Josiah White’s Gravity Railway
In the early decades of the nineteenth century, Josiah White pioneered a striking number of technological fields. He made major advances in iron and steel manufacture, he built the earliest example of an important type of bridge, he taught Americans how to burn a new kind of coal, and he invented the country’s first railroad of any importance. Like most inventors, White is little remembered today. Few biographical directories contain his name, and even histories of technology tend to ignore him. Moreover, when White’s name does come up, it is usually in connection with an accidental invention that he would no doubt have considered frivolous: the roller coaster.
The story begins in Philadelphia in 1796, with a fifteen-year-old hardwarestore clerk so young he needed his mother’s signature to buy the stock of a bankrupt competitor. Eight years later White had parlayed a simple hardware store into enough wealth to retire for life. But genius rests poorly, and retirement did not suit him.
By 1810 White was tinkering with canal navigation on the Schuylkill River, and he had patented an important method of mechanically drawing and cutting iron nails and fencing wire. Within two years he and his partner, Erskine Hazard, had built the Fairmount Nail and Wire Works to massproduce these commodities. In 1816 they would erect the world’s first wirerope suspension bridge on the Schuylkill, just outside Philadelphia.
The new factory struggled. The War of 1812, which cut off trade with Europe, greatly expanded the domestic market for manufactures, but it also eliminated imports of bituminous coal. Some deposits of the stuff had been found in America, but most of it was in remote areas. With no railways and only very crude roads, coal had been cheaper to bring in from across the ocean. Now, with his furnace guttering, White cast about for alternatives.
He experimented with anthracite, the “black rock” that a few entrepreneurs had dug out of mountains along eastern Pennsylvania’s Lehigh River. It was said to be combustible, but no one had yet figured out how to light it up. Indeed, one frustrated experimenter concluded, “If the world should take fire, the Lehigh Coal Mine would be the safest retreat, the last place to burn.” Further, any efforts to sell the new type of coal would be doomed by the difficulties of getting it to market.
White did not give up easily. After some years of experimentation he found not only that anthracite could indeed be burned, but that if the proper equipment and techniques were used (such as grinding the coal into small pieces and using a special type of grate), it was far superior to any other known fuel. It burned with a very intense flame and was nearly smokeless, making it ideal for home heating. Realizing the potential, White and Hazard secured leases on 20,000 acres of mountainous Pennsylvania wilderness.
In 1818 the land was wild and rugged, inhabited only by Indians, trappers, and a handful of pioneering farmers. There were no roads, navigable waterways, or towns. The Lehigh River, a rough, tumbling, rocky stream with a precipitous drop, might possibly be improved, allowing transit to its junction with the Delaware at Easton. But there remained the problem of getting the coal down from the mountains to the Lehigh’s shore. And even if they could succeed in bringing the coal to Philadelphia, White and Hazard faced a difficult task in persuading consumers to give it a try.
THE FIRST SCHEME EOR EX ploiting the mine did not involve rails. Summit Hill, nine miles west of the Lehigh, had a rough, abandoned wagon road left behind from a previous mining venture that had ended in failure. (White and Hazard bought the only two loads of coal it had managed to deliver to Philadelphia.) White proposed to restore the road, bring the coal down in wagons, and float it downstream. To this end he designed and built a fleet of coal barges with iron hinges in the middle that allowed the front and back sections to pivot over rocky areas. He also plated the hulls with sheets of iron for protection.
The next step was to tame the worst of the rapids. The partners worked side by side with a company of three hundred men in water that was often up to their chests. They cleared the river’s center channel of rocks and other obstructions and built stone walls to concentrate the current in the middle, providing a minimum depth of eighteen inches. Plans called for stockpiling loaded arks during the winter, then awaiting spring floods to flush them downstream. To accommodate the scheme, the company built a river landing that they called Mauch Chunk, an Indian phrase meaning “Bear Mountain.” (In 1954 the town that grew up around it was renamed Jim Thorpe, in honor of the great Indian athlete of that name who is buried there.)
Next they rebuilt the road down Summit Hill. With the company running so low on money that White had to borrow a set of surveyor’s tools, the route was regraded so that every foot of its nine-mile run sloped downhill.
As it turned out, the river would not be so tractable. Wagons and mules moved the coal downhill to Mauch Chunk, and in the winter of 1818-19 the fleet of arks was prepared and loaded in an artificial pool behind a rock dam. If all went according to plan, when the annual spring floods arrived, arks, coal, and men could be released to ride downriver on a crest of high water. But the spring floods never came, not in 1819 and not in 1820. By the latter year the arks sat grounded on the dry riverbed, stranded by the drought.
White concluded that the only way the Lehigh would prove dependable was if he could control and manipulate an artificial supply of water. In the winter of 1819-20 he had designed and patented a combination dam and canal lock. By the summer of 1820 twelve of the new locks were built along the thirty-seven-mile stretch between Mauch Chunk and the Delaware. They came to be called “bear traps,” as workmen and curious bystanders remarked that the novel contraptions looked and worked like giant versions of their namesake.
