The great leap forward in combine technology
Monday, February 28, 2011
The past 50 years has witnessed great strides in combine design. What's ahead? Perhaps completely robotic, remote-controlled combines
by RALPH WINFIELD
Some of us older folk can remember when the objective of the combine manufacturers was to have a combine on every 100-acre farm in Ontario. These were the self-propelled units such as the Massey-Ferguson "35" and the International Harvester "91."
They were replacing the Massey Harris "Clipper" and the Allis-Chalmers "All-Crop" series. These pull-type units crushed some crop and tied up the main farm tractor, which was usually about 35 to 50 h.p.
In the early 1960s, as an aspiring agricultural/mechanical engineer, I had the burning desire to work in combine design and development. My primary objective was to make combines more service- and repair-friendly. I had previously done a significant amount of machinery repair on tractors and some early combines that had the engine down on the main frame.
I soon learned that only one company – Massey Ferguson – was designing and developing combines in Canada. Working in the United States at that time would have meant a two-year stint serving Uncle Sam.
I served one summer in the R&D lab at Massey Ferguson testing engines, governors/carburetors/cooling systems and hydraulic components. What I really learned was that the manufacturer did not want a powerful, high torque engine in the combine.
The rationale was that it would just plug the combine more often and a lot tighter. The objective was to use an engine that had a very flat torque curve, so the engine would stall immediately if the cylinder plugged.
Do remember that most combines at that time were not designed to shell corn in the late fall when fields were muddy and powerful, high-torque engines would be required just to propel the combine.
But times changed. By the early 1970s, field shelling of corn was becoming a standard practice. Most combines were still relatively small, carrying only a two- or three-row header.
By the late 1970s, the pendulum had swung full cycle. Combines and headers were becoming bigger. Higher horsepower diesel engines, with good torque reserves, were necessary to maintain constant component speeds.
Feeder house reversers became popular as design changes made the feeder house the limiting factor to avoid plugging the cylinder. How many of you remember trying to clear a plugged cylinder? My first combine, an IH-91, which only handled cereal crops and beans, came with a long cylinder-rocking wrench. Some of the newer wheat varieties of that era still had very tough straw when the grain was dry enough to harvest. I remember having to let the concaves down on one occasion to clear the cylinder!
By the 1980s, the size/capacity race was on. John Deere introduced the 20 series combines with the 8820 having over 200 h.p. These larger-sized combines were expected to cover a bigger acreage each year to justify the increased capital costs.
Enter the grain buggy era. It became evident that if you could unload the combine on-the-go, its "field efficiency" could easily be doubled. Thus, we needed even more power available to unload the combine while it was operating under full load conditions.
The capacity and power race was in full swing as the higher capital cost now had to be spread over more and more acres.
It should also be mentioned that rotor technology came into its own as more threshing area could be provided to increase the throughput rate of crop. But along with increased throughput rate came the need for increased cleaning area to ensure that the seed was not being discharged back onto the field.
A quick review of some 2010 combine specifications reveals that we have indeed broken the 500-h.p barrier with most units in the 300-plus horsepower range. These large diesel engines have more "power bulge" than the total power available in the 1960s combines, when torque was limited to prevent serious plugging!
The addition of cabs in the 1960s was a great step forward as operators were given more creature comforts so that they could be more relaxed and responsive. Air conditioning became a required add-on, because an enclosed cab which eliminated dust often became an oven during wheat harvest.
But wait. As we entered the 1990s, yield monitors became readily available. They were great. As an operator you could see the yield variation in or between fields. But wait again. Could you remember all that data as you concentrated on operating the combine? Not a chance.
The GPS attachment to the yield monitor brought it all together. The data card allowed for fantastic coloured yield maps to be drawn. It showed yield variations across the field(s). What a great source of information about the field! You could then do area fertility tests as well as compaction tests using a penetrometer.
What followed was of course variable rate fertilizer application as well as variable rate planting. We truly entered the information overload era.
So what did some ingenious technology experts do for us combine operators? They brought forward systems for hands-free steering so that we would have more time to pay attention to the big yields and know what to do about the lower yields.
What's in the future? Perhaps completely robotic, remote-controlled combines. As the farming population ages, it will make it easier to harvest the crop from the comfort of a lawn chair on the sidelines. BF
Agricultural engineer Ralph Winfield farms at Belmont in Elgin County.