COMBINE HARVESTER
Harry Metcalfe is a petrolhead. He’s also a farmer. So this is one of his favourite machines…
The biggest machine in Harry’s Garage
Idon’t often mention the Case 7088 when asked about what’s hiding in my garage but, since you ask, yes, I do have a Case combine harvester in there and it’s one of my favourite toys. There are lots of things to like on a combine: for starters, they tend to be quite big. Mine stands 3.8m tall and has a track width (across the front axle) of 4.3m, which can be quite testing down a narrow country road. It also has a very un-Lotus-like kerbweight of 15.2 tonnes, and that’s when empty; fill the on-board grain tank and that figure balloons to 24.3 tonnes, which even I was a bit shocked by. To be honest, I’d never bothered to work it out until now.
There’s plenty of power there to keep things moving, though, and you could describe the combine as having a mid-engined layout, not that that makes it handle any better (I think it’s fair to say a combine driver has little interest in its cornering ability), being much more to do with packaging. The surprise is that you have to first climb up a swing-down ladder fitted at the back of the combine before you can find the impressive 9.0-litre, straight-six turbodiesel engine, pumping out a healthy 375bhp at a precise 2410rpm. It sits two metres above the ground, which does nothing for the machine’s centre of gravity.
Now, despite the fun facts I’ve listed above, you’re probably wondering why on Earth I own a combine and I can see your point, so perhaps I should explain. Go back to when the idea of founding evo [performance car magazine and Octane’s sister title] was embryonic, circa 1998, and, if you’d asked me what my main occupation was, I would have said farming. I was then working around 2100 acres of arable land, mainly on short-term rental agreements, but, as evo started to become a success, the farming enterprise was really suffering thanks to historically low grain prices, and it soon became obvious that the sensible option was to drop the farmed acreage right down and concentrate on evo instead.
That’s exactly what we did and by 2003 I was farming only 300 acres, with all the work being done by an outside contractor, leaving me completely free to run the magazine. But as the years ticked by, I really started to miss farming the land myself way more than I’d expected, so, when the contractor I was using decided to retire in 2017, it seemed a good time to have a rethink.
The best bit of farming for me was always the excitement of harvest and being able to gather the crops exactly at the point when they were at their best. But to do that would mean buying a combine, which is the most expensive bit of farm machinery of all. And then I’d need a tractor, and a grain trailer to take the grain from the combine to the grain-shed. Oh, and maybe a loader to load the grain onto a lorry would be a good idea, too.
The man-maths kicked in (we used to call it
‘evonomics’) and, by buying good secondhand kit, I thought the total bill for this little assembly might be £160,000.
But where would the money come from? Aha, what about selling that Bond Defender thing used during the filming of the Bond movie Spectre, the one that sat in the corner of Harry’s Garage, usually for months on end? I’d bought it a couple of years previously in an act of extreme rashness, thinking it looked spectacular, but later discovering that it was actually pretty useless as a car and wasn’t even road-legal. I only once got it properly muddy but I then spent nearly a week cleaning it before I could park it back in the garage without it dropping mud everywhere, and I swore I’d never bother doing it again…
A deal on the Defender was done and so the hunt for a combine began. The last few harvests (2015-17) on our farm had turned
‘YOU COULD DESCRIBE THE COMBINE AS HAVING A MIDENGINED LAYOUT, NOT THAT THAT MAKES IT HANDLE ANY BETTER’
into a breakdown nightmare for the contractor, mainly due to random electrical sensor issues on his reasonably new Claas combine, plus two complete gearbox failures (circa £40,000 to repair) over a three-year period.
Hmm… After his experience, I decided I wanted a combine with the minimal number of sensors but one that was new enough to have all the recent tech on board, such as instantaneous read-outs for crop yield and moisture content of the grain being harvested, and satellite tracking to allow the combine to produce a yield map of the field being worked.
‘BEING COCOONED IN THAT BUBBLE OF A CAB CAN BE A VERY SATISFYING PLACE TO SPEND TIME’
Now, I used to have a Case combine back in the 1990s and liked their relative simplicity and general toughness, so that became my first choice. It also helped that my local dealer was a Case franchise and the people there didn’t take long to find an ideal-spec machine for me – the one you see here. When new (in 2010) it had a list price nudging £200,000 but, after seven harvest seasons and 1500 hours of running, I could buy it for £86,500.
With a 24ft header (the detachable bit at the front), it had been the sole combine on a big family farm, cutting around 1100 acres of arable crops per year, meaning my 300 acres would be a doddle in comparison. Well, that was the hope anyway. Because it had hydraulic steering rather than electric, even though it was fully hooked-up for satellite tracking, it didn’t have the self-steer option that most modern combines have now and which allows handsfree operation when in work, with the driver having to steer only when out of work or turning round on field headlands. To get this feature would have meant buying a later version, costing at least £30,000 more, which didn’t seem worth it. My son, who drives the combine on the farm, vigorously disagrees with me on this point, but my son doesn’t have to pay the bills.
If you’re wondering why I don’t drive the combine myself, it’s because once you’re in the cab you tend to get trapped there for the whole day, which makes it hard to manage the harvest and do all the extra bits you need to do to keep the combine working flat-out. This includes checking which field is ready to be harvested
next, dealing with the grain store, and pushing up the heap so all the harvest can fit in. Then there might be lorries to be loaded, too; it’s best to think of the combine as being a bit like a queen bee, with a battalion of the worker bees flat out hovering around it, doing all the menial work.
