The earthquake-damaged Washington Monument has extensive cracking and chipped stones near its peak that left it highly vulnerable to rainfall, and inspectors found cracks and loose stones along the entire length of the 555-foot structure, according to a report released Thursday by the National Park Service.
The report was prepared by the engineering firm whose employees rappelled down the sides of the monument in September to inspect the damage. It offers the most detailed portrait yet of damage to the 127-year-old monument, which has been closed to visitors since a 5.8-magnitude earthquake shook the nation's capital on Aug. 23.
The report does not estimate how long repairs would take or how much they would cost. The federal spending bill approved last week allocates $7.5 million to fix the monument, with the understanding that the National Park Service will raise an equal amount through private donations.
The repairs recommended by the report include reinforcing the cracks with stainless steel plates and filling them with sealant; replacing as many loose pieces of marble as possible and shoring them up with steel anchors or mortar; and cleaning and re-sealing all joints in the top portion of the monument to keep water out.
The report also recommends a seismic study to gauge the monument's vulnerability to future earthquakes.
While the monument remains structurally sound, the cracks left it so exposed that after rainstorms, “a substantial amount of standing water collects on the floors of the display and observation levels,” the report found.
The inspection found six cracks that extend through the full thickness of the marble panels that form the exterior of the monument's pyramidion, the uppermost portion of the obelisk where it begins narrowing to a point. Cracks and chipped or loose stones, found all along the structure, were more concentrated at the 450-foot mark and above.
The largest piece of stone to become dislodged was in the interior of the monument and weighed more than 200 pounds.
The corners of the pyramidion, which are topped by metal lightning rods, sustained particularly complex damage, and the entire lightning protection apparatus will need to be removed so that portions can be replaced before it is reinstalled, the report says.
There is no timetable for repairing and reopening the monument. The park service plans to solicit bids for the work, and it's not clear whether the monument could reopen before repairs have concluded.
Construction began on the monument in 1848 and, after an interruption during the Civil War, it was completed in 1884. It remains the tallest structure in Washington and was the world's tallest manmade structure until it was eclipsed by the Eiffel Tower.