photo of the Verrazano Bridge Jordan Weinstein
The Verrazzano Bridge at sunrise, as photographed by Jordan Weinstein, structural engineer and former student of Brian Brenner's.

Brian Brenner writes about bridges.

Specifically, his series is called More Water Under the Bridge.

Every month, the bridge engineer and professor spins a yarn for us from his Massachusetts home.

His essays are entertaining, funny, quirky, and sometimes even odd.

But, you know what, they’re also incredibly educational.

Let’s look back at the year of More Water Under the Bridge and the 5 things we learned from Brian Brenner in 2023:

The proper way to spell ‘schistosity’

This was a surprise addition to the vocab list this year.

“The new Nice Bridge is supported on piles that likely extend down to rock. I am not sure, but if it is metamorphic rock, it could be gneiss. Gneiss is thought to have poorly developed schistosity. I have included that fact as part of our discussion because I am intrigued by the word schistosity.

“Occasionally, the top of rock layers is poorly weathered. In terms of bridge support for the Nice Bridge, that would not be nice gneiss. In all likelihood, if poorly weathered rock of any type was encountered during construction, appropriate procedures were applied. Ultimately, the bridge would be supported by nice gneiss (assuming there was gneiss).” – Brian Brenner, A ‘Nice’ bridge

The proper way to pronounce ‘quetzal’

To be fair, we still might not know the exact way to say “quetzal,” given that More Water Under the Bridge is delivered in a decidedly written medium. But Mr. Brenner did his best to help.

“I asked ChatGPT, ‘Can a Quetzal design a bridge?’

“It responded:

“‘No, a Quetzal, which is a bird, cannot design a bridge as it does not possess the necessary knowledge or skills required to do so. Bridge design requires a combination of engineering knowledge, mathematics, physics, and material science, among other technical fields.” – Brian Brenner, “Can you pronounce ‘Quetzal’?”

Despite what you may think, suspension bridges aren’t just for cities

Rural suspension bridges provide a degree of surprise you don’t find in urban settings.

“There are other suspension bridges in rural areas that provide a different visual impression. They seem separate from their surrounding landscapes. These bridges can be sighted at remote locations, and they are often startling to see. At these crossings, I am always surprised and delighted. The experience is of a suspension bridge, which is always excellent. But the bridges look out of place. There is no big city attached, only farmland, woods, or desert.” – Brian Brenner, “Suspension bridges in the wilderness”

French bridges are masculine; German bridges are feminine

Syntax matters. Maybe?

“For English speakers, French and other Romance languages have what appears to be a peculiar quirk. Inanimate nouns are designated as masculine or feminine. In French, a bridge is referred to by the designation ‘le,’ a masculine article. ‘La’ refers to feminine objects. Therefore, bridges in France are considered to have a masculine gender, like ‘le Pont d’Avignon.’

“However, in neighboring Germany, bridges receive a feminine designation in the German language. There is no discernable structural difference between bridges in France and Germany, at least related to gender issues. But does it make a difference in bridge perception if the structure is the subject of a masculine or feminine designation?” – Brian Brenner, “Sur le Pont d’Avignon”

The lack of design standards for squirrel pedestrian bridges is a real gap in the industry

Perhaps a new ASCE standards subcommittee is in order.

“If an average squirrel weighs about 2 pounds, then only one axle of an AASHTO LRFD Design Truck would account for approximately 16,000 squirrels. A full Design Truck would be the equivalent of about 82,000 squirrels. That is a lot of squirrels. Therefore, it would be over-conservative to use AASHTO vehicular loading. Furthermore, we can assume that squirrel bridges in Longview Washington, while being in the ‘pedestrian’ design category, do not need to account for emergency vehicles like ambulances or firetrucks. While many pedestrian bridges are designed for emergency vehicular use, the vehicles are not operated in treetops.” – Brian Brenner, “Nutty narrows”


Brian Brenner, P.E., F.ASCE, is a professor of the practice at Tufts University and a principal engineer with Tighe & Bond in Westwood, Massachusetts. His collections of essays, Don’t Throw This Away!, Bridginess, and Too Much Information, were published by ASCE Press and are available in the ASCE Library.

You can browse his complete archive of More Water Under the Bridge articles.