Your technology is almost correct, it rammed a spar into the target that had percussion cap fired explosive charge on it, then backed away and a lanyard fired the charge.
I have been a supporter of the project, but I’m not current. I’m eager to hear what they’ve got. I always figured that they popped a bunch of seams when the charge went off and made it partway home before the submarine flooded.
True... the shockwave through the water could have been too much for the craft. Lousy testing.
The article says the HUNLEY’s spar explosive detonated the gunpowder and other explosive aboard the USS HOUSATONIC, resulting in an explosion perhaps one hundred times stronger than the HUNLEY’s crew had expected. The much larger than expected explosion of the USS HOUSATONIC they speculate immediately killed and/or rendered the crew of the HUNLEY unconscious with its tremendous concussion wave passing through the sea to strike the nearby HUNLEY and its crew. The HUNLEY it is believed then drifted for a distance with its dead and/or unconscious crew before flooding and sinking to the seafloor.
I toured the Warren Lasch Conservatory in North Charleston, SC, back in 2007. I fulfilled a lifetime dream to see the H.L. Hunley. There is a picture of a hole in 1 on the 2 conning towers next to 1 of the glass portholes. There were reports that Federal sailors onboard the Housatonic fired their rifles at the H.L. Hunley when it was spotted near their ship. Confederate general Beauregard had ordered the Hunley's commanding officer not to do a deep submerge during the mission because at least 2 previous crews had drowned during sea trials. Early conservation efforts speculated that the hole in the conning tower was a rifle bullet hole.