INSTITUTE OF NAUTICAL ARCHAEOLOGY - Bodrum, Turkey |
| SERÇE LIMANI |
THE ANCHORS: A limited technology, A sophisticated design
by Frederick van Doorninck, Jr.
The Serçe Limani ship was carrying eight iron anchors when she sank. Five were spare anchors stacked on the deck between the two masts. The remaining three were bower anchors mounted on the bulwarks in the bow ready for use, two on the port side and one on the starboard side. Perhaps an anchor of like size and design found on the seabed near the wreck is the other starboard bower. If so, it was probably the cause of the ship's untimely end, since its shank had been broken while it was being used.
The anchors have apertures for removable wooden stocks, straight arms that form obtuse angles with the shank and spade-shaped teeth set at right angles to the arms.
Anchors of this Y-shaped design were unknown until just two decades ago and when first found were thought possibly to be a type of anchor used primarily by the Arabs. We now know, however, that they were widely used in the Mediterranean and in the Black Sea, and Gerhard Kapitan, the well-known German nautical archaeologist, has recently demonstrated that these anchors in fact represent the last stage in the evolutionary development of the ancient iron anchor in the Mediterranean world.
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The earliest iron anchors presently known date to the Hellenistic period. They imitate the ancient wooden anchor in form, having straight arms set at an acute angle with the shank (Fig. 3A). As time went on, however, the arms evolved into a more and more open shape. By the time of Christ, the arms had become lunate in shape (Fig. 3B), by the 4th century, straight and perpendicular to the shank (Fig. 3D), and by the 9th or l0th century, the Y-shaped anchor had begun to appear (Fig. 3E). Kapitan has suggested that one reason for this evolution had been a need to design anchors that broke out from the seabed more easily when lifted. However, our study of the anchors from both the Serçe Limani and the 7thcentury Yassi Ada ships has led us to conclude that the primary impetus behind this evolution was a desire to minimize the length of the anchor shank. By increasing the openness of the arms, the shank length could be decreased without at the same time decreasing the distance between the teeth and the stock and consequently the stock's leverage in forcing one of the teeth down into the seabed.
The need to minimize shank length was a consequence of the limited technology generally available for the manufacture of iron anchors in the ancient and medieval Mediterranean world. A closer look at the Serçe Limani anchors will reveal why this was so. The anchors, which weigh only from some 50 to some 60 kg each, appear normally to have been fabricated from 15 pieces of iron forge-welded together, each piece weighing about 4 to 5 kg. Either arm was made of four pieces; the shank, of six pieces; and the ring, of one piece. As can be seen in Figure 1, the four pieces in either arm were forged together end to end. The middle weld was nothing more than a butt weld, while the other two welds were diagonal scarf welds. The shank pieces were also joined together by diagonal scarf welds. The inner ends of the arms partially overlap the shank on opposite sides, and the three components were welded together through hammering the arm ends against the shank and the shank against the arm ends. The smaller an anchor's cross-sectional dimensions were made, the easier it was to hand-forge welds that were sound and not likely to break. This is undoubtedly the basic reason why ancient and medieval ships of any particular size carried the thinnest, lightest iron anchors possible. To compensate for anchor lightness, it was normal practice to use a number of anchors simultaneously. Thus, for example, the 7th-century Yassi Ada ship carried four bower anchors ready for use, and it is very likely that the Serçe Limani ship did so as well.
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Samples of unoxidized iron from the Serçe Limani anchors have been analyzed at the University of Pennsylvania by Drs. Robert Maddin and Tamara Stech. They report that the anchors were made of a soft bloomery iron that is, however, often rendered brittle by inclusions of slag, creating zones of weakness that made the anchors prone to breakage. Analysis of samples from one of the 7th-century Yassi Ada anchors revealed that the iron of that anchor was of an identical structure. It is easy to see, then, why the ancient iron anchor underwent the evolution in design that it did. The shorter the thin, brittle shank of an anchor was made, the less chance there was that the shank would break. Even in the case of Y-shaped anchors, however, shanks frequently broke under stress. As has already been noted, the breaking of an anchor shank may even have caused the sinking of the Serçe Limani ship. In any event, it is clear that the shanks of at least three of the ship's anchors had been broken sometime earlier and had then been repaired. In one instance, the repaired anchor appears to consist of the upper part of one anchor and the lower part of another. In the other two instances, the two parts of the broken anchor were simply forge-welded back together. That it had been possible to retrieve both parts of these anchors when their shank broke was probably due to the normal practice of fastening a buoy line to the bottom of the shank to mark an anchor's location. The Y-shaped anchor was the evolutionary product of over a millennium of seafaring experience. A strange-looking anchor to modern eyes, it was a sophisticated design in its time, but became outmoded by the advent of an improved iron-making technology toward the end of the medieval period, was replaced by the modern iron anchor with lunate arms and fixed wooden stock, and was totally forgotten. Nautical archaeology is now restoring it to its rightful place in maritime history.
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