Category Archives: Conservation

Conservation Around Site – Harpoon

People have hunted whales around the world for thousands of years, primarily for meat and blubber. In America, the practice really took off in the colonial 18th century and hit its peak in the mid-19th. The most lucrative product at this point was whale oil, derived from boiling down blubber or harvesting the head of sperm whales. As the American industry grew and expanded, so did the whaling practices and technology, which is where our conservation topic comes in today.

There is a harpoon that is part of an education collection in the oil house. While the whaling industry was never directly involved with the St. Augustine Lighthouse and Maritime Museum, it was still a part of the lighthouse world. The refined whale oil was a highly sought after commodity used for lantern fuel and many lighthouses were lit in such a manner.

Harpoon in whaling display, with scrimshaw and baleen.
Harpoon in whaling display, with scrimshaw and baleen.

In order to get the whale oil, crews had to somehow hunt and harvest them. Early harpoons were made of wood, bone and stone. They were thrown or shot into the whale and attached to a floating object. The idea was to tire the whale out until the hunters could finish it off.  Eventually, as larger whale species were targeted, larger, deadlier and more durable harpoons were created. Our particular artifact is an interesting variation that became a gold-standard for harpoons. The style is referred to as a “standard improved toggle” harpoon. It is credited as being designed by Lewis Temple, a freed slave and blacksmith. He opened a shop in the whaling community of New Bedford around 1845 and his style became incredibly popular, partly because he never patented the design and since it was so effective. This does make it difficult to definitively identify our harpoon, though, as many manufacturers made and sold them.

Standard improved toggle head. http://americanhistory.si.edu/onthewater/collection/TR_072824.html
Standard improved toggle head.
http://americanhistory.si.edu/onthewater/collection/TR_072824.html

The small head is designed to cut and penetrate deep into the whale skin easily. The rear of the head has a sweeping barb that holds the harpoon in place. The ingenuity of Temple’s invention, though, is a pivot in the center of the head. When the harpoon is pulled back, the barb turns outward and rotates the head into a T-shape, locking it in. Another clever bit of engineering is the long, skinny shaft. The cast iron used in the harpoon is strong, but flexible, so that it can twist and bend after insertion and during the pursuit.

Bent toggle harpoon. http://americanhistory.si.edu/onthewater/collection/AG_056237.html
Bent toggle harpoon.
http://americanhistory.si.edu/onthewater/collection/AG_056237.html

The conservation for the harpoon was very easy and unobtrusive since the artifact does not actually belong to the St. Augustine Lighthouse and Maritime Museum. I did not want to add any chemicals or sealants that would be difficult for a future curator or conservator to remove, should the need arise.

Overall the condition of the metal was pretty good. There were a few spots here and there on the bare cast iron that showed signs of corrosion. These were exclusively on the head and base of the shaft. The paint on the shaft of the harpoon, however, looked good and did not need any treatment.

I started by carefully brushing off the rust and corrosion product from the iron using a toothbrush. For the more stubborn spots I used a small wire wheel and bit of steel mesh. When the metal was clean, I then covered the exposed parts with a light coat of air tool oil to penetrate and prevent additional oxidation. The oil has few additives that would strip the iron or gum up the surface while it dried. After the oil, I then sealed both ends of the harpoon using heated microcrystalline wax. The molten wax is able to seep into all the pores of the metal and seal the surfaces from exposure to the atmosphere.

Oil house harpoon with toggle pivoted.
Oil house harpoon with toggle pivoted.

Clothing Mysteries

The vast majority of artifacts that come through conservation are from our shipwrecks excavated by LAMP. There are hundreds, if not thousands, of objects from the Storm and Anniversary wrecks waiting to be worked on. However, conservation activities for the LAMP sites have slowed down as we pack up and organize for the new building construction. There was also a little event called Hurricane Matthew that stifled conservation duties.

We boarded up the Light Station for Hurricane Matthew. Fortunately, we suffered minimal damage and were able to re-open the Monday after the storm.
We boarded up the Light Station for Hurricane Matthew. Fortunately, we suffered minimal damage and were able to re-open the Monday after the storm.

Fortunately, there was no significant damage to the lighthouse, the museum or any of the offices. Once everyone was back safely and cleaned up the grounds, work could get back to some semblance of normal.

So, knowing that we would not want to begin any new long-term conservation projects or open up new concretions because of the impending construction; coupled with most everything being packed up for the storm, I started a fun, fast project.

