Treasure Under the Bench: The Discovery of Carpenter's Marks on the Colonial Gunboat Philadelphia Taras Pevny 2010 Archaeological Assessment: 42-87 in Colonial Gunboat Philadelphia Preservation Assessment and Conservation Plan (Vol. I) Peter Fix, editor report on file: Smithsonian Institution's National Museum of American History Washington, D.C. 42 ARCHAEOLOGICAL ASSESSMENT Taras Pevny A Treasure Under the Bench: The discovery of carpenter’s marks on the colonial gunboat Philadelphia I. Summary of Findings When working on a conservation assessment of the Revolutionary War gunboat Philadelphia (Fig.1.) for the Smithsonian Institution’s National Museum of American History, Peter Fix and I had the opportunity to closely examine the remains of the vessel (Figs. 2-3). The Philadelphia has been on display at the museum for almost fifty years and has been studied thoroughly (see Section III); therefore, we were not expecting to make any new archaeological discoveries. To our surprise, we found a variety of previously undocumented carpenter’s marks scribed into the timbers by the original builders in 1776. During our preliminary survey, we discovered eight types of marks and one construction feature relating to the vessel’s design: Fig. 1. Model of the Philadelphia. (From Sands 1988: 154) Fig. 2 & 3. Peter Fix working on the stern deck of the Philadelphia. Note the bench/locker on either side of the vessel. Taras Pevny looking for marks under the starboard bench. (Photos by T. Pevny & P. Fix) 1. A “V” scribe mark on the inboard face of the bottom planking along the centerline axis (see Section V-1.1 & Figs. 22-23). NOTE: Although the official report is dated 2010, this part is essentially my field report from 2006. It presents important new discoveries as well an introductory discussion of the design theory that led to them. For a more in-depth look at the design theory see Pevny 2017. 43 2. Scribe lines used by the shipwrights to mark floor timber positions and spacing (see Section V-1.3 & Figs. 25-28). 3. “V” scribe marks at the ends of the floor scribe lines used to mark the offsets for the outer curve of the bottom (see Section V-1.4 & Figs. 31-33). 4. Scribe/cut marks used to “line out” the runs of the outer hull planks (see Sections V-2.3 & V-2.4). 5. Side frames (standing knees) that are not smooth curves, as previously believed, but are polygonal with flats cut for fitting the planking (knuckled frames) (see Sections V-2.3 & V-2.4 & Figs. 55-56). The cut marks visible in the seams, #4, gave us the first clue to identify this significant construction feature. Our attention was drawn to the runs of these planks by unfairness expressed as a bump in the run of wale, a thicker plank, in the starboard stern (see Section V-2.3 & Fig. 53). 6. Scribe marks, at frame positions, across the edge thickness of the outer hull planks – a product of shaping these planks (see Section V-2.5 & Fig. 58). 7. “V” scribe marks, at frame positions, along the edge of the inboard face of some ceiling planks. They were used to lay out the shapes of these planks. Such marks are referred to as spiling marks (see Section V-3.1 & Figs. 62-73). 8. Scribe marks for locating the positions of notches for fitting beams (see Section V-4.1 & Figs. 75-76). 9. Rough cut marks for laying out part of the stern deck structure (see Section _& Figs. 77-78). These discoveries led to the identification of previously unrecognized ratios and layout procedures used by the shipwrights to determine the overall shape of the hull. For example: • • The flat bottom has a breadth to length ratio of 1:4 (see Section V-1.2 & V-1.3 & Fig. 24). The widest point of the bottom (maximum breadth at midships) is located five divisions from the forward most point of the central bottom plank and eight divisions from the aft end. These divisions fall at every third floor timber. In total there are 15 consecutive frame divisions (room and space) forward of midships and 24 divisions aft (see Section V-1.3 & Figs. 24, 29). These discoveries and their implications are discussed in detail in separate sections below. It is important to emphasize that this write-up is based on information gathered during a conservation assessment. Our primary purpose was not to study the hull’s design and construction, but to document the physical state of preservation of the vessel’s overall structure and individual elements. In reference to the archaeological evidence, the goal during our assessment and for any future conservation treatment was/is to limit the disturbance of the existing archaeological record and preserve it. In light of these new discoveries, the Philadelphia’s design and construction warrant further archaeological study (see Section VI). 44 Identification of American shipwrights’ marks relating to the design and assembly of hulls is rare. Worldwide, such marks have been identified on only a small number of archaeological hull remains. The majority of such marks have been found on four wrecks discovered along the coasts of the Iberian Peninsula.1 These ships date from the 14th to the 17th centuries. Two ancient Mediterranean wrecks, dating to the 6th & 3rd centuries B.C., have design and/or assembly marks preserved on their timbers.2 In North America design marks have been discovered on the remains of a 16th -century Basque ship which sank off Labrador and on La Belle, a 17th -century French ship discovered on the Texas coast.3 Although an extensive literature search may result in several more “marked” wrecks, to my knowledge the examples listed above are the most prominent . Tool marks resulting from the actual cutting and shaping of the timbers have been more thoroughly studied and documented.4 In general methods of design, as compared to construction, have been negligibly studied and poorly documented with regard to archaeological remains. The study of ship design based on historical evidence is far more extensive, although relatively few nautical archaeologists are familiar with this research.5 This limited exposure to the history of ship-design methods on the part of most investigators is a great hindrance to the archaeological study of hull design. The study of original design and building techniques is an essential prerequisite for mining hull remains for information. It is critical for the investigator to be able to differentiate between how the original shipwright approached the definition of a hull’s shape versus the methods an archaeologist uses to document the preserved shape. Too often a dependency on modern ship-drafting methods used in the process of recording and studying a vessel’s remains masks the original logic of the shipwright (see Sections IV & V-1.4). Such documentation is essential, but it has to be recognized as a modern tool and not as a reflection of original design and construction methods. The need for familiarity with historical ship-design methods as an aid to archaeological investigation is discussed in greater depth in Section IV. Defining the complex curvature of hulls has been a challenge throughout millennia. Very few structures through history have incorporated curvature as part of their basic structure. Not only do ships and boats incorporate curves as part of their basic shape, the curvature changes along the length of the vessel – complex and irregular curvature. The various solutions to the challenge of designing hull shapes through time have, in general, been underrepresented and underappreciated in the study of architectural history. Part of the problem is the difficulty in conveying fundamental issues of hull design to the uninitiated reader. The conceptual simplicity of the Philadelphia’s design and construction makes it an ideal case study for the presentation of some of the basic principles underlying hull design (see Sections V-1.5 & V-3.1). In fact, this simplicity is the reason why vessel types like the Philadelphia were so prominent on the American frontiers (see Section II). 45 II. Meeting a Need: The Historical Role of Bateaux The Philadelphia was one of eight bateaux out of a total of 13 vessels built or completed in the summer of 1776 to meet a pressing military need – to place as much cannon power on the waters of Lake Champlain as possible.6 This was a response to a British plan to move a force down from Canada via the Lake Champlain – Lake George – Hudson River corridor in an attempt to cut the New England colonies from the south (Fig. 4). This situation developed after a failed attempt the previous year by American colonial forces to capture Quebec. The Americans ultimately retreated south to the area around Crown Point and Fort Ticonderoga on Lake Champlain (Fig. 4). The colonists had very few armed vessels on the lake and it was believed that the British were planning to build up a naval force north of the lake along the Richelieu River (Fig. 4). The Americans had to assemble an opposing force as fast as possible. Far removed from any shipbuilding centers, this Fig. 4. Lake Champlain – Lake George – Hudson need had to be met. Without a large force of River corridor. (From Bratten 1997: 10) experienced shipwrights, nor stockpiles of curved shipbuilding timber (compass timber), the building of numerous complex hulls was not an option. It was decided to build as many gondolas (large bateaux-type vessels) as possible to supplement a few larger and more elaborate vessels such as schooners, sloops