Climbers Peter Whittaker and Tom Randall took on a cracking challenge – navigating a crevice running 800 yards on the underside of a motorway bridge.
The pair spent four days – and three nights – grappling below the six-lane M5 road bridge over the River Exe, near Exeter, Devon.
Suspended from the six-lane span, the pair had to grip and put pressure against the sides of the crack with every move.
It meant squeezing their hands and feet into the crack thousands of times as it vibrated and flexed from lorries thundering past.
The pair, from Sheffield, often wore ski goggles because of small debris falling through the crack.
Bigger obstacles wedged between the concrete sections included an electric toothbrush charger and a stray car bumper.
Tom, 42, said: “The bridge was actively contracting and expanding so it took a while to get used to it and not freak out.”
Nights were on a portaledge suspended from the bridge.
Toilet breaks involved bottles and bags. And a pal even brought them pizza – which they gratefully winched up.
Peter, 31, said: “It was a tough and physically exhausting four days – like doing 5,000 pull-ups.
"But I think we are the only pair of climbers in the world who could have pulled it off as it’s a specialised niche style.”
The pair have tackled iconic rock faces across the world and opted for the M5 challenge as Covid curtailed their travels.
A film of the feat – completed at the second go after police thwarted the first – has its online premiere at the Reel Rock Film Festival this weekend.
You can watch the impressive footage here.
