A Trust in the Truss

With last months entry we explored how a lack of any real framing configuration or behavioral similarities between Long and Paddleford trusses, made any real challenge to Peter from the Long camp, less than likely to succeed. ( The presumption that the choice not to patent was due to such pressure assumes Long’s agents somehow had inside information, and additionally, had they a case they still would’ve sued for royalties no matter what the truss was being called ) And while this does not mean there were no words exchanged, and that there was none of the bluff and bluster of empty threats. All the same, for me, none of this explains the choice which was made.

With why not explored, with this entry, I thought we would explore the potentials in why.

If I were to conjecturalize the whys as to Peter choosing not to patent his truss, this choice would not be for fear of a patent infringement challenge from Moses Long, sales agent to his patent holding brother – Though the Nineteenth Century was as or more litigious than our own period in time – Any such challenge would have been dismissed as groundless, as was the challenge to Howe.(which did and does share structural similarities) I think it more likely that the interest Paddleford had was in building bridges without paying patent royalties, not in any potential in collecting royalties from others – This wrapped around the failure of any realized return on an investment Peter made in patenting a spinning device decades earlier. The incentives to patent were perhaps, simply outweighed by the disincentives.

Long’s solid foothold in the area did lose much market share to the Paddleford, though I think that was maybe more about the typical norm that drove regional preference – Familiarity and area Bridgewright preference.

With some irony, the success the Truss Type enjoyed in the area is perhaps in part attributable to the type being patent and royalty free. The pattern of its area dominance suggests it also had to do with a willingness to work with others. A cooperative willingness, which created the very familiarity which drove acceptance and success. Both in towns willing to specify and purchase a trusted Truss, and an ability to assemble a trained and capable crew familiar with the complex joinery found in Paddlefords.

Many Intersections

From the beginning Peter partnered with Bridgewrights local to his contracts – Conway’s Jacob E. Berry, sometimes said to be participant in the first known Paddleford, would go onto specialize in the type, as would his namesake son. Both would help make Paddleford’s the dominant type in the Saco valley, and on over into Maine.

Peter’s own son, Philip “Henry” would go onto build his fathers truss with great regularity, in their home area on both sides of the river that forms the Vermont and New Hampshire border, and as far afield as the state Capitol. It is more than probable that he too collaborated with capable local framers.

The type continued to be built in numbers in its pockets of dominance, for decades after the two P. Paddleford’s time had passed, often with the use of even the unique detailing found only in Paddleford Bridges, unrelated to the trusswork.

At one time I wondered how the type had somehow not spread beyond a home range in which it enjoyed such huge success. Clearly it was none so much about a lack of patent royalties, as it was about trust and collaboration. Trust in a truss, both by the public, both in buying and and in choosing to trust their lives and livelihoods in daily crossing them, and also that of the carpenters who chose to frame them.

Even without the fine details, this is the stuff of fine story.

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Long Puzzling over the Puzzlement over Paddleford

A brief diversion…

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 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.


The Last Master Builder

In our delayed return to things Trussed Arch, we must first acknowledge two Bridgewrights we have already touched on here on the weblog. Both built in this form and tradition, both were contemporaries of the subject of this entry – Timothy Palmer of Great Arch & Permanant Bridge fame, and Theodore Burr, his name forever appended to Arch type bridges, though paradoxically not for his ahead of its time Delaware River masterwork.

Both were Master Builders, an archetype then long recognized – Those not just who had reached the complete command in a “physical” ability in their chosen craft at a skill level beyond their brethren, and also that uncommon ability, to see every layer of intricacy necessary to the planning and management of any project – And somehow also, an innate ability to visualize, design, and then draw, anything, (no matter how complicated) they were planning to build.

We cannot fully explore this Truss Type without discussing Lewis Wernwag, the Bridgewright whose works suggest he was the master of this typology. His prolific life’s work is most often exemplified in descriptions of his 340′ clearspan Schuylkill River masterwork known to history as The Colossus. This best illustrated in Lee H. Nelson’s highly recommendable book devoted to this single bridge – The Colossus of 1812: An American Engineering Superlative.

So much in fact has been written about the man and his works that we’ll not directly discuss his life in any bio type format, nor will we have a full hard look at The Colossus.

