So my buddy was on a submarine that was in shipyard when this happened. I am still in and this didn’t happen too long ago so I won’t be sharing any specific details to identify anyone involved or the boat that this happened on.

Context: There are nuclear trained (“nukes”) and non nuclear trained personnel on a submarine. Nukes work in the engine room and non nuclear trained personnel or “coners” work in the front half of the boat (with some exceptions). For those who don’t know, a tag is a piece of paper that is attached to equipment that is either in a degraded/out of commission status (either for maintenance or repair). It prevents someone from operating said equipment the tag is placed on.

So here’s a story: coner was hanging a tag on an engine room switchboard to tag out a component that they had opcon of. Turns out there was already another tag on this switch. only switches is a small hole to run the string that holds the tag up through. It’s not big enough to hold two strings for two tags. once he realizes this, he goes to the wardroom and asks what to do (this is where our on duty chain of command tends to hang out). Also, in the wardroom at this time was a shipyard representative. The shipyard representative pulls out a paper clip, unfolded and hands it to this person, and says “use this to push the string through the hole”. The coner takes this paper clip and goes to do just that. Unfortunately, in the mist of doing this, he manages to drop the paper clip into the switchboard and contacts 440 V. this causes an arc blast.

Now and arc blast is what happens when metal contacts high voltage, and is vaporized. When metal vapor rises, it expands 67,000 times at 700 miles an hour with a peak temperature of three times hotter than the surface of the sun.

This explosion shears, 12 bolts holding on a 30 pound metal cover on the switchboard and blows the cover off, this sins the worker flying backwards about 6 feet and causes a fire. Fires on a submarine is a situation that we train for rigorously.

We fight the fire and get this dude to the hospital (he miraculously survived) and an incident report was filed.

Dude never went to mast based on the fact that he had “learned his lesson”. I’ll say this, there is no electrical safety training that will ever put the fear of god in you like witnessing an actual arc ballast will. There was melted metal, blackened bulkheads, and tags that were straight up incinerated.