Category Archives: Timberframing

My Metaphoric London Bridge

A tangential slightly off-topic entry this go.

On part of the hows and whys on the road of life experiences and how a long ago project, (though I then had no sense of this connection and what would in time unfold) served quite literally as the very bridge on my career path crossing the void from Timberframing to Bridgewrighting.


A conjectural drawing by C. Walter Hodges – CC BY-SA Liscense 4.0 – via Wikimedia Commons – I had the great fortune to meet Mr. Hodges as he attended a festival held by the North Carolina effort – He was at that moment happily watching two efforts to replicate The Globe play out on two different continents

What I then saw and still see as an opportunity not to be missed, for the promise it held in sharing a then little practiced (at least on this continent) form of timber layout, was accepting a position on a crew assembled to replicate The Globe Playhouse in North Carolina and the opportunity it afforded to work with its chosen Brit Master Carpenter, Paul Russel.


Paul Russell explaining the nuances of Plumb Line Scribe in the 1993 Cruck Framing Workshop we came to know each other through – A life’s work mentor I will forever be grateful to

The Globe itself was borne of a bit of turnabout is fair play in a story of both cunning and cooperation, One worthy of retelling here, particularly in that it drives home the potential portability of timber framed constructions.

The predecessor of the Playhouse was built in 1576 by James Burbage on leased land. Burbage died twenty one years later in the closing months of the lease. The lease specified the lessee could remove any construction built upon the leased land should the landholder refuse to re-let their land. As an underhanded attempt to steal their building, the landholder simply repeatedly put off renewing the lease until it expired while technically never refusing to do so and then intimated that full possession of The Theatre then fell to him. Burbage’s sons and five fellow members of The Lord Chamberlain’s Company, this number including William Shakespeare, formed a “syndicate” a jointly held company to build and operate a new theatre. To do so they would first retrieve their rightful property, taking advantage of their former landlords holiday absence from the city, they would with their chosen “cheefe carpenter” Peter Street begin dismantling it on the evening of 28 December 1598. They would transport the dismantled frame over the frozen Thames to a newly leased plot of land in the “liberty” of the Clink. They then revamped the frame and the Playhouse and reopened it in the Summer of 1599 as The Globe. Their former landlord petitioned the court for damages, his pleas falling on deaf ears. The syndicate would go onto cooperatively run their playhouse for years to come. It like its predecessor would host the inaugural run of many of times most celebrated plays penned by one of its renowned co-owners.


One facet of the of the efforts eighteen sides – Note the specifically chosen naturally cranked Plate – This Plate held a crank at either end all the others to follow would have had but one


This replication was to have in time filled this entire area

As a joiner of wood and longtime admirer of this fellow Will, our languages greatest “joyner of words” I am ever disappointed that there are still those doubters that work to deny Will his works and insist they must have been penned by a learned, well traveled man of a far higher social status. I would suggest genius and natural ability does not know any social status and turn their very argument on its head in suggesting that only someone who straddled both worlds could hold his understanding of trades and tradesman and carpentry and joinery, and I think it plausible some of that understanding came from the part he played in the “theft” of The Theatre and the work he engaged in in helping morph it into The Globe in the late Winter and warming Spring of 1599.


The frame was to have been embellished with the type of carvings typical to the Elizabethan era


Naturally cranked Samson Plates were to have topped the Posts at the vertices supporting the timbers carrying the inner galleries

I have time and time again here on the pages of The Bridgewright Blog alluded to how scribe was and is for reason how timber bridge trusses were and should be laid out. The Plumb Line Scribe I came to fully understand on this months long failed attempt (full funding failed to materialize) to replicate The Globe, is the most versatile, efficient and accurate form of Scribe timber layout I have learned to date. I continue to this day to use it and its advantages and to share it with fellow framers, most recently and currently I am teaching this system of timber layout to a National Park Service – Historic Architecture Conservation & Engineering – (NPS – HACE) – Construction Conservation & Training – Preservation Carpentry crew as we work to replicate one of the timber sluiceways at the Saugus Iron Works National Historic Site.


