Archive for the 'Archaeological Conservation' Category

Jan 11

H.L. Hunley Fully Visible for the First Time

Wednesday, January 11, 2012 11:06 AM

HL Hunley in its conservation tank at the Warren Lasch Conservation Center, Charleston.

On February 17, 1864, Confederate-built H.L. Hunley became the world’s first successful combat submarine when it attacked and sank the 1240-short ton screw sloop USS Housatonic at the entrance to the harbor of Charleston, South Carolina. H.L. Hunley surfaced briefly to signal a successful mission to comrades on shore with a blue magnesium light, after which it was never seen again. All eight of its crewmen were presumed lost and despite multiple search efforts, the submarine could not be relocated. 

Over 136 years later, on 8 August, 2000, H.L. Hunley was raised from the sea floor using a specially-designed support frame, or truss. A multi-disciplinary team, under Project Director and Head of the NHHC Underwater Archaeology Branch, Dr. Robert Neyland, coordinated Hunley‘s recovery. 

Post recovery, the 40-foot, 17,000 pound truss continued to support the sub in a custom built, 90,000-gallon conservation tank at Warren Lasch Conservation Center in Charleston, SC while it underwent archaeological investigation. During the careful, year long excavation of its interior, H.L. Hunley remained in the same tilted position in which it was found to ensure minimal disturbance of its contents. Conservation of the recovered artifacts is being conducted by professionals from the Warren Lasch Conservation Center and Clemson University. In 2011, after the interior of the hull had been completely excavated, Hunley was re-positioned so that it now sits upright and no longer requires the support of the truss, which will be removed tomorrow morning on 12 January, 2012.

Throughout its treatment, the submarine has been on display to the public, however, when the truss is removed, visitors finally will be able to have a fully-unobstructed view of the vessel in its conservation tank.

A 3-D animation of the recovery and rotation of H.L. Hunley may be viewed here: Hunley Submarine Rotation

For more information on the H.L. Hunley project, please visit the Friends of the Hunley website: http://www.hunley.org/ 

HL Hunley in its truss at the Warren Lasch Conservation Center, Charleston.

 
Oct 17

Innovative Scientific Analysis Tool at Underwater Archaeology Conservation Lab

Monday, October 17, 2011 1:54 PM

Dr. Raymond Hayes (left) and Head Conservator George Schwarz examine p-XRF data taken from a Civil War-era Aston pistol recovered from USS HOUSATONIC at the Underwater Archaeology & Conservation Laboratory.

NHHC volunteer, Dr. Raymond Hayes, Professor Emeritus at Howard University, Washington DC, and Woods Hole Biological Laboratory, Woods Hole, MA, has partnered with the Underwater Archaeology & Conservation Laboratory (UACL) to analyze archaeological materials from historic naval shipwrecks.

Dr. Hayes has been awarded a Research & Discovery Grant from Olympus INNOV-X to examine archaeological components from shipwrecks using an innovative Delta portable X-Ray Fluorescence (pXRF) unit. This state-of-the-art technology uses an x-ray beam to identify the specific elements present within archaeological material. Dr. Hayes’ research endeavors to use this data to trace the elemental composition of a wood sample back to original construction materials, marine sediments, and sealing or fastening materials applied to wooden ships. Included in the study are data from USS Housatonic, USS Tulip, and CSS Alabama, as well as recently recovered artifacts from the 2011 USS Scorpion field project, the archaeological investigation of a Patuxent River shipwreck believed to be the flagship of the Chesapeake Bay Flotilla, which fought to defend Washington D.C. from the British during the War of 1812. As part of the Navy’s commemoration of the Flotilla’s important role in the War of 1812, a full excavation of the USS Scorpion site is anticipated.

Scientific technologies like pXRF provide archaeologists and conservators valuable chemical information that can be used to better conserve and interpret submerged cultural heritage. An innovative feature of pXRF devices is that they can be used in both the laboratory and the field to analyze artifacts recovered from wet environments. Artifacts from underwater sites can be difficult to initially identify as they may be encased within thick concretions or obscured by unidentifiable corrosion products, however, pXRF data can give archaeologists data which can signal the presence of an artifact. 

Detail of portable X-Ray Fluorescence machine collecting data from Civil War-era pistol.

Following recovery from underwater archaeological sites, artifacts are particularly susceptible to damage caused by soluble salts (e.g., chlorides) accumulated from the water or sediment that surrounded them for decades or even centuries. If allowed to crystallize, the salts expand and cause catastrophic damage which may result in complete destruction of the artifact. Data from pXRF can determine the concentration of chlorine within an artifact to help conservators understand the degree of salt contamination and mitigate it properly. During conservation, pXRF can help conservators develop the most optimal treatment plan for artifacts and reveal the presence of toxic components, such as lead, cadmium or arsenic. Comparative data may also reveal similarities or differences in artifact composition that could suggest age and geographic origins.

