Ship construction Madrague de Giens (shipwreck)

a schematic of mortise , tenon technique shipbuilding dominated mediterranean until 7th century bc.

the vessel contained framing composed of various elements (keel, fore foot, stempost, cutwater, sternpost, inner post, false post), double planking (assembled entirely mortise-and-tenon joints pegged inside) , covered sheet of lead. referred large keelson 7.5m long mast-step timber made of oak doubles axial frame. stringers, nailed onto frames, reinforced hull longitudinally. regularly alternated floor timbers , half frames comprised framing of vessel. wreck indicates vessel 40m long (35.10m remains preserved on seabed), 9m wide, , 4.5m deep length-to-beam coefficient of 4.4(if l=40m, l/w=4.4). coefficient of elongation-rate of length width allows ship faster lower coefficient.

the vessel built method of construction known shell-first or plating, meaning frame built first later addition of skeleton. was, however, not built entirely shell-first, involved elements of skeleton or frame-first construction. keel, extended long fore foot ending concave stempost tilted towards back, laid first, edge jointed mortise (10 12 cm deep , 8 cm wide) , tenon (20 22 cm long, 8 cm wide, , 1.5 cm thick), construction 3 strakes. first section of ship, keel , first 3 planks, made elm. floor timbers bolted directly keel, giving greater rigidity internal skeleton. next, rest of framing added, joined straight nails , treenails. these few frames acted guides , supports during construction. then, rest of planking added, lower skeleton first, followed upper shell (independent of frames, treenails inserted inside hull). futtocks inserted last , second skin of thinner planks of fir fitted exterior of ship , covered in lead. layer of planks, 6 cm thick, fitted inside in order cover internal frames, strengthening hull through double planking , elaborate, complex keel scarves. massive cutwater, on length of 1.45m, placed against front-butt protected , strengthened stern of axial frame.

the deck or ship superstructure has not survived, although baulk of timber , supports found, fitted onto lowest frames of hull. mast-step timber indicates sockets correspond main mast, foremast, of bilge pump well, , of various interior architectural characteristics. kept @ height of 1.10m above floor of hold, 1.5m long 1.25m wide , consisted of 4 vertical supporting cross-coated plates.