Preservation ABCs: K is for King Post

Preservation ABCs is a series that will work its way from A to Z, bringing words into conversation that are relevant to historic preservation, whether it’s an idea, feature or vocabulary term. The idea is to help you see preservation everywhere you look and wherever you go. Enjoy! See previous letters.

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K is for King Post (Truss)

Pine Brook Bridge in Fayston, VT: A king post truss bridge. Source: Library of Congress. Click for source.

Pine Brook Bridge in Fayston, VT: A king post truss bridge. Source: Library of Congress. Click for source.

A king post is a type of truss, and can refer to building or bridge construction. Being able to identify a truss is an important part of preservation conversation, whether you are working on an architectural description or talking to a contractor or an engineer. As an introduction to trusses, start with an easy one: the king post truss. It is a simple truss and most often used for short spans. Think of it as a triangle. An easy definition of a king post is borrowed from Cyril Harris’ book, American Architecture: an Illustrated Glossary:

A structural support for a roof formed by two inclined rafters joined at the apex of their intersection. A horizontal tie beam connects the rafters their lower ends, and a vertical central member (called the king post) connects the apex with the midpoint of the tie beam. 

See the triangle? This triangle is a truss and can repeat in bridges (then called multiple king post truss) and structures. They are easiest to identify on covered bridges or metal truss bridges or in attics. Take a look next time your passing over a bridge or hanging around an attic.

Got it? You can always jump to the HAER truss poster and dive right into studying.

How to Photograph a Bridge

In the world of transportation and preservation, I spend a lot of time around bridges, conducting resource IDs, evaluating the historic significance of these bridges and reviewing projects for any adverse effects to our historic bridges and adjacent historic resources. Anyone who conducts resources IDs in the field knows that photographing the project area and the resource is a vital part of documentation and research. Why are photographs important? By photographing particular elements of structures – whether buildings or bridges – it is possible to date the historic resource by construction methods and materials used. Architectural styles date buildings, but also date bridges. Railings, deck systems and truss types allow for dating bridges.

Most often, preservationists photograph buildings and districts, but not necessarily bridges.  Just as it is important to properly photograph a building (all elevations, 3/4 shots, details, context), there is a correct way to photograph bridges. The Historic American Buildings Survey and the National Park Service have similar guidelines (your State Historic Preservation Office has likely adopted these same guidelines) for photographing architectural structures. HABS/HAER documentation includes (1) historical research, (2) measured drawings and (3) photography.

The Historic American Engineering Record (HAER) provides four main guidelines (see page 4) for photographing bridges. While these are somewhat vague, it is a good starting point and basic checklist. All bridges are different, so it would be hard to have one comprehensive list.  Want some preservation jargon? We usually say “photo-doc” for short – obviously for photographic documentation. Up for some photo-doc? Let’s go through these four HAER guidelines with a variety of examples.

1. General views of all sides.

Photograph all sides/elevations of a bridge.

The Windsor-Cornish Covered Bridge, connecting Windsor VT to Cornish NH. Actually, this is from NH, so it's the Cornish-Windsor Bridge. This photograph is not ideal because it doesn't capture the entire bridge; it should. Smaller bridges are much easier. If I were documenting this one, I'd have to find a better view or go for a swim in the river.

The bridge openings count as sides and should be photographed, too, along with the approach to the bridge and the contextual surroundings. Context is important for determining the significance of a bridge. This is also helpful for an approach detail photo.

2. Detail views of portals, portal connections, upper chord connections, vertical members, traffic deck, bridge plates, manufacturer’s badge and any decorative features.

Truss bridges are more complicated to document (I think) but again, take note and photograph the connection details like on this pin truss.

Photograph the connection details. This picture shows the hand cut connection for the metal baluster and the bolt connection to the concrete post.

Photograph the railing connection to the endwall or post.

Many bridges have the date stamped on the endwall and have a state bridge plaque. These are important historic features of the bridge.

Of course, make sure to photograph the truss members in order to identify which type of truss. This a Town Lattice Truss covered bridge. On some bridges, you will be able to photograph this detail from the outside (e.g. on metal truss bridges). If not, photograph the details inside.

Photograph truss bridge chords and diagonals and connection bolts.

Railings! Photograph the railings, whether concrete, metal, cable or other.

3. If accessible, the traffic deck support system (such as floor beams and stringers viewed from underneath the bridge).

Underneath the bridge you can see the connections of chords, joists, floor beams, etc.

If you can safely access the bank adjacent to the bridge, photograph the bridge piers. This photograph shows the center pier, one abutment, and a general view of the deck support.

This photograph shows the detail of the pier, deck support, and the railing in addition to the steel girders.