The efforts flag held the Shakespeare Coat of Arms – In the Globes’ time the raising of the flag signaled to those out of earshot that a play was about to begin – With this play over we lowered the flag to half-staff and returned to the greater world in search of future productions

I would some months after helping raise then lower the Shakespeare Flag to half-staff, return to my home State of New Hampshire with an old, somewhat simple, though very powerful tool in my kit, and somehow found myself that very Autumn, recognized in the pit in a large group of groundlings by The Globes former engineer and he would call me over the fence.

Though as I recall, that is a tale,  I have already told –

                           All the world’s a stage, 
                 And all the men and women merely players; 
                 They have their exits and their entrances, 
                And one man in his time plays many parts... 
                     As You Like It - Act II Scene VII

The Most Important Tool in the Kit

With this entry we speak to tools, or at least the simplest and most important of tools in our kit, and the one which therefore allows for the accurate and proper use of all those that follow.

String is the most important tool in any box – It is a line running though time and history and most every building that ever was or ever will ever be. It is the very beginning, and is even now like a living truth and a real world Möbius Strip, a concept ever connected to an end that never comes…

String, in all likelihood developed from a simple tool used to bind items together for storage or transport, to then be used to build snares and traps and then towards its slightly more complex use in defining strait and true, none so long after our long ago ancestors first pounded and separated natural fibers apart and then twisted them back into cohesion and a potentially unending bit of cordage. This perhaps within generations of that first great leap forward.

All this development coming about long before recorded history. How much time had or has since passed before the first human mind noticed a taut line was strait and then went on to run a string through powdered charcoal with the intent of marking a strait line on something he wished to straiten and to then affix a line to Batters is something we can never know.

It is fitting that those beginnings are yet still just that, the beginnings of most any construction – It all begins with a taut line and Batter Boards, plumbs and the snapping of lines.

My focus on it as still being primary amongst the many tools we have since developed is in part to do with my traditional approach/es to timber layout, though in truth this goes back to my first week in my first carpentry job, in being taught the proper way to string a line and my asking my then mentor who it had been who had taught him the technique he had just demonstrated. His eyes acted almost as a line that day as they belayed the thoughtful recollections and truths spinning in his mind as he thought about it a moment, then he simply said “Well hell, I don’t know, that goes back to way on before the pyramids”


This image of a Merchet and its companion Plumb is seen here as a courtesy of Wikimedia Commons

In part this focus goes to my primary chosen system of timber layout being Plumb-Line Scribe. Though no matter the chosen layout,  (Square Rule or Scribe) I am datum-dependent. I almost without exception snap lines on every stick, more often than not I do so on all four sides. These lines physically represent two perfectly perpendicular planes of reference.

In Square Rule these snapline planes of reference are used to accurately cancel out bow and wind and to overcome any lack of squareness not achieved in the milling of the timbers, as well as lending reliable accuracy to an organic and imperfect timber in the layout and shaping of timbers to chosen mathematical constants at each of their connections. In Scribe Rule these snaplines likewise are used to cancel out bow and wind as each timber is lined out and are then used to place each timber into scribe layups aligning the two planes of reference to Plumb and Level, this often over a lofting floor on which is drawn a full sized diagram, itself described with snaplines, pinged not with a line enveloped in charcoal or chalk but one dampened with ink. Upon such placement in these layups timbers and the inconsistencies (unlike the smaller pieces of wood found in benchwork, timbers cannot reliably be milled strait and true – Timberwork requires systems of layout which therefore deal with those expected and natural inconsistencies) found in their surfaces, are scribed to each other, often with the use of a Plumb-line used to gauge those inconsistencies.


Note the Level Mark adjacent to the 6″ Level – It is from that mark that the Datums are unwound – It is with both the Datums and the Level Mark that the timber is placed in the layup over the Lofting Floor – This allowing use of the Plumb Line to covey quantifiable information from each timber to the other

A snapped line, like a line on paper or a computer screen can also be used as a base line from which to develop the geometry to layout any required angles or an Arch or a desired radius or as a control line from which a trusses camber is re-conditioned in a bridge rehab/restoration or developed in a new build.

And in all forms of construction, lines then go onto be used all through the assembly and erection process as a constant reference to insure things are both strait and true and plumb and level.

Though recent advances and circumstance will sometimes demand a laser be the line of choice in the field, reels of string, be they Dry or Chalk Boxes or Ink Lines, will forever and always be, the most important of tools in our kit.

