By Mike Williams

FIFTEEN YEARS ago, Frank Bowser designed his own combi-drill after trying several different versions at his 231ha (570-acre) Roads Farm, Boston, Lincs.

He liked many of the features of a power harrow and drill combination including the one-pass till-and-drill capability. The power harrow”s capacity to make a tilth in a wide range of soil conditions proved another bonus, but typical mounted combis also have their limitations, he decided.

The modest lift capacity of tractors 15 years ago restricted the working width and weight of seed that could be carried in the hopper.

Mr Bowser based his trailed combination machine on a frame or carriage, hence “Carriage Drill”. The frame was carried on two low ground pressure tyres, with press wheels at the front of the frame to consolidate the soil between the transport wheels.

A Kuhn power harrow was mounted at the rear of the frame and seed from a hopper mounted above the frame was metered by an Accord mechanism with coulters positioned behind the power harrow. A coil-type press followed at the rear.

Mr Bowser was drilling about 324ha (800 acres) a year, including some contract work, and the results encouraged him to form a company to develop the Carriage Drill commercially alongside partner Richard Austin, while Lincs-based Burdens became the UK distributor.

The drill attracted a great deal of interest and for farmers with about 200ha (500 acres) of drilling it offered the advantages of a conventional combi with greater hopper capacity than mounted versions.

Production started in 1992 with 3m and 4m models, but the sales total only reached 10 machines. “I think the concept was right and a trailed drill has advantages in most conditions,” says Mr Bowser.

“A lot of the modern high capacity drills are trailed, using a frame with the seed hopper mounted on the top. We could have used tines instead of a power harrow, but I think power harrows are better for difficult conditions.

“The price was a problem because the Carriage Drill was more expensive than an ordinary piggy back” combination. Another problem was that we were a small organisation competing against big companies, but the fact that none of them were interested in taking over the concept was the biggest disappointment.

” Although most Carriage Drills are now 10 years or more old, some are still working.