A full schedule of Blue Mountains trackwork and shutdown periods has been released up to May next year.
The work is being done to cater for railway line modifications to support the rollout of the new intercity fleet.
Twelve days of trackwork finished on September 13. The next period is marked for October 28-November 8.
Standard construction hours are 7am to 6pm Monday to Friday and 8am to 1pm Saturday, but work outside construction hours is expected in these shutdown periods, according to Transport NSW information.
During October 28-November 8, Faulconbridge, Linden, Hazelbrook, Bullaburra, Wentworth Falls, Katoomba, Mt Victoria, Lithgow and the Ten Tunnels (between Newnes Junction Station and Zig Zag Station) will be affected.
There is also trackwork planned from December 26-30. It will affect Ten Tunnels, Woodford, Lawson, Leura, Katoomba, Mt Victoria and Lithgow.
Subject to verification, work is set for February 21 to March 6, 2020, affecting Ten Tunnels, Lawson, Katoomba, Medlow Bath, Blackheath, Bell, Mt Victoria and Lithgow.
Work commissioning Faulconbridge to Lithgow is expected from May 11-22, 2020, but this is still to be confirmed.
Platforms are being extended at Katoomba, Lithgow and Mt Victoria.
A NSW government brochure said the modifications were "always planned as part of the new intercity fleet project, [to] make the Blue Mountains line consistent with the rest of the electrified train network".
It's a comment consistently refuted by Blue Mountains Labor member Trish Doyle.
"When this fiasco first unfolded, we were promised the work to modify the tracks, tunnels and platforms would be done during routine maintenance days, on weekends, and there would not be any substantial interruption," Ms Doyle said. "Now, we find out they might shut down the whole line more than ten days at a time."
"We still haven't been told what the financial hit to taxpayers has been to do all of this extra work, but the true cost of the Liberals' folly with their 'off the shelf', Korean-built trains will ultimately be borne by passengers. These trains don't fit, they never did fit and now our community has to suffer while the government cleans up a big mess it created."
A Sydney Trains spokesperson said: "Sydney Trains and NSW TrainLink always work to minimise inconvenience for customers while essential trackwork is taking place".
"During the New Intercity Fleet enabling works on the Blue Mountains Line, there will be changes to some train services, including rail replacement buses."
"We encourage customers to plan their trip ahead of time and get the latest trackwork information by visiting www.transportnsw.info or using real time trip planning apps."
The new trains are due to start mid-2020.