Alexandria's volunteer firemen, infuriated when the city threw cold water on their firefighting efforts 18 months ago, have filed suit in federal court, claiming that rules prohibiting them from assisting full-time firefighters are illegal.

The volunteers, in slow eclipse since the late 1940s when Alexandria began hiring professional firefighters, were stung last year by new city regulations that barred any volunteer who could not meet stringent physical and training requirements and threatened the arrest of those who failed to comply.

In a complaint prepared by the American Civil Liberties Union and filed in U.S. District Court in Alexandria, the volunteer group claims the rules violate constitutional guarantees of equal protection and due process. Professional firefighters hired before 1977 are exempted from the strict standards, the complaint alleges.

The feud intensified two months ago when, according to the complaint, city officials approved the destruction of trophies, plaques and other historical items belonging to the volunteers. The complaint alleges the items were discarded by paid firefighters who broke into lockers assigned to the volunteers.

City Manager Douglas Harman, a defendant in the complaint, declines to discuss the allegations. Fire Chief Charles H. Rule, also a defendant, did not return a telephone inquiry, but reportedly has labeled the allegations "malicious lies."

The dispute marks the passing of a long tradition in a city that normally dotes on its colonial heritage. The Alexandria Volunteer Fire Department Inc. traces its ancestry to a fire company organized with the help of George Washington, according to the complaint.

The volunteers have been bypassed, however, in more recent times, reflecting the "urbanization" of Alexandria, says Harman. "It's a question of liability not only for those people (volunteers) at a fire but what they may do at a fire. Inevitably, the responsibility lies with the city."

"They're good old boys," says council member Donald E. Casey, "holdovers from the old machine that used to operate out of the police and fire departments. It's Byrd machine stuff."

Three years ago the City Council passed Resolution No. 699, recognizing the volunteers as an integral part of Alexandria's firefighting services. The complaint alleges that although Chief Rule has sought to have the resolution abolished, it remains in effect.

The volunteers also contend that attempts to reach a compromise with city officials have been futile. Negotiations, they say, have been broken off by the city without explanation.

"There was a maxim I remember from law school: 'Equity runneth not in aid of a volunteer,' " says Casey. "If we lose this lawsuit, we'll abolish 'em."