4. Abutments and approach details.

This photograph shows the railing and endwall connection and the barely visible wood & cable approach rail.

Under the bridges you can see the abutments (that massive concrete abutment is not original to this covered bridge) and the floor beam system.

This photograph shows the abutment (new concrete abutment faced in dry laid stone. You can see the concrete on the bottom left of this image and above the top row of stone on the far side of the bridge).

Photograph the approach to this bridge to show the height of the portal (opening), the type of guardrail (weathered W-beam mounted on wood posts) and other details such as the narrow single lane approach.

And there you have it. In review, when photographing a bridge, remember to include

(1) all sides of the bridge; 

(2) details such as connections, railings, plaques;

(3) the deck and piers – what supports the bridge from below; and

(4) approach details: the abutment, guard rail, endwall.

By all means, you do not have to be a professional to photograph bridges. Some bridges are beautiful and make quite the statement on the landscape and built environment. I don’t claim to be an expert; I’m always working to improve my documentation skills.  Hopefully this gets you more familiar with bridges and ready to practice your photography on more than buildings. Enjoy!

Sometimes you have crawl on the abutments to really see what's going on with the bridge.

P.S. A few safety notes. Climbing over, under and around bridges can be dangerous. Do  not do this alone. Abutments, wingwalls and all sections of the bridges can be slippery and treacherous. Beware of swiftly moving waterways below. If you park on the side of the road, leave your flashers on and wear reflective gear. Do not trespass. If you photographing deteriorated or abandoned bridges, beware of holes in the deck and unsafe structures. Basically, use your common sense and be safe.

Vilas Bridge

View of the Vilas Bridge from Bellows Falls, VT.

The Vilas Bridge connects Bellows Falls, VT to Walpole, NH. It is an open spandrel concrete arch bridge constructed in 1930. The Vilas Bridge has been closed since 2009 due to deterioration of the reinforced concrete deck. The bridge is jointly owned by the New Hampshire Department of Transporation and the Vermont Agency of Transportation, however, NHDOT owns 93% of the bridge and VTrans owns only 7%, making NHDOT the lead agency. The Vilas Bridge is not scheduled for rehabilitation until 2015.

Looking to Walpole, NH.

View to the center of the bridge.

Closer view of the open spandrel arch.

So intimidating.

My love for concrete bridges is well documented, but I had never seen the Vilas Bridge before. How sad to only visit it when it’s long closed and deteriorating. Check out the features of this bridge:

The curved concrete rail.

Bridge plaques, probably with the date, have since been removed.

Cast urn balustrade.

The Vilas Bridge and the adjacent stone arch railroad bridge appear to meet each other in New Hampshire.

I cannot find much written about the Vilas Bridge, but it is eligible for the National Register of Historic Places. News articles here and there question the timeline for rehabilitation and wonder about the fate of the bridge. Hopefully it will be rehabilitated before the deterioration becomes so great that the cost of rehabilitation is not feasible and prudent. Do you live in New Hampshire? Contact your NHDOT to ask questions about the bridge and urge the rehabilitation.

Vilas Bridge under construction. Image courtesy of UVM Landscape Change. Click for source and details.

Losing another spectacular bridge in Bellows Falls and Walpole would be a crying shame. The first bridge lost was a three-pinned steel through arch. It was closed in 1971 and dismantled in 1982. Now in its place sits a 4 span steel girder (i.e. boring highway bridge) in its place. The HAER documentation states that its significance was:

When built, the bridge was the longest single span highway bridge in the U.S. and is was among the largest three-hinged arch bridges in the world. The structure has also played an important role in socio-economic development of the Bellows Falls and North Walpole.

Bellows Falls Arch Bridge. Image credit: HAER. Click for source.

Moral of the story? Love your bridges. Save your bridges.

Historic Preservation Basics No. 7

Series introduction. No. 1 = Ideas You Should Not Believe About Historic Preservation. No. 2 = Vocabulary for Translating and Holding Your Own in a Preservation Conversation. No. 3 = Let’s Talk about Architecture / The Very Beginning of Describing Buildings. No. 4 = Let’s Talk about Buildings A Bit More.     No. 5 = The National Register of Historic Places (What You Should Know). No. 6 = The History of Historic Preservation.

No. 7 = The Basics of Documentation

Much of our work in historic preservation involves recording our past, often by way of documenting the built environment. When our environment is documented, we can connect it to people, events, and other places and tell our collective history.

Simply put, documentation of a historic structure involves three parts: (1) historical research, (2) measured drawings, and (3) photography. Each has standards established by the National Park Service / Historic American Buildings Survey, and these standards remain the industry practice. An excellent source is the book Recording Historic Structures by John Burns, which teaches the reader the HABS/HAER/HALS standards for documentation.

