Most of the fieldwork on a farm is carried out while moving along the field, using an implement attached behind the pulling power source, which performs its task during motion. The implements vary in form according to the work they are designed to do - from the plow, the oldest agricultural tool, to today’s advanced combine harvester. Some implements are towed, such as the plow, the harrow, and various cultivators designed to prepare the soil for sowing and to destroy weeds. Later, traction power was used to operate mechanisms via transport wheels, as needed - for example, the mower (1830), the hay loader, the binder, the rake, seeding and fertilizing machines, and eventually the combine, which was once pulled by 27 mules.
The first pulling power was the human being himself (thousands of years ago), followed by oxen, horses, and mules, until the steam engine appeared - positioned at the edge of the field and pulling the plow back and forth using a cable. When the internal combustion engine appeared, wheels were added to it, creating the tractor, which replaced work animals as the source of pulling power. In the 1930s, the P.T.O. (power take-off) was added to operate mechanisms of various implements the tractor towed.
As tractor engines grew stronger, attention had to be given to the opposing force - traction with the ground. This was first solved by the crawler tractor, which had a large contact surface with the soil. Later came iron wheels with large spikes that penetrated the ground and prevented slipping. Then came rubber tires, 4×4 drive systems, and today there are even tractors with eight tires and 400 horsepower. In the hitching system of the plow to the tractor - invented by Harry Ferguson - the resistance of the soil on the plow is used to increase the tractor’s wheel grip on the ground.
In England in the 1960s, two identical tractors were connected one behind the other, with the driver sitting on the rear tractor and able to control the front one as well. This doubled the pulling power and increased traction with the ground.
Connecting Two Tractors at Home
I attended an exhibition in England and saw the coupled tractors in action. I decided to try creating something similar using my own private collection. I took two Ferguson 28 tractors, both operational and drivable. I removed the front axle from one and rested its front end on the sturdy rear drawbar of the second tractor, connecting them with a pivot joint - much like hitching a wagon. I left the front wheels in place.
The first challenge was how to steer the front tractor using the steering wheel of the rear tractor. I welded a short arm opposite each front wheel spindle and ran a steel cable from them to the steering arms of the rear tractor, through small pulleys positioned beneath the pivot joint - so that when turning, the cable lengths remained constant (the Ferguson has two steering arms).
I solved the clutch problem by installing a vertical lever above each clutch pedal, with a short arm connected to the pedal itself. A steel cable ran between the two levers through a small pulley above the pivot point. This way, when pulling the lever on the rear tractor, the clutch of the front tractor was also engaged, allowing gear shifting there.
For shifting gears, I used an old car window regulator mechanism, mounted near the front tractor’s gear lever. This allowed the lever to be moved electrically to first gear, neutral, or second gear - all controlled from the rear tractor, including indicator lights showing the lever’s position.
The throttle of the front tractor could be controlled from the rear tractor using a throttle cable from a lawn mower.
To ensure both tractors shared the load equally, I installed digital tachometers near the PTO shafts, with displays in front of the operator, allowing him to monitor and synchronize the tractors’ work.
All control over the attached implements, as well as other operations such as reversing or road travel, was done from the rear tractor, while the front tractor was used only for steering, with its gear lever left in neutral.
The advantages of this system are the doubling of pulling power and improved traction. Another benefit is that the tractors can be separated and used independently for lighter tasks.