Pioneer units are created when you give a colonist tools. Pioneers have several important functions: they clear woods, plow fields, and build roads. In general, Hardy Pioneers perform their tasks faster than ordinary colonists working as pioneers.
A colonist can be equipped with a minimum of 20 tools, and a maximum of 100. Each action performed on the terrain consumes 20 of these tools. Therefore, any Pioneer can perform a maximum of 5 actions before having to be re-equipped with more tools.