WHO BUILT THE COVERED BRIDGES?
THE SOCIAL ORGANIZATION OF BUILDING

JOSEPH D. CONWILL
PO BOX 829, RANGELEY ME 04970 USA

The legendary covered bridge builder is a folk figure like the old-time lumberjack, or the tall ship sailor.  We know the image: self-taught, a farmer in the summer and a bridge-builder in the winter, he may or may not have been able to read and write.  But he was capable of building sturdy bridges, which have lasted in service over a century.

But does the folk image match the reality?  Sometimes it does.  James F. Tasker of Cornish, New Hampshire was such a man.  We know that he could not read or write from the testimony of his former employee, Cyrus Barton, in the archives of the National Society for the Preservation of Covered Bridges, Richard Sanders Allen collection. A closer look shows that more often than not, the folk image is not true.

 

Today I want to discuss the diversity of covered bridge builders as a social group, and also to highlight some historical problems, which sometimes cause the wrong person to be credited as builder.  Finally I will mention some special areas where research is needed, and if you know someone in need of an idea for a Ph.D. thesis, there is opportunity in this field.

First, though, we need to look at some terminology.  The bridge designer, and the builder, may or may not have been the same person.  Today there is a clear difference between an engineer, who specializes in the structural work of holding buildings up, and an architect, who is concerned with aesthetic design and layout.  The building contractor is someone else yet again.  But even today, in some forms of architecture, an architect may function as his own engineer without the title.  And in less elaborate residential construction, a building contractor may even act as his own architect and engineer.

It was not until the middle 19th century that engineers and architects developed professional organizations and formal certification.  When covered bridge building began in the first decade of the 19th century, the designers were not yet known as engineers, and indeed, before the 1840s there was no commonly accepted body of mathematics for stress analysis.  We know less than we should about the process of design in those days, but apparently it was largely empirical.  Bridge designers were often known then as architects.

But in the very early years, the designers do not fit our folk image.  First, they were usually well educated; not always formally, but they were literate, well read, and in touch with the latest design information by means of professional publications.  Second, many specialized full time in bridges.  Timothy Palmer (1751-1821) and Lewis Wernway (1769-1843) were both full-time bridge architects.  And they were also builders, overseeing the bridge construction itself, although they sometimes had more than one project going at once, and had to rely on trusted superintendents, as they traveled from site to site.  Most of Wernwag‚s later bridges were built by others, using plans drawn up by the great architect.  It is possible the Wernway never visited some of the later projects he designed, and we would like to know more about this period of his career.

For Wernwag documents a movement towards specialization.  All of the very earliest covered bridges were custom-designed project.  But the architects began patenting standard plans.  Afterwards, a local builder might pay a fee to use a patent, whose designer never saw the site.  Thus the architect who patented the plan, and the builder, who used it, were now two separate people.  But the builder still had considerable design responsibility to adapt the patent plan to the project at hand.  This accounts for the wonderful variety in framing details we find in the older patent-plan bridges.

Theodore Burr (1771-1822) was a transitional figure.  His early bridges, before 1810, used a variety of experimental designs; every one built by the architect himself.  But Burr went on to patent a truss, which others were supposed to pay a fee to use.  He continued building bridges in person, but we know little about his management of his patent interests.  Since he died indigent, he seems not to have been a good financial manager.  His truss was widely used, but his main interest was in building.  He was a full-time professional, and he did not fit the folk image of a rustic craftsman.

Still less does Ithiel Town fit the image (1784-1844).  Well educated, erudite, artistic, and a canny businessman, Town brings us to an even greater level of specialization.  He is chiefly known today as one of the major proponents of the Greek Revival style in his churches, state capitol buildings, and other important structures.  But he also patented the Town lattice bridge truss in 1820 and in 1835, and drew considerable income from it.  He was a specialist in design, and so far as we know he only built three bridges himself.  The actual builders of the Town lattice truss were, in many cases, the rural craftsmen of the folk image, farming in the summer and building bridges in the winter.

