The Australian Rail Track Corporation (ARTC) are forecasting a return to rail services for the Northern line in coming weeks.
ARTC engineers have now completed their inspections of the site near Boggabri where six wagons from a coal train derailed on Wednesday last week.
The rail closure has impacted heavily on the region's economy and businesses disrupting the transport of tens of millions of dollars worth of agricultural commodities, coal and freight.
"It is going to be some weeks before the track and the bridge can return to service," an ARTC spokesperson said yesterday.
“With the wagons removed, ARTC engineers have undertaken assessments of the damage to the bridge and track as well as the scale of the repairs required,” the spokesperson said.
“Based on these initial assessments we estimate around three weeks will be required to undertake the program of work needed to return the bridge to operational service.
“As a result, we are currently forecasting a return to rail services by Christmas,” the spokesperson said.
The ATRC said the damage is extensive, including the structure of the bridge itself as well as the track, and a large repair and construction job lies ahead.
“Initial works require repairs to the piers that support the bridge structure, and will include some significant concrete works focused on securing the structural integrity of the bridge.