"A View of Fairmount and the Waterworks" by John Rubens Smith painted just three years prior to its loss to fire

“A View of Fairmount and the Waterworks” by John Rubens Smith painted just three years prior to its loss to fire – Image courtesy of The Library of Congress

Our exploration will center around aspects of his design that suggest his understanding of his use of materials, choices which exemplify his complete understanding of his primary chosen material. And then discuss how his work moved beyond the Arch type bridges so common to this early period of bridge innovation

My intrigue with his chosen detailing goes to two things which deeply illustrate his understanding of wood as a building material, details that are today too often overlooked. These being that unwritten bridgewrighting rule of all timber needing be with every opportunity, spaced apart. In the case of The Colossus, in part by wrought iron “Links” These links, a clamp of sorts to serve as part of the Chord assembly, they also secondarily, though no less importantly served as spacers to provide airflow, and prevent large areas of wood to wood contact. ( The Colossus made great use of Iron – 40 Tons – Wernwag purchased an area nailworks & foundry in anticipation of the project ) And though it went unsaid this was obviously also to provide and maximize the ever- important airflow that affects the quick drying of any unintended wetting. The other detail I find interesting is one often cited in descriptions of this bridge, this of all its timber being “Slit through the heart” Always with this citation too much is seemingly made of his reference that this was done to “Show any defect” – Yes this was a secondary benefit of milling smaller baulks from large diameter sawlogs, (as was the norm to the period) this was without doubt also about other benefits wrought from such milling. His chosen six inch breadth is not just about staggering splices, it is also about rapid seasoning and thereby reducing the dead load of the bridge superstructure as quickly as was possible. It was also probable that in the doing at least twice the amount of curved Chord leaves were realized in the milling of his candidate sawlogs. (in all probability naturally curved – We know Palmer chose such for his Chord Lams) And the benefits of such milling do not end there. I would contend “Slit through the heart” is period jargon for what has come to be known as “Free of heart center” One of the betterment’s gained in FOHC milling is a reduced tendency in season checking, greatly reduced both in size and number. Lewis’ long experience in millwrighting would have him understanding what encouraged rot in wet environment constructions. Large leak catching open checks caked full of moisture holding dirt are one of those avoidable encouragements. And the aspect of FOHC that most overlook is the term Center, meaning heartwood, and the complete absence of sapwood. Sapwood is highly susceptible to the fungi that cause Brown Rot, and in my opinion its use should be avoided in the framing of bridges. With longevity and rot susceptibility clearly being high in his mind as he designed The Fairmount, I think it not a stretch to suggest this is an opinion he and I share. We are also of the same mind that Eastern White Pine for reasons which still hold true, is the go to choice in species for bridge framing.

Somehow today those who specify material for wooden bridges and the rehabilitation of historic spans, rarely spec dense ring count or FOHC even though both are readily available in their go to species of Douglas Fir. A species I do not see as across the board appropriate for all truss types, or to certain timber joints. This though is perhaps a discussion for another time.

Some might see some of what I suggest as just so much supposition. (and I am among those who revile revisionism based on groundless conjecture ) However I am in part reacting to such seen in earlier descriptions of Wernwag’s Collossus, and my conjecture is grounded in an intimate knowledge of these constructions, their methods, and their materials.

It is interesting that unlike his early Arch Bridge contemporaries, Wernwag transcended the Arch and also built in what some call true trusses. This was perhaps driven by an interest in keeping costs down by eliminating the needed mass and added complexities in abutments designed to carry Arches. This interest was perhaps driven by movement requiring repair, which developed in his abutment there on the western bank of the Schuylkill.

A detail from Lewis’ Neshinemy Bridge included because it is an example from one of his “Truss” bridges. That, and I simply love Strong-Arcs, and I see them as under appreciated. This, and with that the source material seen here, dates from the mans very lifetime.

As dusk descended on Wernwag’s life and time, a new age was slowly dawning. The role then long existing in mankind (from the dawning of man’s great works, from standing stones to our ancient temples and pyramids, to builders of tunnels & aqueducts to those who designed and oversaw the building of the great Cathedrals) which he had filled so well, that of a highly technical designer who was also a highly skilled rigger and builder, was then stratifying into specialties seen to no longer overlap, and to be seen by some to have very different places on the societal and hierarchical ladder. In truth, we are perhaps little the better for it. It is only with the possession of both skill sets, and both sets of understanding, each equally and finely honed, that anyone can truly be, a Master Builder.


