BY PETER O'BRIEN
ROTARY combines are somewhat in the minority in Ireland which has a preference for the conventional straw walker machine.
While a rotary combine can be harsher on straw, there is no denying their higher volume of output over their straw walker counterparts.
With most of the combine manufactures now using the rotary concept in their largest combines, it was International Harvester ¬– now Case IH – who were amongst the pioneers of the concept.
Through research in the 1950s, International Harvester’s engineers concluded that a rotary design would have a higher output and great efficiency over the straw walker design. However, it would take almost 20 years of development before the first rotary machine was released in 1977 – the 1460 Axial Flow. A rotary combine uses separating grates and centrifugal force to separate the grain. A single rotor takes the material from the header and moves it rearward in a spiraling path. The rotor uses a series of straight and helical rasp bars to separate the grain over the separating area.
Interestingly, the 1460 had a side discharge for the straw during its developmental stages. This unique design was changed to the traditional rear exit for the straw. As a further side note, New Holland had beaten International Harvester in the ‘rotary race’, launching their first rotary combine, the TR70, in 1975.
Flash forward to 1986, and a new lineup of Axial Flow combines, the 1600 series with the range topping 1680. Early models of the 1680 were fitted with a 225hp 7.6l engine, models from 1989 benefited from the legendary 8.3l Cummins engine ¬– the same powerplant used in Case’s Magnum tractors¬ – developing 235hp. The 1680 has a 7400l grain tank with an unloading rate of 4000l/sec and is equipped with a 30inch diameter rotor – the largest of the 1600 series combines.
It is equipped with a three-speed hydrostatic transmission, variable speed cleaning fan over a cleaning area of 6,400 square inches, twin straw spreaders, and electric header reverser.
In the cab, the grey and black trim gives a purposeful feel, with a foot pedal adjustable steering wheel, with a touch pad control tachometer now introduced, as well as an optional gran scan monitor for checking grain losses and shaft speed monitor which sounds an alarm when rotor speed drops below 70%.
The 1600 series combines were also marketed as Case International with red over black paintwork as part of the Case takeover of International by Tenneco. If you have an Axial Flow combine, please get in touch.
•Contact Peter at [email protected] or see Instagram @flashphotoscork
