In the summer of 1882, in McKean County, Pennsylvania, Octave Chanute stood at the rim of the Kinzua Creek valley, looking down 301 feet to the creek bed below, and ran the calculations that made the New York, Lake Erie and Western Railway trust him with its most audacious work. The valley was half a mile wide at the top, narrowing as it descended. Its walls were soft, forested Pennsylvanian shale and sandstone, the kind that crumbles under a footstep. At the bottom, the creek was so distant that not a sound reached the rim.
Chanute was chief engineer of the Erie Railroad. He had 94 days left on his contract. He had 120 men assembled from the ironworks of western Pennsylvania and Ohio. And he had a design that no one had ever attempted at such a height in the history of American construction.
When it was finished, his bridge would stand 301 feet above the creek, making it the highest railroad bridge in the world. Chanute was 42 years old. He had been building railroads since he was 21. He had surveyed lines in Missouri, Kansas, Wyoming, and across the dense river country of the Ohio Valley.
He had never built anything 301 feet high. What he was about to attempt would mark the first time anyone had. The Erie Railroad needed to push its Bradford branch through this valley on its way to the oil fields of northwestern Pennsylvania. And the only way across was to go over it.
The Kinzua valley was not dramatic by western standards. It had no vertical granite walls like the Sierra Nevada, no dry badlands like the Wyoming high plains. It was a forested Pennsylvania hollow, the sort of terrain that from a distance looks like just a gap between two wooded summits. But from the rim, the floor lay 300 feet below, and the valley was wide enough that the cheap earth-fill solution the railroad used for small crossings would have cost more than a bridge ever could.
The amount of fill needed to level the valley was prohibitive. So the railroad turned to the Phoenixville Bridge Company, by 1882 the most experienced manufacturer of heavy railroad bridges in North America. For two decades the Phoenixville works in Chester County, Pennsylvania, had been fabricating iron bridge components. They had built the Phoenix column, a patented structural form that would be the load-bearing unit of the Kinzua crossing.
Understanding the Phoenix column is the key to understanding how Kinzua was possible at all. A Phoenix column is a hollow cast-iron cylinder built by bolting curved iron segments, called staves, together. A standard Phoenix column consists of eight staves, eight curved iron sections, each roughly a quarter circle in cross section, fastened along their edges to form a complete hollow tube. A hollow tube, properly assembled, is structurally superior to a solid iron rod of the same weight, because the hollow shape resists buckling under compression.
A solid rod loaded from the top tends to bow outward at the middle under stress. A hollow tube of the same weight under the same load distributes the stress around its circumference. Wrinkling a hollow tube requires far more force than bending a rod. Samuel Reeves of the Phoenix Iron Company had patented the Phoenix column in 1862, specifically for railroad bridge trestles.
By 1882 it had become the standard component of heavy American bridge work. The Kinzua bridge used 20 towers of Phoenix columns, spaced at intervals of approximately 100 feet across the valley. Each tower was an assembly of Phoenix columns, bolted together with braces, rising from a concrete base to a cap at the top that carried the bridge deck. The towers varied in height depending on the depth of the valley at each point along the crossing.
The tallest, at the deepest point, measured 301 feet from base to rail. The shortest, near the rim, rose only 52 feet. The deck spans ran between the towers, horizontal iron beams stretching from the top of one tower to the next, carrying ties and rails. Each span was about 100 feet long, 20 spans in all, for a total length of 2,530 feet from end to end.
When complete, the bridge would contain roughly 3 million pounds of iron. Chanute had been born in Paris in 1832, the son of a French history professor who moved the family to New York when Chanute was six. He grew up in American railroading, starting as a surveyor’s helper on the Hudson River Railroad at seventeen, working his way up through locating, grading, and bridge engineering until, in his mid-thirties, he was one of the most prominent civil engineers in the country. By 1873 he was chief engineer of the Erie Railroad, a position he held until 1883.