It’s All in a Name

Things Trussed Arch are still building and burgeoning on the coming horizon, though this entry holds a brief diversion…

A recent comment on an earlier bio-piece entry I had put up on a New Hampshire born Truss patent holder, ( See New Beginnings ) from a friend and fellow bridge historian, pointed to an error made in spelling of the surname of an associate of the subject of the bio-piece. In my reply I defended with reason my decision to use the variation I did.

Being that I pride myself with accuracy relayed in the histories found here on the weblog, and not just the simple rehashing of the work of others. And being that there is also an undercurrent here of working to solve the occasional mysteries sometimes found to be lost or mixed up in the details of history. Particularly when those details twisted or lost have to do with someones name, (as in the needless confusion surrounding Nichols Powers) a deeper look demanded attention and as always, more was there for the finding.

The subject of this ramble was a partner in a Cleveland Ohio bridge building firm and agent of the subject Patent Trusses described in New Beginnings, and himself a patent holder of a a variation of a deep area of interest for me. He holds No. 47,395 a “Splice for Timbers” And though his name appears in ample written records spelled two ways, in almost equal numbers, it was the seeming spelling found in his own signature in his letters patent which drove my earlier decision. A deeper look said more about him, his partner and their bridge building concern. Also revealed was the proper spelling of the mans name.

Both partners served the Union in the war of their time in bridge building units that like others described here in these pages seemed to have been the basis of lifelong relationships. and like others they served under the command of fellow patent holder, Daniel Craig McCallum Military Director and Superintendent of the Union railroads.

In the the years immediately following the war Henry assumed an owners share of Albert McNairy and partners bridge building firm of Thatcher, Burt & Co which then assumed the mantle of McNairy Claflen & Co. Within the decade the company was said to have three hundred and fifty men in their employ and reaching two millions of dollars of business annually. In Cleveland Past & Present published in 1869, NcNairy Clafen is described as “From 1851 to a recent date, the Howe Truss Bridge was nearly the only bridge made by the concern. They now are largely engaged in the construction of iron and combination bridges. The concern has built three thousand two hundred and eighty-one bridges–about sixty miles in the aggregate. The streams of nearly every State east of the Rocky Mountains are spanned by their bridges, and it is a historical fact that not one bridge of their construction has fallen.”

This fits all that was found in the dismantling of the Bell Ford, an amazingly sophisticated construction for 1875. Both the foundry work found in the iron, the castings, and the wrought eyebars, but also in the woodwork. Thatcher & Co’s decade of Howe Truss construction showed itself both in the Shear Block joined Top Chords with their patent Claflen Splices, and also in the compression diagonals (Braces) which swell to a greater dimension at mid-length, something I contend because of amazingly uniform mill & tool marks, are a product almost out of time, and were completely produced by some sort of duplicating machine.

In the Bell Ford even the simple joints joining the Braces to the Cast Sockets which received them were remarkably consistent and lacked any appearance of having been worked by hand - Suggesting a wholly mechanized approach to production

In the Bell Ford even the simple joints joining the Braces to the Cast Sockets which received them were remarkably consistent and lacked any appearance of having been worked by hand – Suggesting a wholly mechanized approach to production

From his time, both a description of the the mans life’s work, his likeness, and his signature.




A Confluence with the Timeless Flow of a Storied River

I have recently been tasked with designing a “Covered” Wooden Through Truss Bridge for one of the worlds most storied rivers…

That said, though that would be the word that is bandied about, I don’t really feel “design” is what I am engaged in. It is more about using a broad depth of knowledge to facilitate a design. To upon reflection, use a potential projects set of circumstance to then choose from a palette of time proven truss types. And wrap that around site circumstance of span and lay of the land, and how a rivers people work with and navigate its eternal flow. Couple that with cultural influences, and something once common to the table in bridge design, and too often for reasons which I will ever fail to understand, something that is now commonly left off that table – This the simple and recurring desire in mankind to surround ourselves in beauty – And in the end, the design, has chosen itself.

