Rock blasting will briefly halt traffic around Cornell University's Engineering Quad beginning as early as Wednesday, Oct. 24. Contractors on the site, which is being excavated for an advanced engineering research building, will be using the explosives to remove rock over a period of about two weeks.

"Security is always a concern with explosives but never more so than in light of recent tragic events," says Robert P. Stundtner, Cornell project manager for the Duffield Hall building project. "We want to get the word out about the blasting as early and as widely as possible to eliminate any possibility of anxiety."

The short-duration blasts will take place twice daily during weekday morning and afternoon classes, in order to minimize the number of pedestrians moving around the quad periphery. No blasting will be scheduled for Friday afternoons, in order to complete the blasting process and secure the site for the weekend. It is expected that traffic will be halted for no more than about 5 to 10 minutes for each blast.

Three long whistles will announce the start of the blast sequence and the halting of all pedestrian and vehicular traffic in the area adjacent to the site, which is enclosed by a wooden fence. About a minute later, two long whistles will announce the imminent blast. Following the blasting, one whistle will announce the all clear, meaning that traffic will be allowed to continue in the area.

The strongest blast is expected to create a noise level of approximately 130 decibels (dB), about the intensity of a jackhammer or power drill. The blasting will be carried out under strict vibration protocols and no adverse impacts are anticipated in surrounding buildings.

The contractors, a joint venture of McCarthy Contractors and Welliver McGuire, and their excavators, Paolangeli Contractors, have been removing soil and rock since preparation of the site for the $62.5 million building project began in early June. Now that the bedrock has

been exposed, blasting has been chosen for the final rock removal because it offers the least impact on teaching and research programs in nearby Phillips Hall and delicate instrumentation and precision research in Knight Lab, the home of the Cornell Nanofabrication Facility.

Blasting techniques will be used to remove about 3,000 cubic yards of bedrock. Alternative methods of rock removal (drilling, jack hammering, ram hoes and ripping with large excavators) were considered too disruptive to the buildings around the Engineering Quad because they require high noise and vibration levels and would extend over a longer period of time. However, these excavation methods are being used to a limited extent in preparation for the blasting.

The contractors have reviewed their plans with the Cornell project team, including representatives from Cornell University Police and Environmental Health and Safety.

Dynamite, which is stored in a secure facility off campus, will be brought to the site daily by truck and kept under lock until loaded in a blast hole. According to the contractors, a series of 3-inch-diameter holes will be drilled and charged with dynamite for each blast. Two-ton blasting mats will be placed on top of the rock before blasting to prevent rock from fragmenting into projectiles.

This is not the first time there has been rock blasting on the central campus. In the early 1990s, Paolangeli Contractors used explosives to dig deep into the bedrock for Carl A. Kroch Library, a state-of-the-art, three-story underground building, which opened in August of 1992. The Kroch Library houses the Division of Rare and Manuscript Collections.

Duffield Hall, which is scheduled for completion in 2004, will be a nanotechnology research facility and the new home of Knight Lab. In addition to the $58.5 million building, which will be the most technologically sophisticated on campus, the Engineering Quad is receiving a $4 million facelift.

Community members with concerns about the impact of the blasts should contact the project team at (607) 255-8951 or send e-mail to duffield@cornell.edu . For daily updates on the blasting, subscribe to Duffield-L, the e-mail list for news and information regarding the Duffield Hall project. To subscribe to the list, send the following message to listproc@cornell.edu : SUBSCRIBE DUFFIELD-L FIRSTNAME LASTNAME, substituting your name for "firstname lastname."