Scientists: Hunley's hatch was unlocked

yahoo news/AP ^ | Jul 14, 2006

[nuconvert]

Scientists: Hunley's hatch was unlocked

Scientists say they may have found an important clue in the mystery of why the Confederate submarine Hunley sank 140 years ago after making history by sinking an enemy warship in battle.

Archaeologists and others working to restore the submarine recovered six years ago from the bottom of the Atlantic Ocean off the coast of Sullivans Island have found evidence the forward hatch may have been opened intentionally on the night the sub sank.

The forward hatch was one of two ways crew members got in and out of the sub. It is covered in a thick layer of sand and other ocean debris, but X-rays show the hatch is open about half an inch, according to a news release Friday from the Friends of the Hunley.

Earlier reports said rods that could have been part of the hatch's watertight locking mechanism were found at the feet of the sub's commander, Lt. George Dixon.

That evidence leads those working on the sub to think the hatch may have been opened intentionally.

"The position of the lock could prove to be the most important clue we have uncovered yet and offers important insight into the possibilities surrounding the final moments before the submarine vanished that night," said Hunley Commission chairman state Sen. Glenn McConnell, R-Charleston.

If the hatch was intentionally unlocked, there are several possible explanations.

Dixon could have opened it to see if the 40-foot, hand-cranked vessel was damaged when it rammed a spar with a black powder charge into the Union blockade ship Housatonic on Feb. 17, 1864, becoming the first sub in history to sink an enemy warship. Or Dixon could have opened the hatch to refresh the air supply in the eight-man crew compartment or to signal that it had completed its mission.

An emergency also could have led the crew to open the hatch to get out. But because the second escape hatch was found in the locked position, that theory seems less likely.

"If the Hunley crew opened the hatch, it must have been for a critical reason," said archaeologist Michael Scafuri. "Even on a calm day, three-foot swells can occur out of nowhere on the waters off Charleston. Every time the hatch was opened, the crew ran the deadly risk of getting swamped."

The Hunley sank three times, killing a total of 21 crew members.

But the reason it sank on the night of its successful mission remains a mystery.

Although scientists said the new discovery could help determine the cause of the sinking, it also is possible that the lock was damaged after the sub sank and the hatch opened while it sat on the ocean floor.

[Richard Kimball]

Thanks, good info.

[TXnMA]

The Hunley Torpedo Deployment Forum files are no longer on line -- nor are they on this computer or its attached 320GB HD. If I can find them on another laptop or on backup CD(s), I will share some other images with you:

• Scale CAD drawing of the Housatonic's hull cross-section at the point of explosion -- with the Hunley in attack position, 2-4 feet from the Housatonic and "barely awash" -- and the 30-degree downward-angled 18 foot spar.

• Sketch of the predicted "Y-yoke" hinge mount for the spar (at the bottom of the bow) -- the as-found mount was virtually identical. (FWIW, the nut on the pivot bolt actually unscrewed -- after over a hundred years in salt water...)

• Enhanced period images of the Hunley on the dock (for refit, following the second sinking that killed H.L. Hunley) -- showing a pivoting spar-attachment at the actual location.

FWIW, much of our info on the relative positions of the vessels during the attack came from the records of the Union Navy's Court of Inquiry called to investigate the sinking of the Housatonic...

I'll see if I can find anything else to share...

Too bad the "slavery haters" have hijacked this otherwise historic and academic thread... :-(

[nuconvert]

Very interesting, thanks

[TXnMA]

I just found a couple of the Hunley Forum images:

Early estimate of the blast area (shown on a model of the Housatonic). Later revised to a slightly farther astern posiiton,

Chapman's sketch of the Hunley during refit after the second sinking. Clearly shows the Y-yoke pivoted iron rod (over which the tubular spar fit) angled down and resting on the dock. Observe that (in this view) there is nothing affixed in the upper hole in the bow casting...

Function of the protrusion(s) midway up the bow is still under debate...

The starboard diving plane has been removed and rags stuffed in the pivot-shaft hole. The forward hatch cover (subject of this article) has also been removed -- probably to facilitate the removal of the bodies of H.L. Hunley and the rest of the crew...

[TXnMA]

Should have copied you on #35.

Since you have taken an active interest in the Hunley, you might find #42 and #44 to be of interest, as well...

[supercat]

During a test of how long the Hunley could stay down with the crew breathing only the enclosed oxygen, the candle went out long before the crew gave up and surfaced. They stayed down two hours (on the bottom, at rest, of course) and the sentry who was waiting for them on shore, gave up and left, thinking that they had perished in the attempt.

