In english 'torpedo' is a missile shaped explosive device.
It have any beer related meaning. You hit the nail on the head with your description as to why its named..
Im betting the beer your drinking is the Sierra Nevada Torpedo? Good beer that one. Try the pale ale from them too. Tends be considered the benchmark for an american pale ale.
Sierra Nevada Torpedo is not just called Torpedo because its a hop bomb
They actually invented a new piece of equipment to make it, the "Hop Torpedo"
Its like a *giant* blichman hop-rocket
Meanwhile,
Winemakers use Brix, some homebrewers might use Plato, which for all intents, is the same as brix. You can convert Brix/Plato to Specific Gravity, which is what other homebrewers use.
Brix/Balling/Plato are all measures of % sucrose by weight in a wort.
So, 10˚P (or Brix) means 100g of Sucrose in 900g (aka 900ml) of water.
And Sucrose is a proxy for Malt Extract
A quick conversion is to multiply by 4, 40, and then make it SG, 1.040, which is not 100% accurate, but perhaps close enough.