Tuesday, September 22, 2009

Reed boat construction and the use of bitumen


Until the Ras al-Jins (Southeast Oman) discoveries, we had no direct information on reed boat structure; iconographical representations and boat models proved unhelpful. However, the reconstruction of a 42.6-foot (13 m) proto-reedcraft based on the Ras al-Jins bitumen impressions, provided valuable information into construction methodologies: there were about 300 fragments of bitumen imprinted with reed, rope and mat impressions on one side and barnacles (Balanus amphitrite) on the other, dating from between 2300 and 2100 BCE.121 The intention in building the prototype was to provide knowledge on the skills needed in its construction, using materials such as reeds (Phragmites australis), rope and bitumen. All materials were sought from Oman. The building process needed the skills to cut reeds, make ropes, put together bundles of reeds (lashing and binding), prepare timber and finally in the mixing of lime and bitumen. Other skills were required to make sails (woollen or mats of reeds or date palm leaf ). The conclusion drawn from this, Tom Vosmer comments, was that Bronze Age shipbuilding required “a highly organized social and manufacturing infrastructure”, and it would be expected that the crew had similar skills for repairing the ship when it sailed across the ocean. The boat finally sailed in February 2002. One question remains unanswered: whether the reed was local or imported from the Meluhha (Indus Valley) region.
Further experimentation was conducted by Tom Vosmer, in coordination with a research team in Ravenna, Italy, by constructing a bundled-reed vessel named “Magan boat”. The team was inspired by the method used by the Marsh Arabs to build their reed houses (mujÏf), as mentioned earlier, i.e. proceeding upside down; that is the keel, like the roof of the house, is first made with a number of tight bundles of reeds (qasab—Phragmites communis) lashed together to form the hull shell and then long reeds are shaped in a U form which are passed from the middle of the keel to the floor. Based on the evidence of the bitumen fragments, the team decided to put mats on the bundles to protect them from heat and the bitumen from melting. It is interesting to note that with Egyptian reed boats it was the custom to use clay on the inside rather than applying another coat of bitumen. Heat keeps clay dry while bitumen melts and becomes sticky.
Textual evidence points to the existence of bitumen-covered reedbundle vessels in the Bronze Age (c. 3000–2000 BCE): an Ur III text from Girsu mentions, among other things, the use of vast quantities of reeds and bitumen; another Ur III text states that 900 kg of bitumen was scraped off a boat.
Coating of reed-boats with bitumen is well-known. The Tell Mashnaqa (Northeast Syria) models show what seems to be bitumen coating. Two large models (from 1–1.5 ft/30.4–38.1 cm to 6 ft/121.9 cm in length) found in Ur were made with bitumen and such models seem to appear throughout the Sumerian period. The recent recovery of 22 bitumen fragments of ocean-going vessels belonging to the Ubaid period at Al-Subiyah (Northeast Kuwait) is a significant find. They point to a maritime trade as early as the sixth millennium BCE. Among these fragments one finds bitumen pieces with reed impressions on one side and barnacles on the other. Other finds include a small boat model made of fired red clay. Interestingly, in Mesopotamia ceramic model boats of the Ubaid period were found coated with bitumen. It is possible to speculate from the discoveries at Al-Subiyah that the bundled-reed vessels were secured with rope or cord and coated with bitumen and that the site was used for repair work and maintenance and possibly boat-building.
From the experimentation conducted by the Ravenna team, Tom Vosmer observed that: a) the impressions left on the bitumen fragments could possibly be caulking remains, b) barnacles grown on the outside of the fragments could suggest that the bundled-reed boats were oceangoing vessels, and c) from the internal side of the fragments one could see that the reed bundles were lashed with rope and covered with woven mats. The finds, primarily the bitumen fragments, indicate that both wooden and reed boats were constructed, or single boats with a hybrid structure of reed and single-plank technology.

North versus South in Naval technology


Large cog with the Latin sail aft and by light gun on the turning ring mount which ruled in the Baltic region and the North Sea almost 300 years.

