The Railway Children will always be remembered for that scene at Oakworth station, the one where Roberta's father emerges through the steam of a departing train. "Daddy, my Daddy!" Plenty of people will admit to weeping when the young Jenny Agutter is reunited with her father. But watching it now, 40 years after it was first released, I find myself welling up long before then: at the birdsong, the music, the Yorkshire countryside, the lost Edwardian world.
Why does it make me cry? "Because you're an old sentimentalist," says Bernard Cribbins, who played Perks, the station porter, and is now an astonishingly frisky 81. "Which would apply to most of the audience who watch The Railway Children." Does Agutter cry? "No, she's hard as nails," says Cribbins. "You have to be an extraordinary person if you don't have a bit of a gulp."
Since it was first published (in serial form) in 1905, Edith Nesbit's tale of a family forced into penury after the mysterious arrest of their father has never been out of print, and has spawned three television series, two films and several plays. The definitive version, the 1970 film directed by Lionel Jeffries, has now been digitally restored; the memories are still fresh for Agutter, Cribbins and Sally Thomsett, who played Roberta's younger sister, Phyllis.
"People still go to me, 'Railway Child!'" says Agutter. She was cycling in London recently and a bus driver swore at her. "These two guys coming towards me said, 'What's his problem? Didn't he realise you're a Railway Child?'" Shethinks about the way Jeffries put the "Daddy, my Daddy" scene together. "The sound goes, so that your reality is suspended. He uses this beautiful music and when the mist is going you just hear this 'ping', this tiny sound, and there's this character coming out of the mist. And you see her running towards him and then you see her feet go off the ground. All those images are just heartbreaking."
The three "children" had an unusual bond on set because they were guarding a secret: while 17-year-old Agutter was close to Roberta's age, Thomsett, playing 11-year-old Phyllis, was already 20. The producers ordered her not to reveal her age to anyone. "It was in my contract: I wasn't allowed to do anything that anybody over 16 could do," says Thomsett. "I couldn't have a cigarette, I couldn't go out with my boyfriend and I couldn't drive my car. I had a fabulous new red Lotus that I just loved. I was sworn to secrecy."
One night, a frustrated Thomsett fled with Agutter to a nightclub in Leeds where a bikini-clad woman danced inside a cage. "We sat down, ordered a drink and a couple of boys came over to ask us to dance," says Thomsett. "The next thing I knew, Lionel Jeffries and our producer were standing there. We were caught red-handed."
Agutter, who had already filmed Walkabout, thinks that working at such a young age probably arrested her development. "You are put among people who are no longer your peers, so you are not trying things out at the same time – the experimental nature of adolescence goes by-the-by. I hadn't really been through any great emotional changes. When I went to America in my 20s there was a delayed adolescence, which Hollywood supports in an awful lot of people."
She eventually returned to Britain, married and became a mother. In 2000, she played Roberta's mother in the TV adaptation of The Railway Children. Which production does she prefer? "Er, you can't ask me that. One is attachedto my childhood and one is attached to my being a mother. That's why it worked for me. I would come across people [who] were quite cross. They felt playing the mother was a betrayal of having been Roberta."
The day after we meet, there is the sad news that Lionel Jeffries has died. Agutter, in particular, has very fond memories: "I see him vividly with his red scarf around his neck, larger than life, being in command." He was only two years older than Cribbins, but she fears his later years were tough; despite his talents, he did not always get work.
Over the years, Agutter has become something of a Railway Children scholar and hopes to make a movie about Nesbit's unconventional life: a radical socialist, she lived in a chaotic ménage a trois with a serially unfaithful husband and an unhappy son, who later committed suicide. "She's this wonderful children's writer, but actually she was amess."
We cry when we watch The Railway Children, Agutter says, because we are mourning our own lost innocence. "You cry because of your sense of yearning. That is what is in her book and that is what Lionel so cleverly gives people. People cry at their own sense of loss, that they don't have that magic they had when they were little. You suddenly become that child again, believing in something that you feel you've lost."
The Railway Children is screened at the National Media Museum, Bradford, on 28 March as part of the Bradford film festival (nationalmediamuseum.org.uk), and is atselected cinemas from 2 April.
