'The older women taught me about life and sex'

"I left school at 14 and got a job in a vinegar-bottling factory – well, shed – on the banks of the canal in Blackburn. It had green doors, like the ones in hospitals that they push stretchers through, with a 1ft gap at the bottom. The rats would run in from the canal, so we sat with our feet up on the chair."

One woman would put a bottle on the carousel, which would turn so that the next could fill it with vinegar, after which the third would jam on the cap and finally Cox would slap on the label. She found it fascinating: not so much the work as the fellow workers.

"They were lovely, very down-to-earth women, in their fifties. They all looked like my Aunty Rosie." And they talked, but perhaps more frankly than an aunt to a niece. "I was learning about life and sex." They showed each other their bras and laughed about their husbands in bed. They sound like the sort of characters who might come out of her warm-hearted novels. This is because some of them do.

Cox used one of her workers as the basis of a character in her first book, Angels Cry Sometimes, and another in her novel based on her own life, Her Father's Sins. In Let Loose the Tigers, outrageous women debag Tommy Trundler and shove him down a chute; he is based on the son who with his father used to come in reluctantly every day to run the ratty enterprise and be harassed by the female workers. Fortunately, the trousers-and-chute bit is fiction but the merciless whistling and winking was only too real.

"Tommy" never complained about being ridiculed but then people don't, not even the nymphomaniac – this wasn't one of the vinegary ladies – described so accurately in another novel that the neighbours knew exactly who it was. Thanks to a wonderful teacher who used to tell her stories and lend her books, Cox had always wanted to be writer: here was her raw material on a plate or, rather, in a bottle.

The work was mechanical and indeed must by now be completely mechanised. Yet Josephine believes it suited the fifty-something women: "It was a good job and paid well. They would have stayed there until they fell off their perches."

Cox lasted only six months, at which point her parents separated and she moved south with her mother and nine siblings. Cox then found work in a plastic-mac factory, where she did the belts. "It was really posh – no rats."

'Girl on the Platform' by Josephine Cox is out now, published by HarperCollins, priced £1.99, as part of the Quick Reads scheme for World Book Day ( www.quickreads.org.uk)