THE LOCKS CREATED LARGE pools just above each shallow stretch of river. When a train of coal-laden arks arrived, a man in the front boat would trip a valve, unleashing a mini-flood that propelled everything in the pool over the bad stretch to the next bear trap. On reaching the Delaware, the arks were turned over to a river navigation crew, and their tenders walked back upstream, closing each lock along the way to prepare for the next day’s flotilla. Since there was no ascending navigation on the Lehigh, each ark made only one trip downstream. When it reached Philadelphia, its metal parts were removed for reuse, and the wooden planks sold as lumber.
The cumbersome bear-trap system was a great success. In later years more traditional canals, capable of handling much greater traffic, would come into use along the Lehigh, but White had surmounted the early challenge of transporting heavy tonnage from a lonely wilderness outpost to the urban market.
The company made its commercial breakthrough in 1824, as White’s techniques for igniting and burning anthracite were finally recognized, while the uninterrupted supply of product at a stable price eased concerns over the wisdom of converting to the new fuel. Pennsylvania’s anthracite production, which had been a mere 450 tons in 1820, rose to 43,000 tons in 1825.
Suddenly the Summit Hill mine couldn’t ship enough coal. The bottleneck was the wagon-and-mule leg. As early as 1818, when White first surveyed the road, he had envisioned a scheme to harness gravity more effectively. At a time when America had no railroads, he described a system consisting of a train of wagons whose wheels would ride down the mountain on twin rails, to be built when there was enough business to justify the expense of construction. In 1826, with coal flying off the dock as fast as it could be shipped, White started work on the nation’s first successful railroad of significant size.
He designed a simple system of parallel ironclad wooden rails, laid down the center of the road from the mine to the foot of the river. The gauge was three feet six inches. Since the road was all downhill, loaded coal cars made the nine-mile journey solely under the power of gravity. The trip took about half an hour. Once unloaded, trains of empty cars could be pulled back up the track by a team of mules. The new railroad made its first trip in May 1827, working exactly as its designer had envisioned, with fourteen-car trains carrying about 3,000 pounds of coal per car—and eight mules.
Each team rode to the bottom with the cars it would pull back up, in what White called the nation’s first regularly scheduled passenger service. To calm the animals and reduce motion sickness, they were fed hay on the down leg. White later boasted that this enterprise should earn him recognition as the inventor of the dining car.
The railroad attracted sightseeing visitors from the start. An 1829 traveler wrote of his journey to the “Mung Chung coal mountain”: “After seeing all the strange operations, and much ingenuity in machinery, &c., we join the cars to make our descent on the rail. We began our descending career in several divisions, fourteen cars to each coal division; I chose my lot with the mule division—twelve of these were in cars, three mules abreast, munching their hay, while we went off ten miles an hour, and sometimes, for change sake, at twenty miles—could go at sixty miles, and more.” After describing a sawmill where four men built a coal-carrying ark in half an hour, the writer continued: “Every thing in this region shows invention , so much so, that it looks like enchantment, and Josiah White himself is the great wizard!”
White kept up his wizardry in the years that followed. He improved the transshipment system by designing and patenting the first automatic tilters, which allowed coal to be loaded directly from railroad cars into boats floating beneath an elevated dock. In 1838 he built a new system of locks that permitted two-way travel on the Lehigh, and he later served as a consultant on the Delaware Canal.
Nor did White neglect the marketing side of the operation. In 1840, after more than a decade of experimentation, he began smelting iron ore with his hard coal, using the British hotblast method. This was America’s first successful use (on a commercial scale) of anthracite rather than charcoal in iron manufacture and the first major expansion of its market beyond domestic heating. (Anthracite, in turn, would eventually give way to coke.) Once again demand skyrocketed. Many new mines opened in the Lehigh Valley, and anthracite production continued its dizzying climb, from 215,000 tons in 1830 to 967,000 in 1840 and 4.138 million in 1850.
By now the mule-drawn uphill trek of empty cars had become another bottleneck. Around 1840 White started planning a new “back track” for his railroad, with two steam-powered inclines hoisting empties up the ascending stretches of the new track. Along with virtually level sections, the route (which opened in 1844) included the two most precipitous runs possible, the very steep faces of nearby Mount Pisgah and Mount Jefferson. On each incline two tracks were laid side by side so that while one side of the system ascended the plane, the other would be descending to await the next batch of empties.
At the summit of each mountain sat a large steam engine whose main shaft drove a drum twenty-eight feet in diameter. As it rotated, the drum wound on one side and unwound on the other a giant flat iron band forged in Sweden to White’s design. The band was like a ribbon, consisting of individual twofoot-long steel bars, each seven inches wide, riveted together at the ends so they could flex as they wrapped around the drum. Each of these had to be slightly more than twice the length of its incline, far exceeding the capability of the wire cable of the day and beyond the tolerance and tensile strength of chain.
When a train of six to fourteen empty cars arrived at the base of the plane, workmen attached its bottom to a “barney car,” which was permanently connected to the iron band. The conductor pulled on a rope, sounding a signal in the enginehouse at the summit, and the engineer put the system in gear, winding the band from the top. The band, which trailed under the carriages on rollers, pulled the barney, pushing the train up the incline. Meanwhile the second barney was heading down on the neighboring track.