and galleys (Figs. 5a-c). The chosen site for the shipyard was Skenesborough on the southern end of Lake Champlain (Fig. 4). Gondolas are double-ended boats with flat bottoms. A double-ended hull comes to a point at both ends, thus the complexity of building the stern structure associated with square transoms is avoided (Fig. 5c). The wide flat bottoms result in a large amount of volume within a short height of hull (depth of hull) (Fig. 5a). As a consequence, due to the laws of buoyancy and displacement, these types of hulls can carry a large amount of cargo, men and artillery in the case of the Philadelphia, without floating very deep in the water (shallow draft). In inland and coastal waterways this limited draft allows for traversing over shallow waters or underwater hazards. It also allows the smaller and/or lighter versions of these vessels to be beached – for the night, to make repairs and/or longterm storage – or portaged from one waterway to another (Figs. 6 & 7). In addition to being well suited for their purpose, it is important to realize that the simplicity of the design and construction of these vessels often reflects the resources of the individuals who built them. Flat-bottom construction of this type avoids the difficulty of defining and building the complex curvature that is a characteristic of the lower parts of most round bottom hulls. Like in the case of the Philadelphia, these types of craft 46 were often built in remote regions, for specific short-term purposes, by individuals with limited finances, tools, shipbuilding skills and time – in short these vessels were appropriate for their building environment. Fig. 5a-c. Overall views of the Philadelphia. Plans by H. Hoffman for the Smithsonian Institution. (After Bratten 1997: 162 &167. Bateaux and other such simple types of vessels were built and used by explorers, traders and settlers throughout colonial America.7 Until the wide spread use of steam powered vessels on the western rivers, simple craft such bateaux, Mackinaw boats, flatboats and keelboats were the workhorses of settlement and trade (Figs. 5-9).8 The Philadelphia and seven other gondolas were built between June and August of 1776. Although there were a large number of carpenters on Fig. 6. Flatbottom Mackinaw boat pulled up on a riverbank. (From American Heritage 1961: 108) 47 hand, the construction fell under the supervision of only a small number of shipwrights.9 Planking lumber was sawn at local watermills, thus alleviating the labor intensive work of hand sawing large oak planks using pit or platform saws. Regularly spaced and parallel saw marks preserved on the Philadelphia’s planks are evidence for the use of such mechanically sawn lumber.10 An adequate supply of pre-sawn planking and the simple structure of the hulls would have contributed greatly to the effective utilization of an unspecialized labor force. Nonetheless, the newly discovered evidence of the extensive use of design marks is a strong indication of the intimate involvement of experienced shipbuilders in the establishment of systematic and regularized design and construction procedures. Individuals with prior experience building these types of craft made it feasible and practical to do this form of simple boat construction throughout the remote regions of colonial America. Although in this report we are limiting our discussion to the American experience, it must be kept in mind that we are discussing a hull type that has a long history throughout the world.11 Similar conceptual issues apply to the study of such hulls worldwide regardless of whether there was any sort of technological transmission or not.12 Archaeological examples of the bateaux-type craft have been discovered in several locations in North America: Lake George in New York & Lake Champlain; James River Canal basin, Virginia; and Quebec.13 These discoveries inspired the construction of replicas of the Lake George and James River bateaux as well as the Philadelphia gondola. Although these replicas share a similar design concept, they serve as examples of the diversity of this vessel type in terms of size, shape and use (Fig. 10-13). Unfortunately, there is no study Fig. 7. Vessels being portaged between waterways. (From American Heritage 1961: 72) Fig. 8. A Flatboat being steered downriver. Flatboats, essentially square barges, could not be taken upriver. (From American Heritage 1962: 26) Fig. 9. A keelboat crew fending off an attack. Keelboats could be poled, rowed or sailed upriver. (From American Heritage 1961: 82) 48 that puts the design and construction characteristics of this vessel type in a broad historical and technological context. Our recent discovery of carpenter marks on the Philadelphia opens up a great opportunity to stimulate such research and publication (see Section VI). Additionally exciting is an ongoing effort to study and possibly raise Philadelphia’s sister ship – another gondola that sank along with the Philadelphia during the battle of Valcour Island in October of 1776.14 Fig. 10. Replica of the Lake George bateau. (From Crisman 1988: 131) Fig. 11. Replica of the James River bateau. (From Crisman 1988: 131) Fig. 12. Replica of the gondola Philadelphia. (From Bratten 2002: 153) 49 III. Prior Research and Publications The remains of the Philadelphia were first described in print by Lorenzo F. Hagglund, who discovered and recovered the vessel in 1935 and was its caretaker till 1961, when it was transferred to the Smithsonian Institution.15 On the basis of this discovery Howard I. Chapelle generated reconstructed plans of the vessel that were published in 1949 in his book The History of the American Sailing Navy (Fig. 13).16 Subsequently, the overall shape and construction of the hull remains were extensively documented, reconstructed, described and illustrated by Howard P. Hoffman in a set of annotated architectural drawings, as well an article in the early 1980’s (Figs. 5, 18, 23, 34, 62, 75).17 The construction of the Philadelphia and that of the Lake Champlain gondolas was also researched in the 1980’s by graduate student William A. Bayreuther.18 The discovery and preservation of the Philadelphia, and the historical events associated with it, inspired the construction of a replica by the Lake Champlain Maritime Museum from 1989 to 1991 (Fig. 12).19 The building of the replica provided an opportunity to once again evaluate the boat’s construction and its performance under sail and oar. The work of Chapelle, Hoffman and Bayreuther, as well as the lessons from building and operating the replica, were incorporated into a dissertation in 1997 and subsequently into a book in 2002 by John R. Bratten, who presented the archaeological remains of this vessel and the associated artifacts in their immediate historical context.20 Fig. 13. Howard Chapelle’s reconstruction drawings of the Philadelphia based on an examination of the remains. (Chapelle 1949: 109) 50 IV. Ship Design Theory and the Process of Archaeological Discovery/Investigation It is not unusual for a fresh look at archaeological remains to reveal some aspect or feature of an artifact that was previously unnoticed or its significance was not fully realized or highlighted in earlier studies. Outside of the field of archaeology, many of us have experienced the frustration of not being able to find the answer to some problem, only to have someone else find the solution with apparent ease. Many factors come into play in those situations, such as experience, degree of concentration, perseverance, emotional state and even luck. Some archaeologists gain a reputation for having an uncanny ability to discover archaeological sites, individual artifacts, or specific artifact features on a consistent basis. What factors, other than an ambiguous sharp eye, can help explain such a talent? In archaeology it is very useful, if not indispensable, to have an extensive knowledge of archaeological parallels – similar sites or artifacts that have been previously documented. What makes such a reference database, whether mental, paper or electronic, a powerful search tool for new discoveries is the development of accompanying theories, formal or informal, of how individual objects or their groupings were made, functioned, and/ or utilized. Data or information is gathered to test a theory, but if a theory has some degree of validity it also helps in the discovery of the data itself. I am using the term theory very broadly and rather generously. Developing a theory or theories of how craftsmen or shipbuilders built various vessels and defined their shapes – the basic logic behind their approaches – can help the archaeologist determine where to look on the remains of a ship for evidence of the design method used and the construction sequence followed. Closer scrutiny of certain features, or key locations on a hull, may result in the discovery of evidence of design and/or construction that would otherwise go undetected. Furthermore, familiarity with such theories allows the archaeologist to recognize the importance of features that would otherwise be deemed insignificant or of secondary importance. In discussing the reconstruction of the processes resulting in the formation of an artifact, i.e. the construction of a boat, it is critical to remember that the archaeologist studies the remains, partial or whole, of the end product of human activity. Only occasionally does the archaeologist, in addition to the finished artifact, also have access to a partially completed artifact on which work was abandoned or which was discarded or rejected at some intermediate stage of production. Archaeologists thus work backward to recreate the original process of an artifact’s creation and utilization. Thus, for example, from the end result C the archaeologist tries to determine stages B and then A. Although it may be possible to determine the defining features of an artifact at stages A, B, and C, it is critical to try to determine how the original craftsman proceeded from one stage to the other. Unlike the archaeologist that has the remains of the finished artifact as his/her starting point, the original craftsman began with nothing but an idea. To add validity to the reconstructed stages the archaeologist must present a logical and feasible conceptual and mechanical scenario by which the original maker proceeded through the proposed sequence of stages. The archaeologist must try to recreate not only the stages of an artifact’s production, but the original creator’s thought processes in relation to each stage. 