- Why the obsession with covered bridges?
- Do I get involved with non-covered bridges?
- Why are they covered?
- What were/are they good for?
- Why do vertical clearance or weight limit signs have to be mounted so they ruin a picture of just the bridge?
Consulting
General Questions
Have a question about Covered Bridges?
Send it to Email - phil at philsbridges.com
Why the obsession with covered bridges?
After more than 20 years of involvement with all types and sizes of bridges and a fairly large number of building projects, including some large timber-framed structures, I had an opportunity to tackle a study of 75 covered bridges in Vermont. The study was going to be very intensive and would involve a lot of people and specialists to address the various aspects of the work. We decided that we were as qualified as any other firm (at that time, I served as the Structures Department Manager of McFarland-Johnson, Inc., Binghamton, NY) to chase the work and I put my heart into it. The process of consultant selection was time consuming, but we were finally notified of selection for the project in late 1992, about a year after the start of the chase.
I found the work totally fascinating from many perspectives, but one of the aspects involved the fact that we could not find many references related to engineering or construction issues. Hence, at many times, we were on our own to develop answers to technical challenges, and then discuss with our client - the Vermont Agency of Transportation.
I have always loved challenges - these wonderful old structures offer so many to an engineer interested in preserving the bridge in a way to maintain or restore it's intended useful function.
back to questionsDo I get involved with non-covered bridges?
Yes, one of my first assignments involved a temporary bridge for installation as a bypass structure during a routine bridge replacement project.
I am currently working with a property owner in Vermont to design a crossing of a river to gain access to the main portion of the property. That work is being done as a "Design / Build" project - one with direct teaming of myself with a local contractor to afford the owner the most cost efficient bridge possible.
Another recent consultation involved a larger three-story timber-framed barn built in the early 1800s.
My nearly thirty years of experience has blessed me with a very diverse exposure to nearly all types of bridges and many buildings projects. Give me a call for your project needs.
back to questionsWhy are they covered?
The following list of reasons are compiled from a variety of sources:
Popular Reasons:
- A covered bridge provided a refuge for horse and buggy from a sudden storm.
- The sides of the bridge prevented horses from shying from the sight of rippling water.
- The bridge provided a romantic hideaway for a stolen hug or kiss.
- The portals and roof were intended to neatly shape a load of hay.
- To prevent a traveler from knowing what kind of Town was coming before it was too late to turn around.
- A bridge with a roof was preferred over a metal bridge which might attract lightning.
- Builders of covered bridges were used to constructing barns, and automatically added a roof.
Actual Reason:
Regardless of the legitimacy of the reasons cited above, the real reason for covering timber bridges was to protect the main timber trusses from the detrimental affects of rain/snow. The intermitant wetting and drying provided an ideal atmosphere for accelerated timber deterioration - rot.
Large timber truss bridges were initially built in the United States without covers. It was not uncommon for such a bridge to fail within 10 or 15 years.
There are original covered bridges still standing that have been in place since the 1820's!
back to questions
What were/are they good for?
- They provided a convenient place for meetings, such as political rallys, religious revivals, weddings...
- They provided a convenient advertising location for posters, handbills, etc.
- They provide(d) a good, shaded fishing spot.
- They provide(d) a convenient diving platform for the adjacent swimming hole.
Why do vertical clearance or weight limit signs have to be mounted so they ruin a picture of just the bridge?
I think most states have something like New York - it's called a Manual for Uniform Traffic Control Devices, published by the New York State Department of Transportation (NYSDOT). This is the guidebook on what signs are required under various scenarios and the specifics about wording, size, and location of the sign. In our New York Manual - the subsection related to the question of weight restriction signs indicates that the signs are to be mounted "immediately adjacent" to the bridge. So what is "immediately adjacent"? I am unaware of any source of definition of this reference within guidelines of NYSDOT. In which case, it is left up to the judgement of the person dealing with the signs.
Both signs are "regulatory" signs and should be posted along the road well before the bridge to give potential restricted vehicles a chance to find an alternate route - usually at the entrance to the road with the restriction and its intersection with adjacent roads. And, there should be signs near the bridge to again state the restrictions so that a restricted vehicle doesn't press forward. Much of the decision about where to locate the signs relates to the physical conditions at the site. It is convenient to mount them to guide rail posts of the approach rail to the bridge - sometimes that railing is quite short, causing the sign to be real close to the bridge.
But, to the extent that I might influence others, and hearing the howls of protest about such situations detracting from an otherwise scenic view, I am advocating relocating such signs farther from the bridge. So what is "farther"? Another judgement call, but certainly, provided the site allows it, the signage could be moved back to 50-100 yards from the bridge and still convey the intended warning, while hopefully, allowing better photography.
back to questions