Crews from Truro and Perranporth were called out yesterday evening after a report from a passing motorist that smoke could be seen in the distance.
A passing motorist called Fire Control reporting seeing smoke from a distance.
Two pumping appliances were mobilised to search the area near Trispen just before 9.30pm.
The firefighters found one tractor, one mini digger and an external catering van on fire.
The two seats of fire were extinguished using four hose reel jets and once all was dampened down the scene was left in the hands of the police.
Arson is suspected.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here