51 I am currently developing a broad theory of the evolution of ship design, a theory that directly led to our discovery of carpenter marks on the Philadelphia within the first few days of examining its hull remains. I must emphasize that I do not attribute the discovery of these marks to some special talent on the part of Peter Fix and myself; we simply asked the appropriate questions and had the benefit of sufficient archaeological preservation to lead us to the discovery of these marks. What is this theory? Throughout the history of western shipbuilding a fundamental factor in the development of various methods of ship design was the way a longitudinal (lengthwise) curve in the area of the bilge – the point of transition in hull curvature between the bottom and sides of the vessel – was defined. I believe that attempts at regulating or regularizing, and subsequently quantifying this and other longitudinal curves along the hull helped lead to the development of methods of predetermining hull shape, i.e. replicable ship design in European and consequently American shipbuilding. The underlying concept was a desire to quantify the normal or natural run of a plank or ribband (a small temporary plank used during construction, also referred to as a batten) along the length of the hull. A “normal” run is the way a plank, specifically a straight plank, bends along the curvature of a hull without any edge-set – forced bending in an edgewise direction (Fig. 14). Currently, the best archaeological example of the culmination of this design concept is the hull of La Belle, a late 17th -century French vessel, whose design I had the privilege to study.21 La Belle has design marks carved into its timbers along two longitudinal bilge curves (Fig. 15). Its design represents the beginning of the final stage in the development of geometric/arithmetic methods of quantifying hull curvature before the introduction of modern orthographic hull design in the form of the lines drawing or lofted half-model sections. Fig. 14. A straight plank’s normal or natural run along the bilge of a hull. (After Greenhill 1988: 137) 52 Fig. 15. Isometric drawing of La Belle’s hull remains with every third “marked” frame set depicted. The red lines depict the diagonal design curves indicated by the shipwright’s marks. (Drawing by T. Pevny) In geometric methods, quantifying the bilge curve is the foundation of the vessel’s design. The bilge curve runs diagonally when viewed from the ends of the vessel (Fig. 16). The locations of points on this curve need to be defined in terms of length, width and height relative to the horizontal and vertical planes. Otherwise, as in French design, they can be defined by length and width on a diagonally inclined plane. In flat bottom boats, like the Philadelphia, points on the bilge curve lie on the same horizontal plane. Drawing the bilge curve is as simple as sketching it in the ground or on a sheet of paper. In terms of coordinates, any point’s location on the curve can be defined by its length and width relative to the vessel’s centerline (Fig. 17). Therefore, in terms of design, the Philadelphia is a relatively simple vessel; one can look through a few books on small boatbuilding and quickly discover several methods used by boat builders to define the shape of such vessels (Fig. 17).22 It may seem a stretch to term this “theory building”. However, the viewpoint that these methods are simple solutions to the challenge of defining the otherwise complex curvature of hulls, highlights some of the fundamental principles of ship design [see also pp.62-71]. Given the opportunity, during our overall assessment of the vessel’s design and construction, Peter and I simply took a very close look at the timbers along the Philadelphia’s bilge. Over time certain theories may begin to look absurdly obvious; nonetheless, they remain indispensable in practical application. After more than 70 years out of the water the study of the Philadelphia’s hull is yielding new discoveries. [For a presentation of a fuller, more in-depth and nuanced version of this theory of the development of ship design methods (e.g. the role of the transverse design elements) see my chapter "Capturing the Curve: Underlying Concepts in the Design of the Hull", in the the 2017 book La Belle: The Archaeology of a Seventeenth-Century Ship of New World Colonization.] 53 Fig. 16. A French drawing from 1683 depicting the “diagonals” method of design. Note in the profile view the diagonals are depicted as actual ribbands. (Afer Boudriot 1998: 54-55) Fig. 17. Basic beginning steps of a flat bottom dory's construction. The chine/bilge curve has been highlighted in red. (Afer Gardner 1987: 58) 54 V. The Findings/Discoveries in Detail 1.1) The Philadelphia is a double-ended flat bottomed vessel. Its bottom is composed of planks laid lengthwise edge-to-edge. The keel less bottom is completely flat with no lengthwise curvature (rocker) or lateral rise (deadrise). In this simple form of construction, the shape of the bottom defines the main shape of the vessel. Because the bottom planks lie in a single flat plane, drawing the shape of the curved edges of the hull is comparable to drawing such a shape on a flat sheet of paper (Fig. 17). Fig. 18. Profile and plan views of the bottom planks and framing of the Philadelphia. The centerline is highlighted in red and the plank seams are highlighted in blue. Adapted from H. Hoffman’s plan for the Smithsonian Institution. (After Bratten 1997: 153) Presumably the planks, cut to approximate lengths, were first laid on some form of building platform or on beams over a pit to allow the builders to drive fastenings from below (Fig. 17).23 Wooden dowels (treenails), driven from underneath the hull, hold the bottom planks to the internal framing timbers. These craft were quite big to be built upside down, as is often done Fig. 19. Upside down dory construction. (From Gardner 1987: 71) with similar smaller craft (Fig. 19).24 The Philadelphia’s central plank, to which the end posts are fastened, has five strakes (full longitudinal runs of planks) to either side (Fig. 18). Although all the bottom planks are laid parallel to centerline and there is an equal number on both sides of the central strake, the corresponding strakes to either side are not all of the same width. The central plank is itself slightly offset to port relative to the centerline (Fig. 18). Symmetry and regularity of laying out the bottom planks is not essential in this type of construction. There are several archaeological examples of such flat bottom craft, from various building traditions and time periods, in which the laying of the bottom planks is very irregular and not parallel to the longitudinal axis (Fig. 20).25 The fact that symmetry and 55 regularity are not critical for the arrangement of the bottom planks themselves, emphasizes the importance of accurately laying out the side curves of the bottom. In small flat bottom boats it is possible to make the whole bottom out of a single plank (Fig. 21). Fig. 20. The construction of a replica of the Bevaix boat based on the remains of this Gallo-Roman boat. (From Hocker 2004: 69) Fig. 21. A turf boat under construction in Britain in 1970. Note the bottom is a single slab of timber. (From Greenhill 1995: 29) Although the Philadelphia’s bottom planking is not laid out symmetrically relative to the centerline the actual chine curves are mirror images of each other. A chine is an angled bilge instead of a round or curved bilge. To lay out these curves symmetrically on either side of the bottom the shipwrights needed to establish a centerline. Presumably a string was stretched between the two end points. Thus far we have not identified a longitudinal centerline scribed into the wood. Unfortunately, the inboard face of the bottom planking can only to be examined in one location along the centerline. However, in this location we did find a scribed-in “V” mark pointing to the centerline (Figs. 22a-b & 23). There is a good chance that this mark is not unique; only future investigation will tell. Fig. 22a-b. “V” scribe mark pointing to the centerline location under the keelson. The mark is highlighted in 22b. (Photo by T. Pevny) 56 Fig. 23. Plan view of