- The Washington Times - Tuesday, December 19, 2000

New slotted manhole covers may be the solution for preventing manhole-cover explosions like those that caused concern about potential injuries or deaths last winter in Georgetown and the downtown area of Washington, D.C.

The slotted manhole covers stayed in place, but an old-fashioned solid cover "popped up" into the Foggy Bottom air amid George Washington University dormitories over the weekend.

The D.C. fire department was called at 5:48 p.m. Sunday when manhole fires were reported in the 2300 block of I Street NW, causing three dormitories to be evacuated. About 100 students were sent to three nearby hotels to spend the night.

Not all seven of the manholes on that block were on fire, and covers remained on all but one manhole around the corner at 22nd and G streets NW.

"That one popped," and there was some cement damage around the manhole, said Bob Dobkin, spokesman for Potomac Electric Power Co. "When you have solid manhole covers, they tend to lift up."

"It's possible," said Mr. Dobkin, that the I Street manhole covers might have popped off Sunday night if they had been the old-fashioned solid types.

Pepco began installing slotted covers in October after fire-explosions were blamed for blowing manhole covers into the air last winter in Georgetown and other sections of the District.

Tests on experimental covers in Massachusetts had indicated that slots in the metal covers allowed smoke, gasses and explosive pressures to escape. So Pepco ordered 3,000 of the covers, each with 218 slots, and began installing them.

Pepco has installed about 1,800 of the 24-inch-diameter covers in Georgetown, throughout the downtown business district and up to Capitol Hill, Mr. Dobkin said.

What happened Sunday was that a 2-foot section of a 13,000-volt cable "faulted." Ordinarily, a breaker would have opened, cutting off electric power going into the cable. But the breaker did not open.

The resulting heat and fire faulted two other 13,000-volt cables whose breakers opened, shutting off electric power. However, the fires had ignited and intense heat burned insulation and other materials. The fires pushed smoke into the dormitory basements and could have followed power lines into the dormitories.

Students were evacuated from Munson, Jacqueline Bouvier Kennedy Onassis and Madison dormitories. Most were sent to the Marvin Student Center, where they were served snacks and pizzas and directed to semiprivate rooms, where they could cram for final exams yesterday.

About 400 students are housed in the three dormitories, but many had completed their final exams and gone home for the holidays, said Bob Ludwig, assistant director for media relations at the university.

Three students were treated for smoke inhalation at the scene and one other person was treated for smoke inhalation at George Washington University Hospital, a fire department spokesman said.

Police cordoned off streets for one block around the dormitories and manholes. Pepco crews cut off the electric power and began repairs. About 50 firefighters and medics with 15 trucks and firefighting apparatus left the scene about five hours later at 11:26 p.m.

By then, Madison student residents were allowed to return. Other students were escorted as they retrieved overnight gear and study materials from Munson and Onassis to spend the night at the nearby State Plaza, George Washington Inn and DoubleTree hotels. Their dormitories reopened shortly before 8 a.m. yesterday.

The slotted covers are mostly installed on sidewalks and crosswalks. The solid covers remain in most roadways to prevent contaminants and road chemicals from eroding the electric cables.

Last winter, salt, sand and snow-melting chemicals often were blamed for eroding cable covers that caused electrical shorts. The resulting heat causes smoke, which sometimes was seen as a warning of impending fire and/or explosion.

There are about 57,000 manholes in the District. The oldest, where most problems occurred a year ago, are in Georgetown, the city's oldest section.

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