Work has started to repair the track at the site of the tragic Stonehaven rail crash.
Three people died when the 6.38am ScotRail Aberdeen to Glasgow Queen Street service derailed at Carmont, near Stonehaven, on August 12.
The train hit a landslip as it tried to return to Aberdeen due to the weather.
A massive recovery operation began to remove the overturned carriages last month, before the bridge and embankment was repaired.
Now Network Rail has announced engineers have started to re-lay 500 metres (1,640ft) of track.
Work will continue into November as teams remove and replace the track and relay 400 metres (1,312ft) of telecoms cables.
Alex Hynes, managing director of Scotland’s Railway, said: “This is a very complex and challenging recovery and repair operation and it will take time for our engineers to fully restore the track and other infrastructure.
“While we will reopen the line for customers as soon as possible, our focus throughout the recovery process has been on making sure we do all we can to learn from this terrible accident and try to prevent similar incidents happening in the future.”
The crews have worked day and night over the past few weeks to complete repairs to 70 metres (230ft) of bridge parapets and remove the crane pad built over the Carron Water for the recovery of the carriages in September.
Engineering work is also being carried out to repair and extend drainage systems on the railway track and lineside embankments at the site.
Train driver Brett McCullough, conductor Donald Dinnie and passenger Christopher Stuchbury died in the crash.
After the incident, Network Rail introduced a range of additional safety measures.
As an immediate precaution, hundreds of sites nationwide with higher-risk trackside slopes, similar to Stonehaven, were inspected.
These inspections were carried out by both in-house engineers and specialist contractors, supplemented by helicopter surveys.
Network Rail has also launched two taskforces, led by independent experts, as part of its long-term response to climate change and the challenge of maintaining its portfolio of earthworks (embankments and cuttings), many of which date from the Victorian era.
Dame Julia Slingo FRS, former chief scientist at the Met Office and a world-renowned expert in climatology, is leading a weather-action taskforce to better equip Network Rail and understand the risk of rainfall to its infrastructure.
She is drawing on the latest scientific developments in monitoring, using real-time observations and weather forecasting.
Lord Robert Mair CBE FREng FRS is spearheading an earthworks management taskforce to see how Network Rail can improve the management of its earthworks portfolio, looking at past incidents, latest technologies and innovations and best practices.
Network Rail has already invested in earthworks and drainage, and spending has increased in recent years from £550m between 2009 and 2014 to a budget of £1.3bn for the period between 2019 and 2024.
ScotRail is operating a shuttle service between Aberdeen and Stonehaven and between Dundee and Montrose to keep customers in the north-east moving.
A replacement bus service also remains in place between Dundee and Stonehaven, and between Dundee and Aberdeen.
Cross-border operators are also running replacement buses between Aberdeen and Edinburgh, with more information available here.