the Philadelphia showing the location of the centerline “V”. In this small area the bottom planks are visible from above. This was probably left open to allow water to be bailed out – a bailing well. Adapted from H. Hoffman’s plan for the Smithsonian Institution. (After Bratten 1997: 157) 1.2) The length of the bottom along the centerline was documented to be 48 feet 10½ inches.26 The dimension of the maximum breadth of the bottom is 12 feet 1½ inches.27 The shipwrights seem to have laid out the bottom with roughly a 4 to 1 length to breadth ratio (Fig. 24). In addition, the maximum breadth was placed at 5/13 of the total length from the forward end of the bottom (Fig. 24). Surprisingly, these simple ratios are not highlighted by previous researchers when presenting the vessel’s overall dimensions. The intentional proportioning of the bottom’s main dimensions is an indication of the execution of a predetermined design. What evidence supports the use of these basic mathematical relationships, and how can we hypothesize that these were intentionally established by the shipwrights and are not the product of archaeological wishful thinking? Fig. 24. Plan view of the bottom planks and framing showing the main proportions and the positioning of the maximum breadth. Adapted from H. Hoffman’s plan for the Smithsonian Institution. (After Bratten 1997: 153) 1.3) We discovered that the positions of the internal framing timbers (floors) that run laterally (side to side) across the bottom planks were marked with scribed lines. These lines are located along the forward edges of the floor timbers (Figs. 25-27). A lack of access to, and visibility of, many surfaces on this well-articulated hull only allowed for the examination of the forward edges of the floors in a limited number of locations. 57 Factoring in the badly eroded state of the timber surfaces, enough floor-scribe marks were identified to strongly support the preliminary conclusion that the floor locations were marked along the entire length of the hull. Traces of such marks were identified at floor divisions #5, #6, #11, #12, #13, #33, #36 & #38. Most importantly, these lateral scribe lines were found in the extreme stern where there are no floor timbers. Fig. 25a-b. Floor scribe line at floor division #38. Frame #38 is labeled in green. Note in this location there is no actual floor, just a marking for its location (i.e. floor division #38). (Photo by T. Pevny) Fig. 26a-b. Floor scribe line at floor division #36 (Floor #34). Frame #36 is labeled in green. (Photo by T. Pevny) Fig. 27a-b. Floor scribe line at floor division #33 (Floor #31). Frame #33 is labeled in green. (Photo by T. Pevny) 58 Fig. 28. View of the lower port stern of the Philadelphia. The floor scribe mark from Fig. 25 is highlighted. Note the missing chine plank. (Photo by T. Pevny) The Philadelphia has 34 floor timbers spaced at 15 inches from the corresponding edge of one timber to another (room and space) (Fig. 27). Beyond the forward most and aftermost of these floor timbers there is room for two more floor timbers respectively. Given the discovery of lateral scribe lines in the extreme stern where there are no floor timbers (Figs. 25, 28, 29), it seems the shipwrights subdivided the bottom into 39 divisions of 15 inches in length thus giving a theoretical length of 48 feet 9 inches (Fig. 29) versus the documented length of 48 feet 10½ inches.28 Bratten notes Hoffman’s suggestion that “the position of posts, floor timbers, and frames could have been marked”.29 Our discovery shows that at least in the case of the floor timbers the positions not only could have been marked – they were marked. Fig. 29. Plan view of the bottom planks and framing. Floors are numbered in red. Floor divisions are highlighted and numbered in blue. Frames are numbered in green. Adapted from H. Hoffman’s plan for the Smithsonian Institution. (After Bratten 1997: 153) 59 Two sets of floor timbers in both the bow and stern were left out to allow the sideframing timbers (essentially standing knees) to be fastened securely. These side timbers are L-shaped knees with curved vertical arms; they are set approximately perpendicular (normal) to the tangent of the chine curve (Fig. 29). Therefore in the ends of the vessel, where the sides curve to a point, there would be insufficient room to secure these knees if the intervening floor timbers were in place (Fig. 29). Based on our discoveries it seems these lateral scribe lines relate directly to the overall layout of the hull. The widest point of the vessel (maximum breadth) falls at floor position #15 from the bow (#13 in actual floor timbers) and 24 “room and space” divisions from the stern (Figs. 24 & 29). This is 5/13 from the bow and 8/13 from the stern. No proposed design logic for locating the midship section appears in prior research on the vessel, and yet it seems the original shipwrights did have a rational and systematic approach. The fact that the first forward frame timber is located in position #3, the aftermost at #36, and midships at #15 draws attention to a possible emphasis on every third floor position (Fig. 29). As was mentioned above, the proposed theoretical length is 48 feet 9 inches compared to the recorded length of 48 feet 10½ inches. One quarter of the theoretical length is 12 feet 2½ inches. The archaeologically recorded breadth is 12 feet 1½ inches. This last measurement is only one inch short of a quarter of the proposed theoretical bottom length and 1 3/8 inches short of a quarter of the documented length. It is possible that the original goal was to have a 48 foot length and 12 foot beam for the bottom. A desire for a given number of even frame spaces at 15 inches may explain the existing discrepancy from this ideal. It is also important to remember that the vessel was underwater for 161 years. At the time the Philadelphia was raised its timbers did not undergo any significant conservation/preservation treatment nor were they documented in their wet state. As a result it must be kept in mind that the dimensions of the individual timbers and the vessel as a whole may have changed since the time of construction. Furthermore, it must be remembered that these vessels were built as fast as possible without any thought given to future archaeological examination. 1.4) Although the standing knees define the actual vertical curvature of the sides, the main shape of the vessel is defined by the bottom. The ship was not built with the concept of adjoining floors and knees defining the transverse/cross-sectional shape of the hull in any given location (Fig. 29). No fastenings join the standing knees to the floor timbers. In the central section of the vessel the standing knees are located in the middle of the space between two consecutive floors. Only as the knees become progressively more canted towards the ends of the vessel do they give a false impression of being associated with a particular floor timber (Figs. 26-29). As was already mentioned, at the two extreme ends of the vessel the floor timbers are left out altogether. The rotation of these knees away from a lateral orientation (canting) reduced the amount the upright arms had to be beveled or trimmed along their outer face to fit the desired hull curvature. When the knees are not canted there is significantly more work involved in beveling their outboard faces to match the curves of the hull (Fig. 30). Beveling is not only labor intensive but requires experience in order to be done correctly and efficiently. Canting Philadelphia’s standing knees saved a lot of time and required a less-experienced workforce. 60 Although the floors are the main structural timbers of the bottom, they were not used to define the shape of the bottom. They simply serve as reinforcing timbers for holding the bottom planks together and contribute to the overall strength of the vessel. More than likely, most of these timbers were added once the bottom planks had been cut to shape. They were placed at the locations indicated by the lateral scribe lines. These lines served yet another, more fundamental, purpose in the design of the vessel. At the ends of the floor-scribe lines we located “V” marks scribed into the wood. These marks were found in the one place the outer edge of the inboard face of the bottom planks is visible. Fig. 30. Cant frames reduce the amount of beveling necessary to fit the outboard curvature In the stern on the port side the chine plank (the of the hull. (After Greenhill 1988: 116) first side hull plank from the bottom) is not installed (Fig. 28). Marks were identified at floor divisions 33, 36, and 38 (Figs. 31-33). Incidentally, this is the area where we first identified the lateral floor scribe lines as well. The tips of the “V’s” point exactly to the chine/bilge curve of the bottom. It is our belief that these marks indicated to the carpenters where to cut the bottom curve. Probably the shipwrights bent a batten (a flexible piece of straight wood) along the points marked by the “V’s” and drew or scribed in the chine curve. The remains of what seems like a nail hole at the tip of one of the “V’s may indicate that nails were used to hold such a batten in place (Fig. 32). With the curve defined, the shipwrights proceeded to cut the laid out platform of boards. We do not yet know if similar “V’s were scribed-in on the starboard side of the vessel. This area of the hull