All that is left is the detailing of fit and finish, and that too, in good and thoughtful design, simply chooses itself. As is also, with quantifying what and how much this or any bridge might carry, and the requisite engineering this demands, such things as the sizing of the timbers are a given.

For this project we have chosen not a patent truss, but one, like the River we propose to span, which is far more timeless -

So for a time my attentions and research return to a truss type we last explored in At the Beginnings, the Trussed Arch -

More, as this trickle now just beginning, reaches steady flow, and our design fully reveals itself in the coming weeks.

If you find yourself in need of a way to reach that opposite bank, do reach out, and we might find our way across the water, together.


Hometown Sons & Timber across Oceans & Rivers & Time

With this entry a Bio piece on a self-made Timber trader. And though he was only tangentially connected to the world of wooden bridges, I mean to complete the circle and paradoxically reconnect his world with ours. In the doing I mean to make comment on how the endless onslaught of time and change needn’t and shouldn’t mean every last aspect of yesterdays technologies be left to those days that have already slipped by.

The hub of the wheel we’ll spin is George B. McQuesten. I became intrigued by the mans story a few years back while working on the earliest still surviving Wooden bridge to have been built for Railroad use, built by the Boston & Maine in 1889, (see Gleanings from the Grit) and finding his firms merchant stamp on one of the Bolster Beams we were there to replace. Being familiar with the surname, curiosity had me look for a possible connection and sure enough he and I share the same hometown and the same home river. He was born in Litchfield New Hampshire in June of 1817. His family is still there, still farming their patch of the finest bottom land in the State.

George’s self-made success story began at just twelve years of age when he left Litchfield for nearby and then newly industrializing Nashua to tend lock gates on the then recently constructed canal there. He would spend the next nine years tending to and watching the canal boats and the floating commerce and trade of others, before he would himself enter the lumber trade at the still tender age of twenty one. He would for many years do business in both Nashua and Concord, both towns like his birthplace stand on the banks of the Merrimack River. He would then in 1872 relocate the business to Boston and initially partner with another timber trader as specialist importers of Longleaf Yellow Pine. After Geo. Fogg’s passing, McQuesten & Fogg would be renamed George McQuesten & Co.

The company would for many years specialize in the in the importation of Longleaf, a species important to the boatbuilding trade, which dovetailed nicely with McQuesten importing a non-native species. The Company and in time his namesake son would regularly commission Schooners to be built by a number of area boatyards from Boston to Gloucester to Rockport Maine. They would also trade in Knees and Trunnels, items common to the Boatbuilding Trade. In the McQuesten employ were buyers in the deep south, and their sizable fleet would regularly trip down the coast to ports in Georgia, Floridia and Texas. They would in time add Doug Fir and other West Coast species to their offerings. McQuesten Lumber long held three piers in Boston diagonally across from the Charlestown Navy Yard, and a large yard and headquarters on Border Street. It survives to this day at a facility in Billerica, a property it acquired from the Boston & Maine RR in 1955. McQuesten was itself recently acquired by a Lumber conglomerate. The name sadly seems to now be being phased out of use, after almost a a full century and a half.

I find the circle made complete, of a life of commerce beginning with canal boats in an emerging mill town to that of a fleet of Schooners plying Bluewater, and shipments amounting to millions of board feet annually flowing through one of the nations best known seaports to be an amazing story worth the telling.

George and his wife Theoline chose to continue to reside in their Nashua home. He lived two days into his seventy fifth year, and together with Theoline is buried at Edgewood Cemetery there in the city.

The once common sight of a wharfside Schooner unloading Timber & Lumber - Photo courtesy of San Francisco National Maritime Museum (Image A12,727nl)

The once common sight of a wharfside Schooner unloading Timber & Lumber – Photo courtesy of San Francisco National Maritime Museum (Image A12,727nl)

Such Schooner borne forest products were commonly crossing the worlds waters well into the 1920′s, moving desirable timber species from their native regions to distant points and seaports. Eastern White Pine was shipped from ports here in Northern New England, It likewise saw shipboard travel in large quantities on The Great Lakes and The St. Lawrence Seaway and points beyond from both Michigan and Wisconsin. Western Species rounded the Cape and are found here in eastern Mill Buildings far earlier than most might expect. And as we see here in the McQuesten story, Longleaf Yellow Pine was being unloaded in ports at distance in quantities almost unfathomable.

