Horse-Powered Disc Mower
by Stuart Pattison of Devon, England
The great advantage of the rotary disc mower over the reciprocating cutter-bar (sickle bar) mower is that it will keep cutting without blocking up even in bad conditions of laid and tangled crop and in grass which is thick and wet in the bottom. This is why nobody uses anything other than high-speed rotary mowers in the maritime areas of western Europe.
With often fickle weather conditions, speed at haymaking time is important. Delays in getting the grass cut result in hay getting rained on before it can be made safe.
Of the older disc mowers, the New Holland 4-disc mower is the lightest in weight (5 ft. 3 inches cut) and they are still fairly common in Britain. I have used a team of 6 on the 4-disc mower with a ground-drive pto speed of around 330 or 440 rpm (see photo).
But I now have also another machine cut down to 3 discs (about 4 ft. cut) for 5 horses to pull which I think works rather better because the reduced traction demand on the drive wheels means that the wheel-strakes do not need to seriously engage the turf so that the ground is hardly disturbed. Also it is easier to keep up the disc tip speed by moving up (by which I mean down since everything is reversed) one or two gears.
Details of this heavy hitchcart used for driving the mower appeared in an article called “GOOD OLD HARRY,” SFJ Fall 1995.
It is possible to buy new disc mowers to fit small garden tractors but is an inescapable fact of dynamics that where you are aiming to achieve high rotary speeds from ground drive with substantial pieces of kit, you must have a heavyweight drive unit to provide the traction.
With due respect to the editor of this Journal whose enthusiasm for sickle-bar mowers is internationally acclaimed, in anything other than clean, light, upstanding crops of grass and cereals, the disc mower provides a wholly more trouble-free and maintenance-free tool for the job.
It is entirely appropriate, even on mixed power farms (horses and tractors), that the horses should cut their own grass and make the hay. This is my preferred way of doing it here in the humid south-west of England.
The second photo shows my 12 volt, 3-point hydraulic hitchcart being used with a Vicon Acrobat hay turner. The hay is then round baled by a (custom) contractor.
It is advisable to wear safety goggles when mowing with high speed rotary mowers because of a theoretical risk of small stones bouncing off the tires.
If anyone wanted to drive this mower with fewer than 5 horses in the team, then probably it would need to have a 25 h.p. engine attached. But I am trying to reduce, not increase, reliance on fossil fuels.
When mowing, the best way of operating is to clear the headlands earlier by zero grazing, tethering stallions or making silage. Then you get a good run at the grass with the mower to keep up the rotary speed at each turn. The disc speed is 3200 rpm at 540 pto speed.
This rig is trouble-free in use and maintenance-free after use.
Stuart Pattison has farmed with horses for 30 years and runs training courses in England, specializing in organic farming and horse-powered weed control in cereals and row-crops.