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.