Notes From the Field
ZOARVILLE, OHIO: The news that America’s last surviving Fink through-truss bridge is in danger has failed, thus far, to electrify the preservationist community. Unlike in 1830, when a plan to scuttle the USS Constitution inspired the young Oliver Wendell Holmes’s first widely noticed poem, or in 1947, when San Franciscans voted by a lopsided margin to keep their beloved cable cars, or in 1962, when the impending demolition of Pennsylvania Station mobilized New Yorkers by the thousand (for all the good it did), few Americans have been stirred to save the 108-foot Zoarville Station Bridge. Yet while the bridge may be less picturesque than these other examples of engineering art, it and hundreds of spans like it played an indispensable role in the spread of railroads across the continent. As Eric DeLony wrote in our Fall 1994 issue, “Of all the basic American bridge types … the rarest and least appreciated is the castand wrought-iron truss. Yet in some ways it is the most technologically significant.”
Instead of being supported with an arch or cables, a truss bridge is held up with a latticework of rods that reinforce its stiffness. A through truss is one that sticks up above the roadway, so that travelers go through it when crossing the bridge. The type of truss found in the Zoarville bridge was originated by Albert Fink, a German immigrant who was one of the most respected railroad engineers of his generation. His truss, patented in 1850, was one of the first intended to be huilt from iron instead of wood.
The bridge itself was designed by Charles Shaler Smith and built in 1868 by his firm, Smith, Latrobe & Company, of Baltimore. Of particular interest are the vertical compression members, which are hollow wrought-iron tubes called Phoenix columns. The distinctive columns—made by bolting together several curved pieces, each one making up part of the circular cross-section—were a specialty of Smith, Latrobe & Company. The design yielded a strong and sturdy member with much lower weight than cast iron, which had been the traditional material for columns. The higher price of wrought iron was not a problem since the design used so little material.
The Zoarville bridge was originally erected as one-third of a three-span bridge at the nearby town of Dover. Like most truss bridges, it became obsolete as locomotives got heavier, but unlike most truss bridges, it was not simply scrapped. In 1905 it was moved to its present location spanning One Leg Creek (now Conotton Creek) on a highway that was abandoned in the 1940s.
Two years ago, with the bridge in critical condition due to recurrent flooding from a dam downstream, rescue efforts became urgent. In July 1997 it was sold for one dollar to the Camp Tuscazoar Foundation (CTF), which runs a nearby camp used by youth and religious groups. The foundation assumed chief responsibility for salvaging the structure.
In October 1997 a volunteer group of local engineers devised a plan to remove the bridge from its abutments and repair the damage resulting from decades of neglect. While the bridge is being fixed, the sandstone abutments will be raised 12 feet to ease the threat from flooding, a project that will require 14,000 cubic yards of fill. With the abutments raised, the repaired bridge will be put back in place. As a first step to reduce the load on the truss, the deck has been removed, as have some nonstructural parts, such as stringers, guardrails, and piping.
DeLony, who is chief of the National Park Service’s Historic American Engineering Record, calls the hybrid Fink truss at Zoarville “extraordinary” and “a major piece of bridge construction.” While he is encouraged by the progress made so far, he says the biggest worry is the possible failure of one of the vertical members. Since the structure, like all pin-connected trusses (as opposed to riveted ones), is nonredundant, removing one post could cause the whole bridge to collapse into the creek.
