For those of you unfamiliar with the technique, the Diamond harrow developed by the Australian Kelly family, uses four chains lined up in a diamond formation. Each chain is formed by a crop-specific row of replaceable metal discs or spiked disc or prickle chain.
Suitable for use on a wide range of soils and conditions, the increased accuracy of the 330mm diameter K4 is due to its lighter weight and shorter 160mm spacing between the disc units. Operating speeds are 12-14km/hr, the K4 requires approximately 24hp/metre of working width.
The new disc slots in between the existing CL2 (concave replaceable 22.6kg disc (11.2kg/m) spaced at 215mm) and CL1 (11.2kg cast steel alloy concave disc (70kg/m) spaced at 163mm). The cutting ability of the new disc is said to be comparable to that of the more aggressive CL2, but the lighter weight of the K4 of 11kg/disc unit (68kg/m) is claimed to be better suited for more precise shallow cultivating.
Diamond harrows made in the South Australian outback town of Booleroo extend up to 24.0m. The R+D is still done in Australia, but European machines have been manufactured under contract at a facility in Germany since 2017. The three European-built models currently in the portfolio (6.0m, 9.0m and 12.0m) all fold to a transport height of below 4.0m.
The K4 has been received well in Germany where it is already fitted to a 9.0m and 12.0m model, and the new disc is also used on a 6.0m model in Italy. Tractor power requirement is from 140-200hp (6.0m), 210-300hp (9.0m) and 290-400hp (12.0m).
UK and Irish dealers wanted
Importers are already in place for the Kelly harrows in the Austria, Estonia, Italy and the Netherlands, and European manager Nicolas Doyle of Kelly Engineering, who operates from an office close to Zurich in Switzerland, is in discussions with potential dealers in the Czech Republic, France, Lithuania, Poland and Spain.
Previously available in the UK through Weaving Machinery, which was supplied with Diamond harrows initially made under licence in Denmark, and from 2015 shipped directly from Australia, Mr Doyle is now looking to appoint a network of UK and Irish dealers.
The headwind has been against him in this Corona year, though, which has made things extremely difficult and almost impossible to meet face to face with potential dealers.
Even so, the European manager reckons to be in discussion with at least one dealer, and is keen to talk to others. “We are working towards having a demonstration machine in the UK sometime 2021,” he says.
“All spare parts are currently stocked in Germany at the factory, but we will encourage dealers to stock parts for shorter lead times and better customer support. We are currently looking at ways to shorten the supply chain throughout Europe and to the UK and Ireland.”
And this brings us to the cost of a 6.0m Diamond harrow in mainland Europe, which as a very rough guide starts from just under €30,000 (front and rear prickle chain) and around €36,500 for a CL1 disc front and rear. The K4 costs more, is the message, and the CL2 is a lot more expensive.
And in case you were wondering, it is possible to swap complete sets of CL1s, CL2s and K4s. “It depends on the situation, but some customers often have a set of CL1 front and rear discs, a lighter set of chains (spiked disc or prickle chain) or a more aggressive set of discs like the K4 or the CL2. It is quite normal for these to be changed between seasons,” adds Mr Doyle.
After de-tensioning the chain and loosening the securing bolt at each end, the chain set is swapped for the replacement. “The removal of a complete length is a job for a tractor loader or telehandler. It is possible to remove the discs manually set by set, but this is obviously much slower.”