Glimmer Glass is the name of a small inlet in Central New Jersey spanned by a small, old, moveable drawbridge. The historic structure is one of two bridges owned, managed, and maintained by Monmouth County, N.J. The Monmouth County Engineering Department currently is involved in an internecine battle with the state’s Department of Environmental Protection (DEP) about what to do with the structure. The Engineering Department is mainly concerned with the safety aspects of the structure; the DEP and the state’s Historic Preservation Office want to maintain the bridge as close to its existing appearance as possible.
According to a New York Times article, "The state’s Historic Preservation Office wants to maintain the [traveled way of the bridge] at its current width of 20 feet, but such a width does not meet current safety standards, according to J. M. Ettore, the Monmouth County Engineer. Ettore said that the bridge … should be widened to at least 28 feet [curb to curb]."
Unfortunately, preservationists insist that the bridge should be preserved substantially in its present condition, rather than be reconstructed. Given the inherent dangers involved in continuing operation of the bridge in its present condition, I’m not so sure that preservationists are being as reasonable as they should be.
An important point, which preservationists seemingly have not considered sufficiently, is that the bridge, which was originally constructed 109 years ago (the main reason that "savers" want to save it) has undergone numerous modifications and structural repairs over the years. In my opinion, based on what I know about the structure, the span is not the same one that was originally built. The bridge that they are trying to save, even though it has been approved for landmark status by a state review board, is an entirely different structure.
Part of the background and long 109-year history of the bridge is that the Monmouth County powers-that-be in 1938 approved a plan to incorporate a steel [bascule] bridge of French design used at the time. In effect, the "historic" portion of the bridge does not date from 1898 or so (107 years) but from 1938 (69 years).
A French design, incorporated into New Jersey’s Glimmer Glass Bridge in 1938, uses rolling counterweights to lift the small drawbridge.
The French design, which was incorporated in the 1938 work, uses rolling counterweights at one end to cause the other end to pivot upward. Ettore told the New York Times that it is this "important and historic aspect of the bridge" which is most relevant and worth salvaging. In addition, in 1949 and 1950, "all of the original timbers were replaced when the bridge was deemed to be too low and was raised by 5 feet."
The bottom line is that the bridge as it exists today is not the same bridge that was built in 1898. So it is not really as historic as some preservationists would like engineers—who are primarily interested in safety issues—to believe.
The case for saving the bridge is now being considered by state authorities while the county wrestles with possible alternatives to rebuilding or removing the bridge. Until the analysis has been completed, reconstruction cannot go forward. One alternative is to move the entire structure, basically as is, to another location in New Jersey or anywhere else in the United States. Although hundreds of letters have been sent to institutions and municipalities, so far there have been no takers.
Nevertheless, it should be possible for the public to have its cake and eat it too. Much of what is historic about the bridge can, and should be, saved, but the safety concerns are more important. Perhaps the significant (historic) portions of the old structure can be saved and stored in a secure place—not on a public right-of-way.
The matter is scheduled for further discussion at a meeting later this year at which residents on both sides of the issue will be allowed to present their viewpoints. I’ll let you know if anything is finally decided and whether bridge reconstruction moves forward or is abandoned, or if bridge conditions cause a serious accident.
Alfred R. Pagan, P.E., P.L.S., is a consulting engineer in Hackensack, N.J. He can be reached at firstname.lastname@example.org.