At the University Senate, several faculty members expressed concern that the Purple Line would cause vibrations, interfering with research on campus.
This is an important concern. We raised it with the Maryland Transit Administration’s engineers, who said that it was a problem that could be solved through track engineering. Indeed, that’s why Light and Heavy Rail transit lines can travel through or near a number of campuses doing similar research as at the University of Maryland. At the University of Washington, the Seattle-area Sound Transit is installing shock absorbers under the rails in a Light Rail line that will travel through the campus.
In order to get some perspective on the issue, a friend wrote to Dr. Mark L. Schattenburg, the director of the Massachusetts Institute of Technology Space Nanotechnology Laboratory. The laboratory he directs is located roughly 800 feet from Boston’s Red Line subway (right). Here’s the answer he sent:
Vibration from vehicles certainly can effect sensitive instruments of many kinds, including electron microscopes. atomic force microscopes, nanolithography tools, etc. Specially designed buildings and instrument vibration isolation systems can reduce the effects of vibration, but this can add millions of dollars to the cost of a research facility.
At MIT the green line does go by my lab a block away, but truthfully the street traffic, elevator, electric generators, MIT steam plant (across the street), rooftop fans, etc., are much worse offenders.
We will continue to research the issue, however we have not heard the locations of existing laboratories and the tolerances required. As Dr. Schattenburg notes, vibrations can have many sources and the heavy on-campus traffic of trucks, buses, and automobiles no doubt already creates significant background vibrations. Replacing many of them with a well-engineered Light Rail may very well enhance the ability of scientists to conduct nano research on campus. The Purple Line is not going away, and the quicker campus leaders and MTA officials can begin substantive discussions about current and future vibration levels the better.