And this brings us back to wooden bridges – Some of this timber transversing the continent was for use in the building of bridges. Species specific traits and design values demanded their use in such important constructions even when they were not indigenous to a given area. Northern grown dense ring count Eastern White Pine being the most appropriate species for bridge truss framing, saw it shipped widely for that purpose. Many if not most of hardwood dominated Ohio’s’ bridges were built using Michigan Pine, as were those built built elsewhere in the Midwest. Spruce was likewise, strength to weight ratio similarly favored and traded. Indiana Bridgewright JJ Daniels spent much of the decade of the 1880′s setting up Longleaf Plantations in Mississippi for shipment upriver to his home state.

McQuesten & Co. seemingly had a long relationship with the bridge building division of the B&M. – Their chief of Engineering and lifelong wooden bridge advocate, JP Snow (see Scarfs) specified Longleaf for the Floorbeams and the Bolsters in The Contoocook and many bridges to follow. In later years as native species became unavailable in the then largely deforested North East, McQuesten supplied timber began to appear in the Truss-work itself.

The McQuesten Merchant Stamp seen on a Counter Brace in a B&M built Boxed Pony dating to 1918

The McQuesten Merchant Stamp seen on a Doug Fir Counter Brace in a B&M built Boxed Pony Howe dating to 1918

As this story unfolded, and the years flipped by with the change wrought by time and circumstance in just the modes of travel and shipping in this the McQuesten story, from canal Boats to Schooners to a foothold in the world of Wooden Bridges and railroading, and then how the Railroads time has since slipped by – I could not help but reflect on which and what change brought the better, and what was perhaps lost for the sake of change alone.

That turned to thoughts on Bridgewrighting and change and the struggle to rediscover the unwritten secrets of this almost lost trade. Of how even advocates of wooden bridges see little if any difference between a traditionally joined bridge and one with simple butt cuts and parts coupled by steel fish plates. And of how few understand that camber is in many ways better formed by knowledge and proven method applied by highly trained individuals, than it is in a curved glulam form by people who will likely never see the parts their semi-skilled labor helps create, become part of a completed structure.

Trusses are designed and constructed in such ways not because that system is superior to that of traditionally joined bridges. These methods and materials are chosen by those who either do not realize there is still a group of people capable of such joined timber constructions, or because wood, and wood to wood joints (most structural engineers simply are not trained in the use of wood as a building material) are not seen as viable method, or a building material worthy of trust. This shortsightedness is something I see as rather silly, with existing examples pushing the one hundred eighty year mark still carrying traffic daily, and being that we happen to reside on a planet blessed with Trees.

Joined Timber Bridge Trusses are the time proven methodology. To my mind their superior service life, (Literally multiples in service lives over those of steel or reenforced concrete – Only exceeded by those of the also now largely abandoned Stone Arch) should have wooden truss bridges seeing a resurgence in their construction for spans between seventy and one sixty or so. My hope is that such work might again become reasonably common so that this, my Trade, might prosper and the knowledge base might continue to roll forward with time.

The Boston & Maine's finest still standing example - The Wright's Ca. 1906 features Encased Laminated Arches and Shear Block Joined Hackmatack Knees - The Knees, Trunnels & Floorbeams in all probability supplied by McQuesten & Co. - Photo courtesy of the Library of Congress and The NPS Historic American Buildings Survey / Historic American Engineering Record – Photo Credit Jet Lowe

The Boston & Maine’s finest still standing example – The Wright’s Ca. 1906 features Encased Laminated Arches and Shear Block Joined Hackmatack Knees – The Knees Trunnels & Floorbeams in all probability supplied by McQuesten & Co. – Photo courtesy of the Library of Congress and The NPS Historic American Buildings Survey / Historic American Engineering Record – Photo Credit Jet Lowe

Another Litchfield son made a name for himself, and is perhaps better known than his cousin George, at least his nickname is familiar to most – Leroy Napoleon “Jack” McQuesten left his mark on The Yukon, but that is another story, one that will require we sit, open a bottle and pour a shot or three…


The Apprentice and the Master – And their many and continuing parallels in legacy

The trekking continues, and as we follow Mr. Childs through time and across borders and find his once prolific life’s work in bridge framing now limited to one standing example. (see Living Legacy) so sadly we also find the living embodiment of his most successful Apprentice’s (see Names & Places) life’s work likewise limited to but one standing example.

