The 2019 series runner-up, who lies fifth in the 2023 standings, crashed his Motorbase Performance Ford Focus ST at McLeans in the closing stages of the first free practice session, moments after setting the quickest time to date.
The damage to the rear end of the Focus following its enormous rear impact with the tyre wall is sufficient to rule him out, although Cammish escaped serious harm.
“My back’s a bit sore, and I’ve been told I’ll be feeling a bit stiff tomorrow morning,” Cammish told Autosport.
“Obviously it was completely unexpected and in the opposite way to what a lot of people would expect.
“The pedal didn’t go floppy, it went solid – it was like trying to press against a brick wall.
“On the data there’s no really no front brake pressure at all, and the rear has gone through a spike when I realise what’s happening, and unfortunately it has curtailed my weekend.
“The car felt great – I was pessimistic after the tyre test [in July] but this morning it felt like a different animal. I was hoping for a lot of points towards the championship, not only for myself but for the team, but that’s been taken away from me now.
“I’m really glad that I got the car turned somehow by luck and I didn’t go in forward, which would have hurt.”
The accident comes amid a backdrop of concerns from teams following the July test that the GP circuit – in use for the first time in the BTCC in 2002 – causes a heavy strain on brakes.
Teams lobbied successfully for a restriction on brake components for the 2023 season, on cost-saving grounds.
But Cammish said the accident was nothing to do with that.
“If the pedal had gone softer then it could have been,” he said, “but this is a failure somewhere else in the system – it’s nothing related to wear.”
Motorbase team manager Oly Collins compared the damage to Rory Butcher’s massive accident at Silverstone in 2020, after which that car was repaired for the following round.
“It has echoes of the Rory Butcher chassis, arguably a little bit worse,” said Collins. “We need to investigate it.”
The BTCC field was already down one car for the weekend due to the absence of the Team Hard Cupra Leon driven to date this season by Nicolas Hamilton, before Rob Huff stepped in last time out at Knockhill.
Huff has prior commitments this weekend in the TCR World Tour at San Luis in Argentina, but has indicated that he is keen to contest the final two BTCC rounds at Silverstone and Brands Hatch.
Autosport understands that just one driver change per season is allowed for each car, and that, due to Huff’s date clash, Hard has been given force majeure dispensation this weekend to retain its TOCA TBL entrants’ licence.
