Jack Tuohey was on his back installing a dishwasher in hs Rockville home when the telephone rang. It was Sunday, Nov. 4. The U.S. Embassy in Tehran had just been taken over. Would he please come to work immediately?

Since then, the days have been a blur of 16-hour shifts, ringing phones, unanswered messages, clacking ticker tape machines, and the constant, controlled chaos of the Iran Working Group's crowded office.

"My kids want to know how come we don't send in the Marines," said Tuohey, a State Department spokesman. "I tell them we're doing the best we can." He sighs.

Tuohey is one of several dozen State Department officers assembled to cope with the Iranian crisis, which entered its 16th day yesterday. The officials work round-the-clock in three rooms down a long, quiet corridor near the office of the secretary of state.

It could be the headquarters of an insurance firm or a real estate office except for all the clocks on the wall. Times are shown for Washington, Tehran, Greenwich, Paris, Seoul and El Salvador (left over from an earlier crisis).

It is 12:10 a.m. in Tehran, 3:40 p.m. in Washington. Three women and six men, some in shirt-sleeves and all with dark circles under their eyes, sit at a large table piled with paper and coffee mugs. Everyone is on the phone. Maps of Iran and Tehran and a black board with names and numbers on it decorate the wall. The voices are low and peope rush in and out with telegrams and other messages.

In the background, a soap opera is on the television. "We keep it on to get the latest news," explained Jack Harrod, another press officer. "Just this afternoon, we had almost no information on which hostages were getting out, and then, suddenly, there they were holding a press conference on TV."

At the end of the table, Reed Clark, a consular officer, quietly tells a caller, "Thank you for your opinion." Later, he says nonchalantly, "It was a psychic, telling us she had a feeling that [Ayatollah Ruhollah] khomeini needs a lot of support."

Earlier, Clark took a call from a woman whose daughter was to have been in Iran on Nov. 4. The mother has not heard from her and is worried. Clark tells her that there is no evidence of danger to Americans outside the embassy and not to worry.

Other officers in the room deal with American businessmen concerned about their Iranian operations, with members of Congress wanting the latest news, and with citizens offering solutions to the crisis. The officers also analyze foreign radio broadcasts and keep an open telephone line to Tehran.

The officers rotate on three shifts and usually manage to get home each day, although on occasion they sleep on small cots in a back room.

Across the hall, in another conference room, Louisa Kennedy, whose husband, Moorhead, is a hostage in Tehran, is telling relatives and friends of other hostages: "Don't worry -- all will be well."

Kennedy was roused at 7:30 a.m. on the day of the takeover. By 9 she was at the State Department organizing a group of Foreign Service wives to help.

"Our first job is to give some kind of psychic support to the families," she said. "We make them feel that the concern is deeply felt on the part of the State Department."

Kenndy, who lived 12 years in the Middle East, added, "I don't understand this lunacy. But I know something about Moslems and I don't believe they slaughter innocent people. My husband and I talked about this possibility, not only this time, but when he was in Beirut. He knows I have not fallen apart and I know he hasn't either."

The atmosphere around the working group is "optimistic," she said.

Rita Ode, whose husband, Robert, is also a hostage, added, "We're too busy not to be."

A third, smaller room, with only one desk in it, is where the top policymakers meet: Harold Saunders, assistant secretary of state; Peter Constable, deputy assistant secretary; Henry Precht, director of the office of Iranian affairs. They are too busy to talk.

"We don't want any glory," Precht said.

"Then you just want to be a faceless bureaucrat?" he is asked. While charging quickly out of range, he answers: "Just a faceless mass of confusion."

The Iran Working Group is next door to the Kampuchea Working Group, assembled to cope with the Cambodian famine. Both are temporary offshoots of the State Department's Operations Center, a large room with telex machines, news tickers, maps, 120-button phone banks and a fierce-looking guard at the door.

While te center's number of "immediate precedence" telegrams has jumped in the last week from about 250 per shift to 500, Ann Evans, a 25-year-old operations assistant, is unfazed. "We take it in stride," she said.

Musing over the past two years on the night shift, she says: "A hijacking can really get us frantic. We have to find out whether Americans are on board and what kind of terrorists they are . . . I remember Guyana . . . And then, of course, the coup in Bolivia. But the most incredible night was last February when our ambassador in Afghanistan was killed, our embassy in Tehran was taken over, something was happening in Chad, and the Chinese and the Vietnamese were fighting. . . .

"Of course there are some nights you bring your knitting and you just doze off. There's no telling what will happen around here."