The year after Kinzua, he left railroad work and spent the 1890s turning to a problem that interested him more than bridge design. Today he is best remembered for his work on the aerodynamics of gliders, work that directly influenced the Wright brothers. His 1894 book, Progress in Flying Machines, sat on Wilbur Wright’s desk in Dayton, Ohio. But in 1882, Chanute was still a railroad man, and Kinzua was his.
The man in charge of the day-to-day work was Thomas Kane, the construction superintendent. Kane was a veteran ironworker, the kind of man who had come up through the trades rather than through engineering school. He was the field supervisor, running the crews, solving the problems that Chanute’s drawings never predicted. We know less about Kane than about Chanute.
What survives are the construction schedules and correspondence with the Phoenixville mills. From those documents, you can trace what Kane accomplished in those 94 days. The pace of construction was astonishing. Phoenixville began shipping fabricated iron components by rail to the site in May 1882.
Site work, excavation, and the pouring of concrete bases had been going on since early spring, so that by the time the first iron arrived on the valley rim, the foundations were ready. Erection began at the bottom. A crew worked in the creek bed on the lower sections of each tower, fitting the staves of the Phoenix columns together around anchor bolts, plumbing the columns with a transit from the rim, and tightening the connecting bolts with long-handled wrenches. A second crew worked from the rim, handling rigging, lifting masts, pulleys, hemp ropes, and later in the season, wire cables that lowered the iron from flatcars on the approach track down to the men on the growing towers below.
The erection of a Phoenix column tower demanded precise choreography. The bottom segment of each tower was raised first. Then the next segment was lowered from above and bolted to it. Then the next.
A tower 301 feet high had to be assembled piece by piece. Each segment was lifted into place, plumbed, and bolted before the next went on. The work required ironworkers who could work at great heights, on narrow unprotected iron platforms, skilled with the heavy wrenches used to tighten the coupling bolts. These men were called bridge men.
In 1882, they earned between $2. 50 and $3. 50 a day, depending on their craft and skill. A laborer handling materials in the creek bed earned $1.
50 a day. A man who worked at altitude, risking his life, with a high level of skill, was paid more. You could replace a man with a shovel. You could not replace a man who could fit iron at 200 feet.
The crew of roughly 120 men broke down this way: perhaps 30 to 40 skilled ironworkers who did the raising and bolting; perhaps 40 to 50 laborers who handled materials, operated lifting gear, and did concrete and excavation work at tower bases; and the remaining 20 to 30, teamsters, blacksmiths, tool men, and camp support. The construction camp sat near the southern rim of the valley, with cookstoves, horse lines, and a blacksmith shop for resharpening drill bits and replacing broken rigging. The work moved tower by tower across the valley. Each tower crew worked while the hoisting crew brought the next load of iron from the railhead above.
The deck spans could not be set until the towers on both sides of each span were complete and plumbed. So the work accelerated in the final stages. Early in the job, towers rose in sequence. By late summer, several towers were under way at once, with the hoisting crews moving back and forth along the rim, feeding iron to several towers at the same time.
The first deck span was rolled into place in mid-August. It was moved on temporary iron rollers from its position on the approach embankment onto the caps of the completed towers at either end, then seated and bolted. The crew on top of the towers guided it into place with hand lines. The crew below watched the plumb of the column to make sure the deck load was centered on the tower cap.
If the load was off-center, the tower would lean out of plumb as successive spans loaded the full deck. There was no room for error. What Chanute added to the Kinzua towers, and what set them apart from earlier American iron bridge construction, was the lateral wind bracing designed into every column group from the start. Each tower was not a single Phoenix column but a group of four to six columns, tied together with horizontal gusset plates and diagonal bracing.
This bracing resisted lateral loads, the sideways push of the wind through the valley. At 301 feet, that wind load was not trivial. The valley funneled the prevailing northwesterly winds, coming off Lake Erie sixty miles to the north, into a gap where late autumn and winter storms crossed. Chanute calculated the wind load using the then-standard American figure for wind pressure on railroad bridges: 30 pounds per square foot on the exposed surface of the structure.
