Results of Hypothesis 1
Results of Hypothesis 2
Results of Hypothesis 3
Results of Hypothesis 4
Results of Hypothesis 5
Results of Hypothesis 6
Results of Hypothesis 7
Results of Hypothesis 8

Interpretations

Field investigations have positively identified the shipwreck under investigation as a sidewheel steamer. Evidence the vessel is the Maple Leaf comes from cargo removed from the aft cargo hold. Although circumstantial in nature, material is clearly marked as belonging to the three regiments known to have had equipment on board at the time of the ship's loss. Further evidence is the site's location at the same position as a wreck identified on early river navigation charts as the Maple Leaf.

The Maple Leaf is deeply buried making most of the hull inaccessible for documentation. The shipwreck is relatively intact from the main deck to the bottom and rests on an even keel. The superstructure has completely disappeared leaving little identifiable debris on the site. Generally, only construction elements of the hull at main deck level were examined. The wooden hull measured 173.2 feet between the stem and stern post and 181 feet over all. Amidships, Maple Leaf had a 24.7 foot beam and 10.6 foot depth of hold (Certificate of Ownership 1851; Daily British Whig 26 March 1851). The hull's length to beam ratio is 7:1. The 1856 ambrotype (Figure 5) shows a fine entrance, a vertical stem and pronounced sheer.

The vessel is constructed entirely of wood and iron fastened. Twenty-six wood samples were taken from the wreck over three field seasons and submitted to the Institute for Wood Analysis, Greenville, North Carolina. Table 2 presents the distribution of wood types. The presence of white oak and white pine fits the pattern of mid-nineteenth century wood use in the American shipbuilding industry described by William Bates (1867:473-474). Using Bates as a baseline, some small discrepancies become apparent. For example, red cedar is normally used for top timber futtocks instead of white cedar. Also, red oak and walnut were not popular for ship construction but were used occasionally for convenience and availability. Only one sample, southern hard pine, came from a species restricted to the southern United States. The use of this wood as a stanchion post probably represents a repair instead of original construction. The general habitat range of the other wood species indicates northern construction consistent with the Maple Leaf (Hayward 1930).

Window glass on the Maple Leaf functioned architecturally to enclose and weather-proof the superstructure, protecting people inside from foul weather. At the same time it allowed light to pass through, providing illumination for activities inside and allowing passengers to view their trip. Analysis of the architectural glass revealed several aspects of the material's manufacture and use. Generally, the glass manufacturing process was indicated by the alignment of seed bubbles in larger glass fragments. Elongated seed bubbles run parallel to each other in linear alignments indicating the glass panes were made from cylinder glass. Many fragments are too small to determine the manufacturing technique but convention suggests they are made from cylinder glass.

The glass analysis revealed several decorative techniques and motifs. One motifs, maple leaves, is mentioned by newspaper descriptions in 1851. However, the 


  White oak group Quercus spp. Red Oak Quercus rubra White Pine Pimus strobus Souther hard pine
Pimus spp.
White cedar Thuja occidentalis Walnut
Juglans spp.
Deck plank     X      
Carling     X      
Stem X          
Futtock         X  
Keelson     X      
Bow cap rail X          
Waterway X          
Fairlead X          
Outer hull plank X          
Deck clamp X          
Paddle beam X          
Guard beam X          
Rudder post X          
Crank Frame: port     X      
Crank Frame:
starboard
    X      
Starboard hogging
truss cord
X          
Gangway stanchion X          
Deck stanchion (aft
hold)
          X
Stanchion post (aft
cargo hatch)
      X    
Lower cargo deck
stanchion
    X      
Lower cargo deck
plank
    X      
Aft engine room
bulkhead
    X      
Paddle wheel arm X          
Paddle wheel arm   X        
Paddle bucket X          
Paddle bucket X          
Table 2. Wood species used in ship construction

small and fragmentary glass sample made it impossible to verify a maple leaf motif. Several other motifs were identified including ivy, pinwheel, and snowflake patterns. The analysis also discovered the decorative technique of combining acid etching with enamel coloring. Historical newspaper descriptions only mention painted glass, not etched glass.

Scratches caused by cleaning were one of the most interesting features found in the collection. It demonstrates some care was taken in maintaining the appearance of the ship. The scratches also confirmed glass use as an architectural element since no physical remains of glazing materials, such as window frames, were found on the site. Scratches caused by cleaning outlined the location of glazing putty used to hold the glass pane in a window frame.
A tremendous amount of data has been collected from the Maple Leaf site. Chapter three presented eight specific hypotheses to compare with field data. The remainder of this chapter discusses the results of testing these hypotheses.


