Monthly Archives: April 2013

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

Advertisements