Tag Archives: H. L. Hunley (submarine)

150 years ago: “The torpedo instantly exploded…. In twenty seconds the hull sank.”

No, that is not a quote from some account of battle.  Rather it comes from a report of experiments conducted at Charleston to perfect a spar torpedo for use against the blockaders.  Captain Francis D. Lee provided this report to Brigadier-General Thomas Jordan (General P.G.T. Beauregard’s Chief of Staff) on March 13, 1863:

In obedience to instructions from department headquarters I made an experiment with my boat torpedo on yesterday. One of the abandoned gunboats was placed at my disposal some days since, which, after loading with rubbish from the burnt district, got a draught of 6½ feet at her bow. I was anxious to obtain a draught of 7½ feet, but was unable to procure a vessel of that class. The torpedo-bearing boat for attacking this hulk was a light-built canoe about 20 feet long, with a spar suspended 6 feet from her keel and projecting beyond her bow 22 feet, at the extremity of which I placed the torpedo, with a charge of nearly 30 pounds of powder. It was my purpose to make the experiment at 1.30 o’clock p.m., that being the hour of high water, but the delays consequent upon the want of dispatch on the part of the steamer engaged to tow the hulk in place prevented the completion of all necessary preparations until 2.30 p.m. At that hour a strong northwest wind, amounting nearly to a gale, was blowing, which, with the ebb tide, rendered it impossible for me to moor the hulk in such position as to attach the lines for striking her side. Every previous preparation having been, however, made, I deemed it proper to make a trial even at the risk of failure, and gave orders to strike the vessel in the stern. After great difficulty, owing to the roughness of the sea, I secured a line to the bow of the torpedo-boat, and after reeving it through a block secured to the hulk returned it through a block in the stern of the torpedo-boat, and thence to a row-boat. I then ordered the row-boat to pull away. The torpedo-boat moved with good speed to the hulk and apparently struck, but without the expected discharge. The position of the torpedo-boat seemed to indicate that the torpedo had passed under the hulk. Leaving the boat in this position I returned to the city, and after giving the hands a recess of an hour returned to the hulk to examine into the true condition of things. I then found that the torpedo, in place of striking directly in the stern, had passed diagonally under the counter of the hulk. On withdrawing it I discovered that the torpedo had not come in contact, and that the lead plugs containing the sensitive tubes and charges of chlorate potassa were entirely uninjured. Night fast coming on I secured the torpedo-boat to the side of the hulk so as to be safe from accident, determining to make a new trial the following morning. On this morning at 8 a.m. I returned to the hulk, accompained by Captain Chisolm, of the general staff, and Mr. W. S. Henerey, machinist, and after anchoring the hulk across the stream put on the lines and struck her about amidships. The torpedo instantly exploded, with little or no displacement of water. In about twenty seconds the hulk sank. On moving up to the torpedo-boat we discovered her entirely uninjured, with a very small quantity of water in her, more than half of which was there before the explosion. From all appearances the spar is uninjured.

Lee’s experiments were designed to perfect the armament of spar torpedo boats, known as “Davids,” then being built.  Involved with ship construction in addition to other engineering chores, Lee was a busy man at this time of the war.

The spar torpedo boat that Lee was working to arm were the “Davids.”  These were low-profile, steam-powered boats.  The hope was, riding low in the water, the Davids could slip up close to anchored blockaders to deploy the deadly payload.

CSS David – showing machinery arrangements

The CSS David may have looked like a submarine, but it was not submersible.  And unlike the H.L. Hunley, a steam engine propelled the David.   Based on the profile and mode of attack, the Davids were arguably predecessors of the light draft torpedo boats and eventually the “PT” boats of World War II fame.

At least two of these type vessels were under construction in Charleston in the spring of 1863.  Further examples constructed in Charleston and elsewhere constituted the largest “class” of any warship built for the Confederacy.  A photo taken after Charleston’s surrender in 1865 shows one of these “Davids” beached.

A beached David at Charleston in 1865

The photo compares well to the drawing.  Notice the spar fixed on the front of the boat.  At the business end of that spar were fixtures to support the contact torpedo…

… the device that Captain Lee was perfecting 150 years ago today.  While not ready for action that spring, soon the Confederates would use these spar torpedo boats in an effort to lift the blockade of Charleston.

Andy Hall has some very good renderings of the Davids on his site, including one view comparing the David to the Hunley.

(Citation from OR, Series I, Volume 14, Serial 20, pages 820-1.)

New Hunley discovery may alter interpretation

I’ve been posting much about the low country of late.  So this news item fits in line.  From the Charleston Post and Courier:

Hunley legend altered by new discovery

For nearly 150 years, the story of the Hunley’s attack on the USS Housatonic has been Civil War legend.

And it has been wrong.

Scientists have discovered a piece of the Confederate submarine’s torpedo still attached to its spar, debunking eyewitness accounts that the Hunley was nearly 100 feet away from the explosion that sent a Union blockade ship to the bottom of the sea off Charleston in 1864.

Instead, the Hunley and its eight-man crew were less than 20 feet from the blast. And that changes everything about the story — and possibly even provides a clue as to why it sank.

“I would say this is the single-most important piece of evidence we have found from the attack,” said Maria Jacobsen, senior archaeologist on the Hunley project.

Basically, Hunley conservators found a piece of the torpedo’s copper shell, peeled back from the blast, when they removed a century of hardened sand and shell from the submarine’s 20-foot spar. The torpedo was bolted to the spar, contradicting the conventional wisdom that the torpedo was planted in the side of the Housatonic with a barb like a fishing hook, slipped off the spar and then detonated by rope trigger when the sub was a safe distance away.

Instead, the Feb. 17, 1864, attack off Charleston was a dangerous, close-quarters assault that risked the sub and crew.

“This changes some things,” said Lt. Gov. Glenn McConnell, longtime chairman of the state Hunley Commission. “They were much closer to the explosion than we believed, but I don’t believe this was a suicide mission.”

Read full article here.  And take a look at the photo gallery here.

By my count this is the third “interpretation” of how the designers of the Hunley fixed the torpedo for the final mission (and I’m sure there are other interpretations I’ve missed).  Prior to the submarine’s recovery in 2000, the most often depicted arrangement was some form of contact device centered on a spar projecting from the top deck of the vessel.  The replica outside the Charleston Museum has just such a setup.

Charleston 4 May 10 097

Replica of H.L. Hunley

Such positioning would require the submarine to be well submerged in order to contact it’s target below the waterline.  And of course it would place the submarine in close proximity to the resultant explosion.  But this was based on contemporary sketches of the submarine.

Later interpretations had some sort of barb on the torpedo to fix the explosive to the target.  That interpretation held that a release line played and triggered the explosion when the submarine had backed off sufficiently.

Depiction on the Friends of the Hunley Site

This interpretation has the spar fixed to the bottom of the vessel and is backed up with documentary evidence.  Andy has a more detailed discussion on this setup posted.   The documents also indicate the torpedo had three fuses, in order to ensure the detonation.

With this latest discovery, the interpretation leans towards the torpedo arranged to explode under the target ship – the USS Housatonic.  If so, that’s actually more dramatic than my mundane description allows.  From a technical perspective, this means the Confederates had already determined the optimum position to detonate a torpedo in order to sink a ship – directly beneath it.  However, not until after World War II would technical advances produce a weapon to achieve such effects with consistency.

One thing for sure, what we know of the Hunley will continue to evolve as the artifacts reveal their portion of the story.