What kind of vault would you expect to find in a London bank of reasonable size? I don't need super specifics (Although a name drop would be awesome, and really help with future research) just an idea of the size and thickness of the door, because I'm going to blow it open. In my head (Because it is a screenplay, after all) I have one of those stylish circular doors set in a thick wall with a lead room behind it - are they still in common usage? Or rather, if the bank already had one like that from when it was built, would they bother to replace it or just add to the security measures?
Once I've figured out what kind of vault and thus what kind of door, what kind of explosives am I going to need to open it? Ideally these would be avaliable to the common criminal, albeit a common criminal with contacts, money, and a First in Chemistry. Again, I don't need specifics, just names - what kind of explosives, detonator, any phrases a demolitions expert working with the police examining the crimescene would use to describe it.