This is only one part of the extensive research that goes on at the Underwater Archaeology & Conservation Lab, where over 2300 artifacts recovered from US Navy shipwrecks and aircraft wrecks are curated, 140 of which are currently undergoing active conservation treatment. The Laboratory, located in BL 46 of WNYD, also hosts public tours showcasing important artifacts that span from the American Revolution to World War II and make the Navy’s history come alive! Please feel free to contact us anytime (202.433.9731) if you’d like to visit!

 For more information about the NHHC Underwater Archaeology Branch and the Underwater Archaeology & Conservation Laboratory, please visit http://www.history.navy.mil/underwater.

 
Aug 12

USS SCORPION Project 2011: Final Week

Friday, August 12, 2011 4:08 PM

1 August, 2011 - 

This begins the final week of excavation on the 2011 USS Scorpion Project! The team will work together this week to continue to investigate the wreck, map the site and recover artifacts. The team was pleased to welcome 7 staff members on site from NHHC Commemorations  and gave them a tour of the barges and explained the details of the archaeological operation.  

 

A diver recovers the starboard cathead.

2 August, 2011-

Today, the archaeology team recovered two important pieces of the ship’s architecture which they believe to be “catheads.” Wooden vessels commonly had a pair of these thick, L-shaped beams incorporated into either side of the bow (one portside, one starboardside). One arm of the “L” projected out over the water and allowed sailors to raise and lower the anchor without causing damage to the side of the ship; the catheads were also strong enough to carry the heavy anchors suspended over the water while the ship was underway. The starboard cathead recovered from the site is in quite good condition and still has the iron components intact…a rare find and an important discovery! 

 
 
 

Archaeologists examine the iron block recovered from the wreck site.

3 August, 2011-

Another interesting find today! The team recovered an iron block from the site; the archaeologists hypothesize that it may have been used as ballast. Sailors often placed heavy material such as stone or metal into the hold of a ship to help stabilize and balance it while underway; the ballast could be moved about the hold as needed to compensate for any changes in the weight distribution of the vessel. Before excavation took place, a magnetometer survey was conducted on the wreck site; several strongly magnetic anomalies were detected…one of which may have been this block! 

 4 August, 2011- 

Today, the UAB dive team spent most of the day near the stern of the vessel measuring and mapping the area. Unlike the bow, the stern is a bit disarticulated with no real structure. When the Chesapeake Bay Flotilla was ordered scuttled, historical accounts are unclear as to how it was actually done. Firsthand accounts from 22 August, 1814 report that the British troops marching on Bladensburg were able to see flames in the distance (presumably from scuttling the Chesapeake Bay Flotilla); this may indicate that rather than puncturing the ships’ hulls to sink the vessels, sailors burned or placed kegs of gunpowder aboard and exploded them to prevent British capture. Although archaeologists have not observed charring on the architecture of the stern, the absence of an intact stern when the bow is so solidly intact, suggests that gunpowder may have been the method used to scuttle the ship. More research will need to be conducted before a solid conclusion is determined. 

Dr. Julie Schablitsky, MSHA, holds the glass pharmaceutical bottle recovered from the wreck site.

 

5 August, 2011 -

 An exciting artifact was recovered today: a small, cylindrical glass bottle with a slightly rounded foot and a flared lip. The bottle is pale green in color, measures approximatly four inches and likely held some type of medicinal liquid or ointment. This bottle is nearly identical to those recovered by Donald Shomette in the original investigation of the wreck in 1980. As flagship of the Chesapeake Bay Flotilla, USS Scorpion would have likely had a surgeon on board; the bottle will join other previously recovered medical artifacts such as a tooth key and surgical scissors, which are on display in the National Museum of the United States Navy on the Washington Navy Yard. The bottle has been brought back to the Underwater Archaeology & Conservation Lab at the Washington Navy Yard for further analysis and conservation.

A pair of surgical scissors recovered from the wreck site.

 6 August, 2011 -

 More exciting artifacts recovered today! In the morning, the team first recovered a pair of scissors. The scissors appear to be made of an iron alloy and are in remarkably good condition. Because of their small size and very fine, sharp blade, such scissors were likely part of a surgeon’s kit. This pair bears a resemblence to another recovered during the 1980 excavation, however the blades on this pair are straight. Later on in the afternoon, the team recovered a small stoneware jug. One of the most exciting details about the jug is that it was recovered with air inside; which may have been produced as the contents of the jug decomposed over time. The team managed to trap the air within the jug following recovery and may be able to chemically analyze it using a process called gas chromatography to determine the original contents of the container.

