Drainage on peat
Plantations established on peat depend on drainage networks to control the water table. Those networks need cutting initially and maintaining continuously, because peat subsides and drains silt up.
Why standard machines struggle
Peat has very low bearing capacity and the drains are usually narrow with limited access along them. Amphibious and low-ground-pressure machines work where conventional equipment would sink, and smaller classes matter here because access between planted rows is constrained.
Continuous maintenance, not a one-off
Drainage maintenance is ongoing work. That changes the economics compared with a one-off construction job: machine reliability, parts availability and running cost dominate over peak productivity, because the machine is expected to work the same network year after year.
Water table management
Drainage depth is a controlled variable rather than something to maximise. Over-drainage accelerates peat oxidation and subsidence, which creates a worse problem than the one being solved. The equipment needs to cut to a specification, not simply as deep as it can.