can only be examined if all or part of the starboard plank is removed (see Section VI). If there are no similar marks on the starboard side, it is possible that the “V’s” on the port side are simply marks for transferring half widths from the starboard side to make the two curves symmetrical. The starboard curve may have been directly laid out with the use of a batten without any other predetermined breadth measurements (offsets) other than that of the maximum beam. If that is the case only a mark at maximum beam would have been necessary. It is also possible that the offsets for the curves were predetermined in some other fashion. For example, they could have been scaled-up from a drawing or were derived from some form of geometric curve, like an arc of a circle or an ellipse. If true, the shipwright would have marked the offsets on the bottom boards in several locations. Thus far we have not been able to identify the curve as geometric. Only future investigation and study may give us the answers. As was mentioned above, the maximum beam of the Philadelphia’s bottom, and the vessel as a whole, falls at a floor scribe line. No standing knee exists at this location. This construction feature highlights one of the dangers of becoming too reliant on modern ship drawings in the process of archaeological investigation of hull remains. The cross-sections of the modern recordings of the Philadelphia are not coordinated with the layout logic of the original shipwrights (Fig. 34). Thus the reliance on the lines drawing 61 may have led previous researchers away from fully deciphering the vessel’s design. The same investigators proposed a hypothetical construction sequence for the vessel that agrees with the evidence we are presenting in this report and yet they were unable to fully utilize the available archaeological evidence.30 Fig. 31a-b. Floor scribe line and “V”at floor division #38. Frame #38 is labeled in green. (Photo by T. Pevny) Fig. 32a-b. Floor scribe line and “V”at floor division #36 (Floor #34). Frame #36 is labeled in green. (Photo by T. Pevny) Fig. 33a-b. Floor scribe line and “V”at floor division #33 (Floor #31). Frame #33 is labeled in green. (Photo by T. Pevny) 62 Fig. 34. Profile view from the lines drawing combined with the plan view of the bottom planking and framing. The lines drawing cross-section lines are highlighted in red. Adapted from H. Hoffman’s plans for the Smithsonian Institution. (After Bratten 1997: 153, 159) 1.5) Although we have emphasized the importance of the construction of the bottom to the overall design of the hull, it is critical to add an important if nuanced clarification. A distinction has to be drawn between the simplicity of building the flat bottom itself and the conceptually simple way this form of construction allows the chine/bilge curve to be defined. On any type of vessel, once the bilge curve is defined, the raising of the sides of the vessel is relatively straightforward. In many types of boat and ship construction, flat bottom or not, the bottom of the hull is partially or completely built prior to any definition of the structure of the sides. This is true regardless of whether the bottom shape is defined primarily by the planking of the vessel, known as shell-based construction, or its framing, known as frame-based construction, or a combination of both (Figs. 35-38, 40). In another type of construction the shape of the vessel is first defined by temporary structures made of battens prior to the raising of any permanent structural timbers. This is referred to as ribband construction (Fig. 39). In this form of Fig. 35. Reconstructed building sequence of the 14 -century AD construction the bilge curve is defined Bremen Cog discovered in Germany. (After Greenhill1988: 54, 56) th 63 before the construction of both the bottom and the sides of the vessel. Battens are used in many types of hull construction to define the curvature of parts of the hull prior to the fitting of permanent structural timbers. The difference between the Philadelphia’s bottom construction and that of round bottom hulls is that the bilge curves lie in a single horizontal plane. Thus it takes only two sets of offset measurements, that of length and width, to define these curves. In other vessel types it takes three sets of offsets to define the bilge curves, that of length, width and height. Even if the whole process of construction is done without any actual measurements, sculpturally versus quantitatively, the latter is conceptually much more complex. A characteristic of many types of vessels with flat, wide bottoms is that the bottom planks tend not to run to the ends of the hull and instead butt into the lowest side plank (Figs. 40-41). Such construction necessitates that this curve be defined in some fashion prior to inserting this side plank. This feature is very evident in hulls like that of the Philadelphia (Fig. 18). However, as a general design concept, it appears in vessels from various time periods and shipbuilding traditions. In round bottom hulls it forms sectors of planking bordered by key curvature-regulating or regularizing planks (Figs. 42). Attention must be paid to such overall planking pattern changes when studying how a vessel’s shape was defined. Once key points of change are identified, the researcher should try to determine how the shipwright defined the desired curvature in these locations. Although it is certain that in the case of the Philadelphia the bilge curves were laid out on a platform of planks it Fig. 36. Two stages in the construction of a 17th -century Dutch fluit. In this building tradition the bottom was built plank-first using temporary cleats to hold the planks together until they were secured with frames. The upper hull was built frame-first. Model by Albert Hoving. (After Hoving 1997: 30-31) Fig. 37. 17th -century French method of frame-first construction. Note the bilge ribband set up early in the early stages of construction. From the Album de Colbert, 1670. (After Rieth 1996: 46) 64 must be kept in mind that small vessels with the same shape can be built by first raising the sides. If two side planks are cut to the appropriate shape they can be joined in the ends and spread apart to give the same flat bottomed hull shape. The bottom planks are then added on afterwards (Figs. 43-44). Usually in these types of vessels, the bottom planks are laid laterally versus longitudinally (Fig. 44). In order for the bottom to turn out flat, the “appropriate” shape for the lower edges of the two planks has to be a curve. The process of determining such curves is discussed below in section V-3.1. Such a process would not be practical because of the large scale of the Philadelphia. However, I believe it serves to highlight the importance of the bilge curve rather than simply focusing on the flat bottom itself. Concerning the study of the history of ship design, more attention must be paid overall to how the bilge curve is defined in relation to the construction sequence. This may aid significantly in our understanding of the reasons for variation in construction between the bottom and the sides within a single vessel, vessel types and even whole building traditions. Fig. 38. 18th -century French method of frame-first construction. Note the bilge ribband set up in the early stages of construction. (After Rieth 1996: 49) Fig. 39. Boat under construction in Turkey in 1995 using the ribband method of design. The shape of the vessel was defined using ribbands on one side of the vessel and complete frames were cut to fit. (Photo by T. Pevny) Fig. 40. Reconstruction of the 2nd -century AD Blackfriars ship discovered in London. Its construction sequence is very similar to that of the Philadelphia. (After Greenhill 1988: 41) 65 Fig. 41. Plans and photograph of the 1st -century BC Commachio wreck discovered in Italy. The seams of the hull planks are sewn together. (After Berti 1990: 36 & 41) 66 Fig. 42. End view of the planking runs of one of the 2nd -century A.D Nemi barges. The seams of the hull planks are joined with mortise-and-tenon joints. (After Ucelli 1950: Plate VIII) Fig. 43. Process of building a skiff by first bending the side planks. (After Chapelle 1941: 217) Fig. 44. Cross-planked bottom on a small boat. (From Gardner 1987: 5) 67 2.1) Cut to shape, the flat bottom forms the foundation for the construction of the remainder of the Philadelphia’s hull. The recent findings support such an interpretation. Raising the sides converts this curved platform into an actual vessel. Unlike the bottom, which was built by first shaping the bottom planks and then adding the floor timbers, the side of the vessel was constructed by first raising the framework, i.e. ribs, and then attaching the planks (Fig. 45). In terms of design, it is important not to overemphasize a dichotomy between the construction sequences of the bottom and the sides of the vessel. It is our belief that the flat plank-first construction of the bottom provides a simple way of defining Fig. 45. A plank being bent onto the raised frames on the chine curve. Once that curve is the replica of the Philadelphia. Note the wales were established it is relatively simple to extend attached first. (After Bratten 2002: 150) up the sides of the vessel. Studying the shape of the standing knees, Smithsonian researcher H. Hoffman came to the conclusion that in the central section of the