ONE BRIDGE I’D LIKE TO WALK
I’ve just read The Great Bridge by David McCullough, a historical account of the building of the Brooklyn Bridge, its construction begun in 1870 and completed in 1883. Designed by John Roebling, a wire and cable manufacturer who died before the work commenced, the chief engineer became his son, Washington Roebling, in whom the father had made known his full faith as successor. Washington managed to live to a ripe old age, but illness beset him badly in his 40s through around half of the construction, and considering what pressure he was under, both self-imposed and from without to build this monumental bridge, his physical ailments were no wonder.
The caissons alone might have made a nervous wreck of me. Caissons are like overturned, open-bottom, watertight boxes, sunken into water and pumped full of compressed air, mainly to provide the excavation workers in them the oxygen they’d require 40-80 feet below water surface, in this case of the East River. These were not “little boxes” of the sort sung about by Malvena Reynolds, regarding the cookie-cutter houses of the American subdivision. These boxes were gargantuan, big enough to accommodate four tennis courts and then some, with nine-foot ceilings for the workers. The roofs of the two boxes, the foundations for the bridge towers, were composed of 12x12-inch, resinous yellow pine timbers from Georgia and Florida, to a thickness of 15 feet. The caissons were slant-sided and given a cutting edge of iron on their bottoms. The one on the New York side was sheathed with iron.
Huge blocks of granite were set to these immense roofs of pine, as inch by inch the boxes dropped to their desired depth—to laboriously leveled bedrock on the Brooklyn side, to twice the depth on the New York side, but not quite to rock. Initial excavation of the river bottom of the latter was through sewer strata, and digging through that made a lot of workers inside the New York box wonder what the hell they had signed on to, because once exposed to oxygen, old odoriferous things consigned to the river became very much alive again. Once the caissons were fully sunken to the chief engineer’s satisfaction, they were pumped full of concrete.
The Brooklyn Bridge had to span about 1,600 feet of water without interference to busy East River boat traffic, hence only two main towers. The total length of the bridge, including anchor towers and approaches on land, is around 700 feet over a mile.
The main towers of granite stand 27 stories above the river’s high-water mark. In 1883 they dwarfed every other structure in New York. The cable-anchoring towers are nearly nine stories tall. The four wrapped cables from which “suspender” cables are hung to support the road and the pedestrian promenade are 15 inches thick. The roadway is 119 feet above the river at high tide.
An initial provider of wire for these main cables, one given the contract because he was the lowest bidder, no matter that his reputation was already in question, pulled a bait-and-switch game with his products that had been inspected and approved, with his wire that wasn’t so good. How anyone could be such a creep as to try to pass inferior wire off as inspected stuff for a suspension bridge that would carry millions of people a year is beyond me. The guy lost his cable contract eventually, but for the remainder of his life I’d wager he didn’t suffer nearly as much as he should have, if in fact he lost a wink of sleep at all.
A fire in the thick roof of one caisson became one of Washington Roebling’s headaches, and his efforts in trying to douse it seemed to herald the onset of his major maladies. It was said that a worker in the Brooklyn caisson had nailed a box of personal effects to an area where timber seams caulked with highly flammable oakum had not been covered with cementitious material. He was gazing into his storage box by the light of a candle, and the super-oxygenated caisson spread the resultant fire up between many layers of timbers that had to be replaced within a five-foot spread, after flooding the caisson didn’t do the extinguishing job.
I hereby raise my glass of scotch on ice to Mr. Washington Roebling.
Read McCullough’s book. It’s all I can do just to encapsulate the bugger.
I’ve just read The Great Bridge by David McCullough, a historical account of the building of the Brooklyn Bridge, its construction begun in 1870 and completed in 1883. Designed by John Roebling, a wire and cable manufacturer who died before the work commenced, the chief engineer became his son, Washington Roebling, in whom the father had made known his full faith as successor. Washington managed to live to a ripe old age, but illness beset him badly in his 40s through around half of the construction, and considering what pressure he was under, both self-imposed and from without to build this monumental bridge, his physical ailments were no wonder.
The caissons alone might have made a nervous wreck of me. Caissons are like overturned, open-bottom, watertight boxes, sunken into water and pumped full of compressed air, mainly to provide the excavation workers in them the oxygen they’d require 40-80 feet below water surface, in this case of the East River. These were not “little boxes” of the sort sung about by Malvena Reynolds, regarding the cookie-cutter houses of the American subdivision. These boxes were gargantuan, big enough to accommodate four tennis courts and then some, with nine-foot ceilings for the workers. The roofs of the two boxes, the foundations for the bridge towers, were composed of 12x12-inch, resinous yellow pine timbers from Georgia and Florida, to a thickness of 15 feet. The caissons were slant-sided and given a cutting edge of iron on their bottoms. The one on the New York side was sheathed with iron.
Huge blocks of granite were set to these immense roofs of pine, as inch by inch the boxes dropped to their desired depth—to laboriously leveled bedrock on the Brooklyn side, to twice the depth on the New York side, but not quite to rock. Initial excavation of the river bottom of the latter was through sewer strata, and digging through that made a lot of workers inside the New York box wonder what the hell they had signed on to, because once exposed to oxygen, old odoriferous things consigned to the river became very much alive again. Once the caissons were fully sunken to the chief engineer’s satisfaction, they were pumped full of concrete.
The Brooklyn Bridge had to span about 1,600 feet of water without interference to busy East River boat traffic, hence only two main towers. The total length of the bridge, including anchor towers and approaches on land, is around 700 feet over a mile.
The main towers of granite stand 27 stories above the river’s high-water mark. In 1883 they dwarfed every other structure in New York. The cable-anchoring towers are nearly nine stories tall. The four wrapped cables from which “suspender” cables are hung to support the road and the pedestrian promenade are 15 inches thick. The roadway is 119 feet above the river at high tide.
An initial provider of wire for these main cables, one given the contract because he was the lowest bidder, no matter that his reputation was already in question, pulled a bait-and-switch game with his products that had been inspected and approved, with his wire that wasn’t so good. How anyone could be such a creep as to try to pass inferior wire off as inspected stuff for a suspension bridge that would carry millions of people a year is beyond me. The guy lost his cable contract eventually, but for the remainder of his life I’d wager he didn’t suffer nearly as much as he should have, if in fact he lost a wink of sleep at all.
A fire in the thick roof of one caisson became one of Washington Roebling’s headaches, and his efforts in trying to douse it seemed to herald the onset of his major maladies. It was said that a worker in the Brooklyn caisson had nailed a box of personal effects to an area where timber seams caulked with highly flammable oakum had not been covered with cementitious material. He was gazing into his storage box by the light of a candle, and the super-oxygenated caisson spread the resultant fire up between many layers of timbers that had to be replaced within a five-foot spread, after flooding the caisson didn’t do the extinguishing job.
I hereby raise my glass of scotch on ice to Mr. Washington Roebling.
Read McCullough’s book. It’s all I can do just to encapsulate the bugger.