This post will not outline the standards, but rather, give you and introduction to what documentation involves, and hopefully inspire you to start practicing on your house.

Keep in mind that more than buildings can and are documented; sites, structures, objects, districts, landscapes… they count, too! Saying historic “building” just streamlines the discussion. Now, let’s begin.

(1) Historical Research

What is the history of ownership of the building? Who has lived there? What functions has the building served? Is there any available information about how it has changed? Are any historic photographs to be found? The extent of research  and details will vary by project (i.e. funding, time, purpose), but the goals are the same.

How do you find this information? Many of these items can be found at your local library.

a) Deed Research (City Hall, Town Offices, County Clerk’s office — depending on where you live. A few lucky places such as Cumberland County, NC have their land records digitized). Some locations will require that you pay for your time and photocopies. Some are charging now for digital photograph permission, too! But if you are a student or an educational endeavor, you can probably ask to have the fee waived.

b) Historic Maps – Beers, Wallingford, Sanborn Insurance Maps, Plat Maps. Check your library and ask for help. In some cases you might find them online through sites such as the David Rumsey Map Collection. Maps will help you date your property and sometimes identify former landowners.

c) City Directories – These are usually only for larger cities and not small towns (like Sanborn Maps), but they can provide information on the use of the building and the owners.

d) Miscellaneous town records and files at the town library, historical societies, state archives.

e) Newspaper articles – Head to the local resource room at your library and get cozy with microfilm. After you’ve used it a time or two, the nauseous feelings should subside.  Historic newspapers often had much more social content that our current papers. You can learn a lot about the local area and its people.

f) Oral history – Ask around! Word of mouth will lead you to the best sources. Asking interviewees to describe buildings and places will often give you great information.

Historic research will often be incorporated into a historical narrative about the property that serves the purpose of recording a fair history.

(2) Measured Drawings

Measured (to scale) drawings document the building as-is. The level of detail might vary, but a full set of drawings will include elevations, sections, and details. Every part and detail of the building is measured. Most are done on CAD nowadays, since it is faster than hand drawing and easier to transmit and share. In order to learn standards and proper methods, it is best to take a drafting class. For instance, different line thicknesses are used to denote types of walls. However, if you aren’t documenting a building professionally, you can do your own “measured drawings” at home. These would probably more akin to field sketches. Draw/sketch your floor plan, elevation, or detail as best as you can. Record your accurate measurements on your sketches.

When sketching your building, think of it from largest to smallest. Draw the outline or frame of the building. Start at the bottom and work your way up. Then include doors and windows. Draw and record details (window frames, cornice details) in a separate drawing so your numbers don’t get mixed together.

Measured drawings are not required by every project, but if a significant resource is to be demolished, measured drawings often serve as a form of mitigation for the loss. For buildings of national significance, the measured drawings would serve as an important research resource for the present and the future.

There is too much to say about measured drawings, but here are a few tips: 1) It is much easier with three people (one for the measuring end of the tape, one for the dumb end (aka zero end), and one to record); 2) Accept that you will probably have to go back more than once because you will inevitably forget to measure a detail; 3) If necessary for your understanding, redraw your field sketches with clear numbers and delineation; 4) Sometimes it helps to photograph a detail with the tape measure in the picture; and 5) Decide if you are rounding up or down and to which segment of the inch.

(3) Photography

Photography is perhaps the most prolific form of documentation, and some would say the easiest, thanks to the aid of digital cameras. However, good photographic documentation requires more practice than a point-and-shoot camera. Standards are changing in terms of which mediums are accepted and which types of ink, but the basics of what to photograph remain the same. To effectively document the building, be sure to include all elevations and corners (N, S, E, W elevation and NE, NW, SE, SW corners for example). These corner shots are often called record shots . Do your best to get both elevations in the picture. It is best to take an image with as little parallax distortion as possible. In other words, stand as far back as you can in order to get the entire plane within the photo frame and do not tilt the camera.  You may find yourself standing on stone walls, cars, or hanging out a window. Just be careful and do not trespass (unless you have permission)! After elevations and record shots, photograph details. Perhaps the door frame is significant or the portico columns. For interior rooms, it is important to have the ceiling, walls, and floor within the frame.

Photographs should be accompanied with the name of the subject of the photograph, the property and its location, the direction from which the picture was taken and to where it is looking, the date, and the name of the photographer. This is the basic necessary information, but, again, keep in mind your SHPO may have different requirements.

