A crawler tractor is a special type of tractor which uses tracks instead of wheels and this gives it several advantages over a conventional tractor:
- Better traction. On a conventional wheeled tractor the contact patch is limited to where the wheels touch the ground. Depending on tyre pressures and loads this may be as little as a few square feet. A Crawler tractor on the other hand may have tracks which extend the entire length of the machine giving a contact patch many square meters in size. The larger the area of contact the tractor has with the ground, the more it is able to hold onto the ground.
- Lower Ground Pressure. The larger conatct patch described above also has another benefit. A major concern in agriculture these days is soil compaction, the phenoninom of soil packing down as vehicles drive over it. Soil compaction destroys the soil's structure making it difficult for water to flow, air to move and roots to grow. The larger the conatct patch the tractor has with the ground the more the wieght of the machine is spread out and the machine exherts a lower pressure on the soil, meaning it takes a lot longer for soil compaction to reach the same levels. It also means that in "soft" conditions a crawler will "float" on the surface where a wheeled machine may break the surface and bog down.
- Greater Stability. Often the tracks on a crawler are a lot wider than the wheels otherwise used and the machine may also sit a lot lower to the ground as well. This wider profile and lower centre of gravity means that the machine can be used on a much greater side-slope before it tips over.
These reasons and a few others make crawler tractors suitable for use in situations where high traction is required, on steep hill sides, in soft conditions or where soil compaction is of concern.