Carpenters and their Marks

They’re everywhere and they are not, and perhaps that is part of the problem. With Carpenter’s Marks being somehow so ingrained in our collective subconscious, most everyone (even those without interest in historic carpentry and its methods) holds for them some blip of understanding, some seemingly just short of intuitive sense of their necessity and purpose. Perhaps this is why so much assumption is intertwined in much of the written description found on what and why they are.

Much of the supposition as to purpose is wound around how Timber Framed structures were often scribed, cut, and partially assembled in Carpenters’ Yards miles or more from where they were ultimately erected. While this is happenstantially true, it is only tangentially a driver in why the marks are necessary, and over-complicates the case. The real driving need for their use is far simpler than that.

Most Timberframe constructions have multiple copies of the same piece, arranged in assemblages of which there are also multiple copies, be they walls or bents or roof planes, or in the case of bridges, a pair of like trusses and the braced Tie and Floor Beam systems which connect them – Much to keep track of.

An atypical five at a Check Brace / Top Chord connection on Berk's County PA's Griesimer's Mill Covered Bridge - Roman numerals as used by carpenters vary from the norm to avoid confusion - Four is expressed as IIII instead of IV simply to make it impossible to confuse it with a VI - The same is true of Nine / VIIII - But Five is always V - This was in all probability mismarked as a Four and corrected with a fifth I

An atypical five at a Check Brace / Top Chord connection on Berk’s County PA’s Griesimer’s Mill Covered Bridge – Roman numerals as used by carpenters vary from the norm to avoid confusion – Four is always expressed as IIII instead of IV simply to make it impossible to confuse it with a VI – The same is true of Nine / VIIII – But Five is always V – This was in all probability mismarked as a Four and then mistake caught, corrected with a fifth I

Carpenters’ Marks are a simple system to identify place for each individual piece to properly maintain its relationship with adjacent pieces – In the most common form in which such marks are found, that means assigning the low number roman numeral to the reference end / reference corner of the frame, this most often chosen as the Southeast corner – The entirety of the first Bent is assigned Roman Numeral I – Differentiation as to East & West corners (and any pieces found between these) is achieved by incising that Roman Numeral with chisels graduating in size. To these numerals there are often slight variations added to delineate and describe placement as to such things as first & second floor…

Pieces can and do share the same Numeral like they share the same address

Pieces can and do share the same Numeral like they share the same address – These marks are found in The Sandown Meeting House ca. 1773 to be part of a Timber Framers Guild conference tour this coming week – See you in the attic – Though but 22 years of age at the time of its framing, Timothy Palmer of Schuylkill Permanent Bridge & Piscatiqua Great Arch fame is said to have been clerk of the works in the construction of this Meeting House

Scribe type layout is also a driver in the need for this system, with each individual piece, no matter how much it looks like a carbon copy of its opposite other, only fitting in the one place into which it was scribed.

Here a small Scribe Layup is in process, the three timbers above are being scribed into the same configuration as the co-planer set below them, a Rafter Pair with a Collar Tie - As this layup is completed individual pieces will receive their mark as they are taken to the horses to be cut

Here a small Scribe Layup is in process, the three timbers above are being scribed into the same configuration as the co-planer set below them, a Rafter Pair with a Collar Tie – As this layup is completed individual pieces will receive their mark as they are taken to the horses to be cut – Placement is assigned as the process begins

The system however survived the transition to Square rule layout, (See Dec ’12 archival entry – Overnight Turn on a Paradigm) simply as a proven aid in efficient assembly on raising day.

I still use traditional Carpenters’ Marks on both Scribed and Square Ruled frames. I find it both simpler and more interesting than a grid described with Sharpie markers & ABC / 123 – I’ve also found it holds appeal for clientele. This driven home some years ago in a newly raised house, with the owner beginning a friends introduction to the frame, not with a view of some interesting detail in the timber-work, but in pointing out the Carpenters’ Marks in the Great-Room. (These typ incised on reference faces in the area of the Brace joinery on both the Posts & Braces – ie: A standing height field of view) In watching his description of their purpose play out, his genuine enthusiasm for what he was working to describe suggested to me that he felt his choosing to build a Timberframed home was in some way including he and his family, through their home, in some nameless and timeless continuum – Something I feel part of each and every day.

