The breakthrough came when Komatsu engineers wanted to build a harvester from scratch, rather than on a modified forwarder chassis as was common at the time. They developed a prototype for a thinning harvester, but the difficulty was stability. After many tests, they came up with the solution that is still a hallmark of Komatsu harvesters today.The concept consists of an innovative swing axle that improved stability by locating the engine at the rear. This design, together with a unique hydraulic levelling solution, allowed the machine to navigate difficult terrain with both high precision and efficiency. The tilt cylinders were linked to the swing axle stability cylinders, which meant very good machine control during work - even in steep terrain.
It sounds complicated - but in practice it means that if the crane is working far out from the machine and carrying a heavy tree, two stabilising cylinders work as an automatic counterforce to maintain stability. This innovation, combined with the automatically levelling cab, makes Komatsu harvesters very stable and comfortable to work in.
And that's probably the most important benefit of a stable machine. The feeling when you can sit safely and upright even though the terrain is sloping. It allows you to work in a more relaxed way and thus feel more alert at the end of the day.
Four decades later, Komatsu's stability concept shows that true innovation not only stands the test of time, but continues to make life easier for operators, whatever the terrain.
If you want to read more about how the stability concept came about, there is an article about it in the 2024 edition of Just Forest which you can find here.
