Quadrant 2200 balers now includes an air blast cleaning system for the knotting mechanism. Replacing the twin electric fans on current models, the system consists of a flywheel-driven air compressor which blasts air, via individual feed lines, to each of the six knotters and the needle trip mechanism. Two air blasts, adjustable from 0.25-2.5 sec, are delivered between each tying cycle – the first when the bale is half formed, the second immediately before the needles trip and tie the bale.