Carpentry Made Easy

Long part of this rolling and ever ongoing obsession I hold in just what this is, this stuff of timber and bridge carpentry, has been an ongoing participation in the recovery of information almost lost.

These Trades nearly fell away as time morphed differing efforts, and materials towards those ends shifted away from what had been the norm for countless generations – Timber and its long evolving and practiced methods, would for a time be almost completely marginalized as dimension lumber and steel in their turn became the chosen norms.

Much in the everyday practice of these trades was no longer shared as the almost unspoken, was little conveyed in the fewer and fewer conversations of instruction were had over timbers on horses, as fewer practitioners found fewer up and comers interested in what was still there to be shared.

I spoke of how some of this, the spoken and shared side of this continuum was but barely saved, in Living Memory

Fortunately, though the everyday in a time when trades training was little written down, but shared one on one in literal Master to Apprentice relationships – Some in these transitional years of morph and change did take the time to put words to paper.

The collection of Treatises on Carpentry and method has also long been an ongoing obsession. This has in recent years become easier as the worlds libraries have become digitized, and the absolute need to find a rare copy of an often little printed work was now made everyday possible in public domain downloads.

I can’t deny I love my e-reader, and it is ripe with the works of among others, Sutcliffe and Dewell, Jacoby and of course Hodgson. And I do love being able to carry what amounts to a sizable electronic library with me anywhere circumstance demands I go.

I do however, still prefer the real thing, this the printed page. With everything this brings, the whole of it. Sounds and smells and a presence and physicality, the literal textural experience, the very textures of text, these often begging a reminder that I again flip open a neglected cover.

So when I became aware a specialty imprint had recently republished a particular favorite, a treatise that touches on the varied intricacies of Timber Carpentry, from the framing of mill buildings to that of spires & steeples, and because it touches on bridge building from a perspective little shared, that of a Bridgewrighting Carpenter…

I am now expecting a hardcopy to soon materialize shrouded in bubblewrap – For now an excerpt from a tome first printed in 1858

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, (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

Commonly Un Common

The Square Rule is, as I suggested in the last entry, not just back on my current, but it is now my actual horizon. A part of my here is now everyday. As is this wondering as to why it was the people who chose to use it, this Square Rule, chose to do so.

It is a funny place to be in in more ways than one. As is the fact that I might gaze through a window few can share – I know what it is to wonder after the efficacy of which system to use for any given Timber Framed construction. To ask which system of Timber Layout, Scribe or Square Rule is the more, or even the most appropriate. This a window common to a few of my contemporaries. Though one last wide open for but a brief while, centuries ago now, when this rapid shift from the Scribe to the Square was yet underway.

And I think the perspective I view all this through, is far from common. To know traditional versions of both systems of layout is not common even among framers. To have a working sense of both historical framing of buildings, and those of bridges is maybe even more so. All this is a circumstance and a happenstance and a perspective, which was once commonly shared. The once sense of everyday of a common country carpenter, but now some of the little explored vagaries of a hyper niche carpenter. That said, I still see myself as a common country carpenter. Perhaps it is the every tree is a timber, commonality traditional timber framing has with the sawlogs we are often involved in “converting” – It is in this work, none so uncommon to choose timber in the woods and on the stump. Something we have done here as part of the Bernhard Barn restoration, the two Tulip stems which will serve as species in kind replacements of the one piece fifty foot hewn from the round Wall Plates still stand in their forest and yet touch the sky, and do not yet know that they will be part of the next chapter in the ongoing story that this Barn will continue to tell.

It often crosses my mind that this thing of being a Framer with an inter-discipline sense of things is an all too small club, one with a membership far far too short in numbers.

So, all that, and with the other high horizon focus, The Blenheim, seem to bring us back to where this blogging adventure began, with Long Trusses and The Square Rule and who might have taught who what, when it came to bridge framing, (see the May & June ’11 archives) now swings back and over into a parallel and perhaps as seemingly and an almost equally unanswerable exploration. Who was it who brought the roots of Square Rule to the table, and where was that place that they called home?

