The latest “compact” disc harrow from Pottinger is designed to not only equip the most powerful of tractors, but also allow streamlined cultivation in a 12/24/26m controlled traffic farming (CTF) system.

At 12.5m, the Terradisc HT 12000 is now the widest model in the range, succeeding the 8m and 9m versions to that title, for working with 450-720hp tractors.

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Like all Terradisc variants, the newcomer deploys two rows of either plain or scalloped 580mm diameter concave discs, set at an aggressive angle for primary or secondary tillage from 50mm deep.

Unlike its siblings, though, its 12.5m breadth is divided into four frame sections that can follow surface contours individually, each of the outer wings being supported by a pair of large tracking wheels, the inners by the tandem wheeled chassis.

While the inner frame sections are free to rise 6deg or drop 3deg, the outer sections can move plus or minus 4.5deg.

This, together with hydraulic pre-tensioning, should ensure all discs remain at the required depth over undulating ground across the entire working width.

Stone protection

Protection against damaging stone impacts is provided by rubber cushions within each clamp securing two disc-arm assemblies to the main frame.

Being 380mm wide, the clamp’s surface area is reckoned to be enough to discourage twisting movements that would alter the working angle of the discs.

Cultivating depth is set using 9mm thick swing clips on the lift/lower hydraulic cylinders for the rear packer, which supports the weight of the implement during headland turns.

Four double-acting spool valves with “intelligent presets” regulate all the key functions and settings, such as working depth, headland lift position, down-pressure on the disc sections and the lengthy cylinders that extend from the chassis to the disc frame to counter any side-pull tendencies.

A tilt and horizontal folding sequence prepares the implement for road travel and, to maintain effective in-field manoeuvrability, the drawbar is reckoned to be long enough to allow tight turning angles of up to 85deg, even with wide, heavyweight wheeled and tracked tractors.