 At the end of the day, the team began to backfill the parts of the wreck where they had been working throughout the project. Backfilling refers to the process of redistributing the previously removed sediment back around the wreck. It is important that the site remain covered until the next and final phase of the Scorpion Project; the thick clay and sediment help protect and preserve the ship and its contents beneath the river bed.

 As the 2011 field season draws to a close, UAB sincerely thanks the Naval History & Heritage Command for its continued support of the USS Scorpion Project, and partners Maryland Historical Trust and Maryland State Highways Administration for their hard work and cooperation. UAB also thanks nautical archaeologists Heather Brown and Bradley Krueger, who joined the UAB team for the project, and also our fantastic summer interns who worked on site: Sarah Cahlan, Melissa Campbell, Ryan Frazier, Maria Grenchik, Chris Kelly, John Rees and Marcus Schweinfurth. Thanks to all who came to visit us on site and followed our progress on the blog. Stay tuned for the next phase of the project and to see the artifacts as they progress through the conservation process!

 
Jul 28

USS SCORPION Project 2011 Day by Day: Week Three

Thursday, July 28, 2011 11:05 AM
 
 

Dr. Robert Neyland, UAB, records measurements and observations from his dive.

 Monday, 18 July 2011-

Today, we were back in the Patuxent trenches continuing our efforts to delineate the boundaries of the suspected USS Scorpion wreck. So far, the team has been successful in uncovering ship timbers in test units placed on the upstream and downstream extremities of the site. These test units allow archaeologists to assess the vessel’s degree of preservation, articulation, and orientation within the river. One of the vessel’s features that we are still trying to determine is which end of the wreck is the bow and which end is the stern. Since Scorpion and the rest of the Chesapeake Flotilla were possibly burned when scuttled in 1814 to prevent British capture, this may have severely damaged the ends of the structure making it difficult to delineate bow from stern. More excavation and analysis is needed before a positive identification can be made.

 Tuesday, 19 July, 2011-

An exciting discovery! Archaeologists working at the north end of the wreck site have determined that it is likely the bow of the ship. One main reason for this hypothesis is the discovery of a “breasthook,” a thick, curved piece of wood that is typically placed across the stem (the very foremost part of a ship) to strengthen it and unite the bows on each side. So far, all of the planking and architectural structure of the ship uncovered by the divers appear to be very strong and solid; after nearly 200 years sealed beneath the thick sediment of the Patuxent, the majority of the vessel appears to be quite sound and very well-preserved.

Immediately following each dive, the team records notes, measurements and observations while underwater. They also produce a detailed sketch of the submerged wreck site based upon the new areas exposed during the dredging. Updated sketches are a necessity to the project as more and more of the wreck is uncovered. The UAB team is currently working to further expose and analyze the southern end of the wreck which, after the discovery this morning, is most likely the stern of the vessel.

 

Iron strop with wood fragment (presumably part of a deadeye) recovered from the wreck site. Image courtesy of MSHA.

Friday, 22 July, 2011-

A very interesting artifact was recovered today! Archaeologists working near the north end of the wreck (now believed to be the bow) recovered a double-looped iron “strop” which typicaly holds a circular wooden piece called a “deadeye,” an essential part of the rigging of a sailing vessel. The deadeye was so called by sailors because of the way it’s three holes resemble the eyes and nose of a skull. The strop was transported back to the NHHC Underwater Archaeology & Conservation Lab and, after further analysis, appears to contain a small wood fragment of the deadeye it once held.

Despite the extreme heat, the team managed to conduct several dives and continue to delineate the extent of the vessel. In the afternoon, underwater visibility improved enough for Dr. Neyland to take down the underwater video camera and film near the southern end of the wreck.

 
 

Anthracite, a high-luster, clean-burning coal commonly used aboard ships. This piece was recovered from the Scorpion project wreck site.

Saturday, 23 July, 2011-

Another interesting artifact was recovered today: a piece of anthracite. Anthracite is a very hard, compact variety of coal that is very lustrous. Although difficult to ignite, anthracite was the preferred coal for use aboard ships as it burned cleanly and produced little smoke. With their considerable expertise, archaeologists are able to sift through several meters of sediment and distinguish very small, seemingly insignificant artifacts like this as potentially important parts of the wreck site. The team continued to excavate key points on the wreck site and sketch the architecture of the ship as more and more of the vessel is revealed. Stay tuned for updates next week!

 
Jul 19

On the Hunt for Bonhomme Richard!

