Images from an HYM Investment Management filing with the Boston Planning & Development Agency show the complex structural conditions in the MBTA's Haymarket Station beneath the partially-demolished Government Center Garage. Image courtesy of BPDA/CBT Architects

MBTA shuttle buses are replacing Orange and Green Line service in portions of downtown Boston and Cambridge after the transit agency said the Bulfinch Crossing development has caused structural weakness to the underground tunnels.

Boston-based HYM Investment Group and National Real Estate Advisors are demolishing a portion of the Government Center garage to make way for a 410,000-square-foot life science building in the third phase of the redevelopment.

MBTA General Manager Steve Poftak blamed the developers for damaging support columns in the tunnels near Haymarket station.

“This service disruption as a result of HYM’s project is unacceptable and the MBTA will seek to hold HYM construction accountable for all costs associated with this event,” MBTA General Manager Steve Poftak said in a statement. “Riders’ safety is our top priority and unfortunately, as a result of this private party’s project, we must divert trains until the tunnels can be inspected and cleared by independent experts.”

But HYM and National Real Estate Advisors said the damage predated their work on the development, which broke ground in 2017.

“A subsurface column in proximity to the Green and Orange Lines was identified as compromised from years of water damage. The condition of this column is unrelated to the demolition work at the Government Center Garage,” developers said in a statement.

Shuttle buses are replacing Green Line service between Lechmere and Government Center, and Orange Line service between North Station and Back Bay.

HYM executives notified the Boston Planning & Development Agency last year that 3D scanning had identified complex subsurface conditions related to the location of the MBTA tunnels and Haymarket station. The tangle of utilities and tunnel structures created complex conditions for column penetration in the east parcel closest to the Rose Kennedy Greenway, according to a submission to the BPDA.

The east parcel was originally approved for three smaller buildings containing offices, retail, and hotel and residential space before the BPDA approved the lab switch in January.

Construction was halted and MBTA service also was disrupted in March after a partial collapse of the Government Center garage during demolition work killed an employee of a subcontractor working on the project.

Along with the life science building, the project also includes the 1 million-square-foot One Congress office tower, scheduled for completion in January, and the Sudbury luxury apartment and condominium tower. One Congress became fully leased in recent weeks.

Thursday’s announcement is the latest in a series of service interruptions and cutbacks by the MBTA in the wake of the Federal Transit Administration’s intervention into T operations because of safety issues. The MBTA was forced to cut back weekday service on the Red, Orange and Blue lines because of insufficient dispatcher staffing.

Photo courtesy of HYM Investment Group

Then the T pulled its fleet of new Orange and Red Line cars out of service this week after one Orange Line vehicle suffered a “battery failure” at the Wellington storage yard in Medford. The vehicles are manufactured by the Chinese firm CRRC in Springfield. The new trains previously were discovered to have improperly-installed braking units.

In the Seaport District, state transportation officials have been monitoring the potential effects of a proposed 1.1-million-square-foot development upon a Massachusetts Turnpike tunnel joint that has shown signs of distress in recent years.

Related Beal’s Channelside project sits over the Interstate 90 Fort Point tunnel’s “Superplug,” a tunnel joint that received $3 million in repairs in 2020 to address water infiltration.

The project was redesigned so that proposed buildings won’t place weight directly on the section of the A Street property located over the tunnel.

MBTA, Developer Trade Blame Over Tunnel Damage

by Steve Adams time to read: 2 min