For years the rivalry between the Montgomery County Police Force and the 23-member Rockville City Police Force amounted to little more than occasional barbed bantering between the officers as the Rockville force - in the shadow of the 770-member county force - attempted to prove that bigger is not necessarily better.

There was the time, for example, recalled county officer Wayne Farrell, when a city policeman tried to ticket him for parking in a restricted area where Farrell said he had stopped to talk with an informant.

The city officers, however, complain about the "my department is better than yours" attitude that they say the county officers often publicly display towards the city police.

"A lot of times," said city officer Mike Keyser, "the county and the city will respond to (the same) calls. So we'll arrive on the scene and the county will say, 'What are you doing here?' And the city officer will say, 'Well, what are you doing here?'"

Lately the customary rivalry has developed into an all-out feud between Chief Charles Wall of Rockville and Chief Robert J. diGrazia after diGrazia accused Rocksville police of deliberately hampering two of the county's crime investigations and generally making life difficult for county police.

The recent disagreements stir up the old controversy over whether the two departments can continue to successfully coexist. It is merely symptomatic, Wall says, of the larger issue: "the big agency wants us done away with."

It is also evidence that the "memorandum of agreement" the two forces signed last April in an effort to avoid running into each other needlessly at crime scenes, has not been working out as well as intended.

And so the two agencies once again find themselves locked in an effort to prove that each could do better if the other were not around.

The results are sometimes dangerous, sometimes comical.

"Once," recalled Farrell of the county department, "we were handling a hit-and-accident, and a sergeant was standing there talking to the girl who's car had been hit, trying to calm her down. All of a sudden a city officer pulls up and he walks over to the girl, puts his arm around her shoulder and walks away with her. My sergeant was just left standing there, like, 'duh.'"

In an angry letter to Wall, diGrazia complains, "when your department and our department are working on rapes in the same general area, there is little or no cooperation." He points out that when the city needed a rape investigation kit recently, it requested one from the state police, rather than the county. The state did not have a kit available and had to request one from the county anyway, diGrazia said.

He also complains that last month Rockville failed to notify the county about two armed robbery suspects who were fleeing a crime scene in a car. That move, diGrazia charged, "unneccessarily jeopardized" the safety of county officers who might have stopped the suspects' car without knowing the men inside were armed.

In a biting response, Wall noted that the county "seldom, if ever" alerts the city police "of ongoing crimes or situations which might endanger city officers."

He said the city police asked the state police for the rape investigation kit because they had been investigating a series of rapes in conjunction with the state police and because "frankly, (the state police) are easier to work with. . . And they don't demand the case be turned over to them."

Wall charged that county officers frequently fail to tell the city about information they have developed in joint investigations.

He said that the county recently released the composite drawing of a Rockville rape suspect to a county newspaper before releasing it to the city police.

At the heart of the conflict and the basic philosophical differences between the two chiefs.Wall supports the concept of a small police department, which, he says, can be closer to the community than a larger county force. A small department is more economical too, he says, since its costs, overhead and salaries are lower.

DiGrazia is on record in opposition to departments of less than 200 members, which he says "cannot possibly provide all of the services neccessary for the interests of the community." He charged that Rockville is currently merely duplicating services the county already provides.

"Since diGrazia has gone on record against small departments, it's an embarrassment for him to have one in his backyard," said a county officer critical of the chief.

"It's very difficult to seriously believe a person wants to cooperate with me when he wants to do away with me," Wall said.

But diGrazia insists he is not interested in adding more men to his department, which could result if the Rockville city department is disbanded. Rather, he says he is concerned about fragmentation of police services within the city.

Currently, Rockville is supposed to handle all calls that come into the city department's dispatching office. The county handles calls that come in on the 911 emergency line. The county usually handles major crimes such as murder, which require extensive follow-up investigation since the city often does not have the manpower to conduct lengthy investigations.

The rivalry between the city and the county is by no means unique, says Norman Darwick, acting director of the International Association of Chiefs of Police. It exists between the federal law enforcement agencies and state police forces; the state police and the county police, and even between the individual members of police departments, Warwick says.

Policing, he adds, "is a competitive business. There's a certain amount of credit and prestige in capturing the enemy, the bad guy. It's unfortunate that [rivalry] exists because each agency can do a lot to complement one another."