Monthly Archives: February 2014

Long Puzzling over the Puzzlement over Paddleford

I have held a decades long interest in the Paddleford Truss, this first brought on by visits to standing examples, these found only here in Northern New England. And then out of a professional interest, first in a bridgewrighting timber frame carpenter’s appreciation for the way the Truss Type is joined, and in how loads are conveyed and resolved. In time my appreciation came from eyes and hands on experience with the typology, this now dating back a full decade to a restoration project I was involved in back in ‘ 04

With the initial and recurring subject of this weblog being Truss Types with roots here In New Hampshire, and my complete favor for this type I have long wanted to pen an entry based on this Truss and its developer Peter Paddleford. Work to find information for a bio-sketch of the man, even with his many successes, and hints of a long running set of shops and mills in his adopted home town of Littleton New Hampshire, any real sense of his life information is sadly proving to be lightly recorded, and a bit of a challenge to churn up.

Attempt to find information on his namesake truss, likewise reveals little but how the type was limited to a smallish home range, and the fact that Peter never patented his truss unlike so many of his fellow truss type developers.

This seems to have puzzled many and has spurred an odd and oft repeated conclusion that has long puzzled me. This being that this failure to patent is directly tied to some similarity shared, and a challenge from agents of Col. Long and his Patent Truss.

To my mind no such similarity exists, nor have I been able to find record of any such challenge, only allusion to said challenge repeated time and again. So I’ve decided this entry will examine this notion, by looking at the dissimilarities between the Truss Types.

With Long and his Trusses also having deep roots in New Hampshire, we have delved into his story time and again here on the Bridgewright Weblog. (click in the search box for a list of entries) His Patent Trusses feature double Posts at each panel point to which are joined double Braces which sandwich a Counter Brace, these wedged to create the Colonel’s groundbreaking pre-stressing of his Truss, (he was first in conceptualizing pre-stressing – One reason some name him as the worlds first “true” engineer) and allowed control of the geometry of each individual Panel.

The arrangement of framing in a Paddleford bears no resemblance to a Long whatever – They are simple single Post / single Brace panel arrangements which feature an ingenious tensile Counterbrace which is joined to not a single panel, but parts of three – It does not form the sandwiched X common to Long’s and Howe’s, (which did spark a challenge) and quite counter to the centered and sandwiched example in Long Trusses, the Counter Brace is not centered and is not a compression member. Paddlefords unlike Long’s are a Multiple King variant, simple MKP Trusses with an added tensile Counterbrace.

This notion that a Paddleford is a modified Long holds no water, and has long done disservice to the man and his Truss, and has caused many to somehow overlook the greatest aspects and the simple genius of his Truss.

The Counter Brace is double dap joined to two Posts and in a symmetrical mirror image arrangemet, to both the Top & Bottom Chords - Buttressing the Posts and countering the moment in the doing

The Counter double daps two Posts and both the Top & Bottom Chords- Buttressing the Posts and countering the moment in the doing

This genius lies in the placement of his Counter and how it both conveys and imparts load along the Truss and in the doing both captures the Brace and locks it in place on its Post abutments and buttresses the moments imparted by the Braces to the Posts which receive them – These bending moments are the Achilles heel of Multiple King variants, and Peter’s carpenterly solution, was and is to this simple bridge carpenter, (like the loads through his tensile Counters) a great leap forward.