Today, we nail down dates. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.
A group of local hobbyists runs a large model rail system. Their models are much larger than the model trains we usually see. Some actually carry people. They call themselves the Houston Area Live Steamers, or HALS, and they send me their monthly newsletter.
This issue has a feature titled "To Date a Spike". It tells about something called a date nail. I didn't know about date nails, so I went looking. They're typically 2-1/2 inches long with broad flat heads -- usually steel, copper, or aluminum.
Their distinguishing feature is a two digit number stamped in the head -- the last two digits of a date. We have to guess the century, but that's easy since they were used for less than a century. And their purpose? Well, they aren't meant to hold anything, only to leave a lasting record of when a new railroad tie was laid.
Wooden ties didn't last as long as steel rails. Railway companies needed a record of when ties were put in, so they'd be alert to replacing them while they were still safe. The nails also helped gauge the lifetime of ties in different situations.
France made the first date nails around 1859, and was using them heavily by the 1870s. America took them up in the late 1890s. Before that, we'd used other means to date ties. We stamped the end, affixed a brass tag, carved notches. But nails were simpler and longer lasting. By the 1920s every new tie carried one.
And the idea spread. The Forest Service used them to mark trees to be felled and to certify that stumps were from legitimate cuttings of trees. Nails appeared in telephone poles and other wood products. Many carried a company logo as well as a date. Sometimes they specified a length or weight of a tie instead of a date.
Naturally with such a rich variety, date nails have become a popular item within a large subterranium of collectors. Those collectors often have a detailed knowledge that rivals philatelists or book collectors. Armed with tools for pulling nails they walk the forests, byroads, and rails. And herein lies a problem:
Date nails are far less used today. We're so much better at preserving wood, and we also use other materials to make railway ties. However, wooden ties are still in use and older ones still carry nails that inform railway maintenance people. A huge temptation, and a huge taboo, for collectors is pulling nails from active rails. It must not be done.
So here is yet another form of historical record. Like the information stamped in bricks, cast into manhole covers, or given on nameplates, they're a wholly new way that our industrialized world invented to keep track of itself. We're so accustomed to learning about technology through the medium of print that we forget how much history rides on the artifact itself.
That's why I like these old nails. They were meant to serve maintenance. But, in the end, it is history that they serve best.
I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.
D. Gillory, To Date a Spike, Stack Talk (Houston: Houston Area Live Steamers, May 2006 Newsletter): pp. 6-7
See also, the following page for images of a large variety of date nails: http://nailhunter.ehost.com/
The image shows a date nail (left) with a railroad spike (right) for comparison. To view a huge variety of the numbers stamped on the heads of date nails, see the excellent web site above.