Barrage of Barricades Corral Crowds

It's a strategy of the stockyards applied to people, and called, appropriately, "the pens."

The New York Police Department applies this crowd-control tactic at demonstrations of any size at or near the United Nations and at the annual New Year's celebrations in Times Square, Capt. Stephen O'Brien, a supervisor at yesterday's huge peace rally, said.

Here's how it worked yesterday: At about 5 a.m., O'Brien said, police began setting up the interlocking metal barricades on First Avenue at 51st Street, thereby enclosing five of the broad avenue's seven traffic lanes as space for demonstrators to stand. The sidewalks were reserved for the use of police, area residents and members of the media.

The rally was officially to begin at noon, but demonstrators began to arrive at about 10 a.m. As people filled the blocks of First Avenue from 51st Street north, police progressively closed off side streets to the west, denying access to First Avenue. Thus, in a kind of fill-the-empty-glass phenomenon, those marching to the rally had to walk farther and farther north along Second or Third avenues before they were allowed to walk east to First Avenue.

Eventually, the rally stretched more than 20 blocks, past 72nd Street, before petering out.

The metal barricades did not extend past 72nd.

The other central component of the crowd-control strategy was the deployment of overwhelming numbers of police officers of every stripe imaginable: 5,000 officers on foot, on motorcycles, on horses and undercover, in riot gear and stationed on tops of buildings.

For example, about 150 officers were stationed along First Avenue between 52nd and 54th streets alone, Det. Kevin Burke said.

For keeping people confined, the metal barricades are far more effective than the blue wooden sawhorses sometimes used by police, Burke said, because they cannot be moved easily.