I need to highlight here a point where historians should be careful, especially historians in New England, where bridge building was usually the responsibility of the town government.  Town Meeting records are usually vague and frustrating when it comes to details of bridge building.  Town Reports, where available, are sometimes better.  But bridge appropriations are often lumped together with those for general roadwork, what we might call today the Summer Roads Account.  Often a bridge project would be under the care of a special committee, whose report is usually missing; Town Meeting minutes will simply say, “the bridge committee report as accepted as read.”  But even where details and a name are given, the name is very often not that of the bridge builder.  Generally it is the name of the town agent; the one legally empowered to sign contracts for the town.  He would have known who the bridge builder was, but unfortunately we can‚t ask him.  Sometimes the town agent may have been some kind of builder himself, and always he was a prominent and respected citizen.  In some cases he may have been entrusted with design matters, merely hiring laborers and boss carpenters, and if so he could be considered the bridge builder.  But in most other cases, the town agent hired an outside bridge-building contractor, perhaps the rustic craftsman of our folk image, perhaps a millwright who also did industrial construction.  The contractor generally did the design work, although the bridge committee or town agent might provide general guidelines, or even specify a truss type.

The contractor must be considered the builder, not the town agent.  To make things even more complicated for the historian, the contractor sometimes hired a framer, or boss carpenter, to do most of the real layout work.  This problem comes to light when descendants of both the contractor and the framer claim their ancestor built the bridge.  If we have in hand a Town Report showing who was really paid, that can solve the question.  Often the details we need are missing, and the historian needs to be very careful about names recorded in old Town Meeting minutes and other sources.

A case in point, though not from New England, is the famed railroad bridge built in 1866 over the mouth of the Susquehanna River between Perryville and Havre de Grace, Maryland.  This was a long, multiple span Howe truss with arches, though not covered.  Sometimes Nichols M. Powers of Clarendon, Vermont is credited as the builder, and Powers was indeed a famous bridge builder.  But on this job, it is clear from Powers‚ own papers at the Vermont Historical Society that he was the chief framer, or construction superintendent, and not the designer, architect, or engineer.  He did indeed oversee the details of putting it together.  But George A. Parker, engineer, who specialized in railroad work, was also on the job site supervising, and it was he who really designed the bridge.  We need to tell the whole story.

William Howe‚s bridge patents in 1840 opened the way to yet more specialization.  The Howe truss could be built of parts prefabricated in a distant factory, and shipped out by rail.  Indeed, the first Howe trusses were railroad bridges.  Builders of the Howe truss formed business arrangements almost as complicated as the corporate structures for railroads.  William Howe himself did very little bridge building, but he was related by marriage to four brothers named Stone who promoted his business interests in various parts of the country.  Stone & Boomer, Stone & Harris, and other groups formed the prototypes for the great 19th-century bridge companies.  The Howe truss brought iron into wide use as a bridge component, along with wood.  Its builders also represented a new breed of urban-based businessman, very different from the rural craftsmen of legend.

Robert W. Smith returned to nearly all-wood construction with his designs from 1867 onwards.  But the Smith Bridge Company was even more a model of corporate centralization and prefabrication than were the various companies, which built the Howe truss.  And the built record reveals this standardization.  Smith trusses show rather little variation in construction details, except for the different plans offered by the company itself.

Here the historian may run into new problems in crediting the builder.  Sometimes a bridge was fabricated by the Smith Bridge Company bridge works, first at Tippecanoe City, Ohio, and later at Toledo, and also erected by a contractor serving as the company‚s own agent.  Except for details such as length of span, design would have been done at corporate headquarters, but we note a difference here between the fabricator, who designed and made the parts, and the contractor or builder who put them together on site.  Occasionally an older pattern was followed, in which design and manufacture of parts was done on or near the site by the contractor himself, paying for patent rights as long as the patent was still in force.  This generally happened outside the territory covered by the official agents of the Smith Bridge Company.  Two such locally-built Smith trusses are known to exist, and there may be a few more.  They do show non-standard variations, such as would be usual in the older truss plans.

Regional culture brought differences in the way bridges were built.  Corporate standardization made very few inroads in New England, except on railroads.  There, the part-time craftsman tradition continued in some areas to the very end of covered bridge construction, which here was around 1910.  Pennsylvania also had many individual craftsmen, although since bridge building there was usually the responsibility of the county, we find styles and builders concentrated by county.  Only in far western Pennsylvania do we first encounter the standardized, corporate-built Smith truss, and there are none at all in New England.  Meanwhile in Ohio and Indiana we find some standardized, company-built Howe and Smith trusses, but also many Burr and Howe trusses built by individual contractors.  The south mainly favored individual contractors too.