So the three main components of documentation are historical research, measured drawings, and photography. Once you are familiar with the tree (and now you are!), you can learn the standards of your organization and start practicing. Many preservation programs have classes in documentation if you are interested professionally. However, if you want to document your own house, you do not have to be a professional. Check out those deed records, draw your house floor plan, and take good, thought-out photographs. It’s fun!

Some Resources:

HABS, HAER, HALS Guidelines from the NPS

Recording Historic Structures by John Burns

Documentation cheat sheet by State of Minnesota

Sacred Places overview of Measured Drawings (very helpful!)

Vermont Division for Historic Preservation – Requirements for Photographic Documentation of Historic Structures

When in doubt, speak with your State Historic Preservation Office or State Historical Society.

 

HAER Trusses

Historic American Engineering Record study on trusses.

Download here (originally from the National Park Service). If that link doesn’t work, try copying and pasting this link: http://www.nps.gov/hdp/samples/HAER/truss%20poster.pdf

I love this poster. I think I should print it in large format and hang it over my desk at work. Does anyone know if the NPS still distributes these in hard copy?

Book: Recording Historic Structures

If you are involved in researching and documenting historic structures (buildings, structures) one of the best books you can invest in is Recording Historic Structures, edited by John A. Burns (see here).  The book covers documentation standards for HABS and HAER, discussing how to properly photograph buildings, teaching readers how to do conduct thorough historical research, and how to do measurements and drawings. Basically, this is everything you need to know for being up to par with the standards of the National Park Service. The lessons in the book are understandable and supplemented with case studies, photographs, and documents.

Aside from the technical side, the book often gives the readers thought provoking statements. One of my favorites so far is, “The effectiveness of the primary sources will depend on the questions being asked” (p. 28). It may sound obvious, but it’s a statement to remind me to stay on my toes. Even if you have all of the information in front of you, it’s only useful if you know how to use it and how something is significant to research.

I read this book for my documentation at the University of Mary Washington and I’m reading it again at UVM. While some may not want to read a textbook more than once, I’m finding that I am learning more the second time around. The beautiful hardcover book is worth the $75 investment, because it you gain more in knowledge and the book serves as a good reference manual.

Historic Bridges

Covered bridges, steel truss bridges, arch bridges, suspension bridges – all of these, and numerous other categories, are found throughout the United States. Many of these are historically significant structures.  Typically, the term historic preservation is accompanied by a mental image of a historic building, or so I would imagine. But, do we give bridges a fair amount of attention? Covered bridges are the easiest to recognize, possibly the most romanticized, but steel truss and arch bridges may be less recognizable and remembered.  The Historic American Buildings Survey (HABS) documents buildings, while the Historic American Landscape Survey (HALS) handles landscape, and the Historic American Engineering Record (HAER) documents structures such as bridges, railroads, ships, canals, and steelworks.  HABS, HALS, and HAER are programs of the National Park Service. Search the collections at the Library of Congress.

Historic bridges provide important information about previous transportation systems, routes, the locations of roads and towns, and by preserving bridges, original character of a roadway can be retained (think scenic byway).  They are just as important to historic preservation as buildings and landscape.  Many historic bridges fall into disrepair and the traffic outgrows the bridges. Sadly, instead of restoration, repair, or reinforcement, they are often replaced with new bridges.

Fortunately, many people begin with small, personal efforts to record and save structures, buildings, and landscapes. The efforts begin small and spread as other find their shared interests. Thank goodness for individual interests.  After all, HABS, HAER, and HALS can only reach so many properties scattered across the vast country in cities and down country dirt roads.  One such example of an effort is the website, Historic Bridges of the United States, which is a database of currently 29,164 bridges across the USA.  Civil engineers, preservationists, historians – all sorts of people contribute to this site.  James Baughn started the site , is the acting webmaster, and continues to add bridges. Everyone is encouraged to send information and photographs. [Read the background of the site and effort here.]

Viewers can search the database by specific geographic locations, designs of bridges, status, waterways, cities, years, roads, or builders.  Or viewers may browse randomly. The site also posts news relating to the bridges.  Even better, existing HAER reports on these bridges are listed on the website.  Each database entry includes a photograph (if available), a map with the bridge’s location, any known history, UTM coordinates, and its status.  It’s a great website and fun to browse, if you’re interested in bridges.  

The photographs below are from my Route 66 road trip in 2006.  

A rainbow curve bridge on Old Route 66 in Kansas.

A rainbow curve bridge on Old Route 66 in Kansas.

Sign at the end of the bridge. (Excuse the camera lens).

Sign at the end of the bridge. (Excuse the camera lens).

Sign at the other end of the rainbow bridge.

Sign at the other end of the rainbow bridge.