Specific Research Methodology
Remote Sensing Survey
A remote sensing survey of the wreck site will be conducted immediately prior to the start of diving operations in June. The survey will be conducted from the Research Vessel Robo, a 65 foot Hatteras. Acoustic data will be collected using a Marine Sonics high resolution digital side scan sonar with a 600khz towfish. Magnetic data will be collected using a Geometrics 886 proton precession magnetometer. The survey will be conducted by Brett Phanuff, personnel form the Naval Historical Center and Principal Investigator Gordon Watts. The purpose of the survey is generate a high resolution image of the wreck site and determine if undiscovered additional wreck structure or material associated with the CSS Alabama lies near the hull structure.
To generate the highest quality data possible, the survey positioning will be generated by differential global positioning. Track line vessel positioning and data collection will be controlled by Hypack survey software. The sonar and magnetometer sensors will be towed as close to 30 feet above the bottom as equipment and environmental conditions permit. Magnetic data and position coordinates will be collected at a rate of once per second and all sonar records will be tied to real world coordinates. A lane spacing of 15 meters will be attempted and the lanes will be set up perpendicular to the wreck and run against and with the current. At slack tide additional lanes will be run parallel to the orientation of the hull. Magnetometer data will be contoured using Surfer, QuickSurf or another data contouring program.
One of the first objectives of on-site research during the 2000 field season will be to deploy an anchor or clump at the wreck site. Deployment of an anchor or clump capable of mooring a Zodiac or small vessel at the wreck site will be essential to supporting more extensive on-site research. The capacity of the anchor or clump must be sufficient to moor the proposed small vessel types on short scope during the slack tide. The position of the mooring should be approximately amidships and off to one side of the surviving hull remains. The location of the anchor or clump must be surveyed to prevent damage to structure or material associated with the wreck. Once in position, a short chain and length of nylon line can be used to attach a buoy. The mooring will serve as a means of extending air lift hose to the bottom so that it can be left on the mooring during the entire survey.
Mapping and Documentation
During the past decade the exposed remains of the CSS Alabama have been mapped. To enhance that site plan additional documentation of the wreck site is planned for 2000. That documentation will combine underwater video and 35mm photographic recording with traditional triangulation and measured drawings. The baseline previously employed to control mapping will be reestablished. In addition a series of web lines will be run to connect major features of the wreck site and provide additional measured references for underwater video and 35mm photographic recording. Each segment of the survey web will be measured and entered into AutoCAD.
Once the web has been established, documented and entered into AutoCAD, the position of additional features of the wreck and associated artifacts will be triangulated. Those features and artifacts will also be documented using measured drawings, underwater video and 35mm photography. Particular attention will be paid to the location and orientation of the artifacts identified for recovery. Documentation of the anchor, cannon and pump to be recovered will be the first objective of mapping and documentation to clear the way for excavation and recovery. Additional priorities will be the remaining ordnance, screw and lifting frame and machinery.
In conjunction with mapping and recording of exposed wreck features and associated artifacts, underwater video and 35mm photography will be used to collect sufficient data to support production of a mosaic of the wreck site. Using the survey web and additional reference lines for control the entire site will be documented from an elevation eight to ten feet above the bottom. The elevation of the cameras will be controlled by two lasers on the camera housings. The lasers will be oriented to produce a single point of light at the desired elevation and identify the center of each image.
Video images recorded on the bottom will be digital and 35mm images will be scanned into a digital file. Those images will be used to support production of a digital mosaic. The mosaic will be produced on a computer using a combination of AutoCAD and one or more photo manipulation programs. A rubber sheeting program may be used to fit digital images around the survey web reference.
Several test excavations are planned for the CSS Alabama 2000 Project. The most extensive testing will be in the stern area. Those tests will be designed to collect information on the stern pivot gun, the screw and lifting frame and the stern pump. Additional testing will be carried out in the bow to identify the area of the wreck that served as the crew's quarters and determine the potential for recovering information about their existence on the Confederate warship. All excavations will be directly supervised by one or more of the project archaeologists.
Test excavation areas will be identified by rigid or nonrigid grids. Shell hash will be removed using the thrust from diver propulsion vehicles. Overburden containing material associated with the wreck will be removed using air lifts. The lifts will be designed to operate on compressed air piped to the site from a surface vessel such as a Zodiac. Documentation of exposed material will be accomplished using video, 35mm photography and measured drawings.
One excavation will be carried out at the base of the lifting screw. That excavation will be designed to collect information concerning the design and weight of the screw and lifting frame. It will also provide insight into the method of attachment employed to secure the frame to the stern and propellor shaft.
A second excavation will be carried out to expose the stern pivot gun. That excavation will be designed to collect information concerning the design and weight of the gun tube and determine if the tube is associated with its carriage and truck. In the event that the carriage and truck remain associated with the gun tube, an effort will be made to document their remains.
In the bow diver propulsion vehicles will be employed to blow away sufficient shell hash to expose any hull remains that extend above the stable bottom sediment. If the area can be cleared the perimeter of the surviving structure will be identified by small fiberglass rods. Efforts will be made to identify the area of the chain locker and bosun's stores. Aft of those areas should be the remains of the crew's quarters. If possible a limited test site will be excavated to determine the research potential for more comprehensive investigation of the area in 2001.
