The Judy and Arthur Zankel Hall

What more can you say about a project that required removing nearly 7,000 cu. yds. of rock from underneath a 110-year-old landmark structure, all without interrupting the daily operations of Carnegie Hall?

"What an unbelievable project!" said one jury panel member.

And another member said the panel's decision to grant the Judy and Arthur Zankel Hall an award was "a no brainer."

The project created a $72 million, 644-seat, 41,000-sq.-ft. flexible performance and education space on a 20,000-sq.-ft. footprint beneath Isaac Stern Auditorium. Carnegie Hall vice chairman Arthur Zankel and his wife, Judy, gave a leadership gift to the project.

From a technological standpoint, Zankel Hall is a 21st Century venue. It has three primary seating configurations - accomplished with the use of nine floor lifts and 12 chair wagons and 212 adjustable ceiling trusses for lighting and other theatrical equipment.

When Carnegie Hall opened in 1891, it had three auditoriums: the Main Hall (now Isaac Stern Auditorium) at the ground level, the intimate Chamber Music Hall (now Joan and Sanford I. Weill Recital Hall) several floors above West 57th Street and the lower-level recital hall (now Zankel Hall.)

The three auditoriums have gone through many physical changes over the years, but none more than the lower level.

Prior to its transformation into Zankel Hall, the space was rented by Cineplex Odeon to be used as a movie theater. When the cinema's lease expired in 1997, Carnegie Hall decided to reclaim the space for music, but decades of makeshift renovations had rendered the space irreversibly compromised.

Carnegie Hall's basic design criteria were to create an intermediate-sized performance venue with excellent acoustics, which was contemporary in style yet sensitive to the landmark building above. The space would double as an educational facility and accommodate the latest in contemporary communications technologies.

Functionally, the main floor of the auditorium consists of a series of lifts, constructed atop screw jacks, which move up and down. The theatrical seats on the main floor area affixed to chair wagons, constructed atop air casters, which move in and out of an adjacent storage "garage." The lifts and chair wagons in tandem enable the auditorium to be reconfigured, including three different-sized end stages - an end stage with orchestra pit, center stage and flat floor.

The ceiling of the auditorium consists of remotely controlled steel trusses that move up and down, allowing theatrical equipment to be readily repositioned to accommodate the different stage positions and to fulfill production requirements for a diversity of events.

Imbedded at the infrastructure level of the auditorium floor and ceiling are conduit and wiring to allow lighting, sound, video, communications and recording equipment to be placed virtually anywhere as needed.

Work on Zankel Hall began in spring 1999 with the removal of bedrock. Before excavation could proceed, the team relocated existing mechanical utilities from the structure, including miles of piping and wiring.

Construction materials for the job had to be transported to and from the site through a 10- by 20-ft. opening in the sidewalk. Workers installed a 20-ton hydraulic custom elevator to transport all construction equipment through the sidewalk opening, and bulldozers were taken apart to fit through the opening, and then reassembled below ground. All rock was removed in 4-cu.-yd. boxes using forklifts.

Workers installed a complex temporary shoring system made of steel supports. To support Isaac Stern Hall's seating area, workers drilled caissons 30 ft. below the excavation line and installed 12 temporary columns to support the structure above. Then loads were transferred to new structural elements. The team performed an extensive structural demolition to remove walls and concrete slabs from the existing space.

With the N and R subway line as close as 9 ft. to Zankel Hall, the team established a rock-monitoring program that consisted of numerous seismic monitors to detect vibration. The ceiling of Zankel Hall below Stern Auditorium is suspended on 6- by 9-ft. steel beams and supported on rubber pads to isolate sound and vibration.