vessel the knees were all cut to the same radial curve of 7 feet 5¼ inches (Fig. 46).31 This allowed many such knees to be mass produced for all the gondolas under construction, thus significantly simplifying their production.32 Towards the ends of the vessel the curves of the knees were flattened by increasing their radii. This melded the curvature of the sides smoothly into the end posts of the vessel (Fig. 47). Fig. 46. Radii used to lay out the Philadelphia’s frames as determined by H. Hoffman. Note that frames 13-30 were determined to have the same radius of 7 feet 5 ¼ inches. (After Hoffman 1982: Sheet 3) 68 The fact that simple ratios were used to set the proportions of the bottom curvature made us suspect that some logical procedure was used by the shipwrights to determine the central shape of the vessel. A little investigation has revealed a probable scenario. As was mentioned above, the maximum width of the bottom is approximately 12 feet. Half that width is 6 feet. Adding 1½ feet to each side results in an overall breadth of 15 feet and the half-breadth is 7½ feet. If at either end of a 15 foot baseline vertical lines are raised that are ¼ of the breadth in height, 3¾ feet, the resulting box contains the archaeologically preserved midship section of the Philadelphia (Fig. 47)). Then when arcs 7½ feet in length are swung from the tops of the side lines and from points at either end of the 12 foot bottom flat, their intersections determine the center points for 7½ foot arcs that define the curvature of the sides (Fig. 47). Given the state of preservation of the hull, this proposed design scenario gives a very close match to the archaeologically documented midship section (Fig. 47). This method of designing the midship section conforms well with methods in prevalent use at the time of Philadelphia’s construction.33 How the terms floor width, width of the flat and bilge point are defined in various building traditions, and how they relate to each other, is a critical issue in the study of the evolution of hull design, but such a discussion is beyond the scope this report. Frames with the same curvature only occupy the central section of the vessel, from knee #13 to #30. How the locations of the endmost of these frames were established, and how the curvature of the rest of the knees was determined, has yet to be revealed. It is probable that the shipwrights ran battens from the central section of frames to the ends of the vessel, possibly with some intermediate knees, to help them determine the radii for the knees in the forward and aft ends of the vessel. Further archaeological investigation may reveal clues as to the exact procedure used. As was already discussed, the knees were canted and there was only a minimal need to trim their outer faces to fit the curvature of the sides, known as dubbing if an adze was used. Once the correct curvature for each of the knees was determined by the shipwrights, the work of cutting and positioning these knees was relatively simple and easy. Fig. 47. Diagram showing the proposed method of designing the midship shape. The design lines are superimposed over H. Hoffman’s cross-sectional drawing of the Philadelphia’s hull shape. (After Hoffman 1982: Sheet 3) 69 2.2) Having raised the knees, the shipwrights had to cover the side of the vessel with a watertight skin of planks. The process of planking a curved surface is a specialized skill that a house carpenter probably did not possess. Many of us are familiar with a common elementary school craft project where a balloon is covered with strips of paper dipped into papier-mâché. When doing such a project it soon becomes evident that parallel-sided strips of paper cannot be placed edge-to-edge on a surface that curves in more than one direction. A flat material, such as paper strips or wooden planks, has to be cut to the appropriate shape or shapes to lay smoothly and without overlap on a complex curved surface. A familiar example of this is the flattened “orange-peel” depiction of a globe. The geometrical process for Fig. 48. Illustration showing how flare of the sides of determining such shapes is known as a vessel results in the rise at the ends of planks. (After development. The process of determining Landstrom 1970: 20) the strake runs on a ship’s hull is known as lining-off or out.34 The process of determining specific planking shapes is known as spiling.35 If the knees of the Philadelphia had perpendicular and straight sides, parallelsided planks set edge-to-edge could be bent on with any need for spiling their shapes. If the sides have any angle (flare) or curvature some spiling is necessary if the bottom is to remain flat in all directions. A simple demonstration serves to illustrate this concept. Two parallel-sided flexible boards attached at the ends and spread evenly apart in the middle will stay flat on a horizontal surface. If the sides are angled out in the middle (flared), the ends will rise up from the horizontal surface forming a rockered bottom (Fig. 48). The more flare the higher the planks will rise at the ends (Fig. 49). To maintain a flatter bottom the gap between raised ends of the plank and the horizontal surface has to Fig. 49. Illustration showing how increasing flare results in greater rise. (After Gardner 1987: 85) be filled in (Fig. 50). The shipwright has to spile the shape of the lower edge of the plank to match the curve of the bottom. 70 The shapes of a dory’s planks are a good illustration of the end result of spiling (Figs.51-52). A dory’s hull shape is a smaller version of that of the Philadelphia with more exaggerated curvature. As in a dory, the lower plank(s) of the Philadelphia had to have been spiled (Fig. 53). In the case of the Philadelphia this was done within the span of the lower two planks. Fig. 50. Illustration of the characteristics of the lower plank run of a dory. The differential gap between a parallelsided plank bent along the hull and the flat bottom is highlighted in red. (After Gardner 1987: 91) Fig. 51 Photograph of the flattened planks that compose a dory. Note the shape of the lowest side planks. (After Greenhill 1995: 66) 2.3) Depending on the shape of the rest of the upper hull and how the plank seams are laid out, it may be necessary to spile other planks as well. When Peter and I were examining the starboard stern quarter of the vessel we noticed a peculiar unfairness, a bump, in the longitudinal curve of the wale (Fig. 53). At first we considered the possibility that this was a result of some deformation in the preserved hull shape. However, we then noticed that the planks above and below the wale were cut to fit this bump (Fig. 53). Since wales are thicker planks (or even half-logs) and often harder to fit, it is not uncommon in Fig. 52. A partially assembled dory illustrating how properly shaped planks enclose the hull. (After Greenhill 1995: 188) Fig. 53. A view of the starboard stern of the Philadelphia. The lower strakes are highlighted in red. The unfairness in the run of the wale is indicated by the red arrows. (Photo by T. Pevny) 71 in various shipbuilding traditions to attach them first and then match the shapes of the adjoining planks to the curves of the wales. We concluded that on the Philadelphia the planks adjoining the wale must have been spiled. When the replica of the Philadelphia was built the wales were in fact bent-on first (Fig. 45). This line of reasoning led us to examine the seams of the vessel for any evidence that might prove that the shipwrights systematically laid out the planking runs and spiled the planks to fit. This examination resulted in several important discoveries. First, we found scribe and cut marks on the outer faces of the frames along the plank seams. Second, we found scribe or cut marks on the edges of the planks at the frame positions (Fig. 58). This new evidence led us to discover that the frames were not smooth curves, as previously believed, but polygons with flats cut for the wide planks – known as knuckled frames (Figs. 55-57).36 2.4) Two types of tool marks run across the outer, or outboard, surface of the frames at the locations of the seams. The first are scribe marks. Presumably they were used by the shipwright to indicate (line off) where the seams were to be located (Fig. 54). The shipwright would have laid out these seam lines with the aid of a batten. A straight batten bent onto a curved surface, without forcing any sideways curvature or edge-set, defines the shortest distance between its two endpoints and the easiest or most relaxed run. Battens are essential tools that allow boat builders to orient themselves on the complex curvature of a hull. For a simple hull like that of the Philadelphia, after establishing the run of the lower two planks and the run of the wale, the heights of the vertical arms of the knees could have been simply subdivided into a roughly equal number of divisions Fig. 54. Using a batten to line-off the seams on a more and the seams laid out accordingly. The second category of marks is complex hull. (After Greenhill 1988: 139) characterized by rougher and deeper cuts. These marks puzzled us at first until we looked between the inner and outer layers of planking at the frame shapes themselves. In several locations, the plank covering the top of the frames – the caprail – is eroded away. We noticed that between the seams the outboard face of the frames