Train-spotting TikTok sensation Francis Bourgeois steamed into a science fair for schools in Hampstead to judge the best railway bridge design.

The 23-year-old social media and television personality, who is originally from Harlesden, met teams of pupils putting together their science projects for the fair, held at St John Hampstead parish church.

The fair was organised by David Luard, head of science at Devonshire House School, who invited the TikTok star to judge the contest.

“This was as much about ‘community’ as about science,” the Year 7 class teacher said. “Yet there was so much enthusiasm and creativity in the student science projects, collaborating with other pupils they had only just met.

“There are so many schools around Hampstead that offer an opportunity for collaboration between them.”

The 120 Year 7 youngsters came from 20 schools in and around Hampstead for the gathering of young scientific minds, including state, prep, independent senior, academies, faith schools and a special school. Children competed in teams of six, working with pupils from other schools they hadn’t met before.

Each pupil gave presentations of their research to science teachers and parents, with projects ranging from “perfecting biscuit-dunking” techniques to ideas for sustainable energy solutions — all testament to the creativity brewing in classrooms.

The fair was sponsored by James Daunt, a diplomat’s son from Islington who owns Daunt bookstore in Marylebone, adding community involvement.

But the highlight for many was meeting Francis Bourgeois, who was judging their engineering projects.

As the nation’s best-known trainspotter he oversaw the bridge-building competition for the design that could bear the most weight.

Francis was a Millennium baby, born in Harlesden in 2000. Originally named Luke Magnus Nicolson, he got into trainspotting aged just three from living near the Willesden Junction depot before the family moved to the West Country.

He suppressed his interest in trains when he was 15 “to fit in better at school”.

But Francis rekindled his trainspotting passion during Covid and began shooting videos, with Willesden Junction his favourite location.

He studied mechanical engineering at Nottingham University with an ambition to revitalise old railways as a civil engineer, inspiring like-minded youngsters from the 20 Hampstead schools he met at the science fair.