Semi parallel interwoven puzzles and a wonder after both, send us in search of clues to either, and we find yet another letter of shameless self promotion from the good Col Long –

All this information for but three pence, the price of a nail so small, most might think of it as a tack.

A Now Two Century Old – Overnight Turn on a Paradigm

My revolving focus is often driven by a particular bridge, or its Truss Type, or an interest in its developer or Patent holder. My current attentions have once again revolved around to focus on something of deep and long interest, something that is the core of who I am and what I do. And interestingly something of a mystery, one which is perhaps this very year, slipping into its third century of wide use.

Traditional / historical timber framing layout systems became a preoccupation of mine something over twenty years ago now. In part with a growing understanding that the non-traditional layout used by the shops in which the first frames I helped cut did not have a practical level of success, and in part because it was a connection to history and a historical continuum which drew me to this Trade. That and ample example that historical layout systems did possess a level of predictable success and practicality “then” suggested to me that they would still share these same practicalities in the now.

I sought out practitioners of these systems – The Scribe Rule & The Square Rule. (Scribe being the direct transfer of information from one timber or set of timbers to another – Square Rule being the shaping of timbers to a mathematical constant at each of its connections) And have gone on to, as a rule not an exception, regularly practice both, and also to teach traditional layouts in a series of workshops over the last dozen or so years.

Though in part it is out of preference, it is happily also out of practicality that I lean towards the Scribe side of things. With much of my work being Bridge related, and with Timber Bridges being the seeming lone exception (this due to slightly dissimilar pieces in what appear to be like, redundant and, mirror image Panels – Small inconsistencies driven by camber) to an amazingly rapid and geographically vast shift (here on the North American continent) away from variations of Scribe which had been the norm for timber carpentry for millennia.

Scribe layout survived all the many changes humanity brought to its fellowship and the need to house itself, including this migration to a new continent, this particularly well exemplified here (forty or so miles from the coast and just outside of first period settlement) in my little patch of Northern New England. Here settlement was, for the best part of the first two centuries of the then Colony’s existence, incredibly slow to expand. Long hostilities with the neighboring colony of New France including cross border raiding, and raids encouraged from those neighboring colonials among Tribal peoples from both sides of the border. This pressure saw to it that settlement here in Northern New England held fast at a standstill from the 1630’s through the 1760’s – As did building technology. As is found elsewhere in the New World, settlement patterns heavily influenced construction, in that colonials brought with them what they knew. This is particularly true of Timber Frame Carpentry, with country of origin and even regional variation in the home country heavily influencing the many regional variations found in the former Colony/ies. Framing style, technique and typology were brought from the Mother Country. Here in New Hampshire that transplanted Mother Country typology would be English Tying, in dominant use from the early 17th Century – the “First Period” on through to an end to the expansion standstill, and on into an area wide expansion and building boom. (settlement beyond coastal areas and nearby river valleys) The building boom and now rapid expansion of settlement brought on by an end to these formerly unending hostilities, this end coming with the close to what is little realized as, but was in truth the real first “world war” one encompassing multiple nations simultaneously on multiple continents – Known here as the French & Indian War, and elsewhere to history as the Seven Years’ War. Both Scribe and English Tying would survive this war and follow the boom of settlement into interior sections and remain in dominance another fifty years until a somewhat mysterious rapid change would morph both long used systems (Scribe & English Tying in both houses & barns) out of use in little more than a decades time.

An English Tying frame in Strafford County NH dating to the post F&I Boom-time

An English Tying frame in Strafford County NH dating to the post F&I Boom-time

This mystery of an almost overnight sensation shift away from what even here was a centuries old tradition in Scribe type layout has been high on my mind of late, with the current project being a Settlement Period barn in Bernhard’s Bay New York (here “settlement” was the mid 1790’s through 1815 or so) on the north shore of Oneida Lake. The Bernhard Barn is Square Ruled, and though the exact year it was first built is not yet determined. (research perhaps including Dendro is in the works) In part due to some unusual detailing, I believe it may be the earliest Square Ruled building I have ever put eyes and hands on.