Results of Hypothesis 1

In 1876, Great Lakes shipbuilders adopted international standards for construction (Dorr 1876). These construction rules, which became effective twenty-six years after the Maple Leaf was launched, require hogging trusses to be joined with the apron forward and the stern post aft to stiffen the keel and keelson. If the archaeological data confirmed the rules they could be viewed as written evidence of a building technique established earlier. Instead, the investigation disproved hypothesis 1 by demonstrating that the trusses are only attached to the upper part of the hull and are one element of a reinforcing system that worked longitudinally and transversely. The two different construction techniques may represent a gradual improvement in truss design or a different building tradition.

The longitudinal reinforcement system used on the Maple Leaf has several components (Figure 38). The hogging trusses are the largest element but instead of stiffening the keel and keelson, they stiffen very large deck clamps that run the length of the ship. First a sole timber was securely fastened above each clamp, tightly sandwiching the deck beams between the clamp and sole timber. This created a massive, composite longitudinal member along each side of the hull. The arch was built on top of the sole timber to counteract hogging forces. Dagger knees were used to further stiffen the clamp. The knee arrangement reverses amidships, providing equilateral support to the clamp at each end of the ship.

In late-eighteenth century England, the use of dagger knees was one of several proposed methods to combat hogging problems on longer ships (Chapelle 1967:206-207). In America, shipbuilders used dagger knees on the frigate President, captured by the British in the War of 1812 (Figure 39). The use of dagger knees for reinforcement spread to the Great Lakes in the nineteenth century. The schooner Bermuda, launched at Oswego, New York, in 1860, utilized an inverted plank arch built into her hull along with dagger knees on the deck beams (Labadie 1989:40, 43). The early propeller Indiana, built in Vermilion, Ohio in 1848, also had dagger knees (Johnston and Robinson 1994:219). These American built vessels, in conjunction with the Maple Leaf, fig 38 fig 39 demonstrate dagger knee use on both sides of the Great Lakes.

A second support system was used transversely across the hull to support the guards. Below main deck level, massive paddle beams and smaller deck beams extended beyond the hull to create a foundation for the paddle guards. The beams are braced underneath by both dagger and hanging knees. Above deck, a system of iron tie rods provided support. Horizontal rods, called cross chains or rolling rods, ran across the ship to connect the top of each hogging truss. Then diagonal rods linked the top of the truss to the outer edge of the sponson to complete the transverse stiffening. The arrangement helped lift the guards and keep the trusses from swaying (Bates 1968:23; Dorr 1876:70-71). A three foot section of tie rod attached to an eye bolt on the paddle beam is a diagonal rod that linked the guard to the hogging truss. The rod is broken at a turn buckle used to put tension on the assembly. A section of tie rod found on the deck nearby is also part of the system. One end is broken and the other end forms an eye attached to a metal plate. The plate has four holes used to bolt it to the hogging truss.


Results of Hypothesis 2

Hypothesis 2 suggested the Maple Leaf's superstructure was lightly built in comparison to the hull. Field work confirmed virtually no cabin structure remained except a few sole plates for the stern cabins. This helps substantiate historical descriptions of the shipwrecking processes presented in chapter three.

Evidence from the Maple Leaf indicates upper cabins were built on top of the main deck and not directly integrated with the hull's main structural timbers. The cabin soles are nailed to the deck and notched for wall studs. No discrete element of the cabin's framework actually passed through the deck. For further support, the cabins probably fastened to structural components that rose above deck, largely the hogging trusses and gallows frame. Built of light materials and without a link to the ship's major timbers, the cabins were inherently weak. This supposition is supported by an 1862 newspaper article which reports the vessel's main deck was completely replaced during annual refitting (Union and Advertiser 19 February 1862). The deck is an integral part of the ship, and replacing it suggests the superstructure was removed or elevated.

After sinking, the main hull and upper cabins were exposed to the same destructive agents, but differential deterioration occurred due to their dissimilar construction. The cause for the cabin's destruction is largely due to prolonged exposure to tidal currents, winds, storms, hurricanes, and wood boring marine organisms. This verifies hypothesis 2a and is indirectly confirmed by First Lieutenant Russell's description of the site (1883). By mentioning all major structures found above the main deck except the cabins, Russell implies their absence. Whatever part of the cabins remained after twenty years in the river was certainly destroyed by Ross's demolition work in 1883.


