FIRE crews battling the northern edge of the Gospers Mountain mega blaze - the largest single ignition point forest fire in Australia's history - are racing against the clock to shore up containment lines in remote and difficult terrain so exhausted volunteers can have Christmas Day off to spend with their families.
The Gospers Mountain monster was sparked by a lightning strike in Wollemi National Park on October 26 and has since burnt through an area of bush seven times the size of Singapore.
The blaze spread further south on Saturday in horrendously hot and windy conditions, with homes damaged or destroyed at Bilpin and Lithgow. On the northern end of the fire in the Hunter, the fire broke containment lines on Saturday at Putty Valley and crews were forced to undertake property protection.
With conditions more favourable on Sunday, crews were heading to remote and difficult terrain in Putty Valley to attempt to shore up containment lines.
"We've got some pretty difficult challenges ahead," Hunter Incident Management Team public liaison officer Leanne Bell said.
"Some of these fires are in really remote or difficult terrain. Down really steep escarpments into the valley and trying to get containment lines around that is really difficult. "We're trying to get everything done and consolidated by Christmas day so that the volunteers can have a day off."
Meanwhile, the Kerry Ridge fire, which started in the Muswellbrook area, made a "significant run to the east" on Saturday, crossing transition lines and burning across the northern part of Putty before the wind changed late in the day.