sapper
soldier who performs a variety of military engineering duties
faber
worker in charge of making or looking for some type of material, for example the carpenters, blacksmiths, etc. Specifically, in the army the fabri formed a body of artisans and workers
miner
soldier whose job was to create a tunnel under the walls of the besieged fortress to collapse the fortress walls with a large explosive charge or provide access to a possible surprise attack without being noticed
army scout
soldier performing reconnaissance and other support duties