Figure 11-5: Marine engineering drawing of Maya cargo vessel. Author’s image.
Construction of the Hull
The entire vessel was carved from the trunk of a single high-strength hardwood tree. Chico zapote (manilkara zapota) was the preferred choice of timber. The timber from this dense tree has a tensile strength of 20,000 psi. This is equal to the tensile strength of low-grade steel.
Composite Plank Elements of Bow and Stern
The profile of the bow and stern was shaped from the tree trunk. The high vertical elements of the bow and stern were assembled from timber planks shaped for that purpose and joined to the timber base structure at the bow and stern. Connections would be implemented using slotted joints interfaced along the base hull structure, connected by latex adhesive, caulking, and high-strength tensile pegs along the intersections of the planks and timber hull. The elevated vertical features at the bow and stern are vertical stabilizers and provide displacement or buoyancy to prevent swamping by allowing the vessel to rise vertically in the event of a head or following sea. Another feature of the high-mounted stabilizer is to provide resistance to complete capsizing; the displacement in the bow and stern structures would stabilize the vessel and prevent complete rollover by limiting capsizing to 90 degrees.
Composite Structural Elements to Extend Freeboard
The section through the hull in Figure 11-5 illustrates the vertical extension along the perimeter of the hull developed by the installation of a timber structural element. This vertical perimeter member is capped with a shaped wood cap rail. This vertical element increases the freeboard and depth of the hull, and significantly increases the displacement capabilities of the vessel. The vertical element installed along the longitude of the hull is constructed from a section of timber connected to the top edge of the hull structure. The composite shape is attached to the hull structure using high-strength wood pegs, latex adhesive, and caulk.
The same feature is found in modern vessels. The increased height of freeboard provides the hull with an added safety factor in providing righting displacement, preventing capsizing, or swamping in heavy seas. It must be noted that the vertical extension of the upper freeboard of the ancient vessels is common only to Maya vessels.
Hull Cross-Section Configuration: Athwart Stability
Figure 11-5 indicates the cross-section configuration of the hull of the vessel. The bottom of Maya vessels was flattened to provide athwart-ship stability about the longitudinal axis. The hard chime or flat-bottom hulls were common to early Greek and Roman vessels. Spanish chronicles report that flat-bottom canoes were used in the central Mexican Basin.
The completed cargo vessel was powered by paddlers kneeling or sitting amidships. This type of craft could accommodate 30 rowers. Some accounts describe 20–22 rowers. The specifications of the craft in the drawing had a gross displacement of 32.5 tons. Considering the size and weight of the construction and the paddlers, a net displacement of 21 tons was available for cargo. This was a lot of goods to be traded. The capacity offered the opportunity to ship a great quantity of goods using the ocean highway. A Maya cargo vessel could transport the equivalent load carried by 328 individual tumpline bearers.
The Maya Paddle Design and Steering Oar
Maya artists, including those who created the carved bone artifact found at Tikal, depict the rowers using an asymmetrical paddle. Recently an actual, intact Maya “paddle” was excavated by Dr. Heather McKillop. The dimension and configuration of the paddle provides a significant insight into its actual use. The asymmetrical paddle is 6 feet 1 inch (1.85 meters) in length. The length of the paddle would be excessive for the typical Maya paddler, who was of short height. The asymmetrical shape would create an imbalance of the hydraulic force generated by the movement of the paddle and would cause rotation in the hands of the paddlers. It appears to be a consensus of experienced marine architects that the asymmetrical paddle of more than 6 feet in length must be a steering oar for large Maya vessels. They are used as a rudder to keep the flat-bottom vessel on a straight course.
Other depictions by Maya artists indicate the use of pointed paddles of symmetrical shapes. This paddle configuration made entry and exiting the water easy. In the middle of the stroke, the wide part of the paddle would be fully immersed and would produce maximum forward force vectors. The pointed symmetrical paddle is hydrostatically superior to the blunt, rectangular paddle used in contemporary canoes. Maya paddlers on long sea voyages would kneel or sit amidships, and use a short paddle with a pointed symmetrical shape.
Construction of Vessels Using Jadeite Tools
Black jadeite or chloromelanite tools for the construction of Maya cargo vessels were used to hollow out the interior of the half-cylinder shaped tree trunk and to shape the exterior of the giant logs. Certain scholars have argued that the Maya used bronze tools to carry out the carving of the giant hull. They cite the account of Christopher Columbus and his encounter on the fourth voyage as evidence of metalworking by the Maya. The copper hatchets and crucibles for smelting ore were described in the journals of the great navigator. This was the 16th century, and the Maya may have learned the techniques of smelting copper and the fabrication of copper or bronze tools from South American trading partners. Columbus’s encounter with the Maya vessel occurred more than 600 years after the collapse of the Classic Period; the design of Maya canoes was more than 1,500 years old at that time. (The prototypical design shown in this chapter was developed using typical design characteristics of Maya seagoing craft and technical capabilities in practice during the Classic Period.)
