A grassfire near the O’Herns Road intersection with the Hume Highway in Epping last Wednesday is believed to have been started by sparks from machinery.
Firefighters manning more than 20 CFA trucks brought the fast-moving fire under control within about an hour of it being reported about 12.30pm.
A CFA spokeswoman told the Weekly the motors of any machinery in use for some time could become hot enough to ignite dry grass.
A series of spot fires along the Hume Highway last month were allegedly started by a truck carting hay, which was pushed up against the exhaust outlet alongside the truck’s cabin.
All vehicle exhausts should be fitted with fire-protective shields.