Having said that, the combine driver really has the top job, and being cocooned in that bubble of a cab can be a very satisfying place to spend time. With a relatively small space to chill, its air-conditioning can easily deliver arctic temperatures in the height of summer, while the four-speaker sound system is top-rate and you can listen to podcasts, that weekend’s Grand Prix or Spotify without interruption for hours on end, thanks to the beautifully insulated environment. Even the fully airsprung armchair (calling it a seat doesn’t do it justice) is trimmed in luxurious red leather, so it doesn’t absorb itchy grain dust like a nylontrimmed seat might.
The big risk with any combine is fire, often caused from tinder-dry crop residues building up in the machine’s many nooks and crannies and then coming into contact with something hot, such as the exhaust or a random bearing somewhere that’s decided to overheat. To prevent this from happening, the first job every morning is to blow all the dust and crud off the combine – we use a leaf blower to do this. Next we have to pump grease into approximately 14 grease nipples scattered around its innards. Then we check there’s enough diesel on board to last the day.
The diesel tank on our combine holds a monstrous-sounding 950 litres, though that’s enough for only two good days’ work. Filling the tank means bringing a bowser out to the field and using a donkey engine to pump diesel up to the top of the tank, which (again) is two metres off the ground.
Everything on a combine is on a big scale and yet mine is a relative baby in comparison to some of the monsters around today. The biggest currently on sale in the UK is the John Deere X9, which lists at £850,000 and is powered by a 700bhp 13.6-litre twin-turbo engine. With a 12.1m (37ft) wide header feeding the crop into the belly of the machine for threshing, its output is frightening – but, then, so is that list price, and it needs to harvest many thousands of acres per season even to begin justifying the thought of owning one.
In a good crop of wheat, my combine would be travelling at 5-7km/h, equating to an output of around 30-40 tonnes an hour, while the X9 might be travelling at 8-9km/h and, with its 50% bigger header, would be producing approximately 120-150 tonnes of threshed grain per hour, a dramatically higher output – yet the surprise is the near-identical way in which both my Case 7088 and this X9 thresh out the grain. Here’s how it works.
The first stage in the process is the header, which cuts the crop and then feeds it into the heart of the combine. The big reel across the header generally runs at the same speed as the combine (or a smidgen faster) and is there to hold the crop steady as the knife cuts it, and to help knock the crop onto the bed of the header, where a big auger captures it and feeds it to the centre of the header.
Here it gets grabbed again and fed into the belly of the combine, where the main threshing takes place. This is done by a large, 76cmdiameter rotor, some three metres long and, on my combine, positioned longitudinally. The crop comes into the concave chamber where this big rotor is spinning inside at around 1000rpm, and its job is to bash the crop to
‘THE DIESEL TANK ON OUR COMBINE HOLDS A MONSTROUS-SOUNDING 950 LITRES – ENOUGH FOR TWO DAYS’ WORK’
thresh the seed out of it without damaging it, while feeding the residue (straw) out the back.
The outside of the concave is like a sieve and any threshed grains simply drop through it to another set of sieves (adjustable from the cab for different seed-sized crops), which separates the grain from the smaller (or larger) bits of residue that have also dropped out of the concave. Air blows along this bank of sieves from an adjustable fan below, to get rid of the lighter bits of residue until you end up with a nice, clean sample of grain right at the base of the combine, which is then lifted up to the top and into the nine-tonne tank by a grain elevator.
All that’s left then is mainly straw, which is either chopped by a massive flail at the back of the combine (and which is responsible for that distinctive combine sound) so it can be incorporated back into the soil, or left in swathes behind the combine ready to be baled. The fact that all these processes take place in one machine earns it the ‘combine’ part of its name.
The driver has a critical part to play, too. Their job is to keep the combine fed with a continual flow of crop, as the threshing system relies on it being full to work properly; you can’t tickle along at 10% capacity, you really need to be at least at 70% before you get a decent grain sample. That’s the driver’s main task but they’ve also got to look out for stones and other harmful stuff (bikes, branches, shopping trolleys, etc) getting picked up on the header and hit the stop button before they can do harm. For most crops it ends up being a balancing job between forward speed, how tight you’ve set the concave (distance between the rotor and the outer sieves), and the quality of the crop you’re harvesting.
What’s great about our combine is that its output is actually much too big for our farm, which is a good thing because it means we should never be up against it and will always have the luxury of combining only when the conditions are perfect (it also leaves me time to do other things, such as Harry’s Garage). For the 2020 harvest, that meant not starting until
‘WE MIGHT USE THIS LEVIATHAN ONLY ONCE A YEAR BUT BOY DO WE LOOK FORWARD TO IT’
around 5pm most evenings, by which time the grain was dry and threshed out beautifully. Even with the late starts, we managed to complete the job by 12 August, just before the arrival of the serious rains that have decimated many UK farmers’ harvests this year.
When I checked the rotor hour meter, it showed that we’d completed this year’s harvest in just 46 hours’ running time. Remarkable really, but they were a deeply satisfying 46 hours and the ease of this year’s harvest means all our grain has gone for top-quality milling spec, as it hadn’t been rain-damaged.
Now it’s over, it’s time to give the combine a thorough clean and put it back in the shed for another year. We might use this leviathan of a machine only once a year but boy do we look forward to harvest time, which was precisely the reason I bought it three seasons ago. Plus I never really liked Land Rover Defenders anyway.
CHECK OUT Harry’s Garage and his parallel video series, Harry’s Farm, on YouTube.