Damage to Old South Church examined

Congregation fears plaster will fall if organ played

Emma Francis (left), aided by Dave Megerle, checked a crack in a wall of Old South Church yesterday caused by an MBTA project. (David L. Ryan/Globe Staff)

An aerial engineer was hoisted up the wall of Old South Church in Copley Square yesterday in an effort to determine whether the loose plaster along a crack caused by MBTA excavation work is at risk of falling if the church's organ is played.

The United Church of Christ congregation, whose church is a National Historic Landmark, has been unable to use its organ since early December, when the foundation-to-roofline interior and exterior crack was caused by preparatory work done by a contractor for the Massachusetts Bay Transportation Authority. The contractor was hired to install an elevator for handicapped access to the Copley Square station.

The church has used other instruments, from a piano to a mandolin to drums, for music, but it is hoping to be able to use the organ for worship, weddings, and concerts. The problem is that the organ, with about 6,500 pipes, causes the building to shake, and there is a fear that the vibrations could dislodge loose plaster.

"We're in a specialty business here - we don't sell a product, our purpose is to worship, and a part of the way we do that is with beautiful music," said the Rev. Nancy S. Taylor, senior minister at the church. "This organ represents to us a particular and unique and precious instrumental treasure that also manages to fill that space, so the thought of being without it for what could be months or years is hard to imagine."

Yesterday, aerial engineer Emma Francis was lifted 70 feet into the air - held fast by ropes run through a window, to examine the crack. Francis found some plaster to be quite loose. Now church officials need to decide whether the loose parts can simply be removed or temporarily repaired or whether the organ will remain unusable.

At the same time, engineers are trying to determine exactly what caused the crack, digging test pits and doing mathematical calculations in an effort to understand what happened. But Taylor said it appears that an MBTA contractor hit the pilings that hold up the church with a high-pressure jet of grout slurry, causing the church's Dartmouth Street wall to shift.

"There's really no agreed understanding as to what happened," Taylor said. "But the MBTA is still taking responsibility and assuring us that the church should bear no cost at all in this."

Michael Paulson can be reached at mpaulson@globe.com./p>