Workers Prepare to Fill a Tall Order
Washington Post Staff Writer
Tuesday, October 13, 1998; Page B1 The sun scorches it and strong winds tilt it. The sides are scarred and stained, the corners chipped and the stone faded. It looks rock-solid, but time and the elements have dealt a serious and previously undisclosed blow to the upper portion of the Washington Monument.
Consultants examining the city's signature landmark discovered several significant cracks on the obelisk, above the 452-foot mark, as long ago as 1992. Although the situation was serious "most alarming" was the term used a recommendation to install electronic sensors and establish the cause of the ruptures was passed up by the National Park Service.
Just how severe the damage is to the marble blocks and to the monument as a whole will not be known until structural engineers and others inspect the 555-foot structure up close, and even then only long-term analysis of the cracks may provide an answer. The monument is now closed for at least three months as workers build a massive aluminum scaffolding grid around the free-standing tower, which is in the early stages of the most ambitious restoration since it was completed in 1884.
The work, to be finished by May 2000, is beginning six years after a little-known study commissioned by the Park Service found significant problems at the landmark and suggested it was "vitally important" to systematically monitor the most serious cracks. The recommendation was rejected by the Park Service in favor of what officials call a "holistic" approach, which took five years to implement and relies heavily on corporate funding.
Vikki Keyes, the deputy superintendent for the Park Service's National Capital Region, said that the study was taken seriously but that the suggestion to install sensors was rejected because officials decided to inspect the cracks when the scaffolding was erected. The renovation received a priority designation within the Park Service but still competed for funding with other projects, which also delayed the work.
The decision not to install sensors means structural engineers will not have the minimum five years of data experts say is required to adequately assess cracks in stone. It is not known, for example, whether the cracks are growing or whether they are affected by temperature, wind velocity or the natural swaying of the monument.
Park Service officials, noting the logistical challenges of examining the exterior of the famed obelisk, say any significant discussion of the health of the 81,120-ton monument is academic until the scaffolding is built and the structure can be viewed up close. But the study and its findings, which have not been made public until now, provide at least a rough blueprint for what workers and engineers will encounter when they examine 93,600 square feet of surface, from the thick base to the pinnacle, where a 100-ounce solid aluminum pyramid is inscribed Laus Deo, or "Praise be to God."
Although the Park Service describes the restoration as a comprehensive face lift, the $56,000 study presents a far more pessimistic view of the monument's condition. The study concludes that the marble on the exterior of the monument has suffered "extensive damage" and raises the possibility that some stone will be beyond saving. Overtures already have been made to the owners of the two historic and now dormant quarries in Baltimore County where most of the stone for the monument was cut, in the event some of the damaged marble has to be replaced.
The worst damage appears to be above the 452-foot level on the east and west sides of the monument, where two cracks run along the middle of several blocks of marble and through the stone itself. The monument's walls vary in thickness from 15 feet at the base to less than four inches where the cracks have appeared. The crack on the east side is 11 feet long and the one on the west side 20 feet long, with both visible from the interior of the monument.
Few Records Available
For reasons that are unclear, the existence of the cracks was not noted until the 1992 study, by which time the situation was serious enough that one fissure was responsible for most of the water that leaked into the monument and damaged the interior. The authors of the study note with some alarm that they were unable to find any documentation in the files of the National Park Service to pinpoint when the stone first cracked through, an important fact in assessing both the possible cause and treatment.
"These through-the-wall cracks apparently have developed since 1973," says the study, noting that a detailed engineering report of the interior conducted that year does not mention the cracks. "Beyond that, when they appeared and how fast they have grown is not known."
Keyes, who defended the Park Service's stewardship of the monument, said researchers were able to unearth only "incomplete reviews dating back to the 1950s." The regional office has had a resource management division for only 10 years, and that explains why information is so scant and scattered. Keyes said she is unaware of the existence of any document that chronicles the condition of the monument over time. "There is no comprehensive documentation of every crack," she said.
James Madison Cutts Inc., the engineering firm that studied the monument in 1992 as part of the Oehrlein analysis, reported that the cracks on the upper portion could have been caused by thermal forces, or the uneven heating of the surfaces by the sun. But in its summary, the Oehrlein study also raises the possibility that these cracks and others are "an indication of structural failure of the load-bearing masonry wall."
