Reengineering the Past
UMaine students use digital modeling to virtually rebuild the 18th-century plantation ruins
It sounds like the perfect spring break. Last March, eight University of Maine students joined two engineering faculty members for a trip to the U.S. Virgin Islands. The students camped on tent platforms under warm skies, a far cry from the snow and cold back home. Each morning, they hiked along the beach, soaking up the tropical sunshine and taking in the sights.
At least that's the way it might have looked from afar. In truth, these students spent much of their time grubbing out vines, shrubs and trees from the ruins of old buildings.
They had to keep an eye out for scorpions and tarantulas. And in addition to their swimsuits and beach towels, they brought along the tools of academic research — laptop computers, global positioning system (GPS) receivers and surveying instruments.
The purpose of their trip was to apply the latest information technologies to a thorny problem in archaeology: how to preserve history in the face of deteriorating physical evidence. The Virgin Islands National Park on St. John, it turns out, is an ideal place — and one with a remarkable history — to apply computer-aided design (CAD) and geographic information system (GIS) software to the needs of historical preservation.
Scratch the surface of this tropical paradise and you'll find a history of colonial shipping and piracy, slave labor to work the sugarcane fields and European power struggles.
On St. John, the third largest of the 68 islands within the U.S. territory, evidence of those times is still visible in the remains of more than 500 buildings, most within the national park.
Many of these buildings date from the 18th century, and some go back to the 1680s, when Spain, Britain, France and Holland vied for economic and military power in the region. The stone structures include well houses, sugarcane mills, storehouses, slave huts, and large homes for plantation managers and owners. Preserving those cultural resources is part of the park's mission, but physical renovation is costly, and many buildings are falling prey to time and the stranglehold of vines and trees.
"These buildings are being destroyed to the point that in a few years, there won't be anything left but piles of stones," says University of Maine engineer Connie Holden. "They can't begin to stabilize what they have." And as buildings fall to ruin, historical clues can be lost forever.
Holden is an instructor in the Department of Spatial Information Science and Engineering. She and Karen Horton, associate professor of mechanical engineering technology, led the eight UMaine undergraduates to St. John to document the precise location, landscape features and structural details of an 18th-century sugar plantation.
"We'll probably never have the money to rebuild them," says Ken Wild, National Park Service archaeologist who initiated the project with Horton. Wild has worked in national parks throughout the southeastern U.S. and first came to St. John in 1984.
Students focused much of their efforts on this well house made of stone, brick and coral, located on the Leinster Bay sugar plantation that is part of the more than 14,500-acre national park on St. John. In addition to the cane fields, the 18th-century plantation included the windmill-powered well, a horse-driven sugar cane mill, slave huts and a large hilltop house for the owners. At the well house, students cleared vegetation, measured walls, took photographs and downloaded data into a laptop computer to generate digital designs of the building. Their renderings preserve details about the structure for future historical analysis and restoration. Leinster plantation, built in 1721, operated for a century before the Caribbean sugar industry collapsed.
Photo by Amy Crosby
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"Some of the buildings have fallen down since I've been here. The technology that Karen and Connie are using will give us a three-dimensional (computer) model that allows us to visualize how these structures were built. Even if one does fall down, you'll still be able to walk through it (on the computer)."
The technology will enable future park visitors to see ruins that, by then, may have deteriorated completely. Moreover, archaeologists and historians will have a thorough and precise record to use for studies of the island's history and culture. And if reconstruction money should become available, the 3-D models can be used to visualize how to rebuild, says Wild.
"Engineers use this technology to design new buildings. Why not use it in reverse to bring these buildings back?" he says.
A photograph provides just one perspective, says Holden. "A 3-D model gives you everything. We're including in the database things like specific measurements, thickness of the walls, places where an arch is holding the building up, how that arch was constructed. These details do not exist in a photograph."
GIS, says Holden, allows historians and archaeologists to create maps that show the relationships among the landscape and building features. For example, understanding how sugar plantations varied with respect to elevation, soils, proximity to the sea and structures can help historians recreate events such as the slave revolt that occurred in 1733.
Also important for historians is information about how data were collected. By knowing how accurate the data are, they can evaluate interpretations of the past as new facts come to light.
"The interest in the enslaved people, from their perspective, is an important aspect of history," says Horton. "Historians would be thrilled to have the ability to visualize where a slave revolt physically began. What are the differences in each of the plantations? Which of the plantations had places where people could be on higher ground, for example? What was the physical relationship between where the slaves were at the time that the revolt started compared to where the people who were enslaving them were located?
"(The GIS) allows an historical analysis. The information for that analysis isn't currently tied together in any way. There's a huge historical record on this (St. John sugar plantations), but the records are scattered."
Students participating in the trip last spring came with backgrounds in engineering, art and even theater. They focused their attention on the old Leinster Bay sugar plantation, which operated with slaves from 1721–1867. During the day, the students cleared trees and other vegetation, took photographs and measurements, and established survey points.
They collected GPS data for the site, although the island's steep topography sometimes blocked their access to the satellites on which the system is based.
The engineering students used MicroStation, CAD software that generated precise 3-D images of the ruins. Once on St. John, they downloaded their photographs and measurements to the CAD program, refining the data and photographic images as they worked. Their goal was to take back all the raw data needed to produce an accurate rendering of one of the buildings and to integrate the rendering into a full GIS package of the site.
Upon returning to Orono, the students worked with Horton and Holden to produce a report for the National Park Service. Eventually, the GIS and CAD renderings will be posted online for public use.
Support for the project came from University of Maine faculty research funds, the Friends of the Virgin Islands National Park and the National Park Service.
by Nick Houtman
January-February, 2005
