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Upper Bluffton Bridge
By
Jason and Birgit
Smith:
Jena,
Germany
Location:
Upper Iowa River
on West Ravine Road, just west of Bluffton, at the entrance to the
Logsdon Campground (Section 9, T99N- R9W Bluffton Twp.)
Description:
Two-span truss
bridge. The west span is a pin-connected pony truss bridge, while the
east span is a six-panel through iron truss bridge with town-lattice
portal and heel bracings (the latter angling at 45° from portal to end
post), and ornamental plaques on the top of the portals and at the joint
where the end post and upper chord meet. Both truss bridges are of Pratt
design [The approach span
is a Queenpost truss].
Dimension:
154 ft. long
total (through truss length:
116 ft ), 14.8 ft. wide, and (14) ft. vertical clearance (through
truss span). Note: The vertical clearance was reduced to 9 ft. last
year.
One of many bridges built by the Wrought Iron Bridge Co. during the
1870s and 1880s in Winneshiek County, the Upper Bluffton
Bridge is significant in
many different ways. First of all, the bridge is one of the
“textbook-truss” bridges that was constructed during this period. This
means that the bridge parts were fabricated at the bridge company in Ohio, before being transferred by train and
wagon to its original destination. There, the bridge was assembled by
local contractors, using pinned connections to hold the structure
together. Like building a house using the Erector set during the 1880s
and 90s and more modern sets a century later, this type of bridge
assembly work became very popular, and many bridge companies including
the King Bridge and Iron Company in Cleveland, OH later adopted this
technique as a way of saving time and labor.
Furthermore, these bridges could be disassembled and reassembled
at a different location if necessary, which served as an advantage for
many who wished to maximize the life span of the bridges and their
usefulness on various roads during those days. Secondly, the Upper Bluffton is unique because it represented change
regarding bridge construction. This meant that at the time of the
bridge’s construction, the Pratt truss bridge became the most preferred
bridge type to be used, because of the structure’s ability to withstand
pressure towards the middle, thanks to the diagonal bracings slanting
downwards towards the center of the bridge. Designed by Thomas and Caleb
Pratt in 1844, the design later expanded to include subdivided types,
some of which can still be found in the county and will be discussed in
later bridge commentaries. Other truss types used during this time,
including the bowstring arch, Howe, Fink, and Bollmann trusses were
being phased out one by one due to structural deficiencies. The Upper
Bluffton
Bridge represented this
changing trend in bridge design.
In
addition, the bridge was constructed at the twilight of the usage of
iron for bridge construction. After its development through the Bessemer process in 1851
(patented in 1855) and in light of the Great Chicago Fire in 1871, steel
became the norm in architectural and bridge construction because of its
durability and flexibility in extreme weather conditions. This made
assembling and reassembling the bridges even easier. Furthermore, steel
bridges were able to withstand more pressure by heavier vehicles
including freight and passenger trains, which resulted in the
construction of longer and heavier spans from the 1880s onwards.
By the 1890s, steel was exclusively used for bridge construction
because of the numerous advantages it had over the iron structures. The
Upper
Bluffton
Bridge
is one of only a few iron bridges still remaining in Iowa and one of the six existing structures
in Winneshiek Co. that was built using the material that eventually
became obsolete for bridge construction. The fourth reason for the
bridge’s significance is its location at the palisades of the
Upper Iowa River. The palisades stretches from the bridge
northwards toward the Chimney Rock area and Hruska campground and
beyond, presenting boaters and tourists with a splendid view of the
river. Many theorists in the field of environment and technology are
sometimes of the opinion that architecture and nature do not mix, that
nature must be controlled through architecture so that people can access
goods and services from far away. However, like covered bridges, metal
truss bridges blend in beautifully with the natural surroundings,
providing the visitors and even photographers with a picturesque view of
the landscape and the peace and tranquillity for those wanting to escape
the sprawling stresses of life we refer to as modernization.
The Upper Bluffton represents a
fine example of how nature and architecture do get along without the
slightest disturbance. Even though the bridge is difficult to reach due
to the sharp curve and a slight downhill grade while leaving the village
(and we must admit, we missed the bridge the first time while we were
trying to photograph it), when crossing it, it presents the driver with
a picturesque view of the steep bluffs of the Upper Iowa River to the
right, and steep wooded hills to the left beyond the campground.
Furthermore, the bridge is a source of recreation for it lies next to
the campground and provides access for canoeists and fishermen alike.
From my own personal experiences visiting and photographing a truss
bridge before and after it was replaced, a person can tell the
difference between a structure that is lightweight but fits perfectly in
the landscape, and one that is modern and able to carry more traffic,
but is a total eyesore. Can you imagine the Upper
Bluffton
Bridge being the next
victim of such modernization?
At
the present time, the
Upper
Bluffton
Bridge
is on the five-year replacement plan and is scheduled to be replaced in
2010. For some, it might be a sigh of relief because the structure
cannot handle the heavy loads anymore as well as it did decades earlier.
The bridge carries a 3-ton weight limit and is further handicapped by
the vertical clearance limit of nine feet. Furthermore, extensive
repairs have been conducted on the bridge, which included the
construction of a reinforcement pier between the pony and high truss
spans in 1995. Most recently, several stringers were replaced with those
taken from a previous truss bridge that existed in Winneshiek Co. This
work took place last year. Despite the restrictions on the bridge, many
drivers choose to ignore the signs and cross the bridge anyway, which
could potentially spell disaster for the bridge in the long run. As
recently as last spring in Missouri, another Pratt high truss design,
also a Wrought Iron Bridge structure, fell into the river as a result of
this ignorance, sparking an outrage from many who believed that the
driver should bear full responsibility for wreckless driving and
intentionally destroying public property. To this day there is no word
on whether he was prosecuted for this incident. However, in many cases,
the driver usually escapes any form of criminal litigation. More
information is available through the link provided at the end of this
commentary.
For many, the bridge’s replacement would not be a welcoming idea for
reasons already mentioned earlier in the commentary. On the one hand,
the Upper
Bluffton
Bridge provides the
shortest direct route to the campground, owned by Randy’s Bluffton
Store, Canoe Rental and Campground. On the other hand, there are
alternatives towards preserving the structure, which has been listed as
historically significant on both the local as well as the national
levels. By considering the alternatives in preserving the bridge in its
place, it could serve as the best of both worlds for everybody. First of
all, the bridge would have another life if it was remodelled and open
only for recreational purposes with access to the campground being
rerouted for all other vehicles. This could be done either by
constructing a bridge on the other side of the campground (which would
eliminate the dangerous steep curve going down to the bridge), or by
rerouting the road, which would mean accessing the campground from the
south and west. The second option (though financially feasible) would be
a long detour and in order to eliminate the temptation of crossing the
bridge, the west approach would have to be taken out or narrowed to make
it only accessible for bikes and pedestrians. In the long term, it would
serve as an asset for many wishing to see the relict of the past being
reused again, which brings us up to the second point. There have been
many examples of bridges that have been renovated and reused again for
the purpose of maintaining its integrity and attraction for passers-by
who love to see the structure in its place. In the case of two bridges,
one in Pennsylvania, the other in
Ohio/Michigan, these structures were built of iron and by the same
bridge company that built the Upper Bluffton,
but were reopened for traffic. Links are available at the end of this
commentary for those who want to know more about it. In the case of the Upper Bluffton
Bridge, it is possible to
refurbish the structure and reconstruct it back in its original spot to
be used again, without having to spoil its historic significance. The
only set back to this is that the bridge would need a new center pier,
for the old one is falling apart. However, despite the costs for that
plus the renovation in general in the short term, in the long term, the
renovation plan, which could take 1-2 years to complete, will be well
worth the cost, for many would like to see this historic wonder of
Winneshiek County be reused in its original location, but only for the
purpose of seeing it, not for travelling across it in supersized RVs.
Imagine taking your child across the bridge and walking (or biking) back
in time to when it was built, when it was used during the 1880s and
beyond, and just witnessing the natural surroundings the bridge provides
you. Imagine doing research on the bridge’s history by looking at the
structure itself (not just the plaques) and relating it to American
history and the age of innovation during the time of its construction.
Imagine fishing from the bridge with your friends when it is all quiet
and the only voice you hear is your cussing because the fish is playing
games with your hook. Imagine yourself on the bridge either writing
about its beauty and tranquility, like Alexander von Humboldt, Paul
Gruchow, and Sigmund Olson (just to name a few) or drawing the structure
and its surroundings for an art competition and receiving a blue ribbon
for the work you have done. But most importantly, imagine yourself
taking a group on a guided tour of the county, where apart from knowing
more about the Scandanavian heritage, you know more about the
architectural and natural aspects of Winneshiek Co., and you happen to
take your group to the campground and especially to this particular
bridge and you allow them to take a look at it. Surely you don’t want
them to see a concrete structure a.k.a. “that ugly boring bridge,” would
you?
Resources:
Frenchman Bluff Bridge Disaster
in Missouri available here:
http://bridgehunter.com/mo/lincoln/frenchmans-bluff/
Examples of bridge preservation in Michigan
and Pennsylvania available
here:
http://www.historicbridges.org/truss/maple/index.htm
http://www.venangoil.com/bridgesjerseybridge.html
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