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European wooden sailing ships plying the South Atlantic and the Americas were subject to predations of the shipworm (Teredo navalis) which quickly devoured outer hull planking below the waterline. To combat this marine borer and to prevent fouling of ship’s hulls by other organisms, shipyard workers devised several methods of coating and sheathing exposed planks. One relatively inexpensive method employed an outer layer of fir planking, backed by felt and caulking, nailed to a ship’s hull to serve as sacrificial sheathing, which was replaced when consumed. A more permanent method used thin lead sheets to cover vulnerable portions of the hull, such as the seams between planks and around through-hull fittings, such as rudder gudgeons. This method appears to have been employed by Spanish ships in the 16th-century, and is evidenced by the remains of lead sheathing found in association with the wreck of San Estéban (Arnold and Weddle 1978; Rosloff and Arnold 1984), the wrecksite at Molasses Reef (Keith 1987), and the Emanuel Point Ship.
Fig. 29. Textile was bedded between this lead patch and the hull, leaving the weave impression.
A large number of pieces of drawn lead sheets (planchas de plombo tirado) or patching material have been recovered to date in the stern portion of the shipwreck. They range in length from fragments of 7 cm to long strips of 75 cm. Widths vary from 6 to 21 cm, and thickness fluctuates between 1 and 3 mm. All have holes left by sheathing tacks (estoperoles), most have tack head impressions, and a few have impressions of caulking fabric. Thirty-five pieces of lead are considered diagnostic, since they are relatively straight and flat, and to varying degrees, they retain their original shapes. Additionally, there are nearly 200 small, mangled, and twisted fragments of lead. One of the smaller fragments (01,028) looks like a flattened tube and has no fastener holes. Most of the lead was recovered loose in sediments outside the hull; other pieces were found still attached to the hull, and were left in place. From shapes and sizes of the lead, the number and arrangement of fastener holes, and preserved impressions, a general pattern of sheathing can be deduced.
All of the diagnostic pieces have regular rows of sheathing tack holes. Of these, twenty-two have three distinct rows of holes. Spacing between these rows varies according to the widths of the lead strips, but all have a row along the upper and the lower edge, and a row along the middle of the strip. These lead strips appear to have been used to cover the seams (comentos) between hull planks and keep the caulking (estopa) from working out of the seams. One piece was observed in place, covering the hood ends of planks where they joined the sternpost. The outer rows of tacks would have been driven into the wooden planks, while the center row were driven directly into the caulked seam between the planks. Varying widths of the strips reflect differing widths of planks; strips with three rows of holes vary in width between 6 cm and 17 cm, while planks widths in the stern vary between 14 cm and 33 cm in width. Five other diagnostic strips probably belong in this category as well. Although they only have two rows of holes, their edges appear to have been ripped; originally they could have been wider, containing the usual three rows. Lead strips for seam sheathing have been reported on the wreck of San Estéban (Arnold and Weddle 1978:263); however, the strips were much narrower, covering only the seams between the planking with one row of fasteners, instead of three.
Fig. 30. Lead sheathing from sternpost area demonstrates typical fastening pattern (three rows with tack head impressions).
Five other diagnostic lead strips all have two rows of tack holes. Two of these pieces (00,545 and 00,321) were sheathing for a rudder gudgeon arm, beaten flush with the surrounding planking and tacked in place. They are 15 cm and 17 cm in width respectively and retain the raised impression of the gudgeon arm. The fastener rows run alongside the gudgeon and encircle it at the end. Two other strips (00,511 and 00,547) probably represent gudgeon sheathing as well. They are 13 cm and 17 cm in width respectively, and appear to be unripped. The remaining piece (01.031) is curious. Only 6.2 cm wide, with one edge ripped along a row of fastener holes, the unripped edge has no evidence of fasteners, and could have been partially overlapped by another strip.
Fig. 31. Lead patch with impression of gudgeon strap end.
Sheathing tack sizes range from 4 mm in cross section with a head of 2 cm in diameter, to 5.5 mm to 6.3 mm in cross section with a head of 2.4 cm. These measurements are based on the dimensions of the undistorted holes and head impressions, and the few remaining nail fragments. Spacing between the tacks on a row varies from 3 cm to 7 cm, measured from center to center. On some rows the spacing was quite regular, while on others it varied greatly, giving the impression of neat and sloppy—possibly the work of different individuals, or work carried out under different conditions or time constraints. In no case, however, were fastener holes close enough together for the heads to touch, as observed with examples of seam sheathing found on San Estéban (Arnold and Weddle 1978:236).
Three additional diagnostic lead sheets have no clear pattern of tack holes. One of these (01,073) measures 21 cm in width; the other two (00,015 and 00,027) are both 16 cm in width. These sheets may have been used as patching materials. Palacio (1944:110) listed lead and sheathing nails as necessary repair stores taken to sea aboard a ship. He also described the process of patching a warship that has just received a shot below the waterline and is leaking. He advised the captain to break away from the battle, and
. . . put the ship on the opposite tack, and with that, the ship will heel to the other side, and the leak will remain above water . . . . The hole being covered, caulked, and a sheet of lead, lined with canvas . . . applied over it the ship will be able to navigate and return to fight, if such is agreeable (Palacio 1944:126).
Examination of lead sheathing and patching materials from the stern of the Emanuel Point Ship suggest that use of lead on this vessel’s hull was more extensive than on those of other sixteenth-century ships excavated so far. The English-built Woolwich ship, dated to the first half of the century, was kept watertight by wooden seam ribbands, and had lead sheathing only on the butt of the garboard strake (Salisbury 1961:85). Another early site, the Cattewater wreck, yielded one piece identified as lead sheet (Rednap 1984:47-48). On San Estéban, somewhat more lead was used. Narrow strips, only slightly wider than the diameter of the fastener heads, were used only to cover the edges of the gudgeon arm and the seams between deadwood timbers of the keel (Arnold and Weddle 1978: 261-263). Larger amounts of lead were found on the Molasses Reef Wreck; some were apparently forced into seams between strakes, rather than fastened over them, others may represent patching materials (Keith 1987:104-105).
The amounts of lead thus far observed on the Emanuel Point Ship suggest extensive, though not total, sheathing of the hull, primarily to protect planking seams and areas where the rudder hardware was fastened to the stern. Widths of lead sheets were more than sufficient to cover seams, but not to overlap adjacent pieces of lead sheathing. This practice may have been a practical compromise between protection against loss of caulking and shipworm attack and the expense and weight of total sheathing. The irregularity of strip and tack dimensions may indicate that partial resheathing of seams was necessary after an initial application. Lastly, the ship was in use long enough to require at least some patching of leaks that developed over its sailing career.