A small reverse-winding cable on the backs of the two barney cars maintained tension in the main band. This was anchored to a giant pulley at the base of the tracks that wound one side as it unwound the other (like its cousin at the top of the incline), providing for continuous but variable back pressure. This small cable kept the main band pulled tight, preventing it from flopping around or getting tangled in other parts of the system.
Realizing the need for emergency stopping power in case the band broke, White invented a simple ratcheting brake that is still commonly used. A serrated third rail ran alongside the incline track, and an arm hanging freely from the backs of the cars rode easily from tooth to tooth when pulling forward. But if the arm suddenly pushed backward—as would happen with a broken band—it would catch in the foward-angled teeth and stop the train. Fortunately the band was so reliable that the mechanical emergency brake was never once tested in actual use.
On the downhill run cars went fifteen miles per hour, the braking controlled by a simple friction lever, operated by winding a rope to apply tension to the lever around a windlass, much like on a sailboat. White also experimented with a hydraulic water brake, which he patented but did not adopt. Such brakes are also still in use, slowing or stopping passenger cars in modern gravity-based amusementpark rides.
THE ENTIRE SYSTEM WAS SO ingenious, so practical, and so simple that the Mauch Chunk and Summit Hill Gravity Railroad exceeded everyone’s expectations, making Josiah White a wealthy man once again. As additional mines were hooked into the system, White used a rolling gravity-operated switchback system to ease cars slowly up and down from the new mines onto the main line. The term Switch Back was added to the name of the line shortly before White’s death in 1850.
While America’s heavy industry thrived, nurtured by White’s gravity railroad, the basis for a whole new venture had been laid on the rails of Mount Pisgah. In 1870 the Switch Back’s freight operation went out of business, after major railroads had started moving into the area. But as it turned out, the railroad was just entering its busiest period. It had achieved such a reputation that crowds of curious visitors regularly came to Mauch Chunk to watch it. A group of local businessmen bought the railroad, opened a hotel for tourists, and offered passenger service for those who sought the thrill of a freewheeling ride down the mountain. In its inaugural year of 1873 the line, which was open only in warm weather, carried 35,000 passengers at a nickel apiece. Besides the ride itself, visitors enjoyed the Pocono Mountains scenery, a look into the workings of an open anthracite quarry, and “The Amazing Burning Mine,” which had been on fire since 1832.
So many people came to visit the gravity line that new depots had to be built to handle the business. Even Thomas Edison showed up, and when asked by reporters if he had any suggestions, he replied that he wouldn’t change a thing. The Switch Back became the nation’s first exclusively passenger excursion railroad. By the turn of the century it was said to be North America’s second most visited tourist attraction, behind only Niagara Falls. Of the ascent to Summit Hill, a tourist wrote: “Up, up we go, until the mountain tops, which just now towered above us, sink into the valleys and become pigmy hills, and the whole face of the surrounding country, in an immense circuit, opens under us like one vast flower bed. Novel emotions crowd upon the mind as the enchanting and exciting scene unfolds itself with new and almost appalling grandeur, as the summit is approached, and the soul is transported with awe as the great works of the Creator stand out in their imposing contrast to our littleness as we hang suspended, as it were, in mid air!”
The ride down proved equally thrilling to another visitor: “Faster, and faster, down through long stretches of shaded roadway, around wondrous curves, along giddy cliffs, under shadows of great ivy grown crags, and still down, down, down, at a dizzy speed, and as if borne on the wings of the wind; there like a toy village in the distance, before and far below us, we once more descry Mauch Chunk, with its familiar church spire, so indelibly impressed upon all who have visited the town!” The Switch Back drew crowds for more than half a century before slowing down with the onset of the Great Depression. Operations ceased in 1933, and the line was cut up and sold for scrap in 1937.
Meanwhile the idea of a gravity railroad had been taken out of its mountainous context and reinvented as an amusement-park ride. Most of the credit goes to LaMarcus Adna Thompson, who in 1884, after riding the Switch Back, returned to Coney Island, in Brooklyn, New York, and built a much smaller model with twin 45-foot towers and a 450-foot run in between. Thompson’s design was similar to one that had been patented by Richard Knudsen of Brooklyn in 1878. To cash in on the real railroad’s popularity, he named it the Gravity Pleasure Switch Back Railway. The ride was such a hit that Thompson often sold more than 12,000 tickets per day at five cents each. He recouped his initial investment in just three weeks and went on to design and build more than forty similar rides, which eventually became known as roller coasters, around the world. In the spirit of Josiah White, he introduced many innovations along the way, from safety devices to scary tunnels, and of course almost immediately abandoned the actual switchback configuration.
Josiah White’s Switch Back railroad was thus America’s first roller coaster. In much the same way, his bear trap lock served as a model and inspiration for recreational water rides all over the world. In a fashion he never could have expected, this seriousminded Quaker, for all his industrial and technological achievements, stands out as the father of the modern amusement park.
