The engineers who are liable for stuff like this. If they sign off paperwork and not actually check it and something happens, they're liable. Vampire takes so long every single morning to be signed over because they have to physically check every part of the train, which includes every bolt including the 4 holding each wheel together, and ride before handing it over to rides staff. It'll be the same anywhere in tussauds/merlin parks as thats the standard they do.