The Migdal ship may represent small merchantmen (naves oneraria) with a crew of five or six men; four rowers, a helmsman and the captain (kybernetes). To deduce the load capacity of this ship we may rely on two sources:
1. The results of anthropological studies on skeletons dated to the period of Josephus 13. These studies showed that the average weight of a man was 62-67 kg. Thus, a vessel with a crew of six men, their own gear, anchors, and the rigging would indicate a capacity of between 800 to 1.5 ton.
2. The discovery of "Jesus Boat", on the northwest coast of the Sea of
Galilee, at Ginnosar, and excavated in 1986 14 . It was dated to the
period between the end of the 2nd century BCE and the first part of the
1st century AD. The Kinneret boat is a fishing craft and the Migdal ship
may represent a small merchant craft, or a assenger transporter that
also could be used for fishing. The Kinneret boat was built in the
traditional Mediterranean fashion, of shell-first with mortise-and-tenon
joints. Hypothetically, if we take the length of the ship in the mosaic
and the Kinneret boat, one can see that the model indicates a reduced
scale of approximately 1:25 15.
Althiburus, in Tunisia
Althiburus (modern Medina) is situated on the central plateau of Tunisia, about 200km off the northeast coast. The ancient city was built before the Roman conquest. The location of the city at a strategic point on the trade route between the Sahara Desert and the Mediterranean shore placed Althiburus as an important storage center of the products that were shipped to Rome from the port of Carthage. The environs of Althiburus consisted of fertile agricultural plains and it has rich deposits of phosphates. During the reigns of Antoninus Pius (138-161 AD) and Septimius Severus (192-211 AD), Althiburus was very prosperous, and became an important grain trading center. The city was abandoned in the Arab conquest, during the 7th century AD.
The first archaeological remains of Althiburus were revealed in 1895. The famous mosaic floor with the "Catalogue of Ships" (fig. 7a) was discovered during this time, in a very large and elaborate villa, the Maison des Muses. The floors of the entire villa were paved with beautiful mosaics, which depicted rich and varied maritime scenes. The room where the catalogue was found has a cross shape (fig. 6). According to the top plan of this room 1 was deduced that it formed the frigidarium of a large bath. In 1961, the entire villa was excavated, and during this period the mosaic with the Catalogue of Ships was removed and put on display in the Bardo Museum, Tunis 16. The mosaic depicts about 25 different types of vessels, which were spread over the entire floor without any specific orientation. The ships are pictured on an olive-green background 17. Only 22 vessels are identified by Greek and Latin inscriptions (fig. 7b). Some of the ships are depicted with putii, their rigging, and some are laden with cargo (jars, horses, fishing nets). The putii are not in proportion to the vessels, but appear to be much larger. The style of the inscriptions and the mosaic work indicates that the villa and its floors were made during the second half of the 3rd century AD.
The largest number of vessels is depicted on the central part of the mosaic (fig. 7a) which measures 8 m in length. The width of the mosaic with the right arm of the cross measures 5 m; the left arm was destroyed. At each end of the cross are depicted water gods; at the top is Okeanus, at the bottom a river god and at the right corner the goddess Venus (fig.7a). The inscriptions associated with the vessels do not necessarily indicate a specific ship.
Types of Vessels
The vessels depicted in the catalogue can be classified according to the shape of the hull, the stem-and-stern posts and the rigging.
A. The Hull
1. Very rounded and spoon-shaped with the stem-and-stern raised almost vertically (figs. 7b/7, 2, 7).
2. Long and slim hulls with an almost vertical stempost with the forward projecting pointed cutwater. The rounded stern is ended either with an inner-turned volute or it is slightly higher than the deck and has a V-shape (figs. 7b/10, 12, 13, 19, 21, 22,25).
3. Long hulls with raised stempost curving above the stem and ended with an inner-turned volute. The stern is rounded and either with rounded tip or a V-shape (figs. 7b/3, 15, 16, 17).
The rigging of the vessels comprised of one or two masts and sails with the adjacent cordage, a pair of steering oars; there is one vessel depicted with three oars:
1. One steering oar on the quarter, one mast and no sail (fig. 7b/7). Attached to the tip of the masthead is a small flag 18. Although only one steering oar is seen on the starboard quarter, the artist probably intended to depict two oars on either quarter.
2. One mast and a sail, a pair of oars (figs. 7b/5, 11, 12, 13). The vessels in figs. 7b/5, 12 are depicted with a mast set fore amidships and a fully open sail. The yard is secured to the mast by lifts. On the fore side of the sail a checkerboard pattern is visible, representing the brails used to work the sail. These vessels are also maneuvered by a rower who is working a pair of oars set on either side of the hull amidships.
The vessels depicted in figs. 7b/11, 13 are rigged with one mast and a furled sail beneath the yard. The yard is secured to the masthead with lifts. In fig. 7b/11 one putt works the halyard. The angled left-hand line that stretches from beneath the sail to the port gunwale may indicate the left shroud. There is a single oar lain on the starboard gunwale with its loom behind the putii. The vessel in fig. 7b/73 is occupied by three putii. One puti is rowing a pair of oars placed on either side amidships, another one is climbing the ladder on the mast and the third figure is holding a hammer in his right hand. The mast is set fore amidships. The yard is attached to the masthead by lifts. On both sides of the lower corners of the furled sail a free hanging rope is seen. This line may indicate the right and left sheets.
3. Two masts and sails (figs. 7b/2, 3, 4). These vessels are rigged with a
large main mast and sail, and the second mast is the artemon
(foresail). In figs. 7b/2, 3 both sails are furled. The yard is secured to
the mast by the lifts. At the tip of both left-yardarms is seen the brail or
the sheet. The masts are secured with a series of ropes that represent
the fore-and-back stays. Both vessels are rigged with a pair of oars on
either quarter. The oars have long and wide blades. Most probably
they indicate the rudders.
The vessel in fig. 7b/4 is rigged with two masts and fully open sails. The main mast is set amidships and a bit higher than the artemon (set at a slight angle from the main mast). Both yards are secured to the masthead by a series of lifts. On the fore face of the sails is a checkerboard pattern, indicating the brails. One puti seems to work the halyard of the artemon and the loom of the starboard steering oar.
4. There are several vessels rigged only with a pair of oars set on either
side (figs. 7b/7, 8, 9, 10, 14, 15, 16, 17, 20, 21, 22, 23). Some of them
are worked by one puto(figs. 7b/7, 8, 10, 15, 16, 21, 22, 23).
The Hippago ship (fig. 7b/6) is rigged with three oars lain at an angle on the starboard hull. The looms are pointed to the stem. It is probable that the vessels had the same number of oars on the port hull as well. The oars are not worked by anybody. The fishing boat in fig. 7b/79 is rigged with two oars laid on the starboard rubbing-wale. The looms are pointed towards the putii who are lifting a fishing net full of fish.
Almost all the vessels are depicted with a long lateral strake beneath the gunwale (figs. 7b/3, 4, 5, 7, 9, 12, 16, 17, 78), slightly above it, or at the same level (figs. 7b/2, 6, 8, 10, 11, 13, 15, 19, 20, 21, 22, 23, 24). Both ends of these strakes are protruding from the stem and aft the stern. This element indicates that the upper strake or the rubbing-strake that was used to reinforce the outer lateral hull, and protect it when the vessel was anchored at the quay. This strake also supported the shafts of the oar. There are some vessels depicted with a small protrusion above the gunwale. This element may signify the thole-pins used to secure the looms of the oar (figs. 7b/7, 9, 10, 13, 14) or the bitts used for the running and standing rig (figs. 7b/73).