had been cut flat – resulting in knuckled frames (see Figs. 55-56). This was done to allow the fairly wide and thick planks to lay flat against the frame. If the frames were curved within the width of the plank there would be gaps between the edges of the inner plank surface and the outer surface of the frame. Such gaps result in stress points when a plank is bent into place, and there is the possibility that the plank fastenings may work loose. If flats are not cut into the frames, the planks must be crowned or hollowed in order to fit snuggly against the curves of the frames (Fig. 57). This is much more time consuming and requires the supervision of a shipwright. On the other hand, if the shipwright scribed the locations of the plank seams onto the frames it would be 72 straightforward for the less experienced carpenters to cut the flats between these marks. Once the shipwright determined their shapes, the planks would be cut, and it would be clear where they needed to be fitted on the hull. Fig. 55. A view of one of Philadelphia’s frames between the inner and outer planking. Note the flats between the seams. (Photo by P. Fix) Fig. 57. Crowning and hollowing of planks to fit the curved surface of a frame. (After Greenhill 1988: 141) Fig. 56. Knuckled frames of a Swampscott dory. (After Gardner 1987: 76) 2.5) The outer surface of the hull planks is highly degraded, and, thus far, we have not found any spiling marks. Fortunately, such marks were found elsewhere on the hull (see Section V-3.1). Nonetheless, the marks across the edges of the hull planks at the frame locations seem to directly relate to the process of cutting out and/or shaping the laid-out plank shapes (Fig. 58a-b). A cursory examination of just two seams in the starboard stern revealed 26 such marks at consecutive frame locations. Several possibilities exist as to what construction procedure resulted in these marks. The frame locations could have been marked by the shipwrights in the process of spiling out the plank shapes (see Section V-3.1). At these spots the carpenters may have cut-in with a saw or axe right to the lined-out plank edge. Such relieving cuts make it 73 easier to saw or hew the long curved edges of the timber (Fig. 59). Traces of relieving cuts would be left on the edge of the plank after its final shape was cut. Remains of evident relieving cuts are preserved on the forward face of the Philadelphia’s stem (the centerline timber in the bow) (Fig. 60). At first glance these marks seem to be scribed in draft marks – marks used to indicate how deep the vessel is sitting in the water. However, they are not set at increments in feet nor are they regularly spaced (Fig. 61a-b). These marks are simply cuts made to ease the shaping of the curve of the stem timber. The stem rabbet, like the midship frames, is cut to a 7½ foot radius curve. The rabbet is the notch into which the ends of the hull planks are fitted. The outer edge of the stem is an 8½ foot radius curve.37 Fig. 58a-b. Edge mark across the edge of a hull plank at a frame location. (Photo by T. Pevny) Fig. 59. The use of relieving cuts when cutting a curved timber (From Greenhill 1988: 108) Fig. 60. Closeup of relieving cut marks on the stem of the Philadelphia. (Photo by T. Pevny) The plank edges were angled or beveled to form a wedge-shaped seam for caulking. Caulking is usually some form of fiber, coconut fiber in the Philadelphia’s case, which is driven into the seams with caulking irons to make them watertight.38 Shipwrights usually measure the bevel angles at the frame locations and then cut notches at those angles at corresponding positions along the plank edge. These cuts guide the beveling of the entire edge of the plank. It is possible that the preserved edge marks are the remains of such beveling notches. 74 Fig. 61a-b. Relieving marks on the stem of the Philadelphia. (Photo T. Pevny) Another possibility is that these scribe or cut lines are simply marks for the proper positioning of the planks. They could also relate to some process of duplicating the plank shapes of one side of the vessel for use on the other side or even for use on other gondolas under construction. We believe that further examination of the hull will provide us with clues as to the exact nature and purpose of these marks. 75 3.1) Fortunately, and quite unexpectedly, we did find probable spiling marks preserved on some of the Philadelphia’s internal planks (ceiling planks). In the stern of the vessel there are two benches/lockers along either side of the hull (see Figs. 2, 62). When we lifted the seat on the port side, we noticed that the plank surface was better preserved than in other places on the hull. Brushing off the accumulated dust and shining a raking light over the inboard surface of the ceiling plank (Fig. 3) revealed five fairly well-preserved “V” scribe marks pointing to the upper edge of the ceiling plank (Figs. 62-69). One of the “V’s” also had traces of a centerline (Fig. 69). We are unaware of any other marks such as these having been archaeologically identified on American shipwreck remains. Fig. 62. Profile and plan views of the deck structures of the Philadelphia. The red arrows point to the benches/lockers. In the profile view the port spiling marks are drawn in red at their approximate locations. In this view the side of the locker is not shown for the marks to be visible. Adapted from H. Hoffman’s plan for the Smithsonian Institution. (After Bratten 1997: 162) Fig. 63. The port spiling marks highlighted in red. (Photo by T. Pevny) Fig. 64. The port spiling marks highlighted in red. Note the curvature of the upper edge of the plank. (Photo by T. Pevny) In the construction of vessels with thinner and narrower planking it is possible to avoid spiling to some extent. Such planks can be bent sideways to fit against an adjoining plank or to match a desired curve – this is known as edge-setting. Because the plank is being bent in two directions there is a danger of kinking or buckling the plank 76 away from the frame surfaces if the edge-set is excessive.39 In the case of the Philadelphia’s relatively thick and wide planks, edge-setting could only be utilized to a minimum extent and spiling was necessary. Fig. 65a-b. Port spiling mark #1 from the stern. Note that the mark is preserved in the very fragile and fragmented outer surface of the plank. (Photo by T. Pevny) Fig. 66a-b. Port spiling mark #2 from the stern. (Photo by T. Pevny) Fig. 67a-b. Port spiling mark #3 from the stern. (Photo by T. Pevny) 77 Fig. 68a-b. Port spiling mark #4 from the stern. (Photo by T. Pevny) Fig. 69a-b. Port spiling mark #5 from the stern. (Photo by T. Pevny) There are several different ways to properly spile a plank, but they all have the same underlying concepts. A thin plank known as a spiling plank is bent onto the hull in the area where the finished plank will ultimately be fitted. Planks bend in a very characteristic way, and thus the spiling plank reflects the way the finished plank will bend. The shipwright then marks along the length of the spiling plank the distances to the desired curve. These distances/offsets can be measured or marked with a compass or a spacing block (Figs. 70).40 The spiling plank is then removed from the hull and placed on top of the planking timber. By reversing the offset process, points indicating the desired curve are marked on the planking timber. Usually a curve is drawn or scribed on the surface of the timber with the aid of a batten that is bent along these spiling points. The marks found on the Philadelphia locate such spiling points. In terms of the history of ship construction, a real treasure was discovered under the bench. Of course the Philadelphia has two benches in the stern. We were very excited by the prospect of finding similar marks preserved on the starboard side. After lifting the bench cover and brushing off the surface we did indeed find more spiling marks. The surface of the starboard ceiling plank is more degraded, but nonetheless we were able to identify “V” marks at two frame positions (Figs. 71-72). The finding of these additional 78 marks supports our conclusion that the shipwrights spiled planks throughout the process of the hull’s construction. Fig. 70. Compass method of spiling the chine plank on a dory. (After Gardner 1987: 89, 92) Fig. 71. The starboard spiling marks highlighted in red. (Photo by T. Pevny) 79 Fig. 72. Starboard spiling mark #1 from the stern. (Photo by T. Pevny) Fig. 73. Starboard spiling mark #2 from the stern. (Photo by T. Pevny) 3.2) Using a “V” or an “X” to mark a point or a measurement is common to carpentry in general. After working on the Philadelphia, I helped remodel our 1940’s bathroom. The bathroom was completely gutted down to the framing and I was very amused to find several “V” marks penciled on the timbers (Fig. 74). As a local carpenter relayed to me: “With such a mark there is no guessing where exactly the measurement is meant to be. I’ve always done it this way.” The finding of such marks is more than just evidence for understanding a specific construction sequence; such marks bring to life the thinking or conceptual processes of the original builder. For me, more than the whole structure itself, these marks highlight the commonality of the human experience. Fig. 74. One of the carpenter marks uncovered during the renovation of a 1940’s bathroom. (Photo by T. Pevny) 