Underwater excavation will be accomplished through use of one or more air lifts powered by a surface supplied compressed air. Air will be supplied by from two to four 4500 psi cylinder banks holding approximately 1,760 cubic feet of air. The outlet pressure will be reduced to around 200 psi through use of a high pressure regulator. This will yield an outlet pressure on the bottom of about 100 psi. The air is then directed from the bottom up a tube toward the surface. As the air expands the venturi effect creates suction for removing sand and shell hash on the bottom. The 3/8 inch i.d. hose will be permanently affixed to a mooring on the bottom and to a float at the surface. A quick disconnect fitting will allow surface connection during slack tide dive windows and will remain in place for the duration of the project season.
One of the objectives of the CSS Alabama 2000 Project will be recovery of artifacts from the wreck. Three specific artifacts have been identified for recovery during the first phase of diving in June. Those are one of the Trotman patent anchors, one of the 32-pounder smoothbore cannon cast by Liverpool firm of Faucett and Preston specifically for the Alabama and the previously documented aft fire pump.
During the first reconnaissance of the site, one of the two Trotman anchors will be selected for recovery. Shell hash around that anchor will be removed using one of the diver propulsion vehicles. Excavation of sediment around the anchor will be removed using one of the air lifts. If the chain cannot be removed by disassembling the clevis that likely attaches it, to the anchor, one link of the chain may have to be cut. Once the anchor is free of the chain a lift bag will be connected to the clevis or crown. A buoy will also be attached to the crown to provide a surface reference and identify the location of the anchor in the event of complications with the lift bag. Once the bag is attached it will be filled with air to lift the anchor to the surface. At the surface the anchor will be lifted aboard the French navy vessel Vulcan. On board the Vulcan it will be additionally documented and kept wet for the trip to Cherbourg. There it can be loaded on a suitable vehicle for transportation to temporary laboratory facilities.
Prior to the first reconnaissance one of the 32-pounder cannon cast for the CSS Alabama by Faucette and Preston will be identified for recovery. During the first reconnaissance that gun will be measured to confirm that it is one of the Faucette and Preston guns. In the event that it is, shell hash around the gun tube will be removed using one of the diver propulsion vehicles. One of the air lifts will be used to remove sufficient sediment to rig the gun for lifting. Nylon straps will be placed around the barrel fore and aft of the trunions and a nylon line run from the lift straps to the cascabel. A buoy will also be attached to the muzzle or cascabel to provide a surface reference and identify the location of the anchor in the event of complications with the lift bag. Once the bag is attached it will be filled with air to lift the cannon to the surface. At the surface the cannon will be lifted aboard the French navy vessel Vulcan. On board the Vulcan it will be additionally documented and kept wet for the trip to Cherbourg. There it can be loaded on a suitable vehicle for transportation to temporary laboratory facilities.
During the first reconnaissance dive the aft fire pump will also be examined and shell hash cleared away using one of the diver propulsion vehicles. Excavation of sediment around the pump will be removed using one of the air lifts. Any mechanical connections between the pump and the hull of the Alabama will be disassembled. If at all possible the pump will be disconnected using the original fastners. If not the pipe to the pickup pipe may have to be cut. Once the pump is free it will be rigged for lifting using straps or a cradle. A buoy will also be attached to the straps or cradle to provide a surface reference and identify the location of the pump in the event of complications with the lift bag. Once the bag is attached it will be filled with air to lift the pump to the surface. At the surface the pump will be lifted aboard the French navy vessel Vulcan. On board the Vulcan it will be additionally documented and kept wet for the trip to Cherbourg. There it can be loaded on a suitable vehicle for transportation to temporary laboratory facilities.
Test excavations and environmental changes at the wreck site may also expose artifacts that require recovery. In the past small items recovered in conjunction with onsite research have been raised using partitioned plastic cages. Once the location of artifacts has been recorded they can be placed inside partitions in the recovery cage that protect them from damage. When the cage is full it can be brought to the surface by divers of sent up one of the buoy lines by small lift bags. On board the surface support vessel they will be additionally documented and kept wet for the trip to Cherbourg. There they can be loaded on a suitable vehicle for transportation to temporary laboratory facilities.
Artifact Cataloging and Field Conservation
Material recovered from the CSS Alabama during the 2000 project will be cataloged, documented and stabilized in the field. Arrangements will be made to keep material wet once it has been lifted aboard the recovery vessel. Weather permitting, preliminary documentation will take place on deck enroute to Cherbourg. There material will be wet packed and transported to field laboratory facilities secured by the Association CSS Alabama. Under the direction of a trained conservator retained by the Association CSS Alabama, artifacts will be cleaned, cataloged, recorded and packaged for shipment to designated laboratories in the United States and France for conservation. The most appropriate conservation methodology will be determined by the conservator in conjunction with personnel from the Naval Historical Center. Field conservation will be handled by Phillipe de Vivies.
Base of Operations
The onshore base of operations will be located in Cherbourg. Docking facilities for the Robo and Little Pockets will be at the Cherbourg harbor yacht basin. French Navy vessels will be berthed at the Cherbourg Navy Base. Briefings and Debriefings will be held at the CNP clubhouse in Cherbourg. Project participants will be housed at the Bachelor Officers Quarters at the Cercle Naval in Cherbourg.
Dive operations planned for the CSS Alabama 2000Project will be carried out using open circuit scuba.
Click on the titles below for further reading on the C.S.S. Alabama artifact recovery efforts.
Artifact Recovery Main Page
Synopsis of Previous Research
Wreck Site Environment
Description of the Vessel Remains
Approved Scope of On-site Investigation 2000
Specific Research Methodology
Surface Support Vessels
Proposed Project Schedule