Their lives and works understandably forever paralleled in their own time, and curiously, now with little more than happenstance to connect them, these parallels somehow seemingly continue on into ours.

I recently visited the Town of Warner, a town both Master & Apprentice knew well, with both having built bridges in numbers on its namesake River, for both highway travel and for the Railroad which formerly paralleled the rivers banks. There I took in the Waterloo Station Bridge hoping to find a better sense of how the Masters Apprentice, Dutton Woods approached his work. With The Waterloo being the last still standing to speak for him, my intent was to find a better sense of Dutton the framer, Dutton the Bridgewright, but found that voice somewhat muffled, by probable impact damage and a successive series of repairs and attempts to increase capacity.

Named for the adjacent Railroad Station

Sometimes known as The Waterloo Station Bridge it is said to be named for the adjacent Railroad Station

Unlike the Childs legacy standing in the Rowell’s and its intact Tie and Lateral Bracing System, in the Waterloo there is a mish-mash of repair, and even entire system replacement.

These odd external angle blocks for the steel Lateral Bracing a feature of one of the many incursions and attempts at improvement

These odd external angle blocks for the steel Lateral Bracing a feature of one of the many incursions and attempts at improvement

With true timber joinery in Town Trusses limited to the Tie’s and Laterals, there is little of the mans voice there to suggest how he originally configured the framing, (photographs will have to speak for him) or what he might think of what remains if again he were to tread this ground.

Lightly framed originally, all the Lattice in this Town Truss has been sistered

Lightly framed originally, all the Lattice in this Town Truss has been sistered

The Waterloo’s lightness in framing speaks to the builders varied abilities, and this Railroad Bridgewrights’ capacity to design a bridge to fit the need at hand. To fit both the traffic the bridge would carry, and the towns budget.

It is near time for a tune-up, and the replacement steel rod Lateral Bracing systems are bent and tired, rusted and worn. Perhaps it is not too forward thinking to hope and suggest that a cohesive and compatible, original type wooden system should see a return to both the Woods and Wooden Bridge legacies.


There and Back

Recent treks around the State, have somehow dovetailed nicely with both this weblog, and recent treks around the Nation. I’ve found myself within the confines of Henniker New Hampshire in recent days. A town I’ve made mention of in prior entries as a hotbed of wooden bridge building, and home to a number of the States storied Bridgewrights, and to a now long forgotten Bridgewrighting yard.

The almost unknown ripples of good and enterprise in the bridge building world, found from seeds sown and knowledge shared here, in this one town, were and are widely cast.

Recent treks across some of the Nation bring me full circle back to “The only Henniker on Earth” – When this past month, as part of my participation and demonstrations at the Second National Covered Bridge Conference in Dayton Ohio. I, along with fellow attendees on the last day of the conference, took in a tour of the bridges of nearby Preble County, home of a collection of bridges of a Truss Type patented by Henniker native Horace Childs.

This tour and their bridges had me again ramp up our research on Mr. Childs – Though I’ve posted a number of entries on his work, I found this bit of town lore on the Childs brothers, and other town Bridgewrights as worthy of sharing.

Other bits are churning up, more to follow…

From Cogswell’s 1880 History of Henniker -



This town history published two years prior to the notice in the Engineering News and American Contract Journal citing the expiration of the Childs Patent, (see the archival entry cited in the caption four photos below) said to have inspired Sherman to make this his chosen truss type.

