To clarify a recent flurry of misinformation about two local suspension bridges, Waldo-Hancock and Deer Isle-Sedgwick: Both bridges are in the good hands of the Maine Department of Transportation and are safe to cross. Neither one has had anything to do with the ill-fated 1940 Tacoma Narrows Bridge in the state of Washington, known as “Galloping Gertie.” Both Maine bridges have been checked regularly and were designed by a world-renowned engineer, David Steinman, whose only connection with the Tacoma Narrows Bridge was to offer advice to its designer, Leon S. Moisseiff, on bridge oscillations. Mr. Moisseiff is said to have responded with a polite, No thank you. The Narrows bridge undulated wildly and collapsed four months after it was built.

The Waldo-Hancock Bridge has been closed to loads of 24,000 pounds and over, which rules out heavy trucks and some big recreational vehicles, because an inspection showed deterioration of the main cables. The pedestrian walkway is being removed and additional cables are to be installed to increase the safety factor until a new bridge is built within two or three years. In the meantime, new acoustical sensors are recording any further snapping of any of the hundreds of tiny wires that compose the main suspension cables. None has been detected.

The Deer Isle-Sedgwick Bridge, across Eggemoggin Reach, caused brief worries in 1978 when high winds and a heat wave caused severe undulations. After a brief closure and a temporary 40,000-pound load limitation, inspections by the DOT and Gastogne Arango of the Steinman engineering firm determined that the bridge was safe and sound. Mr. Arango said: “It moves like a spring. The structure is slender, thin and flexible. But there is no cause for concern.” He did advise against driving over the bridge whenever it was undulating. He said the long waves would not toss a car around, but the movement might cause a driver to panic and lose control of the car. Drivers may find 10-minute delays when the DOT is conducting load tests.

A specialist in engineering failures, who happens to be vacationing near Bath, expressed confidence in the DOT’s handling of both bridges. He is Henry Petroski, a civil engineering professor at Duke University and author of the 1985 book “To Engineer Is Human: The Role of Failure in Successful Design.” He said in a telephone interview that he had followed developments in the Waldo-Hancock Bridge but was not directly familiar with the Deer Isle-Sedgwick Bridge. He said: “I have a high level of confidence in the DOT engineers. If they had any doubts about the bridges’ safety, they would close them.” He added that he personally would not hesitate to drive across either bridge.

So the best advice is don’t panic, don’t listen to rumors and drive carefully – on a suspension bridge and anywhere else. As for the many rumors circulating, they’re just so much water under the bridge.