State Correctional Institution Phoenix, the $400 million concrete prison to house 4,000 Philadelphia-area offenders and 1,000 officers and staff, which has risen next door to the aging stone Graterford penal fortress since 2013, has a new completion date -- Sept. 29 2017 -- after blowing through 2015 and 2016 deadlines, state officials say.

"Activity has stepped up since mid-March," with more than 50 contractor, subcontractor and state officials returning to the site of what will be Pennsylvania's largest prison to prepare and finish inspections on 30 prison buildings, says Troy Thompson, spokesman for the state Department of General Services, which oversees construction projects.

That date is a month (corrected) after the one proposed last winter by Walsh Heery Joint Venture, the Pittsburgh-based partnership of Chicago and Atlanta contractors overseeing the work.

The state's construction representative, Hill International of Philadelphia, and Walsh Heery blamed each other for inspection delays that have held up the opening for the past 18 months, according to letters I obtained under the state right-to-know act last year.

Last winter, Walsh Heery offered to finish the job, but also demanded the state agree not to impose $35,000-a-day delay penalties, which the state state started levying in November 2015. That could cost the contractors $20 million, cutting profit margins and forcing the companies to find other funds if they are to pay subcontractors.

State officials initially insisted on their right to the penalties. Both sides seem to have agreed to put the question aside for now: These liquidated-damages payments "are still being evaluated," Thompson told me. (Update 2 pm)

As of last week, five of the 30 main buildings at Phoenix "are done," with 25 still pending approvals. (The complex will total more than 1 million square feet, larger than the old or new Comcast towers, Philadelphia's tallest buildings.)

State General Services and Corrections staff are now on site full-time. Employees of Philadelphia-based Urban Engineers Inc. are "ticking off" items to be reviewed and approved, though there is not yet a final "punch list" of last projects. The state Department of Labor and Industry is issuing certificates-of-occupancy as buildings are approved.

What of Hill, which was paid $21 million to represent the state? "Hill is not on site currently," Thompson told me. "Their return and role is being determined at this point." Hill has refused comment on the project.

The expense of the Phoenix prison, at a time when the state is closing other prisons after its prisoner population dropped below 50,000, has been justified by Corrections Secretary John Wetzel on grounds that it will be cheaper to run than Graterford. Plus it will include extra classrooms, a women's unit and a Death Row. (Pennsylvania continues to sentence offenders to death, but hasn't actually executed anyone since the 1990s, so it needs more places to put them.)

The state has followed a torturous legal path to get Phoenix built. Contracts were bid under Gov. Rendell to require a project-labor agreement, which typically puts labor unions and contractors under a single management regime to ensure the job gets done on time. The Pennsylvania Convention Center expansion, the only state job in Pennsylvania history that cost more than Phoenix, came in on schedule using a PLA.

But Corbett had the job re-bid, using a design-build model, in which architects, engineers and builders work together closely, and contractors can more easily choose union or non-union subcontractors. Neither the state nor its paid agents have up until now been able to get the resulting project finished on schedule.