Chapter 5 presented the use of jadeite tools by Maya technicians. The appropriate tool for shaping logs has been the adze. The jadeite adze was mounted on a high-strength wood handle with a 45-degree contiguous element to connect the adze at the optimum angle for maximum cutting efficiency. The connection of the jadeite adze is made of latex adhesive and leather or henequen ties. The adze was the principal tool used in the hull-shaping operation of the vessel. Other critical tasks, including fine cutting of the composite components and drilling, were carried out using jadeite chisels and drills. The finished hull was completed by connecting the composite elements with wood pegs and latex adhesives.
The marine engineering drawing in Figure 11-5 illustrated the design for a basic vessel for seagoing trading. The drawing does not include the cabin structure as described by Columbus or other possible design features such as a sail. The use of a sail on this type of craft has been argued among maritime experts. It is highly possible that a civilization with sophisticated science and technology that independently conceived the number zero, calculated periodicities of the planets to minute accuracies, and created one of the five original written languages in the world could have conceived of a simple device as a sail for their seagoing vessels. In 2000, a French-Mexican team of sailors sailed a replica seagoing canoe with a square, rigged sail in the Caribbean near Belize. The team covered a distance of 30 miles per day under sail and determined that the sail was a logical progression of marine engineering.
The Long-Lived Service of Seagoing Vessels
The Maya seagoing cargo vessels traversed the tropical seas surrounding the Yucatán Peninsula. Their maritime trading network extended north along the Gulf of Mexico, south to Panama, and eastward to the islands of the Caribbean. Fleets of the trading vessels traveled up navigable rivers to trading posts that were connected to overland trading networks. Cities in Mesoamerica and south along the Caribbean were drawn into an “international,” Pan-American trading network with lively commerce and ideas spreading over large distances. Evidence of Maya long-distance trading has been encountered on the far-flung islands of Antigua and Barbados. Jadeite axes found on these islands have been traced to sources in Guatemala. This trading product found its way on a 3,000-kilometer voyage to the east of its source, the Montagua Valley. These long-range voyages that were out of sight of land required sophisticated celestial navigation. This was a specialty of
Maya navigators. Maya navigators did not rely on the North Star but viewed the entire sky as a charted map to steer the way to distant islands.
The Maya seagoing vessel served the culture for 2,000 years as viable trading vessels. Trade was terminated during the conquest when Spanish conquistadors took over the lucrative trade routes. During the conquest, during Spanish colonial rule, and later on, they served as seagoing passenger and cargo vessels. These working seagoing vessels were used by the Maya until the 19th century, when industrialized modifications were made to produce larger-sized craft, and plank hulls were substituted for the traditional carved tree hull. The spirit of these hardy craft can be seen today as their direct descendants, cayucos, transport agriculture goods, cattle, and passengers in the Bay of Terminus, over the mighty Usumacinta River and other rivers of the Yucatán. Today, however, the paddlers have been replaced by a 200-horsepower Mercury outboard engine.
12
The Collapse of Maya Civilization
The achievements of the Maya civilization reached an apogee during their Classic Period. This golden age was marked by the sophistication of its urban life style, made possible by the success of Maya technology. The population growth was reflected by the continual expansion of the cities and their monumental architecture; the achievement of its arts, science, and technology; the bountiful harvest of agriculture; and high economic levels generated by industry and trade throughout the city-states and to markets far beyond the domain of the Maya.
The intellectual creativity of Maya engineering and technology had uncovered unique solutions to overcome the fragility of their natural environment, with its capricious rainfall, lack of surface water, poor soil conditions, and seasonal desert. Maya society optimized their disposable time for advancing science and expanding ideas. This disposable time was made possible by the bountiful harvests that enabled city dwellers freedom from farm labor. These food surpluses were a benefit of their triumph over the vagaries of their environment.
The Triumph of Maya Technology
Maya technology employed engineering solutions that kept pace with the expanding needs of their population of 15,000,000 inhabitants. Their engineered water-management systems satisfied the yearly demand for water, plus provided a factor of safety in the event of shortfalls in the annual rainfall. Sufficient rainfall meant life and survival to the Maya civilization.
Maya cities were masterpieces of artistic and technological creativity brought to realization by the invention of cast-in-place concrete, tall structures, efficient infrastructure, and city planning. The urban city-states were a tour de force of Maya intellectualism. The Maya transportation systems with all-weather roads and seagoing vessels brought wealth to the city-states by enabling successful trade throughout Mesoamerica and across the seas.
Maya-engineered water-management systems developed reservoirs, chultunes, and canal systems that provided water for the survival of cities and the enhancement of agricultural yield. The technological advancement of agronomy and engineered agriculture systems for irrigation, including raised fields and terraces for agriculture, enhanced the ability of Maya farmers to produce food to keep pace with the growing population plus a food surplus for trade. Maya farmers constituted 70 percent of the population, and they were able to produce 200 percent of the food requirement for their families, creating a sufficient food supply for the urban populations and a 40-percent surplus for trade.
