UPDATE: "We didn't think we could come back to Philadelphia after 2005," said Jim Greenwood, the former U.S. Congressman (R-Bucks) and state representative, who is now president of the Biotechnology Industry Organization, which brought 17,000 BIO delegates to the center for its international conference that year. But BIO is back, with its 1,100-person Industrial Biotechnology event this year, and its much larger World Conference next year, "because the Center has grown," thanks to its 2011 state-funded expansion, Greenwood told me. "With the addition, we could do this."

How does he feel running the first show under the new labor rules, which allow exhibitors to do more of their own set-up? "It's been smooth so far," he said. "We're glad at least most of the unions have agreed" to the new rules. Behind him, in Hall A, exhibitors and members of the unions who approved the new work rules – the Electrical Workers, Laborers and Stagehands – were setting up booths. Security and Center employees declined to let non-exhibitors into the hall.

EARLIER: The Pennsylvania Convention Center opened for work at 7:45 a.m. Monday as IBEW Local 98 leader John Dougherty, Sam Staten Jr. and Ryan Boyer of Laborers Local 332, and Michael Barnes of the Stagehands joined about 30 members of their unions going into the halls to begin work on exhibits for the Bio 2014 industrial conference. (Center spokesman Pete Peterson said later that about 40 union workers were on the job today. He couldn't say whether that was less than would have worked under the old rules.)

They walked past picket lines of about 30 members of Teamsters Local 107, one of two unions displaced from the center starting this week because their leaders did not sign new work rules by last week's deadline. The pickets, along 11th St. from Arch to Vine, were outnumbered by city uniformed and plainclothes police officers. Other officers and supervisors stood on corners all the way west to the center's Broad St. entrance. Agents of the Wilmington-based Gettier private security agency checked credentials and turned non-employees away at center doors.

About five members of the other ousted union, Carpenters Local 107, picketed near the center's 12th and Arch St. entrance, handing out a lime-green flier that denounced "this heartless decision," and adding, "All we want is fairness, the return of our jobs and the right to work." The Teamsters' Sean Dougherty, coordinating pickets from 11th and Vine, referred questions to officers at Local 107's Southampton office. Carpenters referred queries to union chief Ed Coryell Sr. at the union's Spring Garden St. headquarters.

The unions that are working today agreed to a new set of work rules that give exhibitors expanded rights to set up their own booths without paying union wages of around $25-50 an hour plus benefits; allows management to set up a list of preferred Convention Center workers; and streamlines drug testing and grievance rules. The Carpenters and Teamsters complained the rules would reduce union work hours by as much as half.

The center claims the rules will enable union workers to more than make up lost hours by attracting many new shows. State taxpayers committed nearly $800 milllion to an expansion of the center, completed in 2011, which was supposed to house up to 30 major multi-day shows a year, but only one-quarter to one-half that number are scheduled for each of this and the next three years.

In his office upstairs, Center CEO John McNichol Jr. said work is on schedule to set up the Bio show, which is expected to draw 1,100 delegates including DuPont Co. chief executive Ellen Kullman and other industry figures over the next three days. Center general manager Lorenz Hassenstein moved quickly up stairs and down the long central hallway, coordinating staff by phone.

The Bio 2014 show will open later today, "and we're looking forward to it," Bio spokesman Paul Winter said at a City Hall press event introducing a Dodge fitted with a $200 manufacturers' kit that burns 85% ethanol. (According to this Reuters story, U.S. Rep. Bob Brady, D-Phila, a member of the Carpenters local now protesting the center, was instrumental in appealing to Vice President Joe Biden, on behalf of the Philadelphia-area oil refinery operators Monroe (Delta), Carlyle (Sunoco) and PBY (Delaware City and Paulsboro), in delaying EPA rules that would have boosted mandatory ethanol fuel use above today's levels.)

Asked if leaders of the Carpenters and Teamsters had miscalculated -- both offered to sign the new work rules belatedly, after the center's deadline and after the other unions had agreed to new terms -- McNichol declined to characterize their response.

Asked about Teamster claims they were ready to sign but officers were out of town last week, McNichol said, "Had we any indication from either union that they had any intent to sign before the deadline, that would have potentially changed the equation. But we didn't get that."

The Carpenters' Coryell has argued that the center wrongly abandoned negotiations on a contract extension and attempted to impose new work rules unfairly. McNichol and other center officers have said these are two separate documents and the unions understood the choices they were making.

"All the contractors are moving forward," McNichol added, speaking of the firms that set up and take down convention exhibits. "Like us, they don't have a choice. They do this for a living."

Exhibitor rules in Philadelphia have been controversial for years; why did the question come to a head now? McNichol said the old 10-year agreement's expiration this year set a "natural timeline" for new rules. He noted the board had first brought in SMG and streamlined the center's administration before asking for new work rules.  "We had several iterations of a deal on the table that I think labor would have viewed as more favorable, but they couldn't come to an agreement. After last week's (May 1 Carpenter's) strike, it forced the board's hand. We had to draw a line in the sand."

The board laid the groundwork by binging in SMG, McNichol added. "A private operations manager was a meaningful change," he said. "They have industry depth and breadth and knowledge of best practices." He said complaints from shows to the Philadelphia Conventions and Visitors Bureau dropped to near zero since SMG took over late last fall.