Results of Hypothesis 3

Hypothesis 3 suggests very few decorative elements will be present on the site. As expected, non-architectural embellishments such as furniture and curtains installed early in the ship's career were not found. The same site formation processes which destroyed the cabins also destroyed furnishings. Whether decorative furnishings were removed prior to military service as stated in hypothesis 3a, or lost to natural deterioration while submerged in the river cannot be satisfactorily resolved.

Decorative architectural elements faired little better. Hypothesis 3b postulates these elements were removed prior to the ship's military service. Many decorative features built into the cabin structure were lost with the superstructure if they were on board when the vessel sank. However, some durable items, such as window glass, survived. As woodwork deteriorated, window glass, including decorative glass, broke and fragments settled on the aft deck. Unlike wood, glass is relatively immune to decomposition and did not float off the site. Ultimately, archaeological investigations found some of the decorative features that reportedly gave the ship fine character and an excellent reputation during her career as a passenger vessel. The Maple Leaf is intact below the main deck but has limited value for investigating any aspect of the steamboat's upper cabin structure, whether decorative or functional.

Part of hypothesis 3 suggests the Maple Leaf was modified by removing cabins to create open deck space to accommodate large cargo. Contemporary accounts of military cargo shipped on the vessel suggest this space existed somewhere on the main deck. For example, on her last trip from Jacksonville to Palatka she carried eighty-seven horses. The 1856 ambrotype shows space was not available aft of the engineering spaces where cabins covered the main deck. This is confirmed by archaeological evidence. On the remaining deck forward, two possible open areas for handling deck cargo are located between the bow and pilot house or between the pilot house and engineering. No evidence of cabins was found in either area but both areas required space for functional purposes related to normal ship operation. The first area, near the bow, is occupied by the windlass used to raise the anchors. Space is needed to turn the windlass barrel, handle anchor cable, and store the anchors. The area further aft is near the engineering hatch. Space was required to load fuel through the engineering hatch into the bunkers below or to store fuel on the main deck near the hatch. When not in use, both areas could be utilized for deck cargo. Prior to military service, the Maple Leaf needed deck space to carry livestock and wagons. Whether or not the two open areas existed before military service or represent later modifications for war-time use cannot be determined by available evidence.


Results of Hypothesis 4

Hypothesis 4 suggests the Maple Leaf's hull was copper sheathed to prevent fouling and to protect against wood boring mollusks while operating on saltwater. In 1991, SJAEI discovered brass sheathing on the hull near the rudder, verifying the use of a protective barrier on the outer hull (Cantelas 1992:35). Although other areas of the bottom have not been examined, sheathing was probably used to cover the entire hull below the water line. Copper was often used for sheathing, but brass, a copper alloy, accomplished the same thing.


Results of Hypothesis 5

Hypothesis 5 suggests damage caused by the Confederate torpedo will be found in the bow area. To test this hypothesis it is necessary to distinguish between torpedo damage and damage caused by other agents. The crew's vivid description of damage they saw while abandoning ship is vital to interpreting the present condition of the bow area. The most obvious damage probably occurred on the hull bottom where the torpedo exploded. Excavation undertaken inside the forward hold in 1992 found the cargo badly damaged and in extreme disarray. However, damage to the ship's lower hull could not be verified because the excavation did not reach the bottom of the hold (Cantelas 1993:39).

On the main deck, a badly damaged area is located on the starboard side, approximately twenty feet from the bow. This roughly corresponds to Second Officer Charles Farnham's statement: "The hog frame was broken and the whole side of the vessel was stove in. The force of the explosion was about thirty feet from the stem and on the starboard side" (1864). The smashed area found on the deck is just forward of the hogging truss reportedly broken during the explosion. Farnham's statement explains the damage to the ship and demonstrates the destructive power of the torpedo.

River pilot, Romeo Murray, described other damage on the main deck. The pilot house toppled and the mast fell forward. The 1856 ambrotype (Figure 25) shows the mast located just in front of the pilot house. The deck in that area, between the forecastle hatch and the forward cargo hatch, is largely missing along with any evidence of the mast's location. Part of the damage occurred when the explosion forced the mast out of its step and it fell over. This must have strained the supporting mast partners and surrounding deck, causing them to buckle and break. Later salvage efforts, discussed under hypothesis 6, may explain additional damage to the area.