A settlement period building, the Bernhard Barn is an early Square Ruled example of a common barn typology

A settlement period building, the Bernhard Barn is an early Square Ruled example of a common barn typology

Tax records suggest the property was held by John Bernhard - The Farm was developed by his son John - Improvements beginning in 1815

Tax records suggest the property was held by John Bernhard – The Farm was developed by his son John – Improvements beginning in 1815

With long study, exploration and preservation work on historic structures in my home region on the edge of First Period development and what might be the Nation’s first building boom, the sudden move to Square Rule and the concurrent move away from English Tying has long intrigued me. This seems to have begun sometime in the second decade of the 19th Century, and somehow saw total acceptance as the norm as not just common practice here in layout, this rapid shift to Square Rule would become dominant practice over the entirety of the then young nation. Everywhere north to south and as far west as settlement carried, and in this same contracted time-frame.

Some few have suggested, and having seen first hand great numbers of timber framed structures from the period, in not just my home region, but also in most all of those areas then settled – I adhere to the theory that the rapidity of this universal acceptance over a hugely wide geographic area is directly attributable to another violent international struggle, one this year marking its bicentennial – The War of 1812 – The theory holds that high hundreds if not thousands of Carpenter’s from all over the country were brought into the war effort (Hundreds did participate in a strategic effort to build Naval ships at pace on Lake Erie to outnumber British craft in what came to be known as the “The Battle of the Carpenter’s”) to build watercraft, bridges, earthworks & barracks buildings. They shared ideas and also a need to produce needed constructions quickly. An ability to throw more carpenters into an effort which lays out individual pieces mathematically than could possibly fit / fold into a Scribe layup assemblage, made this sheer numbers strategic advantage of Square Rule the Layout of choice for the wars duration, and upon its end Carpenter’s in great numbers returned home with a new tool in their kit, one that despite a generations long practice and tradition, and a tendency in humankind to resist change – Somehow, this became a new beginning, a foundational shift, a season change uncountable hundreds chose to use and share. And in little more than a decade’s time, carpentry would forever be changed.

It is not impossible that Square Rule is also now marking its bicentennial year as a widely accepted widely used system, and that this paradigm shift was in part responsible for setting the tone that the rest of the century would take. That conceptually the idea of interchangeable parts and mass production became an accepted norm and expectation and became part of the human psyche. All through this paradoxical chain of events, this bit about the horrors of war somehow leading to wide and rapid dissemination of a useful idea, coupled with humanity’s unending and simple need to house itself – And that this would in time and in turn, lead to techniques of mass production being used to also build, The Cotton Gin, The Springfield Rifle, and one day, The Tin Lizzy.


Quite Laterally, Here We Go Again –

Frequent fliers likely recall my June entry Meritocracy, (click on the highlighted & underlined text to be linked to the entry) in which I puzzled over the frequency with which contracts to repair and rehabilitate wooden spans are often awarded to companies who, know the ins and outs of bidding public works projects, but who hold nothing in their scope of experience to suggest they have the required tooling, knowledge, or abilities, to in-house execute such work. And somehow, nor are they necessarily required to pre-qualify, or ride the resumé of pre-qualified specialist subcontractors when preparing proposals to bid such contracts. Recent turns of event have again shown how sadly and commonly this circumstance happens.

A recent string of extreme truck damage incidents, leaving horrific levels of Portal to Portal damage, have splintered Tie Beams or dislodged and distorted Tie Rods and ruptured Braces in Upper Lateral Bracing Systems, in two bridges, one in Pennsylvania, one in Indiana.

Though it is often overlooked, complexity in a bridges framing is not limited to the Trusses proper. In some Truss types such as Towns, the more demanding framing is that found in the connecting systems which unify the two trusses and complete the “Through Truss”.

Tie & Lateral Bracing systems are far from simple carpentry, but are a complex bit of advanced Timberframing. (for all the camber driven subtleties and varied reasons I articulated in Meritocracy – Foremost among these being that proper fit requires the acknowledgement that these shoulders and abutments are, more often than not, not “simple” angles, but are in point of fact, compound angles. These necessarily need be laid out and cut to match real world camber driven circumstance – To drive home this point > In Bridge work, every joint which fails to have hard up full bearing through not just the visible portions, but the entirety of the joint, means undue crush and loss of geometry – This including, loss of camber) This circumstance of navigational error truck damage taking out such systems near or in their entirety, and the developing response to it, does drive home particularly well, this paradox of contracting concrete and steel outfits to repair or rehabilitate wooden bridges. At least it does from my perspective – Maybe from yours.

