Describing the urban dig site as very “dynamic,” Kocabaş says his early educational background in mechanical engineering, his father’s profession, came in handy for devising new apparatuses to lift out parts of the ancient ships as they were uncovered. “We couldn’t use mechanical tools in the excavation area because there were so many artifacts. Everything had to be moved by hand, but the wood was so soft, you couldn’t even touch it,” he says, showing photos of the L-shaped brackets and Styrofoam supports he designed so the workers could move the waterlogged vessels without damaging them. On the high-tech side, the team employed a total station device — a tripod-mounted cameralike instrument used by surveyors and engineers to measure distance and angles. It captured up to 30,000 digital reference points on each in situ shipwreck to be assembled later into large-scale 3-D images.
Excavations were completed before the subway station’s grand opening in fall 2013, but work to document and analyze the finds continues under Kocabaş’s supervision at the Yenikapı Shipwrecks Project lab. Wooden timbers from the sunken ships are kept submerged in narrow rectangular tanks measuring some 10 to 30 feet long and housed inside the warehouse as well as in an adjacent lot. The timbers stay there, protected by the water until a lab tech is able to clean, photograph and digitally measure them, noting the size, shape and placement of every nail, tool mark or glob of pitch. Pieces ready for storage are impregnated with polyethylene glycol or melamine resin to prevent cracking. Smaller pieces are then dried in an oven while larger ones go into a 2.5-meter-long freeze-dryer/condenser that resembles an MRI machine and is housed in its own trailer on the lab grounds.
“A vacuum moves all the water from the wood to the condenser section, where it quickly turns to vapor to keep the wood from cracking under the high tension,” Kocabaş explains, proudly noting that the $80,000 device is the first of its kind used in Turkey. Similar equipment was used to preserve the largest Viking warship ever found after it was excavated from the banks of Denmark’s Roskilde fjord. “Texas A&M University is the birthplace of nautical archaeology, but even they didn’t have one like this when we got ours!”
The archaeologist smiled just as broadly, if perhaps a bit more mischievously, when pointing out his two secret weapons to keep the timbers still in the tanks from being damaged by bacteria, fungi or insect larvae. “That’s Guardian, and that’s Death Angel,” he says, gesturing to two tiny fish swimming around one of the vats. “I took my son’s goldfish when he was away at our summer house and told him they had to be put to work. They clean everything.”