Built in 1887 by Everett Sherman - The Brubaker was rehabbed in 2005

Built in 1887 by Everett Sherman – The Brubaker was rehabbed in 2005

Oblique view of a Preble County Sherman variant Childs Truss

Oblique view of a Preble County variant Childs Truss

The merchant stamp of a Michigan Sawmill - Being hardwood country, Ohio imported the Bridgewright specified & desired for max minimization of Dead load Michigan White Pine for hundreds of its bridges

The merchant stamp of a Michigan Sawmill – Being hardwood country, Ohio imported the Bridgewright specified & Dead load desired Michigan White Pine for hundreds of its bridges

As described in July '11 archival Childs bio entry "Children of Childs"  - The only known existing timber constructions attributable to Horace are a Long Truss Bridge in neighboring Hopkinton - And this, the former Henniker Academy building - Now home to the Henniker Historical Society - No Childs Truss bridges exist here in New Hampshire, most such bridges were constructed for area Railroads and were long ago replaced

As described in July ’11 archival Childs bio entry “Children of Childs” – The only known existing timber constructions attributable to Horace are a Long Truss Bridge in neighboring Hopkinton, the hometown of Col. Long – And this, the former Henniker Academy building – Now home to the Henniker Historical Society – No Childs Truss bridges exist here in New Hampshire – Most such bridges were constructed for area Railroads and were sadly, long ago replaced


As it Was

Those from among my longtime readership will recognize that my ofttimes mention of Maryland’s Gilpin’s Falls Bridge, go all the way back to a description of its system of un-nailed flooring, and how it came to be returned to this long neglected Burr in my maiden voyage entry.

That first of frequent mentions having to do with the return of The Gilpin’s to its original fastener free flooring system, and the connection of that system to many early Bridgewrights, and Wooden Truss patent holder Col. Stephen Harriman Long.

The Floor and the Truss Framing as viewed looking towards the north Portal

The Floor and the Truss Framing as viewed looking towards the north Portal

While recently back in the area involved in a non bridge related timberframe Preservation effort, I stopped back in at The Gilpin’s to check on how both the replacement timber, and the once common and now uniquely applied flooring, was seasoning in, in the three years which have now passed since the bridges celebrated and awarded restoration saw completion.

The North Portal

The North Portal

I was happy to see a second return of tradition and methodology to the Gilpin’s. One that like other aspects of followups in Bridgewrighting, ( See August ’12 entry – Less Than Hardwired for Hardware – for example of other similar seasoning driven followups ) and how a full understanding of the materials used, demand and require a return to the bridge for simple maintenance as timbers in these bridges, and their claddings and other wooden elements of finish and enclosure necessitate.

To use the terminology of the day through the words of Col. Long – After seasoning and shrinkage of the Flooring, the “Binders” had been taken up, the un-nailed Flooring had been moved to remove the gaps left by seasoning, and every eight or ten feet along the bridges length – A new piece of Flooring had been added to cancel out the aggregate of those 3/16” gaps. A dozen or so pieces in total along the bridges length.

The added pieces obvious both for their coloration and for the lack of this mysterious red chalk line just adjacent to the “Binders” – Note also the Arches descending past the Flooring and the nearby Chords

The full return of this system of Flooring, has with these added pieces of Flooring, now been returned to our Nations Covered Spans.

The work we were following on the restoration of The Gilpin's, was that of Cecil County Bridgewright Joseph Johnson - Photo courtesy of Mike Dixon & Window on Cecil County's Past

The work we were following on the restoration of The Gilpin’s, was that of this fine gentleman, Cecil County Bridgewright Joseph Johnson – Photo courtesy of Mike Dixon & Window on Cecil County’s Past


On Sunday the 28th of the coming month, The National Society for the Preservation of Covered Bridges will hold one of its Summer meetings at The Gilpin’s. My longtime associate Tim Andrews, the fellow Bridgewright I subcontracted to on this restoration effort, will discuss challenges, victories and aspects of the effort both structural and logistic. As well as this now revived system of Flooring.

As it was, at least for this piece of Maryland history, is for the foreseeable future, as it will be…


A Book by its Cover

The travel my work often demands can at times grow monotonous, both out here on the road, and for those patiently waiting on the home front. One of the perks the road does afford, is not just opportunity to build, maintain, and effect repair on bridges and other historic timber framed structures both far and near, but such extended travel also provides an ability to visit wooden bridges in distant States and regions, and in their many regional variations. This I have done in a dozen States now, and in numbers approaching two hundred examples.

