Park Service tries to hold together crumbling fort

FORT WASHINGTON, Md. -- Long before fighter jet overflights, chemical sensors and extra police patrols, homeland security for the nation's capital relied on a brick-walled fort on the Potomac River.

Perched on a commanding bluff about 10 miles below Washington, Fort Washington and its thick walls, fortified with cannons, stood ready to take on any enemy ship that might try to sail upriver. Built in 1824, Fort Washington guarded the capital through World War I before being decommissioned in the 1940s.

Now a national park, the aging fort is fighting a new battle that poses a threat graver than enemy guns. Nearly two centuries of rain and poor drainage, neglect and misguided repairs have left Fort Washington's walls precariously fragile. A section near the gate collapsed in 1999, lime from dissolving mortar has formed mini-stalactites on ceilings, and vegetation -- including a tree -- has taken root in cracks.

"Birds would alight on the wall and bricks would fall," said Bill Clark, who oversees the fort for the National Park Service. "The wind would blow and bricks would fall."

To keep the crumbling site from becoming unusable, the park service has undertaken a six-year renovation that will overhaul Fort Washington by 2006. Clark, with the help of Maryland's congressional delegation, secured about half of the estimated $10 million cost.

The collapsed wall is nearly repaired and workers are removing a portion of wall next to the front gate, brick by brick, and rebuilding it with new mortar. Work will intensify this fall when $4.8 million in federal money arrives, Clark said.

The need for a strong southern defense of the young American capital became painfully clear during the War of 1812, when British ships sailed up the Potomac. Fort Warburton, a smaller post near what is now Fort Washington, was abandoned and destroyed, allowing the British to continue upriver and seize Alexandria, Va., in 1814.

Fort Washington was completed in 1824, part of a system of seacoast batteries built after the war. The stone installation was based on a plan drafted by Pierre L'Enfant, the designer of the District of Columbia.

The walls were strengthened in the 1840s, according to Clark, when engineers who included then-Lt. Robert E. Lee of the U.S. Army added thick layers of red brick that made the walls 60 feet high in some points. During the Civil War, it was the primary coastal fortification protecting Washington.

Advances in naval guns and ships eventually made the fort obsolete, but new, concrete gun emplacements were built outside the fort's walls during World War I. The fort's last military use was during World War II as an officer school for the Adjutant General's Corps.

It was handed over to the Department of the Interior in 1946.

Park officials say about 260,000 people visited the serene site last year, mostly tourists and Washingtonians "getting tired of the downtown hustle and bustle," said Ranger Don Steiner.

What they see is a structure in decay. Repairs were done over the years, Clark said, but were mostly patchwork, with materials that ended up doing more harm than good.

Chief among those was Portland cement, a common, durable mortar used for most repairs on the fort in the 20th century. While Portland cement is strong, it proved to be the wrong material for the fort's walls, Clark said.

Lime-based mortar, a flexible material that allowed the structure to absorb and release water with little damage, was used during the 19th century. The newer Portland cement trapped water that seeped into the walls, causing deep cracks.

The lime and Portland cement also reacted to each other, essentially dissolving the mortar and weakening the walls, according to Ananth Badrinath, a lead project manager for the reconstruction.

Desbuild consulted with castle historians in Switzerland and studied historical building plans to figure out how to repair the building. The only solution is to replace most of the Portland cement with lime mortar, Badrinath said. That requires workers to remove scores of bricks and replace them after the cement is scraped away.

"It is a very slow and tedious process," he said.

Clark expects that process will pay off. The restoration will make the fort look much as it did when it first opened nearly 180 years ago.

"It'll be like walking back into time, back to 1824," he said.

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On the Net:

Fort Washington Park: http://www.nps.gov/fowa