The galley, be it of Greek, Roman, Byzantine, Arab, or Turkish design, was not an effective seagoing weapon system. Galley fleets were too unseaworthy and too logistically short-legged to act independently. As a result, well into the sixteenth century Mediterranean navies were still tethered to the shore. Galley fleets had limited radii of operations—five hundred miles at best—and that piloting along coasts, not sailing or rowing along a straight line from point to point. At night, galley commanders preferred to back their ships onto a safe beach, where the crew could sleep and search for fresh food and water. A blockade of a distant enemy port was virtually impossible. Only if a friendly army held a nearby stretch of coast could a galley squadron attempt a blockade. Navies, leashed as they were, usually operated as flanking forces for the armies to which they were attached. Until the sixteenth century, naval operations were extensions of land warfare, more amphibious than truly naval.
The changes in ship design, navigation, cartography, and armament that occurred between the fourteenth and sixteenth centuries were not simply incremental steps in the evolution of sea power, but a collection of advances that engendered a maritime revolution. By the mid-seventeenth century the nature, scope, and scale of both maritime commerce and naval warfare had changed dramatically. Previously, only states with large and mighty armies—such as the Macedonians, Romans, Arabs, and Mongols—had been able to forge global domains. But now the world’s new empires were maritime states more akin to Athens than to Rome. Sea power was no longer merely an adjunct to land power. “The sea,” in the words of Fernand Braudel, had become “the gateway to wealth.”
That Europe’s maritime empires all fronted the North Atlantic, a harsh, challenging sea, was no coincidence. Northern Europeans were never as enamored of the galley as their southern cousins. Northern seas, even coastal waters, were too rough for vessels with low freeboards. Many of the tides and currents of the English Channel ebbed and flowed more quickly than the best speed of a rowed vessel. The Vikings conducted most of their distant oceanic voyages, not in their rowed longships or war galleys, but in more functional sailing vessels.
The harsh Atlantic environment forced northern Europeans to give more thought to the design and rigging of sailing ships, and to navigation techniques, than did the people of the Mediterranean basin. Often facing overcast or foggy conditions, northern mariners relied heavily on soundings and, when it became available, the compass. Eventually northerners developed several types of vessels notable for their seaworthiness, carrying capacity, range, and ability to sail upwind.
Northern shipbuilders enjoyed no monopoly on design improvements. Shipwrights in the Mediterranean also refined their roundships, not only by incorporating ideas imported from the north, but also through their own advances in construction techniques and rigging plans, advances northerners were more than ready to adopt. Shipbuilding know-how flowed freely between the Atlantic and the Mediterranean.
Northern Europeans owed their maritime dominance over their southern neighbors, and ultimately over the entire world, to a pair of interrelated developments. First, northerners quickly adopted, by necessity rather than choice, improved roundships as war platforms; the Mediterranean states, both Christian and Muslim, did not. Second, the northern Europeans’ continued refinement of the sailing man-of-war in the fourteenth and fifteenth centuries positioned them, unlike their southern neighbors, to take full advantage of the development of cheap iron cannon late in the sixteenth century.
Since the galley was never as satisfactory a platform for ship-to-ship fighting in rough northern waters as in the Mediterranean, as shipwrights constructed larger, more strongly built, more maneuverable roundships in the thirteenth century, states fronting the Atlantic began to incorporate the new vessels into their naval forces. The late-twelfth-century English navy, for example, consisted principally of assorted types of galleys, but by the early thirteenth century powerful roundships formed the core of English battlefleets. By the early fourteenth century galleys had all but disappeared from English orders of battle. In contrast, well into the sixteenth century Mediterranean navies clung to their battleproven galleys, which continued to hold their own against roundships.
As a result, northern shipbuilders had a three-century head start, not in the design and development of sailing ships as such, but in the refinement of the roundship as a fighting platform. While most sailing ships taken into the fleet in wartime were merchant vessels pressed temporarily into service, northern European states began to look to shipwrights to design and build sailing vessels specifically for wartime use. These new ships incorporated several prominent design features, such as towering fore and aft “castles,” or fighting platforms, from which soldiers could hurl projectiles down onto their enemies. Gradually, the recognizable design of purpose-built sailing warships began to emerge.
Nevertheless, these early sailing men-of-war, even when armed with the primitive gunpowder weapons of the day, did not yet ensure technological superiority for northern navies beyond their home waters. Until the sixteenth century reliable cannon were too expensive to be used extensively, whether on land or on sea. States generally consigned their heavy guns to siege trains, of which the Muslim Ottomans, not the Christian Europeans, had the most powerful. Navies, both northern and Mediterranean, mounted only small numbers of heavy cannon, mostly brass or bronze, in the bows of their ships.
The costliness of the great guns masked the true nature of the technological changes taking place in the maritime world and lulled the Mediterranean powers into unwarranted complacency. As long as fiscal concerns limited the naval use of artillery, the galley was a viable fighting platform. Since bow-mounted guns fired forward, in battle they could be used more efficiently by the highly maneuverable galleys than by sailing ships. Thus in 1500 no one recognized that the war galley had reached the end of its long history of development; no one foresaw that the fighting roundship would continue to evolve as a weapons system for another 350 years; no one knew that by the end of the century the advent of cheap iron cannon would allow the larger, longer-ranged roundship to carry powerful broadside batteries to the four corners of the globe; no one suspected that the age of galley warfare was drawing to a close.
Cannon and sailing ships consummated their marriage unobtrusively. Only in the fifteenth century did ships begin to mount guns broadside. Not until 1501 did a Frenchman cut gun ports in the hull of a ship. Only a few men-of-war, such as the English Harry Grace à Dieu and the French François, mounted large batteries with numerous broadside cannon. And of the Harry’s 141 guns, only 21 were heavy cannon, all brass and rather expensive.
In the late sixteenth century the development by the English of cheap cast-iron cannon began to ensure the preeminence of the roundship over the galley. Cast-iron cannon weighed more than brass or bronze guns, did not last as long, and were more apt to explode. But new casting methods enabled English ironsmiths to produce large numbers of admittedly inferior but very inexpensive cannon. The use of both English methods and iron guns quickly spread throughout the navies of the north. As a result, northern Europeans possessed a monopoly on both the raw materials and the technological know-how to furnish enough guns to line the decks of their ships of war.
Early in the seventeenth century the Mediterranean powers discovered that their navies were obsolescent, if not obsolete. Refinements could no longer make the galley a viable warship. The southern Europeans, Turks, Arabs, and the rest of the world had fallen behind the northerners, so quickly, so imperceptibly, and so far.