From Monday, August 3, until Friday, August 7, about 300 workers are expected to conduct more than 100 separate maintenance jobs including:

The ARTC has also kick-started a two-year program to replace three rail bridges (the Hunter River Bridge, Muscle Creek Bridge and Bridge Street bridge) in Muswellbrook.

"In the upcoming rail shutdown, sheet piling will be undertaken near Bridge Street and we plan to work both day and night to minimise the duration of disruption to the community and rail network," group executive Hunter Valley Wayne Johnson said.

He added the project would provide a solid economic boost for the Muswellbrook area, with up to 200 people working on it at various stages over the next 24 months.

"Delivering this construction project will help jump-start the economy and during these difficult times that is absolutely critical," Mr Johnson said.

Major work is taking place in Quirindi with the replacement of the bridge across Jacob and Joseph Creek, too.

This involves the removal of the existing bridge and installation of a large steel rail bridge, which will significantly reduce the maintenance for the structure.

Mr Johnson said the original steel bridge was built in 1927 and will be replaced with a new 85-metre longsteel bridge.

"The Quirindi works have been underway since last October with significant earthworks, concrete piling and concrete preparation now complete," he explained.

"It's a huge undertaking to remove the existing steel bridge and then to install by crane 28 precast concrete bridge girders and a new steel walkway and access stairs."

Signage and traffic control will be in place during the single lane closure to safely allow pedestrian and vehicle movements.

Mr Johnson said the work requires the shutdown of rail traffic of the Hunter Valley network to allow for the orchestrated sequence of activities to be carried out safely.

"COVID-19 requires ongoing vigilance in many aspects, as such, the health and safety throughout the works is of critical importance so we have ongoing strict hygiene protocols in place to minimise potential risks to the community and the teams involved in the Hunter Valley maintenance shutdown," he stated.

"The work will generally start at 6.30am on Monday, August 3, and is expected to be completed about 6.30am on Friday, August 7.

"We thank our customers, community and motorists across the network for their patience while we carry out this important planned maintenance program."

Alternative bus services will be provided for impacted passenger services, and details and schedules can be found at the Transport NSW website.

The next major maintenance shutdown is scheduled from September 22 to 24.

For further details, visit www.artc.com.au/community/track-work/

Single lane road closures of Bridge Street underneath the existing rail bridges between Market and Haydon streets: