Tuesday, September 12, 2006
Dear Sir or Madam:
The Balls Bridge over the Maitland River is a historically significant and rare
bridge and its preservation is a worthwhile and important endeavor. I understand
that you have reviewed my website at
www.historicbridges.org, and seeing the large number of metal truss bridges
present on my website, have questioned how rare the Balls Bridge is. In order to
understand why Balls Bridge is indeed rare and historic, some background on
metal truss bridge design and history can help. I can provide some details to
help make clearer why the Balls Bridge is indeed historically and
technologically significant. I can also explain how and why my website might
have misled you to think that truss bridges are much more common than they
really are.
As an individual with limited income and no outside financial support, I am
forced to be thrifty in the way I spend money in the pursuit of historic bridge
documentation. As such, when I travel to photograph historic bridges, I travel
to locations that have an unusually high number of historic metal truss bridges
so I can visit as many bridges as possible during my trip. I have made metal
truss bridges my priority to document since they are among the rarest and due to
age and lack of preservation efforts, are the most threatened type of historic
bridge. The fact that areas of extensive coverage on my website include western
Pennsylvania, southern Michigan, and counties along the Ohio River is no
coincidence, as those are areas with high numbers of truss bridges. Western
Pennsylvania in particular has more truss bridges than any other region in the
United States. Some states have hardly any metal truss bridges, and as such I
have not visited them. There are many counties in Michigan that do not have any
truss bridges of any kind at all, let along multi-span pin connected truss
bridges like the Balls bridge, and many of these northern counties have no
website pages as a result. Take a look at my 1995 truss bridges of Michigan list
available on the main page of my website, which shows that truss bridges have
been being demolished frequently over the past ten years and are becoming
increasingly rare. I also encourage you to visit another bridge website,
www.bridgehunter.com and inspect the
remaining truss bridges in the western, southern, and the northern Great Plains
states of the United States. This website inventories bridges by county
regardless of whether anyone has photographed them or not, so it provides a
clearer picture of how few pre-1900 truss bridges there are. Canada does not
have a national inventory of bridges, and so it is impossible for me to easily
assess what remains in Ontario. However, I suspect that the pattern would be
that southern Ontario is where most of the truss bridges are, due to the
population of the area and location to steel mills and bridge companies both in
Ontario and the United States. I hope that this helps clarify the fact that
truss bridges are nationally rare, and given that, they should be preserved
wherever they are regardless of whether there are more metal truss bridges in
the region that a particular bridge resides.
There is another even more important factor to consider when evaluating the
significance of the Balls Bridge, which is to compare it to other metal truss
bridges and see how it ranks. I personally believe that all metal truss bridges
are historically significant to some extent which accounts for me including so
many metal truss bridges on my website. I am however at the same time very clear
about elements of an especially rare bridge that makes it stand out and as such
more worthy of preservation efforts. There are three basic categories that I use
to compare metal truss bridges, and I outline them below.
First, metal truss bridges fall into two different design categories. There are
those with pinned connections, which typically are lightweight structures dating
before 1900 and those with riveted connections which generally date after 1900.
Lambton County, Ontario has a number of metal truss bridges, but not one has
pinned connections. A number of the truss bridges you will find in the state of
Pennsylvania or in Cook County, Illinois, are these newer rivet-connected truss
bridges, which offer no real comparison to the Balls Bridge since they were
built in a different era using different construction and design methods. Pin
connected truss bridges are rarer than rivet-connected truss bridges and thus
are more significant.
Second, in evaluating the significance of a structure, the length of the bridge
must be considered, since longer and/or multi-span structures are less common.
Indeed, most remaining pin connected truss bridges in Ontario and the United
States are single span. In contrast, Balls Bridge is a two-span bridge. Crawford
County, Pennsylvania is one of the richest truss bridge counties in the United
States, and has over 20 pin connected truss bridges remaining today, yet only
two are multi-span. Take a look at the Venango Veterans Memorial Bridge, which
is structurally similar to Balls Bridge, yet is eight years newer, at
http://www.historicbridges.org/truss/venangov/index.htm and look at the
green table showing the findings of the Pennsylvania historic bridge inventory.
These state historic bridge inventories are mandated by Federal government, and
states like Pennsylvania, who prefer to demolish and replace bridges, can be
rather conservative in assessing the significance of a bridge. At the time of
this inventory the finding was that, “Crawford County is rich in pin connected,
metal truss bridges with 35 ranging in date from 1870 through the early 20th
century remaining.” Yet despite that, they found that the bridge “…stands out as
a long, complete, multiple span example of its type and design,” and found that
“The bridge is historically and technologically significant.”
Thirdly, there is the consideration that the older a truss bridge is, the rarer
it is. The design of Pin connected Pratt truss bridges such as the Balls Bridge
started being built around 1876, but did not gain real popularity until 1880,
with the height of the era being in the 1890s. With a construction date of 1885,
Balls Bridge falls well into the earlier portion of this era of bridge
construction.
There is a final reason to preserve the Balls Bridge, and that is the aesthetic
value of the bridge. The rarity of a bridge is only one among many factors in
the evaluation of a historic bridge. In 1991, Ontario’s Ministry of
Transportation and Ministry of Culture published a document entitled “Ontario
Historic Bridge Program.” In it, there is a description of criterion that is
used when bridges in Ontario are officially evaluated by the Ministry of
Cultural or perhaps a county or region conducting a survey. In it, the rarity of
a structure is only one of many criteria. Among the other criteria is a score
for aesthetic value, as well as bridges that positively influence and contribute
to their surroundings, or are well known by the local public as landmarks. These
additional criteria suggest the many of the other elements that make Balls
Bridge unique and important to preserve. In my time photographing metal truss
bridges, I have never encountered two pin connected truss bridges that offer an
identical presence. The technical design of these bridges vary either in their
overall appearance or even in terms of small details that the builders of the
day took time to design. In addition, each truss bridge forms its own identity
as an unusual structure in a unique location. Certainly the Balls Bridge is in
one of Huron County’s most scenic areas, and the combination of the Maitland
River landscape and Balls Bridge form a scene of history and beauty that is
irreplaceable and replicated in no other place.
I stand by my original assessment that the Balls Bridge is a rare and historic
structure. Balls Bridge should be preserved on those grounds alone. The group of
citizens who have spoken out in favor of its preservation are yet another
reason. I apologize if my website led you to believe that 1880s multi-span pin
connected truss bridges are a common transportation-related resource, as nothing
could be further from the truth. The Balls Bridge is rare, historic, and
beautiful, and deserves to be restored!
Sincerely,
Nathan Holth
Author/Webmaster
http://www.historicbridges.org
