La Bourse (Lacydon), late 2nd–early 3rd century AD
Country: France
Place: Lacydon inlet, Vieux Port, Marseille (Bouches-du-Rhône); found on land during the construction of the Centre Bourse. Now in the Musée d’Histoire de Marseille
Coordinates (approximate): 43.30, 5.38
Type: Roman merchant ship
Identified: No
Dated: Abandoned at the beginning of the 3rd century AD, or perhaps at the end of the 2nd century AD.
Beam: Reconstructed at 9 m.
Keel Length: Unknown.
Length Overall: Reconstructed at 23 m.
Number of Masts: One mast step is attested.
History of the wreck
The La Bourse wreck1 was found in the Vieux Port of Marseille in 1974, inside the harbour basin, in the Lacydon inlet, during the construction of the new Centre Bourse. It is a ship abandoned at the beginning of the 3rd century, or perhaps at the end of the 2nd century, when the inner harbour silted up and became a graveyard for laid-up ships. The La Bourse wreck is now in the Musée d’Histoire de Marseille (then being refurbished for the 2013 European Capital of Culture) and is kept in an accessible cold room (Figures 2 and 3).
Description of the site
A large portion of the hull was preserved under the sand, 20 m long and 7 m wide, which allowed its length to be established at 23 m and its beam at 9 m (Figure 1).
Figure 1. Plan of the La Bourse wreck (photogrammetry by Courrier, CNRS, CRA, after Gassend and Cuomo 1982: 272).
Cargo
Not applicable; the ship had been abandoned in the harbour.
Ballast
Not reported.
Anchors
Not reported.
Guns
Not applicable.
Iron concretions
Not reported. Copper nails and bolts were used in the construction.
Hull Remains
The hull, with flat floor timbers, had a slight longitudinal curvature. In section, La Bourse had flat floor timbers along the centreline, a characteristic feature of ships of the western Imperial architectural family.
Keel, keelson and mast step
The keel, of trapezoidal section, was 17–28 cm wide and 29 cm high. It had a simple bevelled rabbet that changed to a notched rabbet towards its ends, at the joints with the stem and the sternpost (Figures 2 and 3). The garboard strakes were joined to the keel by tenons, but only by copper nails at the stem and sternpost. The mortises were 6 cm wide, 10 cm deep and 1 cm thick, spaced 12 to 15 cm apart.
The La Bourse wreck had two parallel or twin keelsons, one on each side of the position of the keel (Figure 1). Although the mast step was not found, its existence is proved by the notches recorded in the sister keelsons, and it can be reconstructed. Likewise, portions of keelson could be reconstructed at each end of the hull as an extension of the mast step itself (that is, this piece would have served both functions), as suggested by the height of the bolts that would have joined keel, frame and keelson.
Figure 2. The notched rabbet of the sternpost of the La Bourse wreck (photo: C. de Juan Fuertes).
Figure 3. Side view of the scarf joining the keel to a forefoot at the stem (photo: C. de Juan Fuertes).
Frames
In the framing, floor timbers and half-frames generally alternated, some of them off-centre or crossing the keel. The frames were 8 cm sided and 15 cm moulded, with a room-and-space (malla) of 25 cm, and were fastened to the hull by vertical treenails 1.5 to 2 cm in diameter; there was no connection between the various pieces making up a single frame (e.g. floor timber and futtocks). Eight floor timbers were fastened directly to the keel by copper bolts 2 cm in diameter, four of them associated with the trait de Jupiter scarfs joining the keel to its end posts, to reinforce these joints. The other four bolts were placed along the keel every 8 or 10 frames. The flat floor timbers (Larix decidua), of varied dimensions and bolted to the keel with copper bolts, indicate that in the building process these pieces were perhaps fitted at the same time as the garboard strakes were raised, and may well have helped to shape the hull.
One of the most interesting questions raised by this site is whether a mixed formula was used in the design and construction of the ship. In 1982, on the basis of La Bourse, Cuomo and Gassend proposed the existence of a building process that was a hybrid between shell and skeleton. This argument was based on the presence of conical pegs driven from the inside of the hull together with cylindrical pegs driven from the outside. They considered that a conical peg driven from the inside is more watertight than the reverse, and that the use of outside pegs was due solely to the precedence of the frame over the planking, since the frame would have been in place before the tenon was “closed” with pegs. According to Cuomo and Gassend (1982: 263), the conical shape of the pegs means that when they swell with moisture they tend to work out of the hole; that is why those driven from the outside of the hull, which were difficult to trim, were cylindrical. Moreover, in some of them a wooden wedge was placed in the hole before hammering, so that the head of the cylindrical peg would burst into a conical shape (Figures 4 and 5). These authors understood that the method consisted of leaving the tenons locked with conical pegs, driven from the inside, in the strake that was to be joined to the hull. Since some frames were already in place, when the tenons were secured in the hull plank itself, the joints that coincided with the frames made it impossible to drive the peg from the inside, so these cylindrical pegs were driven from the outside. Once the building system was understood, they made a detailed study to reconstruct the building process of the La Bourse wreck.
