Mystery of how H.L. Hunley's crew died is solved after 150 years: American Civil War submarine were killled
- 7 years ago
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.Ms Lance said that when it crossed the lungs of the crewmen, the shockwave was slowed to about 100 feet (30 m) per second.
While a normal blast shockwave travelling in air should last less than 10 milliseconds, Ms Lance calculates that the Hunley crew's lungs were subjected to 60 milliseconds or more of trauma.
'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,' Ms Lance added.'That creates kind of a worst case scenario for the lungs.'
Shear forces would have torn apart the delicate structures where the blood supply meets the air supply, filling the lungs with blood and killing the crew instantly.
It us likely they also suffered traumatic brain injuries from being so close to such a large blast.
The Hunley's first and last combat mission occurred during the Civil War on Feb 17, 1864, when it sank a 1,200-ton Union warship, the USS Housatonic, outside Charleston Harbour.
The Hunley delivered a blast from 135 pounds (60 kg) of black powder below the waterline at the stern of the Housatonic, sinking the Union ship in less than five minutes.
Housatonic lost five seamen, but came to rest upright in 30 feet (ten metres) of water, which allowed the remaining crew to be rescued after climbing the rigging and deploying lifeboats.
The Hunley was raised from the bottom of the ocean in 2000, and initially, the discovery of the submarine only seemed to deepen the mystery.The crewmen's skeletons were found still at their stations along a hand-crank that drove the cigar-shaped craft.
They suffered no broken bones, the bilge pumps hadn't been used and the air hatches were closed.
Except for a hole in one conning tower and a small window that may have been broken, the sub was remarkably intact.
The eight crew members were buried in an elaborate ceremony at a Confederate cemetery in Charleston in 2004.
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.Ms Lance said that when it crossed the lungs of the crewmen, the shockwave was slowed to about 100 feet (30 m) per second.
While a normal blast shockwave travelling in air should last less than 10 milliseconds, Ms Lance calculates that the Hunley crew's lungs were subjected to 60 milliseconds or more of trauma.
'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,' Ms Lance added.'That creates kind of a worst case scenario for the lungs.'
Shear forces would have torn apart the delicate structures where the blood supply meets the air supply, filling the lungs with blood and killing the crew instantly.
It us likely they also suffered traumatic brain injuries from being so close to such a large blast.
The Hunley's first and last combat mission occurred during the Civil War on Feb 17, 1864, when it sank a 1,200-ton Union warship, the USS Housatonic, outside Charleston Harbour.
The Hunley delivered a blast from 135 pounds (60 kg) of black powder below the waterline at the stern of the Housatonic, sinking the Union ship in less than five minutes.
Housatonic lost five seamen, but came to rest upright in 30 feet (ten metres) of water, which allowed the remaining crew to be rescued after climbing the rigging and deploying lifeboats.
The Hunley was raised from the bottom of the ocean in 2000, and initially, the discovery of the submarine only seemed to deepen the mystery.The crewmen's skeletons were found still at their stations along a hand-crank that drove the cigar-shaped craft.
They suffered no broken bones, the bilge pumps hadn't been used and the air hatches were closed.
Except for a hole in one conning tower and a small window that may have been broken, the sub was remarkably intact.
The eight crew members were buried in an elaborate ceremony at a Confederate cemetery in Charleston in 2004.