Structural Investigation of a Historic Lighthouse Using Nondestructive Testing

August 8 , 2007– Boulder, Colorado - Construction began on the Piedras Blancas Light Station in 1874. “Piedras Blancas” is Spanish for “white rock,” a reference to the large outcropping just yards from the lighthouse.

Today the site includes two of the original historic structures—a lighthouse building completed in 1875 and a fog signal building completed in 1906. The lighthouse building was originally 115 feet tall, including a first-order Fresnel lens manufactured in Paris , France . The tower is approximately 34 feet in diameter at its base with walls almost 5 feet thick.

The Piedras Blancas lighthouse is located along scenic California Highway 1. The rugged coastline in this area is a regular habitat for numerous marine mammals and other wildlife. Harbor and elephant seals are often seen on the rocks surrounding the lighthouse, and whales can be seen migrating through the nearby waters. Numerous pelicans and other birds also frequent the Piedras Blancas site. The lighthouse is minutes away from the extraordinary Hearst Castle , and can be seen from various balconies and terraces by visitors touring the elaborate estate.

The clay brick masonry materials for the Piedras Blancas light station were shipped from San Francisco .

The U.S. Lighthouse Service operated the station until 1939, when the Coast Guard assumed control of the site. A 1949 earthquake centered near the site damaged the upper portion of the lighthouse. Later, the heavy original lens was removed along with the uppermost portion of the lighthouse tower for structural reasons. The lens is on display in the nearby town of Cambria .

In October 2001, the Coast Guard turned over control and management of the Piedras Blancas lighthouse to The Bureau of Land Management.

Atkinson-Noland & Associates is a Nondestructive Evaluation company based in Boulder and will be serving as the masonry consultant in a structural investigation of the historic Piedras Blancas Light Station north of San Simeon , Calif.

The study was requested by the Bureau of Land Management in hope that the lighthouse and accompanying fog station on the property might be opened in the future to allow visitors to experience this spectacular structure and its incredible views of the coastline and wildlife.

Atkinson-Noland is among several engineers and consultants evaluating the structures in preparation for historic restoration, said Donald Harvey, of Atkinson-Noland. Restoration will include masonry restoration and recoating.

The forensic investigation includes identifying existing structural conditions and material properties as part of an overall structural assessment. To do so, Atkinson-Noland performed several types of nondestructive evaluation (NDE) and nondestructive testing (NDT) at the light station including flatjack testing and ground penetrating radar (GPR) - also known as impulse radar- testing of masonry.

About Atkinson-Noland

Atkinson-Noland & Associates has provided structural engineering services including nondestructive testing, nondestructive evaluation and infrared thermography (IRT) for federal, state and private organizations since its founding in 1975. The company provides a variety of professional engineering services for building assessment, repair and evaluation. It specializes in nondestructive and in-place testing of masonry structures. With expertise in masonry, nondestructive evaluation and historic preservation, their services can be customized to meet clients' needs.

Atkinson-Noland & Associates is based in Boulder , Colo. Contact them for more information: (303) 444-3620, (800) 735-3629. Or email them: info@ana-usa.com .

© 2007 Sinai Marketing and Atkinson-Noland & Associates. Authorization to post is granted, with the stipulation that Sinai Marketing is credited as sole source. Linking to other sites from this article is strictly prohibited, with the exception of herein imbedded links.

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