A fire in a rail tunnel, on the line from York to Manchester, has disrupted train services.
It will be Thursday morning before they can run through the tunnel again.
West Yorkshire Fire and Rescue crews were sent into Standege Tunnel, at Marsden, which is over 3 miles long, to fight a blaze involving heavy railway machinery.
It happened about a mile inside the two track tunnel which sees regular express services between North Yorkshire and the North West.
Access was made via the service tunnel alongside, with firefighters progressing on foot with their equipment in an operation that was described as challenging.
It took around two hours to get water onto the fire due to several operational factors.
These included the exact location of the fire being initially unknown, restricted access routes, limited initial water supplies and large volumes of smoke, significantly reducing visibility and slowing safe progression.
Once the fire was located, crews were able to quickly put it out.
The incident required close working with Network Rail, alongside support from Greater Manchester Fire and Rescue Service.
Once the fire had been extinguished, damage to the tunnel structure was discovered that requires extensive repair work before it can be deemed safe for the passage of trains again.
As a result of this, some lines are currently closed and trains running between Huddersfield / Rochdale and Manchester Victoria will either be cancelled, delayed, revised or diverted via an alternative route where this is possible.
This is expected to last until Thursday morning.
