The first combat submarine to sink an enemy ship also instantly killed its own eight-man crew with the powerful explosive torpedo it carried, new research has found.
The HL Hunley fought for the confederacy in the US civil war and was sunk near North Charleston, South Carolina, in 1864.
Speculation about the crew’s deaths has included suffocation and drowning, but a new study claims that a shockwave created by their own weapon was to blame.
Researchers from Duke University in North Carolina set blasts near a scale model of the vessel to calculate their impact.
They also shot authentic weapons at historically accurate iron plates.
They used this data to work out the mathematics behind human respiration and the transmission of blast energy.
Ms Rachel Lance, one of the researchers on the study, says the crew died instantly from the force of the explosion travelling through the soft tissues of their bodies, especially their lungs and brains.
Ms Lance calculates the likelihood of immediately fatal lung trauma to be at least 85 per cent for each member of the Hunley crew.
She believes 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 Ms Lance.
‘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 Ms Lance calls ‘the hot chocolate effect.’
The shockwave of the blast would travel about 4,920 feet (1,500 metres) per second in water, and 1,115 feet (340 m) per second in air.
The Hunley’s torpedo…