Engineering the National Parks: 3D Scans and Hand-Laid Stone at Harpers Ferry

At Harpers Ferry National Historical Park, a 19th-century retaining wall was failing. The National Park Service's Masonry Team did not patch it. They recorded it with modern documentation techniques, including 3D photogrammetry, then used traditional masonry skills to take it apart and rebuild it, stone by stone. The large section of wall was dismantled by hand over two weeks.

The work crew nears the end of dismantling the retaining wall and approaches the footing, after two weeks of taking it apart by hand. Credit: National Park Service.

Old techniques, new tools

The project shows a hallmark of good engineering in the parks: blending new technology with long-established preservation methods, and adapting to the particular problems of each place. The Park Service relies on engineers for everything from towering bridges to work around delicate ecosystems, designing, building and maintaining the infrastructure that keeps parks open and sustainable. Their challenges might include designing a bridge that suits a spectacular landscape, or a sustainable trail system that treads lightly on sensitive ground.

The Gateway Arch. Credit: National Park Service.

The Gateway Arch, a monument to westward expansion, is a reminder of how far engineering ingenuity can go — the engineers who designed its innovative tram system had to think far outside the box. Park engineers face their own one-of-a-kind problems every day.

Nobody builds alone

Successful park projects rarely happen in isolation. Engineers coordinate with architects, biologists and park rangers to finish projects on time and on budget, and good communication lets different kinds of expertise shape the result. A project to improve accessibility at a historic site, for example, means working closely with preservationists and accessibility experts to find solutions that respect both the site's historic character and the needs of every visitor.

The Park Service wrote this for Engineers Week, to celebrate the engineers who do this work — for whom it is public service as well as a technical job.

Sources

Based on "Discover How Engineers Are Designing the Future for America's National Parks," National Park Service, a work of the United States government in the public domain.