He designed his bracing to that number. He was right. The wind bracing worked. The Kinzua bridge never failed under wind load in 121 years of service.
Not in the blizzard of 1888. Not in any of the Lake Erie storms that hit that corner of Pennsylvania in the decades between 1882 and 2003. The design held. The bridge was completed on September 25, 1882.
The first train crossed on October 2, 1882. From the laying of foundations to the passage of the first train, the job took 94 working days. In October 1882, the American press called the Kinzua bridge the Eighth Wonder of the World. The New York Times ran a description.
Scientific American published an illustrated article with an engraving of the completed bridge and a technical account of the Phoenix column construction. The engraving shows the bridge from the creek bed, 20 iron towers rising out of the Pennsylvania forest, connected by the thin horizontal lines of the deck spans, a locomotive barely visible at the top. At 301 feet, the Kinzua bridge was, by documented measurement, the highest railroad bridge in the world in 1882. It surpassed the Garabit bridge in France, which was not completed until 1884.
It outdid any existing bridge in Britain or Germany for roughly two years. The highest railroad bridge on earth was in McKean County, Pennsylvania, built in 94 days by ironworkers earning $3 a day. There were deaths during the construction of Kinzua. The nature of the work, ironworkers at 200 and 300 feet with no safety nets, no harnesses, no form of fall protection, made fatal accidents a possibility on any given day.
The construction records held by the McKean County Historical Society and the Erie Railroad operating files at the Hagley Museum and Library in Wilmington, Delaware, contain no complete list of worker deaths. What the records show is tonnage and freight rates and bolt specifications, not names. What the Bradford Era, the local paper of record for McKean County in 1882, records is that at least two men died during the building of Kinzua. In its July issue, the paper reported the death of a man identified only by his surname, Callahan, who fell from the top of a tower under construction.
The paper gave no first name, no age, no place of residence. It noted that he was brought up from the valley on a litter and that his body was taken to Bradford on a work train. It gave his place of burial. The second recorded death that summer was an accident during rigging near the valley rim, where a broken cable struck a man identified in the report only as a German immigrant with the surname Muller.
Nothing else was recorded. There were almost certainly other deaths. The Bradford Era did not cover every accident at the site. The Erie Railroad’s construction office filed no death report to any outside agency.
The accounting records logged quantities of iron and shipping costs, not the names of the fallen. The men who built these structures died on them, and most often the company did not record their names. When you stand today in Kinzua Bridge State Park and look at what remains of the original towers, you are looking at a monument to men whose names are not on it. The Kinzua bridge was rebuilt in 1900.
The original Phoenix column iron structure, for all its strength, was not designed for the heavier locomotive loads that reached the Erie Railroad in the 1890s. A locomotive that weighed 60 tons in 1882 had been replaced by engines of 100 tons or more by 1898. The deck spans Chanute designed for the axle loads of 1882 were inadequate for the new equipment. The choice was either to restrict the bridge to the older, lighter engines or to rebuild it.
The Erie rebuilt it. The 1900 reconstruction used the same 20 tower sites, the same 2,530-foot length, the same basic structural approach, but replaced wrought iron with steel. The new towers used riveted steel columns in place of the bolted Phoenix column groups. The deck spans were heavier, and so was the wind bracing.
The new bridge of 1900 stood on the same foundations as the original of 1882 and looked nearly identical from the creek bed. It was built to carry the full loads of early twentieth-century freight locomotives. The steel, rebuilt Kinzua bridge stood from 1900 to 2003. On July 21, 2003, a tornado struck McKean County, Pennsylvania, passing directly over the Kinzua Creek valley.
Wind speeds at ground level reached about 100 miles per hour. Pennsylvania was in the middle of restoring the bridge at the time. It had been closed to rail service since 1959, when the Erie Railroad abandoned the Bradford branch. Pennsylvania had purchased the bridge in 1963 and maintained it as a pedestrian tourist attraction for forty years.
