Progress > April 2007
Making room for something bigger and better…
The future location of Kroon Hall is undergoing a transformation from carbon emission to carbon neutrality. For over eighty years, Sage Hall, the hub of activity for F&ES, has been located right next to a fossil fuel consuming power plant. In a year and a half, Sage’s next-door neighbor will be one of the greenest buildings in the world. Currently, the view out the backdoor of Sage or through the windows of Bowers Auditorium is of little more than a big hole in the ground. But to the team from Turner Construction, that hole represents a year of work and is the blank slate upon which a new model of sustainability will be built.
The Pierson-Sage Power Plant, a squat, unwelcoming, brownstone structure just down Prospect Street from Sage Hall, was built in 1913. For decades the boiler plant burned heavy fuel oil to provide central heating for Science Hill. In 1964, an extension to the back of the building was added to house a chiller plant that began providing air conditioning to the nearby laboratories. By 1998, expansions of Yale’s Central Power Plant had rendered Pierson-Sage unnecessary. The chiller plant was promptly decommissioned, with all of the heavy equipment removed, while the boiler plant was upgraded to run on natural gas and kept in place as a back-up system.
The team from Turner Construction arrived on the scene in April of 2006, setting up an office in a trailer behind Sage Hall. Turner is the construction firm hired by F&ES to turn the vision of the design architects for Kroon Hall into a reality, and their first task was clearing the site of the Pierson-Sage power plant. While building demolition calls to mind images of explosion and collapse, the process in this case was much less dramatic and required precision and patience.
The first, and easiest, step was the decommissioning of the boiler plant. After the burners and other machinery had been removed, a vast network of pipes – which carried steam for heating, chilled water for air-conditioning, and electricity and telecommunication systems from Central Power Plant to Science Hill – still ran through the boiler and chiller plants. Before the building could come down, the pipes had to be painstakingly moved.
Chris Meyer, Construction Manager from Turner, described the process as being like a giant game of Jenga. The construction team had to move the infrastructure with minimal disruption to heating and electricity services, so parallel sections of new utility pipes were laid, and, when the time was right, the services briefly shut down and the systems transferred from old to new (a Jenga block carefully removed without bringing the whole structure crashing down). By the beginning of 2007, the utility infrastructure had been removed from the chiller plant, and consolidated in the basement level of the boiler plant. The chiller plant was cleared for demolition.
The demolition of the chiller plant, a sturdy, bunker-like building, took three weeks. The tools of the trade include a giant jackhammer mounted on an excavator that pounded holes in the walls, massive lobster claw shears that concentrated pressure to weaken the structure, and pulverizing metal teeth (picture a mechanical Tyrannosaurus rex) that crushed concrete into fine chunks. On April 5th, almost a year after the demolition prep work began, the last load of concrete debris was trucked off to Hamden where it will be recycled for use as roadbed.
The Kroon site continues to hum with activity. Excavators deep in the crater where the chiller plant once stood are clearing the overburden, which is the soil above the rock upon which the building foundation will be laid. A drilling rig is perforating the rock at the edge of the site with a line holes in preparation for the controlled, low-level blasting that will take place in May. And workers are salvaging the brownstone façade of the boiler plant, the original and only remaining section of the Pierson-Sage power plant.
The old boiler plant remains a hub for campus utility lines, but soon a cement cap will be poured over this infrastructure, the exterior of the old building removed, and Pierson-Sage reborn as a landscaped piazza leading from Prospect Street to Kroon Hall.
Photos by Peter Otis
Edward P. Bass
Susan & Coleman P. Burke
Michael F. O. Harris Family
Carl W. Knobloch, Jr.
Mary Jane & Richard E. Kroon
Evelyn and Bonnie Lee
Diana Calthorpe & Jonathan F. P. Rose
Joan O. L. Tweedy
William D. Waxter III
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The site, as seen from Kline Biology Tower.
"T-Rex" takes down the Fish House.
Removing brownstones from the power plant.