From mine, the perspective is particularly sharp. I cut my Bridgewrighting teeth on Laterals. I came into my first bridge rehab with seasoned timber joinery chops, and was pointed at Laterals – I took it as the performance challenge it was…

Since then, Laterals have kinda been my thing, and I’ve been privileged to help replicate whole sets. Both, all too many Lowers lost to high water, and the flotsam it inevitably carries with it. And in an odd bit of happenstance, multiple sets of Uppers & Ties lost to wet heavy snowload driven roof collapse on three different bridges in three different States. These all lost decades before, (one the year before I was born) and either badly replicated, or done with an inappropriately heavy species, or both, or replaced with inappropriate, not true to original framing systems. I have also of course, helped replace Wind Braces, as well as Ties & Laterals lost to truck damage.

These Bracing systems tend to vary in detail, this sometimes driven by Truss Type, and sometimes by regional norms, the date of construction, or the preferences of the Bridgewright who built the span.

Repair / replacement of the truck damaged Pennsylvania spans upper timber-work was recently awarded to a highway construction outfit. It had / has the Wind Braced Ties and Over / Under Laterals typical to Town Trusses, the dominate Truss type in that corner of PA. It remains to be seen if they will subcontract in a concern with a familiarity in these materials and construction methods to replicate the destroyed framing.

Said to be the work of Nichols Powers, in this “Village Bridge” NH’s Ashuelot, (Ash-wool-it) the terminus for the Lateral Bracing load was formerly shared by two Ties through this Centered Straining Beam- The Design Engineer specified placement of a final set of Double Laterals in either end bay as part of a late 90’s restoration.

I’ve long admired this detail used on Indiana’s Williams – Often incorrectly attributed to JJ Daniels, The Williams is a product of the Massillon Bridge Co.

In process Scribe layout of a Lower Lateral to replacement Floor Beams at Maryland’s Gilpin’s Falls – For more information on this Floor and the now unusual Rebated Sleepers seen here – See the May of ’11 & June of ’13 Archives

The most recent truck damage repairs I’ve had a hand in mending – Portal to Portal damage to the 266′ Mt. Orne

Also Scribed in-situ – The normally unseen connection where the Mt. Orne’s Laterals join each other

Less than Hardwired for Hardware

If I were to define what it is I do, the description I see as mayhaps that one most accurately describing it, with both eloquence and in as few words as is possible, is simply to suggest that “I join timber”

My work is to take one of our planets greatest blessings, Trees. And to take their only modestly converted stems, (With variation, but in essence with only four sapwood slabs removed) and then join this blessing into useful configurations. Be it, houses, barns, or bridges.

In most such efforts joining timber, I find myself working to wholly avoid the use of large metal fasteners – This is almost one of the sub-definitions of what it is to be a Timberframer. Wood to wood is what we do.

Bridgewrighting, as allied a trade as it is, is a bit different. Even those Truss types without iron in them – Longs, Paddlefords, Burrs and Towns, still are often peppered with a smattering of bolts…

Many Truss types, share iron as almost an equal partner, equal in effort if not proportion of material used. A Symbiont of sorts, necessary to allow a largely wooden truss, to do what is asked of it.

Pratt’s are one of these “types” – So, echoed in the lyrics of one of my favored songs, with The First Day in August, last years local Timber Framers Guild project – The Wason Pond Bridge marked the passing of its first year, (see July / August ’11 archives) and I recently found myself willingly engaged in a once common bridgewrighting chore – A first of several, wrench in hand scheduled visits, to tighten Truss Rods and assorted Bolts to compensate for expected and predictable shrinkage as the Timber in the Through Truss seasons.

Joints again fully seated, camber re-tuned. All went as hoped for and expected, with but one small exception. The washers on some of the smaller Bolts sunk into the now dry White Pine wood grain as an attempt was made to re-tighten. I chose to replace these. My first thought was to go to the cast Ogee’s found so commonly in this application. Their cost and limited availability saw me turn to the second most common washer type found on Wooden Bridge Bolts – Large Square Flats.

