There are almost unintentional undercurrents here on the Bridgewright Weblog. Yes I’m intrigued by those we follow, my fellow practitioners in this trade, they in its heyday, we almost entirely from a preservation perspective. They with knowledge in abundance shared by necessity, from Master to Journeyman to Apprentice. We are left to glean what we can from what we might – Most of this is to be found not on paper, but in physical example.
So in this entry we dip the paddle and turn briefly, to follow a parallel current in the study of wooden bridges and bridgewrighting, and through their work, the people who built them.
That brings us back to an undercurrent, Railroads drove change and innovation, and though their connection with wooden bridges is all but forgotten, being that this connection held a then almost unique place in straddling the emerging worlds of corporate style big business, civil engineering and academia, it is almost no surprise that railroading’s ties to wooden bridges are well represented in the written record. Part of the other undercurrent we ride is found as we run our fingers though and sift the dirt, the stuff, the sluff – The grit still left to us for interpretation in still standing examples is there to find, despite the passing of time.
What is sometimes hard to see, is that it might just be in the dirt under our nails in which we find much of what we are looking for –
It is tool marks left in long tightly closed timber joinery that no one has gazed into in multiple lifetimes, It is scribed marking knife and awl marks and remnants of layout lines and faded numbering left to us in the cursive grease pencil handiwork of some almost forgotten carpenter, the pride with which he executed his work daily still evident in the elegance found in his handwriting. It is a shear failure, and how the woods grain reacted to it. It is an expected depth of crush created by fifteen decades of constant and massive force. It is how a needlessly neglected leak led to unnecessary failure, and how that failure effected load-paths, and how those shifting load-paths effected the through truss as a whole.
As much or more is to be gleaned in the hands on side of things, as anything we might find on the written page.