Results of Hypothesis 6

Hypotheses 6 predicted evidence that cargo and/or ship's equipment was salvaged. Immediately after sinking, the ship became a target for local citizens who took off small belongings. Crew members, who returned the following day, broke through the saloon deck to retrieve belongings from lower cabins (Dale 1864; Johnson 1864). This salvage had minor impact and was limited to the superstructure and not to the cargo spaces.

While hypotheses 6a suggests cargo was salvaged, it could not be conclusively confirmed. Damage to the forward deck, between the forecastle hatch and the forward cargo hatch, is more extensive than expected from descriptions of the collapsing pilot house and fallen mast. The ship superstructure in the 1856 ambrotype shows the forward area of the main deck as the easiest location to enter the hull. Aft of the pilot house, the saloon on the hurricane deck covers the main deck, creating a major obstruction to salvage efforts in the holds. Forward of the pilot house an open weather deck (on the hurricane deck level) covered the area in question. Also, the forward main deck probably remained open to handle cargo and work the windlass. Salvers without the means to remove the superstructure would find this open area the easiest route to enter the hold. This may also explain why there are no holes in the aft deck except the one made by SJAEI in 1989.

The most glaring evidence of salvage is the absence of the Maple Leaf's anchors and anchor chain at the bow, confirming hypotheses 6b. They were probably salvaged by Union forces stationed in Jacksonville soon after the vessel sank. On April 9, 1864, a boat was sent to the wreck "to recover some of her equipment and anchors", but the outcome of the operation is not known (Hatch 1864c). If the anchors were not removed during the war, Roderick Ross probably recovered them during his salvage operations in the 1880's. A marine contractor like Ross would have many uses for anchors and chain.


Results of Hypothesis 7

Hypothesis 7 postulates demolition work conducted on the site in the 1880's caused extensive damage to the steam propulsion system and/or the ship's structure. The best historic source on the 1880's demolition is First Lieutenant William Russell's description of activities in 1883. According to Russell, Ross removed the hogging trusses, gallows frame, and paddle wheels with explosives. Archaeological evidence supports this statement. These structures are missing or badly damaged but the exact mechanism of their destruction is generally not apparent.

The most compelling evidence for the use of explosives is the steam dome on the port boiler. It is shattered and the metal plates flare away from the dome's center indicating a strong outward blast. The blast also caused the boiler face to separate and lean forward, and blew the fire box doors open. A charge placed down the stack could produce this damage. A boiler explosion at the time of the sinking might also cause this damage but testimony taken at a board of inquiry the day after the loss does not support this. Chief Engineer Samuel Johnson (1864) adamantly stated a boiler explosion did not occur. He was still on board when the vessel settled to the bottom and did not mention an explosion as river water filled the engine spaces.

Curiously, Russell did not mention the superstructure or engine. In the decades following the sinking, most of the superstructure succumbed to natural weathering forces as described in hypothesis 2. In fact, one of the most distinct features of the site is the lack of superstructure debris in the overburden and the site's low relief above the main deck. Whether or not Ross destroyed the steam engine is problematic. The air pump fragments recovered from the site suggests the engine was blown up because it threatened navigation. If the engine were salvaged, this necessary component would have been removed along with the engine. In addition, salvaging the engine for reuse had to occur soon after the loss because saltwater corrosion would destroy machinery tolerances necessary for the engine to run.

Destruction of major engineering components in the midships area caused massive structural damage to the main deck. This damage extends from roughly 70 to 120 feet from the bow. It includes missing and broken deck planking, deck beams, and paddle beams. All or most of the damage observed in the amidships area during field investigations resulted from the 1880's demolition. Evidence confirmed the destruction of the steam propulsion system and the ship's structure as proposed by hypothesis 7.


Results of Hypothesis 8

Hypothesis 8 suggests the Maple Leaf's remains are well preserved by anaerobic sediments. Three material types, which directly relate to the ship's construction, will be examined by general observation; wood, metal, and glass. Preservation conditions are complicated by many interrelated micro and macro variables operating on the site. These include exposure to wind, tides and currents before burial, water chemistry ( salinity and ph), bottom sediment chemistry, groundwater intrusion, marine organisms, anaerobic bacteria, fungus, and electrochemical corrosion.

Except for damage inflicted by channel clearing operations in the 1880's, the physical condition of wood used to construct the vessel is very good. Many unsecured wood fragments that floated to the surface when uncovered. There does not appear to be any differential preservation based on wood types. As mentioned above, white oak was used in all major components of ship construction. White pine and walnut are also represented.

