Firefighters on Tuesday held the Fir Mountain Fire within its perimeter in spite of breezy afternoon winds, with the only activity from consumption of unburned fuels within the perimeter.  The Oregon Department of Forestry reports that fire behavior moderated from the last few days, allowing firefighters to focus on establishing and reinforcing firelines.  Containment for the fire has increased to 30%, and it remains 313 acres in size.  Helicopters were used on Tuesday to drop water and cool the spot fires on the eastern flank to allow ground resources to build fireline on the edge of the fire, with heavy equipment being used where possible while hand crews work in more difficult terrain.  Heavy fuels continue to be a problem, and but on the east flank construction of hoselays has begun to deliver water to that area of the fire.  Additional personnel arrived on Tuesday to bring the total number to 400.  The fire was first reported last Saturday, and remains under investigation.