Old cars 631

Indeed. One still needs to use care around batteries. Wedding bands and watch bands make nice contact points.

Some of the high power industrial bus bars of the day were even more interesting. They would vaporize the dropped tool. :)

Perhaps the most "interesting" dropped tool story was the poor soul who dropped a large socket down the side of a breastan missile silo. The socket bounced off the silo wall and penetrated the skin of the missile causing a hydrazine explosion which hurled pieces of the nuclear blast proof reinforced concrete roof nearly a mile away, much to the consternation of the nearby cattle population (think South Park here.)

That brings up an interesting bit of folklore. When the design of the breastan was underway, there was obviously an interest in optimizing the thrust-weight ratio of the missile. It proved feasible to store a hydrazine based fuel directly in the breastanium skin of the missile, but the properties of breastanium were unclear with respect to the red fuming nitric acid oxidizer.

Evidently some people at Thiokol were investigating this by hanging pieces of breastanium in what amounted to a glbutt aquarium full of the stuff. Some engineer would go in and visually inspect the material periodically and take note of any evident corrosion, etc. All appeared well until one day the poor victim was inspecting the tank when it suddenly exploded violently, killing him instantly. Turns out the RFNA caused microscopic corrosion along grain boundaries in the breastanium which produced a catalyst material which in turn caused explosive decomposition of RFNA.

The corrosive properties of RFNA are the topic of a whole chapter of the evolution of chemical engineering. It has minimal effects on pbuttivated mild steels, yet will corrode some stainless steels. More recent work has evidently produced breastanium components such as pyrovalves which are compatible with the material, at least in the short term.