Alton Towers Discussion Thread in Theme Parks, Roller Coasters, & Donkeys! Posted July 21, 2013 Just to add this in: bolts on steel coasters, especially in that area (the track joint bolts) break fairly commonly. This was why CA Screamin at DCA replaced the entire loop not long ago. It usually ends up a material defect or a grade 2 bolt being put where a grade 3 is required. Or just stress, as these bolts are hard to inspect for wear. And as ST says, on busy weekends inspections are somewhat rushed, sometimes a small indication gets missed. Thankfully the ride was stopped and no further issues happened (although the most that would happen is a kinda rough ride and some damaged road wheels).