IT has yellowed over time and become ragged at the edges, but the newsprint remains clear, detailing the horror of one of Britain’s worst train crashes.

A copy of The Herald dated December 11, 1937, lists the names of those killed in the Castlecary rail disaster and tells how the tragic events unfolded the previous evening.

Bought by the widow of Edward Nelson after he died in the disaster, it provides eyewitness accounts of the horrific crash and its aftermath.

A total of 35 people were killed and hundreds of others injured when blizzard conditions and signalling problems led to the Edinburgh to Glasgow express ploughing into a stationary train just west of Castlecary in Lanarkshire.

Today marks the 83rd anniversary of the tragedy and the tattered newspaper has been passed down the generations of the Nelson family and is now in the possession of Mr Nelson’s granddaughter, Bafta-winning director Alice Nelson.

It is now set to form the basis of a feature-length film about the crash and the impact it had on the family.

Half Nelson tells the story of the 37-year-old’s fateful journey and how his wife, Eileen, went on to adopt a baby boy – Ms Nelson’s father – in the months following the crash.

Part animation, part documentary, the film’s aesthetic is inspired by the fragile copy of The Herald.

The filmmaker said: “I’ve known this story about Edward my whole life. And the things that Eileen kept after the fact, and have been in my family’s possession for years and years, are The Glasgow Herald from the day after and Edward’s diary that he was carrying on the day.

“Eileen had to go and identify his body and she was given a brown paper bag with his personal effects and one of the things in the bag was his diary, and she must have taken it home and started writing in it herself.

“So I’ve had these two objects for many years and the story’s always been at the back of my mind. I inherited the copy of The Herald and the diary, as well as his death certificate, but I don’t have any photographs of him, so I think part of my desire to make the film is that I feel like I’m kind of putting him back together piece by piece.”

The crash occurred at 4.37pm on a Friday after the Dundee to Glasgow train stopped at signals outside Castlecary station.

An investigation after the incident found a signaller error was to blame, with driver error and challenging weather conditions contributing factors.

At the time, the then Glasgow Herald reported: “The locomotive tore through the rear portion of the stationary train, crumbling the carriages to matchwood and throwing the rear coach into the air. It landed broadside across the track.

“With the impetus of the train the foremost carriages of the Edinburgh train reared high in the air, and rode up over the engine. The two following carriages heaved themselves partially on top of each other.”

It reported scenes of “twisted iron” and “wheels buckled almost beyond recognition”.  Among the dead was an eight-year-old girl, who was first counted as missing.

 Ms Nelson said: “Inside the newspaper, the editorial is very visual. It was obviously dark at the time and the noise from the impact was heard from a nearby mine and all the miners ran down the hillside to help, to pull the injured and the dead from the train. 

“The only light they had to work with was the lamp on their own helmets, and they built bonfires along the trackside. It’s so rich, from a filmmaker’s point of view, in terms of how to stage that scene.

“The newspaper is full of incredible information, so much so that the whole film pivots on that edition of the Glasgow Herald.  The animation is very much inspired by the newspaper. The whole look and feel of the animation is constructed out of newsprint.”

The film goes on to tell the story of Ms Nelson’s father’s struggle to fit in with the Nelson family, him not being biologically related to them.

The production is still at an early stage, with some funding being provided by the BFI to create a promotional teaser which will hopefully be used to secure further funding. John Archer from Hopscotch Films is executive producer of the film, while Bafta-winning animators Will Adams and Rory Lowe from Wild Child Animation are also on board.

Ms Nelson hopes the film will go some way to ensure that Mr Nelson, and the others who died, are not forgotten.

She said: “There’s an element of feeling a debt of gratitude towards Edward. Eileen adopted a baby almost nine months to the day after Edward was killed and that baby was my father. None of that would’ve happened had Edward taken a different train that day.

“There’s also a need to remember – 35 people died that day and it is important to remember them.”