The leader of Poland's free trade unions joined ranking Communist and Roman Catholic spokesmen in calling for national reconciliation and unity tonight at an unprecedented outdoor rally paying tribute to shipyard workers killed by Communist government forces 10 years ago.

Addressing more than 500,000 Poles, who gathered here despite a chilly drizzle to attend the unveiling of a 140-foot monument to those killed, Lech Walesa, leader of the free trade union Solidarity, asserted that "we need internal peace."

"I call on Poles to take full responsibility for the fate of our country. I call on them to maintain peace and order, to show reason and common sense and watch over the country's security and sovereignty."

Walesa's words were echoed by Gdansk's Communist Party chief Tadeusz Fiszbach, who called for cooperation between the government and people. They were symbolically endorsed by Pope John Paul's successor as archbishop of Krakow, Cardinal Francisek Macharski, who conducted an outdoor mass at an altar beneath the monument of three towering crosses.

As gusting winds from the Baltic swept through the winter darkness over the Lenin shipyard, which was the center of the workers' uprising a decade ago and the birthplace of the free trade union movement last summer, the calls for national unity and reconciliation carried implicit allusions that any further labor turmoil could invite Soviet intervention in Poland.

There could scarcely have been a greater contrast between today's well-disciplined ceremony here and the pitched battles that raged along the Baltic Coast in December 1970. A decade ago, this city reverberated to the rumbling of tanks, the explosion of tear-gas grenades, the shootings of unarmed civilians and the burning of public buildings.

At precisely 5 p.m. today, sirens and church bells echoed throughout the city. Ships at anchor in the harbor sounded their horns. The Polish Army, which helped suppress the 1970 unrest, was represented by an honor guard of soldiers drawn up beneath the monument to the fallen shipyard workers. Order was kept by the shipyard workers themselves.

The fact that the ceremony passed peacefully came as a considerable relief to the Communist authorities and the Solidarity union. Both sides had feared that some provocation or incident might mar the occasion, which was being closely watched by Poland's Soviet Bloc allies.

The names of 28 workers killed during the 1970 riots were read by one of Poland's best-known actors, Daniel Olbrychski. After each name, the crowd chanted, "He remains among us."

Olbrychski also paid tribute to those "whose names we do not know." It has never been established exactly how many people were killed as a result of the riots, but the official figure is 45.

Telegrams of sympathy were read from the pope and the primate of Poland, Cardinal Stefan Wyszynski.

Loud cheers greeted the Solidarity and church leaders as their names were announced over loudspeakers to the crowds filling up the huge open space outside the shipyard. There was applause, too, for the local commander of the Polish Navy who is understood to have said he would not allow his forces to be used to break last August's strike.

The names of party officials were read out in silence.

Carefully stage-managed by Andrze Wajda, the film director, the floodlit ceremony was grave and dignified. There was little trace of the exuberant spontaneity that marked the strikes of last summer. This, however, reflects the extent to which Solidarity has become a national institution over the last four months.

Attending the ceremony were delegates from Solidarity branches all over Poland. They came in countless buses: Silesian miners in magnificent black uniforms with plumed hats, mountaineers from southern Poland in white breeches, women textile workers from western Poland.

Little groups gathered in the streets of Gdansk as the delegates exchanged Solidarity badges, copies of their union newspapers and memories of this year's strikes.

In 1970, there was considerable illfeeling among workers along the coast because they did not receive support from the industrialized south. This tirggered off street debates as miners sought to persuade the yellow-helmeted dockworkers that they were not to blame. As one remarked: "We hardly had any information about what was happening in the rest of the country in 1970. The authorities had a policy of divide and rule."

In an editorial today, the Gdansk newspaper Voice of the Coast marked the occasion by saying: "Here, on this tragic place where people were killed, the bullets have remained forever embedded in the minds of Poles. Nothing can push them out of the history of this town -- but neither should anything be done which will turn them into hatred."