This afternoon I took the walking tour across the Brooklyn Bridge, starting on the Manhattan side at South Street Seaport, mentioned in my earlier post. Ten of us, including Jack, our guide (in cap and sunglasses in the photo) gathered on a sultry day to make the long hike from the Seaport to Brooklyn. Along the way, Jack ably interspersed descriptions of the Bridge's physical features and engineering details (anchorages, expansion joints, cables, the caissons used to make the foundations for the towers) with stories about the people involved in its design and construction, especially the Roeblings: John Augustus, who designed it, but died before it was built; his son Washington, who oversaw its construction after his father's death; and Washington's wife, Emily, who effectively took over supervision after her husband became incapacitated from "caisson disease", the sometimes-fatal illness that struck many workers who spent long periods of time in the highly compressed air inside the caissons.
An interesting fact that Jack pointed out is that all of the Bridge's essential structural features: the towers, suspension cables, expansion joints and anchorages, are original nineteenth century fabric, with the exception of the smaller vertical (suspender) and diagonal (bracing) cables that descend from the heavy suspension cables, the former holding up the roadway and the latter stabilizing the Bridge from excessive lateral movement in high winds. In June 1981, one of the bracing cables snapped, and the loose end whipped onto the pedestrian walkway, killing a 33 year old Japanese tourist, photographer Akira Aimi. The ensuing investigation showed that the suspender and bracing cables' connections to the deck holding the roadway and pedestrian walkway had been weakened by corrosion caused by pigeon droppings. These cables were all replaced, and the new ones given an aluminum alloy and epoxy coating resistant to bird poop and other caustic substances.