Biodegradation appears to be the main factor causing wood decomposition on the site. The most visible agents are wood boring mollusks which have caused limited damage to exposed areas such as the bow cap rail displayed in the Jacksonville Museum of Science and History (Cantelas 1992:27). These organisms may have played a major part in the disappearance of the exposed superstructure. No wood borer damage was found on deeply buried portions of the wreck suggesting the vessel settled rapidly into the river mud before the mollusks could impact the hull. On the microscopic level, ligniferous marine fungi and marine bacteria have caused wood degradation. These agents remove lignin and cellulose from cell walls, weakening the wood's structure and increasing water content (waterlogging) (Gratten 1987:64-66). However, burial in anaerobic river sediment slowed the process considerably and is responsible for the wood's excellent condition.

Iron and brass, the most common metals on the Maple Leaf, are present in the ship's construction and artifact assemblage. Although this discussion focuses on ship construction, the same factors effecting preservation operate on all metals found on the site. The quality of metal preservation differs depending on many known and unknown factors including metal type and location within the site. The mechanisms causing corrosion include water movement, salinity, marine growth, pH, galvanic coupling, sulphate reducing bacteria, and methogenic bacteria (North and MacLeod 1987:74-76; Rodgers 1989:336). Except for the paddle shaft, the site is too deeply buried to be affected by salinity, water movement, and marine growth. Also, galvanic coupling, caused by dissimilar metals touching, does not appear to be a major factor in metal corrosion observed inside the hull. The ship contains very little structural brass compared to iron so there are few opportunities for galvanic coupling to occur. The brass, or copper, sheathing on the outer hull probably affected exterior hull fasteners but the extent of corrosion is not known. In containers packed in the holds, many different types of metals are present but galvanic corrosion occurring inside the containers has little impact on the ship.

Sulfate reducing and methogenic bacteria living in the anaerobic sediments probably caused most of the iron corrosion on the site. The microbes colonized the wreck due to the lack of oxygen and the availability of food in the form of wooden ship timbers. The bacteria cause cathodic depolarization in iron, creating corrosion products, and produce methane and hydrogen sulfide gas as a by-product. Corrosion products become a factor in causing other organic and inorganic artifacts to deteriorate. For example, iron salts stain ceramic, glass, leather, wood, and many other material types. Also, iron eventually causes textiles to break down. The sulphate reducing environment increases the rate of copper corrosion and the increased pH levels caused by microbial activity increases the breakdown of glass, paper, wood, and other materials found predominantly in the cargo (Rodgers 1989:336, 339). Although these factors chiefly affected artifacts in the cargo, they also impacted iron used in the ship’s structure.

The presence of methane and hydrogen sulfide gas would indicate the presence of methogenic and sulphate reducing bacteria, respectively. The noxious smell of hydrogen sulphide was not noticed on the site. However, wood artifacts stored in fresh water developed a sulphur smell indicating an active colony of sulphate reducing bacteria. These bacteria were probably present in the wood before it was recovered, then proliferated when storage conditions became anaerobic. Methane does not have an odor but its presence is suggested by the buoyant timbers found on the site. As methogenic bacteria feed on wood they release methane that is trapped inside the timbers causing them to become very buoyant. There is strong indirect evidence the Maple Leaf harbors methogenic and sulphate reducing bacteria and these microbes in turn have tremendous impact on iron preservation.

Generally, the anaerobic environment caused little damage to glass found on the site. Fragmentary architectural window glass was found on the aft deck. This glass is one of the few vestiges of cabin remains on the site and is present due to its inert nature. It consists of undecorated window glass and window glass decorated by coloring, enameling, and etching. Some of the glass is cracked and melted. This damage occurred the day after the Maple Leaf sank when Confederate forces burned the upper portion of the ship's superstructure (Bryan 1864).

Both decorated and undecorated glass display slight cloudiness and iridescence. This is caused by hydrolytic attack when potassium and sodium ions, the alkali components in glass, are replaced by hydrogen ions. Glass thickness slowly decreases and thin, weak layers of glass are left on the exterior. The extent of damage depends on how long the glass has been submerged and the pH of the surrounding environment, especially if buried. Acidic conditions accelerate decomposition (Singley 1988:23-24). Except for minor clouding, glass from the Maple Leaf is in excellent condition but decomposition will continue in the present site environment.