Tuesday, July 19, 2011 3:39 PM

On July 17th, the NHHC Underwater Archaeology Branch (UAB) along with partners from Ocean Technology Foundation, Naval Oceanographic Office, SUPSALV, Mobile Diving and Salvage Unit (MSDU) 2 and the US Naval Academy, set out to continue the search for one of the Navy’s first fighting vessels, Bonhomme Richard. Captained by the father of our Navy, John Paul Jones, the ship was lost in 1779 after engaging in combat with HMS Serapis off the Yorkshire coast of England. Although Jones emerged victorious, Bonhomme Richard was irreparably damaged. After transferring all men and supplies safely to the captured Serapis, Jones set the beleaguered U.S. frigate adrift to sink into the North Sea. Its final resting place has remained unknown ever since.

USNS Grasp as seen from one of its tenders while conducting AUV operations over four neighboring targets. Photo courtesy of Alexis Catsambis.

Over the next three weeks, the expedition will be conducted aboard Safeguard-class USNS Grasp. The team on deck will use survey data collected from remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) equipped with side-scan sonar and multibeam echosounder equipment to investigate targets of interest gathered from previous surveys. The side-scan sonar and multibeam echosounder relay data to create an image of the sea floor using sound waves; if a particular target looks promising, archaeologists will investigate it more closely and, if possible, deploy divers to take an even closer look.

Officer-in-Charge Ray Miller and midshipman Joseph Walter discuss the Swordfish AUV that is being prepared for the first launch of the mission. Photo courtesy of Alexis Catsambis.

Stay tuned for more updates from the field!

 
Jun 27

USS SCORPION Project: Phase II Begins!

Monday, June 27, 2011 9:41 AM

This bend of the Patuxent River near Upper Marlboro, MD (above) is where UAB archaeologists believe the remains of USS Scorpion, along with several other ships in the flotilla, have settled, virtually undisturbed for nearly 200 years.

 

After months of careful planning and preparation, the NHHC Underwater Archaeology Branch (UAB), in conjunction with Maryland Historical Trust (MHT) and the Maryland State Highway Administration (MSHA), initiated the second phase of the archaeological investigation of what is believed to be the wreck of USS Scorpion. Captained by US Navy hero Joshua Barney, Scorpion served as flagship in the famous Chesapeake Bay Flotilla, which endeavored to defend Washington, D.C. from the British during the War of 1812. On August 21st, 1814, British forces chased the Flotilla up a narrow bend of the Patuxent River where Barney then evacuated his men and ordered the ships scuttled to prevent their capture. The wreck site was discovered by Donald Shomette and Ralph Eshelman in the late 1970s and they conducted an archaeologial investigation in 1980.

UAB archaeologist uses a hydroprobe to determine the location of the wreck beneath the sediment.

 

Starting on June 13th, the UAB team, along with MHT and MSHA, successfully relocated the wreck using precise coordinates via a GPS system and completed an underwater mapping process called “hydroprobing” which helped archaeologists find the orientation and position of the wreck beneath approximately six feet of river sediment and debris. MHT also drilled several core samples near the site to conduct sediment and riverbed stratification analysis. The hydroprobe and core sample data gathered this year is essential for the plans to construct a coffer dam around the site for the third and final phase of the project during the War of 1812 Bicentennial Commemoration in 2012. The coffer dam will allow archaeologists to conduct a dry excavation of the wreck, and visitors to the site will be able to observe the process. This year, limited excavation of the site is expected to start soon after July 4th, so stay tuned for more USS Scorpion Project updates! 

 
Nov 29

UAB Loans MAC Lab a piece of Civil War History

Monday, November 29, 2010 5:05 PM

Loading the 3-ton cannon onto a trailer for transport. UAB photograph.

This morning, UAB welcomed members of the Maryland Archaeology Conservation (MAC) Laboratory team for the transport of a Civil War iron cannon. The 3-ton cannon was made in Liverpool, U.K. in 1862 and served aboard Confederate commerce raider CSS Alabama until she was sunk in 1864 by USS Kearsarge. The cannon was recovered from the shipwreck in 2002 and conserved at Texas A&M University’s Conservation Research Laboratory (CRL). It will be displayed under a UAB Loan Agreement in the MAC Lab facility at Jefferson Patterson Park & Museum in St. Leonard, MD until 2015, with the possibility of renewing the loan at that time. UAB is very pleased to have the cannon available for public appreciation and thanks colleagues at MAC Lab for making this successful partnership possible.

The cannon ready for transporation to MAC Lab.

 
Nov 3

DNU on the Search for Bonhomme Richard

Wednesday, November 3, 2010 9:22 AM

Image courtesy of http://www.public.navy.mil/surfor/lhd6/Pages/history.aspx


NHHC Underwater Archaeology Branch Head, Dr. Robert Neyland, spoke with DMA sailors about the search for Revolutionary War vessel Bonhomme Richard. The interview was featured in a Daily News Update flash and can be viewed using the following link: DMA BHR AHU
 
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