When we reach the Pacific coast the historical pattern is different again.  Early bridge building in California, Oregon and Washington was a mix of individual contractors and company jobs.  But in Oregon, covered bridge building lasted just past the middle of the 20th century.  Because of the availability of high-quality large timber, covered bridges remained cost-competitive here.  The last covered bridge in the United States built solely for economic reasons, with no thought of nostalgia, was the Irish Bend Bridge in Benton County, Oregon, which dated from 1954.

Most of Oregon‚s existing covered bridges were built by county government, with technical assistance from the State Highway Commission.  The state got involved in 1915, making standard covered bridge plans available to counties, partly from a sense that county commissioners were being swindled by fast-talking salesman from the steel bridge companies.  But the county engineer finalized details, and most counties thus developed their own recognizable styles, especially in housing.  Sometimes the county engineer hired an outside contractor to build, but sometimes he used the labor of the county‚s own road crews.  Here, specialization reached its zenith.  A bridge patent, by a designer long deceased, was adapted by a college-trained, civil service engineer, and built by a crew of county employees.  This is a long way from the folk image.

Government covered bridges were also built in Quebec and in New Brunswick, which also had large supplies of good timber.  Quebec really started the trend amidst a special set of cultural circumstances.  In Quebec, throughout the 19th century, many French political leaders rejected modern industrial society in favor of an agrarian model, but to support their growing population it was necessary to expand the land base in agriculture.  In 1887, nationalist Premier Honore Mercier created a Department of Colonization to offer government support for land settlement plans.  Roads and bridges were included in this support, and the bridges were covered ones.

The Department of Colonization modified the Town lattice truss so that it could be built cheaply by unskilled labor.  The details may perhaps have been drawn from some late vernacular bridge building tradition, and more research is needed.  Metal spikes took the place of wooden treenails at the joints.  Plans came from an engineer in Quebec City, the construction superintendent was an agent of the Department of Colonization, and the labor was often provided by the settlers themselves in corvee.  It is truly difficult for the historian to find a single builder to credit: Seventy-one of these „colonization bridges‰ still stand in Quebec, and as in Oregon they were built into the middle 1950s.  Some however were built by professional contractors instead of by settlers.

New Brunswick also had a colonization movement, though less extensive than that of Quebec.  New Brunswick, too, built covered bridges by government plan, up until 1958.  The province also built many non-covered, creosoted timber trusses, these as recently as 1972.  Little is known of the history of New Brunswick‚s covered bridges, but although the plans were drawn up by engineers in Fredericton, it seems they were mostly built by local contractors in the craftsman tradition, who may have fit the folk image in some cases.

New Brunswick brings our attention to that much-neglected structure, the open, or non-housed, timber truss.  Structurally these are nearly identical to covered bridges, and they use the same truss plans.  British Columbia built large numbers of them up until the early 1960s.  We also have several widely scattered across the U.S.A.  They have been almost completely neglected by historians and preservationists, and they are a difficult case because wood, without housing, is inherently impermanent.  But I receive a good measure of attention from historians while there is something left to study.  It may be difficult at times to pin down the builders of covered bridges, but the structures do at least have a following.  So do iron and steel trusses, stone arches, and indeed nearly every other kind of bridge.  The non-housed timber truss is an orphan, and the field really needs some research.

Another area which needs historical attention is the history of bridge construction by railroads.  Many famous builders did railroad work, and research has been done on Benjamin Labrobe, Jr., and on Col. Stephen H. Long.  But many railroad bridge builders, especially in New England, remain surprisingly neglected.  We all know about the highway bridges built by Nichols Powers of Clarendon, Vermont, and we are somewhat aware of his other industrial work, such as for the marble industry.  But Powers also did important work for the construction of the Rutland Railroad, about which nothing is known.  Or take the case of the Childs brothers of Henniker, New Hampshire, one of whom patented his own bridge truss.  The Childs brothers were proficient in various forms, including the Pratt truss.  But their career in railroad building for the Kennebec and Portland Railroad in Maine remains little known.  Rail fans know all about rolling stock and something perhaps about stations, but almost nothing about bridges, without which our rail system would have been impossible.  Here then is another subject for future research.