My understanding is that subacute CO2 poisoning occurs when the body is unable to rid itself of as much CO2 as it produces. The body's ability to rid itself of CO2 is proportional to the difference between the partial pressure of CO2 in the blood and its partial pressure in the atmosphere (the latter being proportional to ambient times atmospheric pressure). A CO2 partial pressure of 7kPa (equivalent to about 7% atmosphere is bad), and a partial pressure of 10kPa (equivalent to about 10% atmosphere) is quickly fatal.

A 4% concentration of CO2 would correspond with a 16% concentration of O2--a 20% reduction. I would expect such a reduction in oxygen levels to noticeably interfere with a candle, but not necessarily to extinguish it. In the absense of CO2, a 20% reduction in oxygen concentration would equate to a 20% reduction in the level of exertion their lung capacity would allow them to perform. On the other hand, a 4% concentration of CO2 would have a huge effect on a person's ability to exhale CO2 during times of heavy exertion when their lungs would be operating near capacity even under normal circumstances. If 8kPa is considered to be the absolute upper limit for CO2 concentration (above that, delerium and other effects would make self-rescue basically impossible), the lung's ability to extract CO2 in a 4% atmosphere would be only half its ability in a 0% atmosphere, even though the air still have 80% of the normal oxygen concentration.

[Non-Sequitur]

BTW A block of subsistance farmers, slave owning or not, is not a middle class.

No, but a block of teachers, lawyers, doctors, and merchants are. And there was a solid middle class in the south, certainly as large a percentage of the population as in the North.

[stand watie]

!!!!!!!!!!!!!!

free dixie,sw

[muir_redwoods]

You are simply wrong and we simply disagree. A middle class is impossible in a culture with a preponderance of the workforce enslaved. It is simply impossible. Rome didn't have one, Ancient Greece didn't have one and it wasn't until capitalism was invented and slavery was done away with that a middle class emerged.

Slavery doomed the south economically depriving it of a middle class with significant purchasing power and it wasn't until slavery was abolished that the south became an economic powerhouse. History and facts cannot be denied.

[smug]

It made sense to the people in that place at that time; it doesn't make sense to us now, when the average educational level is such that the significant majority of people actually understand the basic economics of labor. Which, by the way, is something that you didn't get in schools that "just taught the three 'R's", which was the basic educational system of the era.

I have to differ with you here. I believe that "most" people do not understand basic economics of labor. Otherwise you would not have so many people voting for democRats. Even most Republican's have a fuzzy view of it. Also, a person with an 8th grade education in the mid 1800's was far better educated than most college graduates today. At least as far as a classic education is concerned. Of course, there are always exceptions. Many of which post here on Freerepublic.

[absolootezer0]

Why did the South use slaves, then, rather than simply trying to attract immigrant laborers (who would seem, economically, to offer a better deal)?

that's always been my proof that if licoln had any sense of economics whatsoever, we'd have had no civil war.
slavery was already on the road down. slave importation had already been stopped, so the only source of new slaves were those being born. it wouldn't have been very long before plantation owners would have realised that slaves were no longer worth their trouble.
if licoln had offered (but not forced) to buy all the slaves, at fair market value, war would've been avoided, and even all that expense of buying all the slaves would have been cheaper than paying for the war.

[Non-Sequitur]

slavery was already on the road down. slave importation had already been stopped, so the only source of new slaves were those being born. it wouldn't have been very long before plantation owners would have realised that slaves were no longer worth their trouble.

Based on census data available the slave population was growing at healty clip, as fast as the white population in the South. Demand for slaves was high, prices were high, and there was no substitute for slave labor available. Doesn't sound like slaves were trouble for their owners to me. More like the pillar of Southern society and wealth.

if licoln had offered (but not forced) to buy all the slaves, at fair market value, war would've been avoided, and even all that expense of buying all the slaves would have been cheaper than paying for the war.

Such offers were make by Lincoln during the rebellion, and were ignored by the South. if licoln had offered (but not forced) to buy all the slaves, at fair market value, war would've been avoided, and even all that expense of buying all the slaves would have been cheaper than paying for the war.

[stainlessbanner]

Fantastic analysis TXnMA. I really enjoy reading your posts.

[stainlessbanner]

Right. There was no middle class in the South in 1861.

It was dirt farmers and the privleged class.

[stainlessbanner]

Such offers were make by Lincoln during the rebellion

Licoln refused negotiation with S.C. delegates prior to Ft. Sumter. There were no offers.

[muir_redwoods]

"Right. There was no middle class in the South in 1861.

It was dirt farmers and the privleged class."

There was no entrepreneurial class, no significant buying power outside of the privileged class and no significant industrial base compared to the free states.