As such explorations often do, I went looking for contemporaneous Rules of Thumb in what was seen as a norm for such hardware. In AJ DuBois’ – The Strains in Framed Structures – We find these not only crunched number, but period proven suggestions in his list of specifications.

As always, I like to point out how White Pine was and is, the favored Species for the framing of Wooden Bridges – Also from the DuBois List – Section VIII

In Jacoby’s – Structural Details or Elements of Design in Timber Framing – A wealth of information is found on the seemingly mundane subject of washers, as they are related to Timber Work.

The restoration of Maryland’s Gilpins Falls, is the only time we’ve worked with “Special Countersunk Washers” and their funky headed friction dependent Bolts. This bolt & cast washer type was also that chosen and used by Nichols Powers in The Blenheim.

The Wason Pond Bridge is fitted with a number of “Malleable Iron Washers” on both the smaller section Truss Rods at Mid-Span, and at the Tie Beam Bolts.

And like many other wooden spans, it is now home to a large handful of Squares.

Frères Pontiers

I have in previous entries, alluded to feeling myself as being part of a continuum of sorts. This so ever-present that it perhaps might be better described as something approaching a sense of kinship, both with those few who currently make the work of wooden bridges their chosen field, and maybe more so with those many who built them in the past.

Lately I’ve spent all too much thought on what it is to be Bridgewright. The catalysts driving this wonder being many. My not making my nut, maybe being foremost among those. I’d thought the now years long uptick in potential bridgework, was how I would ride out this time of “downturn”. As it turns out, despite the frequency of rehabilitation’s being let out to bid and the bittersweet windfall of flood damage and loss, this work now comes in no more frequently than in better times when the bread and butter of new houses and barns kept my schedule flush, and the ledger something less than the current state of so damned ugly.

Another influence making me wonder was an unexpected reaction to my last diatribe here on the weblog. I fully expected some negative reaction from some certain direction, I had not held back, my piece was meant to evoke a reaction – Somehow, the expected never materialized.

I was however criticized for my outspoken stand on Glu-Lam. With this coming from someone within the design side of the capitol P Preservation community. I was a bit thunderstruck by this. A seeming condemnation, and this simply because I’d had the audacity to weigh in on both design, and the choice of materials.

I simply did not know how to react – I do know, I can count myself (this being not the time for humility) among those some certain few who share expertise in these structures. Beyond that, timber connections is what I do. Who better might weigh in? I have over time designed timber constructions with regularity. Why would I not?

So this a wake-up call. If some of those within my extended community doubt my sense of who I am, how is it I might expect anybody else might?

Niche carpentry, might be, even in a healthy market, a tough sell…

All the same, my less than trampled road sense of self, is all I have to sell. I also know that almost broken continuum yet exists, and happily, hard as it sometimes is, I am part of it.

I never felt myself more part of a long and continuing brotherhood of carpenters and builders than when I was a decade ago, able to reach through time and hold it in my hands. This while in attendance of the UK’s Carpenter’s Fellowship ’02 conference, speaking and demonstrating on Square Rule timber layout, I sat in on a talk given by Damian Goodburn, Archeologist and expert in ancient woodworks and carpentry. After the lecture we spoke at length, and I was somehow afforded the opportunity to physically examine a tenon which had been part of a Roman built wharf which stood on the banks of the River Thames in the former Londinium, and had survived two millennia in the oxygen deprived silt of the river bottom. The most striking thing about it was that despite the passage of some nineteen centuries and it being an object produced by a far different culture, was just how startlingly familiar it was. Right to the thickness of the tenon itself and its distance from either shoulder, down to the size and placement of the peghole. All measurable in imperial inches, by the six inch rule which still resides daily in the tool pocket of my carpenter’s pants.

Though The Romans are better known for their works of stone and concrete, the oldest wooden bridge we have deep description of is the Bridge of Sublicius, dating to sometime around 500 BC. Then there are the far better known examples of Caesar’s ten day bent piling bridge over the Rhine,

and the segmented arch bridge built by Appolodorus and Trajan which spanned the Danube.

And down through the ages, there are other great bridge building traditions.

Though my kinship felt has little if anything to do with any long lost Benedictine order, except that they also chose to exemplify their devotion in the building of bridges, I feel myself as part of a “Brethren” and find no guilt in borrowing their name.