An analysis of Pre-Columbian balsa raft design to determine the suitability of such rafts for ancient maritime trade between Ecuador and Mexico

Abstract

By approximately 100 BCE Ecuadorian traders had established extensive maritime commercial routes reaching from Chile to Colombia. Historical sources indicate that they transported their merchandise in large, ocean-going sailing rafts made of balsa logs. By about 700 CE the data show that Ecuadorian metalworking technology had reached the west coast of Mexico but remained absent in the intermediate region of Central America. Archaeologists have argued that this technology was most plausibly transmitted via maritime routes. However, no remains of pre-columbian rafts have been found in West Mexico. This thesis uses mechanical and materials engineering analysis to determine whether these craft could have sailed from Ecuador to Mexico. Using historical accounts of the rafts as a data set, this thesis models their aerodynamic and hydrodynamic properties, their buoyancy and cargo capacity, their functional lifetime, and the load-bearing capacities of their components. The analysis shows that these prehistoric rafts were fully functional sailing vessels and could have been sailed between Ecuador and Mexico. This study greatly strengthens the argument that maritime trade transmitted Ecuadorian metallurgical technology from South America to Western Mexico.