John Roebling, the engineer who designed some of the most important US bridges of the middle third of the nineteenth century, is today somewhat overshadowed by his oldest son, Washington Roebling. After John’s death by accident during the earliest stages of the work on the Brooklyn Bridge, Washington became the chief engineer for that project. The success of the Brooklyn Bridge has, with time, overwhelmed in memory their earlier and equally important projects. Yesterday, I was at a Skyscraper Museum lecture by Richard Haw, a professor at John Jay College, on John Roebling’s life and work, based on his book Engineering America. The book is a long-overdue modern biography of Roebling and presents him not as the man who didn’t get to build the Brooklyn Bridge but as one with a long string of successful ventures. The lecture, and a few minutes of us talking, is available here: The Skyscraper Museum: Engineering America.
This topic is, of course, an excuse to indulge in some bridge voyeurism. The illustration above is a Currier & Ives print of the Niagara Falls Suspension Bridge. It was not the biggest or most technically-advanced bridge of Roebling’s career, but it had an incredibly dramatic setting, high over a cliff-faced gorge, downstream of Niagara Falls. The engraving above shows the pertinent structural details: since the towers were on the land on either side of the gorge, only the main span was suspended, leaving the back-spans of the cables straight. The towers for each cable were not linked, so that each cable was supported on an independent pylon at each end. The two decks were joined by side trusses, making the deck structure a big wooden (until 1886, when parts were replaced) box; the upper deck carried a single railroad track to avoid making trains go up or down a sharp grade; pedestrians and carriages used the lower deck. The engraving has a cute little train on top, above the people below, but the reality was possibly not that pleasant. Mark Twain, in the autobiographical story “Niagara” famously described the lower deck:
Then you drive over to Suspension Bridge, and divide your misery between the chances of smashing down two hundred feet into the river below, and the chances of having the railway train overhead smashing down on to you. Either possibility is discomforting taken by itself, but, mixed together, they amount in the aggregate to positive unhappiness.
On to the stereoscopic views! An overall photo from above:
A close up on the truss and cables, showing the falls off in the distance and the wind-bracing cables below the deck:
The upper deck, main cables, suspender cables, pylons, and railroad track:
And the lower deck: