The Institute for the History of Technology & Industrial Archaeology

Lane Truss Documentation Project

 

Lane Truss Patent Drawing

In the latter part of the nineteenth century, entrepreneurial bridge-building companies flourished throughout the United States in response to an insatiable demand for railroad and highway bridges. While monumental bridges like the Brooklyn Bridge dominated the headlines, engineers and inventors were also tinkering with scores of bridge designs meant for shorter spans in remote locals.

The Lane Bridge Works was based in Painted Post, New York, and existed from ca. 1890 to 1901.  In 1890, company founder and civil engineer D. F. Lane patented a bridge made primarily of standard (inexpensive) railroad rails. Lane's bridge was meant to be adaptable to any length up to 100 feet, be easy to erect, and strong enough to carry any sort of farm tractor, traction engine, horse-drawn wagon, or light railroad. While it is still difficult to determine definite numbers, the design clearly  found moderate success in the eastern U.S. up to 1901. In addition to the Lane truss patent, the company constructed a variety of other truss types. Yet the Lane truss was this company's claim to fame.

"Dear Sir--The forty-one foot span of your patent Railroad Iron Bridge we sold to Mercer and Middlsex counties jointly; was duly erected, and, on the day appointed for the committees to meet and inspect it I had two of my largest traction engine out there and after they had examined it otherwise, I had the two engines run across it side by side to the satisfaction of all present, and, to their astonishment the depression was hardly perceptible even in center of span--and of course the bridtge was accepted unanimously."  (An 1894 letter from Hightstown, New Jersey, to the Lane Bridge Company)

In engineering terms, the Lane truss is a modified Queenpost truss, found exclusively in a pony through-truss configuration. The railroad rails were bent, clamped, and bolted together  to form upper and lower chords; steel suspension rods, in tension, support the deck, secured by nuts threaded onto the rods. The deck is supported laterally by inverted Kingpost trusses made of railroad rails (or in some cases structural I-beams) and suspension rods.

During 2000-2001, IHTIA documented two of the now-rare Lane truss bridges. One is at MacDowell, Virginia, and it is the smaller of the pair.  It was built in 1896 to cross a small stream named Crab Run, a tributary of the James River.  The bridge is less than 30 feet long and very narrow, and was bypassed by the main highway fifty to eighty years ago. It was used as a side road until ca.1990, when it was converted to a pedestrian-only bridge. It remains in good condition and is an interesting stopping point along the historic Staunton to Parkersburg Turnpike. 

The most impressive Lane truss is near Martinsburg, West Virginia. Erected in 1894, "Park's Gap Bridge" is 90 feet long and still carries a high volume of vehicular traffic over the waters of Back Creek, a tributary of the Potomac River. This elegant span is slated for decommission and its future is uncertain. Visual inspection suggests the bridge is in excellent condition, yet it lacks in width and maximum weight allowances considering the amount of traffic it receives in this rapidly growing area. Concerning preservation, possibilities include simply bypassing the bridge or disassembling the bridge and re-erecting it elsewhere. The Park's Gap Bridge is on the National Register of Historic Places.

Staff members are now finalizing the drawings and historical narrative, and more will be available on this site in the future. Contact IHTIA historian Michael Caplinger about this project.

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