Confederate submarine crew killed by their own weapon

But after an exhaustive three-year Duke study that involved repeatedly setting blasts near a scale model, shooting authentic weapons at historically accurate iron plate and doing a lot of math on human respiration and the transmission of blast energy, researcher Rachel Lance, a 2016 Ph.D. graduate of Duke Engineering, says it was a powerful shockwave from the Hunley's weapon that killed the crew.

In a paper* appearing Aug. 23 in PLOS ONE, Lance calculates the likelihood of immediately fatal lung trauma to be at least 85 percent for each member of the Hunley crew.

The Hunley's torpedo was not a self-propelled bomb, as we think of them now. Rather, it was a copper keg of gunpowder held ahead and slightly below the Hunley's bow on a 16-foot pole called a spar. The sub rammed this spar into the enemy ship's hull and the bomb exploded. The furthest any of the crew was from the blast was about 42 feet.

Lance says the crew died instantly from the force of the explosion travelling through the soft tissues of their bodies, especially their lungs and brains. She says the crippled sub then drifted out on a falling tide and slowly took on water before sinking.

"This is the characteristic trauma of blast victims, they call it 'blast lung,'" said Lance, who worked as a biomechanist at the U.S. Navy's base in Panama City, Florida for three years before entering graduate school at Duke. "You have an instant fatality that leaves no marks on the skeletal remains. Unfortunately, the soft tissues that would show us what happened have decomposed in the past hundred years."

Blast-lung is a phenomenon of something Lance calls "the hot chocolate effect." The shockwave of the blast would travel about 1500 meters per second in water, and 340 m/sec in air.

"When you mix these speeds together in a frothy combination like the human lungs, or hot chocolate, it combines and it ends up making the energy go slower than it would in either one," thus amplifying the tissue damage. Lance said that when it crossed the lungs of the crewmen, the shockwave was slowed to about 30 m/s.

While a normal blast shockwave travelling in air should last less than 10 milliseconds, Lance calculated that the Hunley crew's lungs were subjected to 60 milliseconds or more of trauma.

"That creates kind of a worst case scenario for the lungs," Lance said. Shear forces would tear apart the delicate structures where the blood supply meets the air supply, filling the lungs with blood and killing the crew instantly. It's likely they also suffered traumatic brain injuries from being so close to such a large blast, Lance added.

Traumatic blast injuries have unfortunately become a familiar part of recent U.S. military history, but "the injuries experienced by soldiers in a Humvee who hit an IED are different because they are injured mostly by shrapnel and the destruction of the vehicle," Lance said. "In that case, there are shrapnel effects and effects from the damage to the vehicle that cause broken bones and other injuries. But the crew of the Hunley were protected by the hull. It was just the blast wave itself that propagated into the vessel, so their injuries would have been purely in the soft tissues, in the lungs and in the brain."

The sub's design was known to be precarious. During development and testing, the Hunley had sunk twice, drowning 13 crewmen including its namesake, Horace L. Hunley, a privateer who had the submarine built from an old ship's boiler in Alabama in 1863.

Lance says the designers of the powderkeg weapon also may have recognized the dangers of being too close to a blast in water. Her historical research found that they stayed hundreds of yards away from test blasts of devices that were significantly smaller than the bomb that sank the Housatonic.

"Blast travels really far underwater," Lance said. "If you're practicing 200 yards away, and then you triple the size of your bomb and put it 16 feet away, you have to be at least aware that there's a possibility of injury."

Informative history lesson.

Be careful with your water bombs, kids

>nstantly killed its own eight-man crew with the powerful explosive torpedo

>>171173
>Blast-lung is a phenomenon of something Lance calls "the hot chocolate effect."
She's fucking with us right?

>>171206
Nope, lungs are really fucking weird. The human body was not designed to handle explosions and other combat injuries.

>>171210
But to describe her Ph.D thesis as "the hot chocolate effect" almost sounds self deprecating.

Interesting. The first worthwhile read I have had here in a while.

>>171213
it is more familiar than the "allasonic effect"

First interesting thing I've read all week on this board and it's 150 years too late to be news.

Not very surprising, given the rapid advancement of tech during U.S. Civil War, but if they did know about the dangers, they probably were on a suicide run or happened across it and didn't want to waste an opportunity like that.

>>171334
Well the news is revealing how the men died.