In 2003, a restoration project had removed four towers for structural work when the tornado hit. Eleven of the 20 towers collapsed. The tornado struck the remaining towers at their bases, exploiting the weakest point of any tall, slender structure. The towers were designed to resist the lateral wind load pressing against their entire height, but they were not designed to resist a tornado whose wind speed was highest at the lower levels and nearly absent at the top.
Each tower snapped, and five of them fell intact, coming to rest on the valley floor as a single unit, preserving their full height. The riveted steel beams held, the rivets still tight, the towers lying on their sides like felled trees. Pennsylvania left those five fallen towers exactly where they landed. They are still there today, at the bottom of the Kinzua Creek valley.
You can walk down to them on a prepared path. The steel from 1900 is still there, bolted and riveted, holding together after 123 years. The other collapsed towers were removed. The nine towers that survived the tornado were stabilized and left standing, though not at their original height, their upper sections removed by the restoration work.
A glass-floor observation deck, installed after the tornado, lets you walk over the valley and look through the glass to the creek 225 feet below. On a clear day, you can see two of the fallen towers lying in the forest on the valley floor. Octave Chanute lived until 1910, dying in Chicago at the age of 78. He outlived the iron version of his most famous bridge, watched it be replaced with steel, and spent his last twenty years corresponding with the Wright brothers about the aerodynamics of flight.
He never built another railroad bridge after Kinzua. The Wright brothers attended his funeral. Callahan, the worker who fell from the tower in July 1882, has no known headstone in McKean County. Muller, the German immigrant killed by the broken cable, has no known headstone.
Their work is displayed in a Pennsylvania state park. This is what remains. Picture a working day in the Kinzua Creek valley in the summer of 1882. Sunrise at 5:30.
The cook lighting the fire in the camp on the south rim. Horse teams pulling flatcars loaded with Phoenix column sections from the rail siding toward the edge. The rigging crew setting up the lifting mast over the next tower site. Ironworkers coming down the valley path in the early morning light, carrying their tools: wrenches the length of a man’s forearm, drift pins to align bolt holes, plumb lines 300 feet long.
The tower in the creek bed is 150 feet high. Today’s work is the next section. It is lowered from the rim by cable, guided into place by men on the top platform, plumbed against a line of sight from the south rim, and bolted. Four bolts per flange connection.
Twenty connections per section. Eighty bolts set by hand in a single day’s work, each one tightened with a wrench from a platform with 150 feet of Pennsylvania air below it. By noon the section is plumbed. By two the bolting is done.
By four the diagonal bracing is in. By six the crew is back on the valley path, climbing toward the rim and the cookstove. Tomorrow, the next section. Ninety-four days of that.
Three months. One valley. Three million pounds of iron. The highest railroad bridge in the world.
The Pecos River High Bridge, built by the Phoenix Bridge Company in the Texas desert in 1892, 321 feet high and 2,180 feet long, completed in 87 days, used some of the same techniques: prefabricated components, the Phoenix column system, a tight schedule. But Pecos was built with heavier machinery, a larger crew, and ten years of lessons learned from Kinzua. Kinzua was the first bridge built without those lessons, in 94 days in a wooded Pennsylvania hollow, by men whose names the company mostly never recorded. The iron structure Chanute designed in 1882 lasted 18 years.
The steel structure that replaced it in 1900 lasted 103. The five towers the tornado toppled in 2003 still lie in the valley, holding together, every rivet tight, 123 years after they were built by ironworkers earning $3 a day. That endurance was not luck. It was the result of men who knew their craft, who did it well under conditions that would shut down any modern construction site before lunch, and who got their measurements right on the first try, because 300 feet above the floor of a Pennsylvania creek, there was no second chance.
Next time you cross a high bridge and feel no movement beneath you, remember that the men who crossed those valleys first felt the movement every time. The wind came off Lake Erie. The tower swayed.
Then they picked up the next wrench and set the next bolt.