For these reasons, both Cutts and Oehrlein recommended close monitoring of the cracks. Electronic monitoring is widely used in Europe and has been implemented in at least one other Washington landmark, the Jefferson Memorial, where James Cutts supervised the installation of sensors to measure how the two components of the dome the exterior is marble and the interior is steel expand and contract.
The two principal authorities in the study, Mary Oehrlein and James Cutts, have been retained by the general contractor for the renovation, Grunley-Walsh Joint Venture. Requests to interview them were denied by the Park Service, which cited the need to centralize the release of all information on the project.
From an engineering perspective, any repair on the damaged upper portion of the monument will have to answer a central question, said Dryver Huston, associate professor of mechanical engineering at the University of Vermont: "Are the cracks stable, are they getting bigger or not?"
That question apparently cannot be answered in the time projected for the restoration. Huston, who chairs the Committee of Methods of Monitoring and Evaluating Structural Performances for the American Society of Civil Engineers, said data would have to be collected for a number of years because stone structures such as the monument "tend to build up large thermal effects," meaning that one year of data could be skewed depending on the severity of the weather.
One possible solution, Huston said, is installing the sensors, sealing the cracks and then monitoring changes for several years before contemplating a more permanent solution. Tall stone structures are more susceptible to wind pressure than to gravity or thermal forces, Huston said, and an analysis of the cracks would have to take these long-term forces into account. Cracks also can be caused by structural flaws, in which case the solution is strengthening the monument. "I don't want to sound alarmist," Huston said, "but these tall masonry towers do have a history of failing catastrophically."
Stone of Contention
The scaffolding superstructure now rising at the site will be covered with an artistic mesh. The effect will be dramatic, particularly at night, when hundreds of lights placed at every level of the scaffolding itself illuminate the obelisk. Aesthetics aside, the aluminum scaffolding is just a very elaborate platform from which workers will clean, repoint, repair and possibly replace stone.
These are sensitive tasks because the monument, and by extension even the smallest fragment of stone, is a historic landmark, one of the nation's most recognizable icons. The contract says "the gentlest means possible" should be used to perform repairs, and workers will be limited in the kinds of tools they can use and even when they can perform the work. The air temperature, for instance, must be between 40 degrees and 85 degrees when the work on the stone is performed, and it must remain so for a full 48 hours.
The contract is unusual because it is open-ended, what the federal government calls an "indefinite quantities contract." The total renovation is estimated at $9.4 million most of that coming through corporate donations but because no one knows how much stone has to be repaired, the sum is speculative.
Manuel Seara, the founder and president of Lorton Construction Co. Inc., the subcontractor that will do the actual stonework on the monument, has gone to one of the quarries that supplied most of the marble, now a well-known swimming spot, and already has identified some blocks that are a "very close" match to the stone on the monument.
The Park Service's position is that no stone will likely be replaced the focus of the project, after all, is restoration. But the last significant renovation, in the 1930s, required the replacement of several stones, including a 1,200-pound slab that had been severely damaged by lightning.
Replacing marble will produce potentially valuable marble fragments, but, surprisingly, the contract does not explicitly say what will happen to them. That has led to some confusion. Loren Raap, the project manager for Grunley-Walsh, initially said that any fragments will belong to the general contractor. Subcontractors were notified, in writing, that fragments belonged to Grunley-Walsh. "Of course, we intend to keep it. Salvage is ours," Raap said at one point.
Park Service officials, alarmed at the prospect of the monument's pieces being sold, looked into the matter. Keyes, the superintendent, said that the Park Service has the authority to determine what stone is removed and, by extension, what happens to it, even though the contract itself is silent on the matter. Depending on the size of the fragment, the old stone will be ground and used in patching and repairing or stored for future use. Fragments will not, Keyes assured, be marketed or claimed as trophies.
Such alarms have been sounded before. The last time the monument was covered with scaffolding, in 1934, a Republican from Richmond saw the landmark and reported to his colleagues: "Something will have to be done about that man Roosevelt. He has the Washington Monument all crated up and is going to ship it away."
© Copyright 1998 The Washington Post Company