These tools helped keep submarine Hunley running -- whether on the surface or underwater. The gizmos are now on exhibit at conservation lab near Charleston

Conserved glass bottle, wrench and hammer carried by sub crew (Friends of the Hunley)

In-depth research and tinkering went into the design and construction of the stealthy submarine H.L. Hunley. While there were predecessors, the Confederate vessel was the first to be an effective weapon, sinking a Union ship off Charleston Harbor.

“We think it was very watertight. The construction was very sound, according to the riveting,” said Nick DeLong, among the Clemson University archaeologists conserving the Hunley at a lab in North Charleston, S.C.The rivets were inverted, creating a smooth exterior and reducing drag in the water.

“They knew a lot more about hydrodynamics than people thought,” DeLong told the Picket on Thursday as the Friends of the Hunley announced “Tools & Tides,” a new exhibit at the Warren Lasch Conservation Center.

The submarine had a rather complex system of drawing, pumping and discharging water, so the moving parts required regular maintenance. The Hunley was a “work in progress” that required the crew to keep it seaworthy with common tools. Adding to the challenge was a tiny environment that featured limited lighting and likely condensation from water, sweat and breathing.

The small exhibit, timed to the anniversary of the Feb. 17, 1864, sinking of the USS Housatonic, features tools that would be useful for quick repairs. The display (left) includes bolts, a wrench, chisel and hammer -- items you would find in a Home Depot, for example. It opens to the public this weekend.

“It was a very basic tool set to help (with) anything on the fly,” said DeLong. “While the submarine was revolutionary, they had to use what they knew to solve problems they could not foresee.”

The eight-man crew perished after the Hunley went down after jamming a torpedo into the Housatonic’s wooden hull. To this day, historians and others disagree on what caused the loss of the Hunley shortly after it became the first submarine to sink an enemy vessel.

It’s tempting to engage in conjecture on how the artifacts could have been used to save the ship. For example, if there was a problem with the ballast tank, perhaps the wrench or a T-shaped tool would have been helpful in making a repair, allowing the Hunley to rise to the surface. But we just don’t know what failed.

Here’s a look at the recently conserved items in the new exhibit, with all photos and most of the captions provided by the Friends of the Hunley. Several tools were discovered beneath Capt. George Dixon’s bench. DeLong said the artifacts likely did not shift much when the Hunley went to the bottom. This is the first time they have been put on exhibit.

Glass bottle

The 12-sided glass apothecary bottle was found on the crew bench still holding liquid from 1864 (The hand-cranked submarine was recovered in 2000 and has proved to be a time capsule holding precious artifacts).

The contents of the bottle remained a mystery until testing revealed it was mercury, which was most likely used for the submarine’s depth gauge. DeLong says the remaining fluid in the container matches the amount of mercury needed to operate the gauge.

T-shaped tool

(Friends of the Hunley)

The artifact was found between the pump mechanism and the frame ring, suggesting it was used to adjust or remove portions of the forward ballast pump. The Hunley had a forward and aft pump, with the crew department in between, DeLong told the Picket.

“They (the pumps) were quite effective. They were connected through piping so if one failed the other would pump water.” The crew opened a valve that would allow water in, making the Hunley descend. The pumps pushed water out so that it could rise to the surface.

Chisel

This wrought-iron tool was uncovered next to the forward bulkhead. It was stuck to the hull and bilge pump pipe due to heavy concretion. It has a flat-blade edge and would have been used for general utilitarian tasks.

Bolts/wedges

The tools served as flat-head wedges, according to DeLong. They were used to hold some of the submarine’s frame rings.

The bolts, with an attached nut, were found beneath the forward pump outflow pipe under the captain seat and could have been integral components in the ballast and pump system's operation.

They were treated using a sub-critical chamber, a cutting-edge conservation technique developed by the Hunley scientific team, officials said in a press release. 

Ball-peen hammer

Clemson conservator Johanna Rivera cleans hammer (Friends of the Hunley)

Made of different materials, the ball-peen hammer required different conservation methods. For example, the treatment used for the iron can be detrimental for the wood handle. The Clemson team removed the head of the hammer and placed it in sodium hydroxide. The handle was immersed in polyethylene glycol.

Wrench

This large adjustable monkey wrench underwent desalination in sodium hydroxide and then was rinsed in deionized water and placed in the lab oven to quickly dry. Next, it was cleaned with air abrasion and a special coating was applied to protect the metal from corrosion.

They plan to dive deeper into use of the tools

Chisel, top left, and other items in display case (Friends of the Hunley)

The Clemson archaeologists intend to do a deeper analysis of the use of these tools and their interaction. The T-shaped item may have been a key, but the project does not know how it was used, said DeLong.

“We want to look at the submarine as a functioning artifact,” he said. Among the topics to be studied was the Hunley’s air intake system

DeLong is among those completing a volume on the crew members and their personal belongings.

The Hunley museum is open from 10 a.m.-5 p.m. on Saturdays and 10 a.m.-3 p.m. on Sundays. The Warren Lasch Conservation Center is at 1250 Supply St. in North Charleston. Tickets for tours can be purchased online here. The cost is $18 for adults and $10 for youth ages 6-12, plus a service charge