Despite these explanations, Pomey took the reflection further, within a historical argument, to show that the alternating building process was not so obvious and that there were some features of the design principle and the building process that had to be taken into account (Pomey 1998: 68). On the one hand, the framing did not form a complete structure, and on the other the spacing of the tenons joining the hull planks showed that the building process was based on a longitudinal conception and a shell-first structure.
Cuomo and Gassend’s observations on the pegs and frames are valid only for some of them (Figure 6), precisely at the level of the eighth to tenth strakes of the hull. These are frames that played an active role in helping to raise the hull, but never as a skeleton-building solution, which lay outside the conception of the shipwrights of the time. It would be a mixed building process with a longitudinal conception. The frames take part in, and have a role in, the building of the hull, in that they are not fitted at the final stage of raising the hull, but are fastened to it almost simultaneously. This does not imply a change in the ship’s conception, but the speed of construction and the control of the hull shape may be better, something very different from true mixed construction as seen in the Yassi Ada II. Logically, where a frame has helped to control the shape or has served as a guide for fitting the planks, when these are finally joined by mortises and tenons the pegs, here cylindrical, must be driven from the outside of the hull.
Figure 4. Schematic view of the placing of the tenon-locking pegs coinciding with the position of an active frame (a and b): cylindrical pegs driven from the outside of the hull, whose heads were burst by a small wedge placed beforehand in the hole, so that, with their now conical profile, they remained fixed in the hull (after Cuomo and Gassend 1982: 264).
Figure 5. Diagram of the placing of the cylindrical pegs from the outside of the hull (after Cuomo and Gassend 1982: 265).
Figure 6. Diagram of the framing of the La Bourse wreck. In grey, the sections of the frames placed before the tenons of the strakes were closed (after Cuomo and Gassend 1982: 272).
Planking
The hull strakes were between 18 and 23 cm wide and 6 cm thick. The tenons joining them were 6 cm wide, 12 to 13 cm long and 1 cm thick, and were spaced 20 cm apart “centre to centre” in the planks. The locking pegs had diameters of 0.8 to 1.5 cm and were driven from the inside of the hull, except in the eighth to tenth strakes, where under some frames (M114, 122 and 139) the locking pegs were cylindrical and possibly driven from the outside of the hull (see Frames and Figure 4). The planks of the same strake were joined to each other by bevelled scarfs, with tenons and with horizontal nails at the ends of the scarf.
Ceiling, thick stuff, and wales
A lower wale, 14 cm wide, was preserved, joined to the hull as if it were just another strake.
Caulking
The timber of the hull had an internal and external coating of resin or pitch to improve its watertightness.
Size and scantlings
The preserved portion of the hull, 20 × 7 m, allowed the ship to be reconstructed at 23 m in length and 9 m in beam. The keel measures 17–28 × 29 cm, the frames 8 × 15 cm at a room-and-space of 25 cm, and the planking is 6 cm thick.
Table 1. Scantling of the timber remains of the La Bourse Shipwreck
| Timber | Sided [cm] | Molded [cm] |
| Keel | 17–28 | 29 |
| Keelson | – | – |
| Maststep Mortise | – – | – – |
| Buttresses | – | – |
| Frames | 8 | 15 |
| Futtocks | – | – |
| Room-and-space At central frames | 25 | |
| Planking | 18–23 | 6 |
| Wale | 14 | – |
| Ceiling | – | – |
| Main mast Ø Chock | – – | – – |
The ship had two sister keelsons; the mast step was not found. Planking and wale: sided = width, moulded = thickness.
Wood
Floor timbers: European larch (Larix decidua). Other species are not reported.
Bibliography
Cuomo, J.-P. and Gassend, J.-M. 1982. La construction alternée des navires antiques et l’épave de la Bourse à Marseille. Revue archéologique de Narbonnaise 15: 263–272.
Pomey, P. 1998. Conception et réalisation des navires dans l’Antiquité méditerranéenne. In E. Rieth (ed.), Concevoir et construire les navires. De la trière au picoteux. Technologies, Idéologies, Pratiques 13.1: 49–72. Ramonville Saint-Agne: Érès.
Pomey, P., Kahanov, Y. and Rieth, E. 2012. Transition from shell to skeleton in ancient Mediterranean ship-construction: analysis, problems, and future research. The International Journal of Nautical Archaeology 41.2: 235–314. doi: 10.1111/j.1095-9270.2012.00357.x.
Notes
1 The summary of this wreck has been taken mainly from the work of Pomey in The International Journal of Nautical Archaeology (2012) 41.2: 235–314, doi: 10.1111/j.1095-9270.2012.00357.x.