Mystery of how H.L. Hunley's crew died is solved after 150 years

UK Daily Mail ^ | 08/23/2017 | Tim Collins

[DFG]

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.

[HandyDandy]

I suppose the crew, at some point, realized they were still attached to the torpedo and the target.

[TXnMA]

No, they knew the situation before they left Breach Inlet: as I said above, the torpedo was bolted solidly to the pipe spar.

I have actual photos of the torpedo's recovered remnants still bolted to the spar -- but, they are Lasch Lab property, and I'm not at liberty to share them...

[fella]

It was not A.S.M.E. certified because the Authorized Inspector did not sign off on it and it was put into use anyway. Big law suits to follow.

[DiogenesLamp]

But, that's not what was found. The remains of the torpedo were found still bolted onto the end of the 20' iron pipe spar!

I'm having trouble grasping how this could have been the intended manner of using their explosive. 20' is clearly not enough distance away from such a powerful charge, and the people of that era were not fools. I've read an account of of a man on board the CSS Virginia in which he noted how people would be killed or injured from the rounds they fired into the turret of the Monitor, so they knew about shock transfer.

Having such a large explosive charge deliberately held at 20' away is a suicide mission. Is there no evidence of any sort of release method?

[central_va]

The sub was supposed to trail a long lanyard to trigger the device to be deployed after the torpedo was planed. That plan backfired, literally.

[DiogenesLamp]

The sub was supposed to trail a long lanyard to trigger the device to be deployed after the torpedo was planed.

Not according to TXnMA. He (I assume it is a he) says that the torpedo was bolted solidly to the spar, and I presume he means that it could not be released.

He says he worked on this project, and so has first hand knowledge of what the evidence shows.

[HangThemHigh]

"Killed two entire crews and most of another."

Design by trial & error with lots of the latter.

[TXnMA]

"The sub was supposed to trail a long lanyard to trigger the device to be deployed after the torpedo was planed [sic]."

~~~~~~~~~~

That is, indeed what we all expected to find. (Note [in #52] that I went to considerable effort to sketch up how the lanyard could have been rigged to pull the trigger pins on all three of the fuzes shown in the B&W "'Singer' sketch". Heck, I even sketched a simple die that could have been used for forming and cutting the copper wire loops for guiding the trigger wires -- with a single hammer blow...)

BUT, that is not at all what was actually found:

And, after final cleanup:

Note how the force of the explosion (at left) shoved the torpedo's "sleeve" back up the spar -- with the bolt ripping thru the copper as the sleeve did so... Could the evidence of the torpedo being bolted on at the time of the explosion be any clearer?

The torpedo was bolted to the spar. The spar was still firmly bolted to the pivoting Y-yoke rod, and the Y-yoke was still attached by the pivot bolt to the lug on the lower bow of the Hunley. And, yes, the separation distance from the explosion of 135 lbs of cannon powder was only twenty (20) feet. That's about as solid a path for shock transmission as one could ask for.

~~~~~~~~~~~~

FWIW, I am a "he", my main work on the project took place before the Hunley was raised -- and I still consult on occasion...

[DiogenesLamp]

The torpedo was bolted to the spar. The spar was still firmly bolted to the pivoting Y-yoke rod, and the Y-yoke was still attached by the pivot bolt to the lug on the lower bow of the Hunley. And, yes, the separation distance from the explosion of 135 lbs of cannon powder was only twenty (20) feet. That's about as solid a path for shock transmission as one could ask for.

Could it be that someone forgot to remove the bolt on the torpedo? That it was intended to lodge in the ship's wood and then slide off, but the bolt was not removed before the attack?

[JimRed]

Never heard of any sailors dying from blast.

Damned few ever survived to document it.

[TXnMA]

"Could it be that someone forgot to remove the bolt on the torpedo?"'

Not likely. Torpedoes designed to detach were held in place by wooden shear pins -- not steel bolts.

In my "The Spar" forum, we had a member (in Poland), who was doing experiments with cross-drilled sliding-fit pipe pieces, pins of various woods, and a bucket of seawater to soak them in. He reported that softwoods like pine would swell, smear, and jam the release -- but that hardwoods (especially maple) sheared and released cleanly and consistently.

FWIW, in addition to archaeologists and engineers, historian, author (and personal submarine owner/operator), Mark K. Ragan was a "Spar" member. A couple of days after we determined that the deployment angle to reach the actual point of explosion was thirty (30) degrees, Mark posted the now-famous B&W drawings of "Singer's Torpedo -- used for blowing up the Housatonic" -- that he had just found in the Archives! As you can see in my #52, here, that torpedo has a socket at exactly thirty (30) degrees! And it shows a cross-hole for a shear pin... '-)

[TXnMA]

Belated OP courtesy pings to my comments, #s 55, 60, 62, 68, & 71...

[HandyDandy]

So the triggering of the explosion of the torpedo, by the Hunley (after somehow securing the torpedo to the Housatonic and detaching it from itself) then backing off enough distance to draw taught a lanyard, .....is out the window. In fact, the Hunley, with the torpedo suspended from, and permanently bolted to a spar, purposefully impacted the Housatonic and the torpedo exploded when a pressure-sensitive trigger mechanism set off the charge. Is that about right?

[TXnMA]

My graphics files show that I did an awful lot of work on the "spike+lanyard" concept -- but...

So far, that's not where the evidence seems to point...

However, aside from some possible insights into physiology, none of this is new news to me. Here's my "Conclusions" slide -- made in early 2014:

I recall that, when I was creating it, there wasn't room for "shocked" on the "Crew" line -- where it really belonged...

Now, I'll consider moving it down -- and re-wording that line to include "lung"...

~~~~~~~~~

The torpedo had to be virtually in contact with the Housatonic to be guaranteed effective -- but, it was bolted to the spar. Until some mechanism for triggering the explosion from inside the Hunley is discovered -- what other scenario fits the evidence?

[DiogenesLamp]

The torpedo had to be virtually in contact with the Housatonic to be guaranteed effective -- but, it was bolted to the spar. Until some mechanism for triggering the explosion from inside the Hunley is discovered -- what other scenario fits the evidence?

There doesn't seem to be one. It appears that someone made some very fatal assumptions.

[rockrr]

Just getting back to this thread. Thanks for posting those pictures - I have never seen any of them before.

[TXnMA]

"Thanks for posting those pictures - I have never seen any of them before."

~~~~~~~~

You're quite welcome -- and, that's not surprising. Many of them are originals from my 1995-2000 private forum, "The Spar" for archaeologists, engineers and historians on the Hunley Project.

I created and hosted "The Spar" for the purpose of analyzing and predicting how the torpedo was deployed on the Hunley -- before Hunley was raised. (Initial excavations revealed no trace of the expected spar mounting atop the bow...)

Others are "slides" from presentations on the Hunley that I occasionally do for select organizations -- again, originals -- that include graphics created for analytical discussions with the Lasch/Clemson labs in Charleston...

~~~~~~~~~~

IOW, I decided to share with my fellow FReepers an "inside peek" at some of my work on a fascinating subject... '-)