Would anybody like to talk about anti wedge devices?

As a boy I saw a Chubb Banker which had been attacked using explosives. It is a very long time ago, 50+ years, but in my memory the door had been blown almost double yet it had held. Around the edge some devices had fired which were small protruding bars about the size of a cotton bobbin. I was told by the man from Chubb, who had come to open the unit, that these were anti wedge devices, but he might have been spinning a yarn to a young boy.

I think I might have related this part of the story before. The police knew who had tried to blow the safe but couldn't prove it. His hallmark was that he always used far too much explosive. In this case he put the escutcheons through a wall with the blast! His criminal career came to an abrupt end when he tried to recruit his waning supply of explosives by robbing a coal mine magazine. How did he get in? Well let me say they found very little of either him or the magazine. Sympathetic detonation is a queer subject.