As of early summer, the CTF had raised enough money to remove the excess steel, develop a restoration plan, and buy new decking material and sandstone. It is looking for funds to pay for the rest of the project. The CTF’s Web site ( www.tuscazoar.org/ZSBUpdate.htm ) has updates on preservation and fundraising as well as photographs and technical drawings. Unlike many of the relics mentioned at the beginning of this section, the Zoarville Station Bridge will probably never become a tourist attraction. Yet its very ordinariness and remote location make it a tangible reminder of how technological innovation was involved at every step of the way in America’s expansion across the continent.Revised Standard Edition
BALTIMORE, MD. : John H. White, Jr.’s American Locomotives: An Engineering History, 1830-1880 was first published in 1968, and unlike many other successes from that year, such as Spiro Agnew, it has never lost its importance. The book is exhaustive on every phase of locomotive design, equipment, and operation; a randomly selected passage reads: “A few years earlier Smith and Perkins used return cranks fitted to the side-rod pin of the rear drivers. This arrangement called for a short connecting rod to the pump plunger.” Now, on the thirtieth anniversary of its original publication, it has been reissued by Johns Hopkins University Press in a revised and enlarged edition.
Some of the new information expands on the earlier text. For example: “There is an erroneous perception that the purpose of the cowcatcher was to save the cows. The primary purpose was actually to save the locomotive and its train of cars.” Elsewhere it is more specialized: “A hint to restorers: an automotive finish that closely resembles Russia iron is Dulux Enamel Charcoal Metallic No. 4980-DX.” Besides the corrections and amplifications, 11 new representative locomotives have been illustrated and documented, including the Forney elevatedrailway locomotive, which was used in urban passenger service. The additions make White’s book even more of a must-have for anyone who is interested in early locomotives or who simply enjoys being immersed in the world of nineteenth-century railroading.invention & Chronology
BOSTON, MASS. : A press release informs us that Inventors’ Digest magazine and two other organizations have designated August 1998 to be National Inventors’ Month. Setting aside part of the calendar for some particular cause is a timeworn ploy, of course, and one might think it rather old-fashioned for a group that purports to promote ingenuity and innovation. But as a spokeswoman exclaims, the idea is “to change the all-too-often negative image of the inventor as the wild-eyed, wild-haired genius in the basement who’s cooking up some concoction that threatens to blow up the neighborhood! … it’s hard to encourage kids to be inventive if they think of inventors as kooks!” In fact, the prospect of blowing up the neighborhood would appeal greatly to most kids we know; calculus is probably much more of a deterrent to would-be inventors. Still, the goal is a worthy one.
Included with the release is a collection of supposedly “Fascinating Facts About Famous Inventions.” For example, did you know that “‘patent leather’ got its name because the process of applying the polished black finish to leather was once patented”? Even more amazing, “Benjamin Franklin invented bifocals because he hated wearing two pairs of glasses.” Remarkable as these nuggets may be, other facts on the list are fascinating only because they are incorrect.
A case in point: “The trademarked name ‘Baby Ruth’ was inspired by President Grover Cleveland’s daughter, Ruth, and not by Babe Ruth.” True, that’s what the Curtiss Candy Company has always said. But the candy bar came out in 1920, the year Ruth had shocked the world by hitting 54 home runs. At the time, Grover Cleveland had been out of office for 23 years and dead for 12 of them. Little Ruth was long gone too, having died of diphtheria in 1904 at the age of 12. Commemorating the deceased child of a deceased President would have been an eccentric way to name a product, though not entirely out of character for an industry that once saw candy bars named Chicken Dinner, Vegetable Sandwich, and Fat Emma.
Similarly, did you know that “when British merchant Peter Durand invented the metal can in 1810, he completely overlooked the need for a device to open it? Believe it or not, some historians contend that the bayonet was invented not as a tool of war but as a can opener!” The first part is true, but bayonets were standard equipment for French infantrymen more than a century before Durand’s invention.
At least the press release doesn’t repeat the line about there being “nothing left to invent,” which no patent-office commissioner ever said. And the names of the magazine and the month show that someone still knows how to use an apostrophe, which is rare these days. So we’ll play along. Readers wishing to know more about the project, or to counsel its promoters on the consequences of overusing exclamation points, can reach them at National Inventors’ Month, 310 Franklin Street, Suite 24, Boston, MA 02110 (617-367-4540). Readers interested in National Pedants’ Month should apply to the writer of this column.