With all this exploration, it becomes more and more evident that Bridgewrighting historically seems to have attracted and or was only open to the best of the best amongst timberframing practitioners. The attention to detail and the average level of workmanship in bridgework (examining dismantled joinery and the workmanship found within the normally unseen faces of timber joints drives this point home particularly well) necessarily tends to run several gradient levels above that found in most (exceptions sometimes being mills and steeples) other types of joined timber structures. I have of course come across examples which exceed even these norms, and count these for this reason as among my favorites. Their Bridgewrights, I likewise hold in a higher regard, and with a level of admiration a notch or two higher than I do most.

As I take up my road warrior weekends with visits to an areas sights and bridges, occasionally the road finds for us that unexpected multiple exception. A bridge that exceeds norms and expectations, and every so often happenstance also happily finds such an example which has seen over its service life the simple maintenance which keep such bridges in near perfect almost original condition, and in a state of service health which will see it continuing to carry traffic well into the future -

Photo courtesy of the Library of Congress and The NPS Historic American Buildings Survey / Historic American Engineering Record - Photo Credit Cervin Robinson Taken during HAER's August '58 documentation

Photo courtesy of the Library of Congress and The NPS Historic American Buildings Survey / Historic American Engineering Record – Photo Credit Cervin Robinson Taken during HAER’s August ’58 documentation

Berk’s County Pennsylvania’s Griesimer’s Mill Covered Bridge is such an example, this despite its current state of a few cracks in the siding and an unkempt appearance suggested by currently peeling paint. This the root of my don’t judge – A Book by its “Cover” reference and entry title. The Griesemer’s has clearly never seen any sustained period of poor care or a failure in simple maintenance, and the workmanship seen in what few repairs it has required over time have been well designed and executed with care and ability. The County even recently announced the bridge will receive a shiny new coat in the coming months, ( bit.ly/12RTsVV – Update Sept ’13) and seems well aware that simple maintenance over long service life is far cheaper than the major repairs which a failure to see to such care all too often necessitates.

A name for The Griesimer’s Bridgewright seems to have fallen from the record, (even its build date is somehow shrouded in minor mystery and often repeated misinformation) and this is unfortunate as such knowledge and ability should be honored and exemplified even all these years later. The details chosen and the the level of care taken in their execution are quite obviously part of how and why this bridge continues to carry traffic and “Positive” Camber into the present day.

In irony it is the amazing condition this Bridge is in which has me antithetically worrying after its future – It is near time for a minor going over. One of the downstream Shelter Panels has racked out of plumb giving the impression the bridge is listing, even though the Truss beyond it is strait and true. The upstream arches have some minor distortion which should be arrested and straitened before this task grows in complexity. A scarf or two could use some slight tightening and tuneup.

My fear is that at the next incursion this extraordinary example of a Burr which has been carrying traffic admirably as constructed for a century and a half, will see the rubber stamp rehab common to this area – And like the nearby Pleasantville, also in Oley, it might well be stripped of its original floor system, and transformed into a Steel Stringer Bridge, and the wooden through truss will in all reality cease to carry the rolling loads it was built for. Rolling loads and future traffic time has proven, it is still and more than well suited to carry, into many tomorrows.

This Bridge was built for better, this Bridge was built for more.

The Griesemer's, an exqisitly joined Burr has all the best details used in its framing including Double Arch Rings

The Griesemer’s, an exquisitely joined Burr has all the best details used in its framing including Double Arch Rings

Joggles to provide an abutment for the load imparted by the Braces – Check Braces to buttress the moment imparted are an all too infrequently used feature to Burr’s – Note also to the left of the Check Brace a Joined Scarf / splice – An unusual detail for a Top Chord

Arch sections are joined in Bolted Half Laps and are identified with the somewhat unusual feature of Carpenter's Marks - A Feature common to other Berk's County spans - Note also the Red Grease Pencil markings

Arch sections are joined in Bolted Half Laps and are identified with the somewhat unusual feature of Carpenter’s Marks – A Feature common to other Berk’s County spans – Note also the Red Grease Pencil markings

Bottom Chord Scarfs of the Stopped Splayed variety with Bolts both shared by and with the Scarfs backed up by the Lower Lateral Bracing system - Our nameless Carpenter a Bridgewright on the ball

Bottom Chord Scarfs of the Stopped Splayed variety with Bolts both shared by and with the Scarfs backed up by the Lower Lateral Bracing system – Our nameless Carpenter a Bridgewright on the ball


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