80 4.1) The spiling marks were not the only marks preserved on these ceiling planks. Originally the Philadelphia had a higher deck in the stern that supported a mortar cannon.41 Notches were cut in the ceiling planks to fit the beams supporting this deck. After an accident in which the mortar exploded, the gun and the deck structure were removed. However, the notches in the ceiling planks remained (Fig. 75). Originally the shipwrights marked the locations for these notches with scribe marks. Such marks are clearly visible on the same plank surface as the ceiling plank spiling marks (Fig. 76). Fig. 75.Profile view of the supporting deck structures of the Philadelphia. The red arrows point to the locations of the beam notches that supported the mortar platform. Adapted from H. Hoffman’s plan for the Smithsonian Institution. (After Bratten 1997: 157) Fig. 76. Scribe marks used to indicate the location of one of the beam notches on the port side of the vessel. (Photo by T. Pevny) 4.2) In the process of laying out the existing stern deck structure the shipwrights must have considered a different layout. In front of the port bench there is a series of rough chop marks that form a straight line running towards the stern post (Fig.77-78). The shipwrights may have first considered building much wider benches; or there were additional diagonal supports when the mortar platform was in place.42 Fig. 77. A series of chop marks define a straight line running towards the stern post. (Photo by T. Pevny) 81 Fig. 78. Close-up of the chop marks in the stern deck planks. (Photo T. Pevny) 82 VI. Recommendations for Further Study and Display We found all the marks discussed above in a brief survey of the Philadelphia’s hull. The discovery of these marks led to a better understanding of how this hull was designed and why this type of vessel was chosen to be built. The restoration of the vessel and the remodeling of the museum offer a great opportunity to fully document these discoveries and to investigate the vessel more thoroughly and systematically for additional evidence. 83 It is our belief that an in-depth exhibit on the design and construction of the Philadelphia can serve as a centerpiece for a broader look at the role of this vessel type in American history as well as an introduction to a larger exhibit on American ship design in general. The museum’s extensive collection of ship plans and half-hull models can be used to tell the rest of the story of the evolution of ship design as well as to present the fundamental concepts of naval architecture to the visiting public. 84 VIII. Bibliography American Heritage, eds. 1961. Trappers and Mountain Men. New York. ———. 1962. Steamboats on the Mississippi. New York. Baldwin, Leland D. 1941. The Keelboat Age on Western Waters. Pittsburg, Pa. Bayreuther, William A. 1981. Revolutionary War Gunboat Construction: The Lake Champlain Continental Gondolas of 1776. In Proceedings of the Sixteenth Conference on Underwater Archaeology. Paul F. Johnston, ed. Society for Historical Archaeology, Special Publication Series, no. 4: 10-12. Berti, Fede 1990. Fortuna Maris: La Nave Romana di Comacchio. Bologna, Italy. Bratten, John R. 1997. The Continental Gondola Philadelphia. Ph.D. diss., Texas A&M Universtiy. ———. 2002. The Gondola Philadelphia & the Battle of Lake Champlain. College Station, TX. Bruseth James E. and Turner Toni S. 2005. From a Watery Grave: The Discovery and Excavation of La Salle’s Shipwreck, La Belle. College Station, TX. Chapelle, Howard I. 1941. Boatbuilding. New York. ———. 1949. The History of the American Sailing Navy. New York. Crisman, Kevin J. 1988. Struggle for a Continent: Naval Battles of the French and Indian Wars. In Ships and Shipwrecks of the Americas: A History Based on Underwater Archaeology. London: 127-148. Delgado, James P. 1997. Encyclopedia of Underwater and Maritime Archaeology. London. Hagglund, Lorenzo F. 1936. The Continental Gondola Philadelphia. In United States Naval Institute Proceedings 62: 655-69. ———. 1949. A Page form the Past: The Story of the Continental Gunboat Philadelphia on Lake Champlain – 1776-1949. 2nd edition. Lake George, NY. Hocker, Frederick M. 1991. The Development of a Bottom-based Shipbuilding Tradition in Northwestern Europe and the New World. Ph.D. diss., Texas A&M Universtity. ———. 2004. Bottom-Based Shipbuilding in Northwestern Europe. In The Philosophy of Shipbuilding. Frederick M. Hocker and Cheryl A. Ward, eds. College Station, TX: 65-93. Hoffman, Howard P. 1982. Graphic Presentation of the Continental Gondola Philadelphia. Washington D.C. ———. 1984. The Gunboat Philadelphia: A Continental Gondola of 1776 and Her Model. In Nautical Research Journal 30: 55-67. Gardner, John 1977. Building Classic Small Craft Vol. 1. 1991 paperback edition. Maine. ———. 1987 The Dory Book. Connecticut. Greenhill, Basil 1988. The Evolution of the Wooden Ship. New York. ———. 1995. The Archaeology of Boats and Ships. Annapolis, Maryland. Grenier, Robert 2001. The Basque whaling ship from Red Bay, Labrador: a treasure trove of data on Iberian Atlantic shipbuilding design and techniques in the mid-16th century. In Proceedings of the International Symposium on Archaeology of Medieval 85 and Modern Ships of the Iberian-Atlantic Tradition – 1998 (Trabalhos de Arqueologia 18) Francisco Alves, ed. Lisbon: 269-293. Lanström, Biörn 1970. Ships of the Pharaohs. New York. Lavery, Brian 1984. The Ship of the Line Volume II: Design, Construction and Fittings. London: 7-27. Loewen, Brad 2001. The structures of Atlantic shipbuilding in the 16th century. An archaeological perspective. In Proceedings of the International Symposium on Archaeology of Medieval and Modern Ships of the Iberian-Atlantic Tradition – 1998 (Trabalhos de Arqueologia 18) Francisco Alves, ed. Lisbon: 241-258. Lundenberg, P. K. 1995. The Continental Gunboat Philadelphia and the Defense of Lake Champlain in 1776. Basin Harbor, Vermont. Pardey, Larry 1991. Details of Classic Boat Construction: The Hull. New York. Pevny, Taras P. 1999. Considerations for the Reassembly and Display of La Belle. Manuscript on file at Texas Historical Commission. Austin. Pomey, Patrice 1999. Les Épaves Grecques du VIe siècle av. J.-C. de la place JulesVerne à Marseille. In Archaeonautica: Construction navale maritime et fluviale: Proceedings of the Seventh International Symposium on Boat and Ship Archaeology – 1994 (Archaeonautica, vol.14, 1998) Paris: 147-153. Rieth, Éric 1996. Le Maître-Gabarit, La Tablette et le Trébuchet: essai sur la conception non-graphique des carènes du Moyen Âge au XXe siècle. Paris. Sands John O. 1988. Gunboats and Warships of the American Revolution. In Ships and Shipwrecks of the Americas: A History Based on Underwater Archaeology. London: 149-168. Viera de Castro, Filipe 2001. The Pepper Wreck: A Portuguese Indiaman at the Mouth of the Tagus River. Ph.D. diss., Texas A&M University. 86 VII. Notes 1. Viera de Castro 2001: 159. 2. The 6th – century B.C. Jules Verne 7 wreck has a series of “V” marks, at frame positions, along a strake on either side of the vessel. See Pomey 1999. The Marsala Punic wreck from the 3rd – century B.C. has Phoenicio-Punic alphabetic signs as well as construction guidelines painted on its timbers. See Delgado 1997: 260-62. 3. Lowen 2001; Greenier 2001: 277. For La Belle see Bruseth 2005: 76-78; Pevny 1999. 4. Texas A&M graduate student William A. Bayreuther examined the Philadelphia’s timbers for tool marks. See Bayreuther 1981; Bratten 2002:111. 5. Reith 1996. 6. Bratten 2002:15-52. 7. Crisman 1998: 130-138; Hocker 1991: 223-248; Chapelle 1951: 33-36, 45-53; Gardner 1987:18-24. 8. Baldwin 1941. 9. Bratten 2002: 111, 159-160; Bayreuther 1981:12 10. Ibid: 111; Bayreuther 1981:11. 11. Hocker 1991 & 2004; Greenhill 1995: numerous references throughout and specifically 186-190, 225-249. 12. Hocker 2004: 66-67; Greenhill 1995: 231-233. 13. Crisman 1998: 130-138. 14. Bratten 2002:162-164. 15. Hagglund 1936. 16. Chapelle 1949:109. 17. Hoffman1982 &1984. 18. Bayreuther 1981. 19. Bratten 2002: 147-158. 20. Bratten 1997 & 2002. 21. Bruseth 2005: 76-78; Pevny 1999. 22. Gardner 1987: 54-125. 23. Bratten 2002: 94, 97. 24. Gardner 1997: 71-72. Note that the bottom of the Philadelphia replica was built upside down, but the rest of the assembly was done right-side-up. See Bratten 2002: 148. 25. Hocker 2004: 66, 68. 26. Bratten 2002: 95. 27. Ibid: 95. 28. Ibid: 95. 29. Ibid: 95; Hoffman 1984: 61. 30. Bratten 2002: 94-95; Hoffman 1984: 61. 31. Bratten 2002: 97-98; Hoffman 1982: sheet ???. 32. Bratten 2002: 97-98; Hoffman 1984: 61. 33. Rieth 1996: 56-57. Lavery 1984. 34. Gardner 1977: 261-272; Gardner 1987: 82-84. Greenhill 1988: 136-139. 87 35. Gardner 1977: 272-277; Gardner 1987:84-95. 36. Gardner 1987: 46 , 80-81, 100 37. Hoffman 1982: sheet 4. Hoffman determined the preserved radii to be 7 feet 5 inches for the rabbet and 8 feet 4 inches for the outside curve of the stem. It is my belief that it was the intention of the shipwrights to lay out the radii at the half foot for each measurement. 38. Samples of caulking collected by Peter Fix indicate that coconut fiber was used to on the Philadelphia. 39. Pardey 1991: 201-02, 235-36. 40. Gardner 1977 272-277; Gardner 1987: 84-95. 41. Bratten 2002: 30, 101. 42. Peter Fix proposed the idea that the mortar deck, which was added on and then removed, may have needed additional support for the beams.