The Balance of Need and Supply in Maya Society
Every sector of Maya culture was in balance due to the successful enhancements of the natural environment by Maya technological and engineering exploits. The balance between survival and disaster was in equilibrium as determined by the quantity of rainfall. For 600 years, the Maya had enjoyed a long string of good fortune, with 600 rainy seasons of sufficient rainfall to replenish the reservoirs of the cities and provide irrigation for the demands of their engineered agricultural systems. The average amount of precipitation was at a level that enabled the society to prosper by balancing the deficiencies of a year of low levels of rain with years of abundant rainfall by application of creative technologies. The chultunes and reservoirs of the cities were designed and constructed to collect and store an 18-month supply of water for the populace of urban places. The surplus would provide an adequate supply of water for the six-month desert of the dry season with a 12-month reserve in the event of an interrupted supply of rainfall. Agriculture, however, did not have the advantage of a safety factor due to insufficient rainfall.
The Maya urban zones had some of the densest population in history, with up to 2,400 people per square mile in populous cities. Their water supply and agriculture systems had maintained a delicate balance due to 600 years without a serious drought throughout the region. However, their streak of good fortune could not continue forever. A serious drought could change the equilibrium between technological improvements and Mother Nature’s largess in precipitation. Without the generosity of natural rainfall, the safety factor in a period of drought would be insufficient. During a drought, the equation for predicting and determining the sufficiency of reserve in the water supply would fall out of balance; the reduction in the reserve would lead to disaster for the Maya population. Without regular rainfall, Maya cities dependent on a technologically enhanced water-supply system would be in a serious situation if 18 months passed without rain. Agriculture would be in serious trouble if a shorter period passed without rain; the success of the Maya agriculture systems required rain rather than a water-storage system. The lack of regular rainfall would lead to a disaster of unprecedented proportions for the Maya
The Balance of Survival Tilts Toward Disaster
The Maya had experienced droughts during their long history—with serious consequences. During the Pre-Classic Period between AD 125 and AD 250, Maya scientific advancements were set back during a serious drought that caused the Pre-Classic abandonment. At this time, Maya cities from the Northern Lowlands to the Pacific Cost were slammed by the severity of a 25-year period of drought that resulted in abandonment or impairment of the cities. The great city of El Mirador was abandoned during this period and was never reoccupied. However, once again the bountiful rainy season returned to the Yucatán, and for 300 years, Maya society prospered with predictable rainy seasons. The cities were reoccupied and unprecedented building programs were the result of the flowering and growth of cities; with population expansion, the power and wealth of the cities flourished as never before.
A period of slow growth occurred from AD 536 to AD 590. This period had a debatable effect on the Maya. Some experts argue that the hiatus was confined to Tikal and was not a widespread event. After the hiatus, the tropical rainy season returned, and, for 200 years, Maya society thrived and experienced a period of expansion of cities, intellectual enlightenment in art and science, economic growth, agricultural abundance, prosperity in trade and commerce, and additional technology-based projects that enhanced the factor of safety against environmental adversity. Then their lucky streak came to an end and Dame Fortune turned against the Maya: between the fateful period of AD 790 to AD 910 the greatest drought in 7,000 years engulfed the Yucatán, brought about demographic devastation on a scale unparalleled in world history, and destroyed their exquisite scientific civilization.
Richardson Gill, in his book The Great Maya Droughts, has developed an interdisciplinary scientific and historical analysis of data that provides a logical, chronological overview of world climatic events and their effect on historic weather conditions in the Yucatán. Mr. Gill’s book reviews weather, droughts, and volcanic activity from 3500 BC through the collapse of the Maya civilization. Gill presents a scientific approach to assembling the history of climatic conditions and meteorology in the Yucatán Peninsula. He develops a logical analysis of historic weather patterns and climatic conditions using myriad scientific studies. His results were a mosaic of critical meteorological data indicating how worldwide weather patterns affected the tropical homeland of the May
a. Gill interprets paleoclimatic records; historical European, African, and Mesopotamia records of climate patterns; and anomalous weather records in Scandinavia and Peru. He presents a concise environmental milieu of data that integrates interdisciplinary sources to develop the history, nature, and causation of extreme weather conditions in the Yucatán.
The principal meteorological hypothesis of the book is that cold periods of weather somewhere in the world can be coincident with drought in the Yucatán. Cold weather in northern latitudes brought drought to the Maya. In addition, during the Classic Period drought, the Maya environment was affected by the negative effects of tropical volcanic eruptions. Gill identifies a number of tropical eruptions that occurred during the drought and compounded Mother Nature’s disaster. The parched environment was attacked by the effects of volcanoes injecting sulfur-rich gases into the tropical stratosphere, reducing the amount of solar energy reaching the troposphere and affecting the weather.
He recounts how millions of Maya suffered and died in total isolation from other civilizations. This is the same isolated condition that prevailed when the Maya evolved their scientific civilization, and this isolation now affected their survival. No one came to their aid in relieving their suffering: no Red Cross, and no international relief organizations or assistance to offer relief. They created one of the world’s greatest scientific civilizations in near isolation and died by the millions in the same geographic vacuum.
The Lost Secrets of Maya Technology Page 29
