Silver-haired and bespectacled, the classic image of a middle-aged professor, William H. Simons is considered by many as the man who built the Washington Teachers Union 17 years ago. He has led it ever since, through the years when the schools were run by whites, through segregation, the track system, short-lived busing and two teacher strikes.

Simons is again vying for the presidency of the 4,200-member union in an election to be held tomorrow. This time he is facing what many teachers consider is his most serious challenge yet from an energetic, if not bombastic Ballou High School teacher, James D. Ricks -- who twice before has lost to Simons by a 2-to-1 margin.

The election comes at a crucial time for Washington teachers. Contract negotiations are scheduled to begin in just a few weeks, and for the first time pay raises can be a part of the discussions.

Budget-pinched school officials have proposed laying off 800 teachers in addition to the 400 who were fired last year -- all because of budget reductions imposed on the school board by Mayor Marion Barry, whom the teachers union endorsed for election in 1978.

And many teachers are still feeling bitter over a 23-day strike in 1979 during which some teachers lost as much as $2,000 in salary.

Despite those problems, many observers interviewed expect Simons to be elected to another two-year term. The concern over the effect of the city's finances had drawn more attention to some longstanding teachers grievances with the union, observers say. But there is not enough dissatisfaction to overthrow Simons -- especially, some say, with Ricks as the only other candidate in the race.

"They might vote against Bill but not necessarily for Ricks," said one well-informed union building representative at one of the city's high schools.

Ricks has attracted many of the teachers disgruntled over the strike and the layoffs forced, they say, by the man Simons urged them to support in 1978.

Barbara Lipscomb, an English teacher at Spingarn High School, was laid off last summer only to be hired back by the system in September at a lower slary. With only four years' teaching experience, she is again in danger of getting a layoff slip.

"I went to the union several times for help. The union leadership itself was discouraged. The attitude I got from them was, there's really nothing we can do," Lipscomb said.

In his effort to capitalize on such sentiments, Ricks criticizes the $45,000 salary and some fringe benefits that Simons gets, but that teachers do not, like auto insurance.

Ricks also questions whether the union has indeed set up a strike fund. No strike is anticipated, but teachers have not forgotten that in 1979, money had to be borrowed to support strikers. Fifteen percent of each teachers regular dues is supposed to go to the fund. (Simons says a fund has been established.) And Ricks contends that despite the high salaries paid to union staff, there is a backlog of grievance cases.

In bitter, aggressive attacks, the Ricks team, based among the teachers in Anacostia, has accused Simons and his staff of having a "sweetheart relationship" with management, of mismanaging the $1 million in dues the union takes in each year and of setting up an "official family" to run the union instead of its rank-and-file members.

Simons has called Ricks' allegations "all absolutely without any foundation" and charged that Ricks, one of only four persons who has ever challenged him for president, is running a "negative campaign . . . He's not talked about anything but union finances."

Indeed Ricks, a husky man with a fuzzy full beard and bushy Afro who sports the latest in styles in marked contrast to the thin, lanky close-cropped Simons in his more conservative, often rumpled suits, has also talked a lot about the layoffs.

Ricks told a group of about 10 teachers who had gathered to hear his views one recent morning at Roosevelt High School -- a school known as Simons territory -- that if he had been union president, he would have tried to take the school board to court to block the layoffs, and gone to the National Labor Relations Board for help.

Simons argues that neither the courts nor the labor relations board would have been the place to argue the teachers' case.He said he took the case to the Merit System Protection Board after the federal court here refused to hear it and is waiting for its decision on whether the school system used "proper procedures" in firing the teachers last year.

Like many Simons supporters, Sarah Banks, a mathematics teacher at McKinely High School, believes the layoffs cannot be blamed on anything the union did or didn't do. "Bill Simons doesn't [control] the funds," Banks said.

The coming contract negotiations are antoehr issue Ricks frequently weaves into his talks with teachers. "You have no fringe benefits. You have a union that follows bad procedures. You are not getting anything. You are being run down a primrose hill," he told the meeting at Roosevelt.

Simons supporters say since this will be the first time the teachers will bargain for their salaries, the union now more than ever needs a man of experience like Simons, who is also a vice president of the American Federation of Teachers. The union president, whose slowed, studied delivery contrasts sharply with Ricks' rapid-fire style, agrees.

"Would that my adversary posses the command of the English language, af knowledge of labor law, an understanding of the parlimentary procedures, and a bit of integrity, a worthy adversary he would be," Simons said in a typical campaign statement.

Simons supporters, many of them longtime teachers who are quick to note they have "been with Bill" since the union began, point out this is the third time Ricks has challenged Simons. Ricks got fewer votes the second time around than in his first try.

"It's always the same group of people who try every election to unseat Bill. I guess they feel because of the RIF [reduction in force], this time they'll have more clout," said Jimmie D. Jackson, director of the Washington Teacher Center, who is running for general vice president and supporting Simons.