Besides the shipwreck artifacts, we have a number of objects in our collections department. A lot of these pieces have been donated by various people over the years. Some, though, come directly from our grounds. Continue reading

Sifting through the muck

Ed Coward sorting dredge spoil.

Every year, our research arm, the Lighthouse Archaeological Maritime Program (LAMP), heads out on the water to either survey for new wrecks, target test potential anomalies from said surveys or locate and excavate archaeological sites underwater.

How exactly does LAMP work underwater and get the artifacts for the conservation team?

Unlike a “traditional” land site, we cannot simply dig up the dirt and move it to the side with shovels and wheelbarrows. We instead do a similar process, but with an all-in-one dredge setup suited for diving. By using gas-powered pumps to shoot water down a dredge head attached to a large diameter hose, it creates a vacuum in the hose. The hose then sucks up any of the sand in the grids and empties out a few meters away.

While dredging underwater, the divers try to carefully clean down to the concretions and avoid sucking up any artifacts. On the offhand chance that something is either too small to see or visibility conditions are too bad, we make sure to collect all the sediment in bags at the other end of the hose.

Dredging underwater.
Dredging underwater.

All the material that is taken up the hose is called dredge spoil. Most of the spoil is small particulates of sand or clay and is filtered out of the mesh bags.

However, after long sessions of dredging a large amount of shell hash builds up. We try to replace the bags every time a new grid is excavated or once the bag is too full. When that happens we have to bring the bags up to the boat using crates and lift bags.

The lift bags are simply bags that are filled with air and help slowly raise the dredge spoil up to the surface. Once we haul everything on board, the next step is to pour the spoil into buckets, make sure they are documented and transport them back to the lighthouse.

Dredge spoil tagged and ready.
Dredge spoil tagged and ready.

One thing we make sure to do is keep the buckets of spoil filled with water. Even though we bring them back at the end of every excavation day, we are not able to sort through them right away. Often times we will not get to the dredge spoil for quite some time, as field school and other conservation tasks take precedence. Continue reading

Conservation On The Move

After moving the logfish vat

The most exciting news around the Lighthouse these days is the imminent construction of new buildings for archaeology and conservation. The new Maritime Archaeology & Education Center will be approximately 2,500 square feet dedicated to offices, public education, exhibits and laboratory space. This community facility will be a welcome addition to the Lighthouse grounds and a fantastic experience for the guests.

« Learn more about the Maritime Archaeology & Education Center and see a video from First Coast News here! »

However, before the buildings are constructed, there is a lot of work to be done. For the conservation team, that means clearing the current working area and prepping for the upcoming build. All the artifacts, storage containers, electrolysis apparatuses and equipment need to be moved for the construction to take place.

Inside the conservation "corral"
Inside the conservation “corral”

The first step to be taken was moving the logfish vat out of the middle of the fenced-in conservation “corral.” The logfish vat is a large wood and fiberglass storage container built to hold ship timbers recovered from a previous excavation. For years it stood as a container (and a table for holding field school equipment), and while useful, went largely unoccupied. We moved the logfish vat to help expedite the next stage in the building process.

After moving the logfish vat
After moving the logfish vat

Before any of the buildings pop up in the conservation area, there will be an addition of new sewage lines. Right now, for conservation we just use a regular septic drain. This limits us to certain chemicals we can use for treatments to what is safe to put down the sink. With the sewage, we can use stronger and better (but not any more dangerous or hazardous to the sewage water) chemicals for conservation. Continue reading

2016 Field School Conservation Work

Diving ops boat Empire Defender. Photo by Michael Resko.

Summer is winding down and the 2016 Lighthouse Archaeological Maritime Program (LAMP) field school has successfully concluded. This year we had 12 students from across the country come to the Lighthouse. They came to learn about underwater archaeology, enhance their diving skills and help excavate our new Anniversary Wreck site. They also were able to learn about the important work that goes on post-field school, such as public outreach and conservation.

With such a large class of students, it was difficult to have them all out on the water and diving every day. To help ease congestion on the boats, the students were divided into three groups. Each group would then rotate through different responsibilities involved with the boat, diving or back on land at the Lighthouse.

Diving ops boat Empire Defender. Photo by Michael Resko.
Diving ops boat Empire Defender. Photo by Michael Resko.

While the field school students were here at the Lighthouse, they shadowed the supervisors and volunteers to learn the behind-the-scenes tour. This way the students were also able to learn about the history of the Lighthouse grounds and the boatworks while engaging the public. Continue reading