Building the Ravenel Bridge

After all the photos I took, I've tried to arrange them in some order based on various topics I found interesting.

And a reminder from T.S. Eliot (East Coker from the Four Quartets)

Old men ought to be explorers
Here and there does not matter
We must be still and still moving
Into another intensity
For a further union, a deeper communion

Erecting Steel

June 27, 2004 - Two messages:

  • Something about the Internet, Open Learning and these photo essays describing the construction of the New Cooper River Bridge
  • Bridge Stuff: Placing fabricated steel on the approach piers: a composition for barge, crane and workers

    For the curious (see Restoring the Joy of Learning (with Gene Stead), the Internet is available to level the playing field for learning. Basically, with the Internet, we all have access to the mostly all the information a Nobel Prize winner would find. For me, my reserach productivity is directly related to my curiosity and my curiosity and thinking is fueled by gathering the thoughts and data from others and rearranging them into new and potentially interesting patterns.

    Google and the Internet provide a new dimension for chasing my curiosity. Google enables "just-in-time" learning for me, which is preferable to my formal university "just-in-case" memory-driven learning. When I see something I don't understand, I ask Google and I ask the viewers of my web page. I always seem to get timely answers. So for me, as an "educator" I realize that I am no longer an educator but a co-learner with the all of you.

    Web pages such as these, Blogs etc, provide ways for us to tell stories that are hopefully interesting. Moreover, as soon as Google crawls these pages, they are readily found by anyone in the world. This is a short essay about me, curiosity, looking and seeing, the Internet, open access to information and the community associated with actually building the Cooper River Bridge (Palmetto Bridge Constructors, SCDOT, High Steel Structures, Freyssinet and many many others).

    This essay started when I took a photo in the morning, did not pay much, took my usual group of photos in the afternoon and suddenly saw a link between the morning photo (of a tug pushing a barge with a crane) and an afternoon photos of the bridge. First, note in the photo below, the tiny vertical crane arm with the beam hanging between the 1st and 2nd left approach piers - click to see the full photo)

    The story around the tug and crane photo below is a good example of looking but not seeing. I took the below photo in the morning along with the other photos of the pylons and cable stays June 27 see the "details" page. While riding my bicycle from one vantage point to another, I noticed the tug, pushing a crane around. I made a few photos but did not understand their significance, so the below photo did not make the first draft of today's essay.

    7:30 am - the tug and crane which I saw and the barges with steel beams which I did not see

    tug, crane, barge with 

    By mid afternoon, I returned to the Aquarium to photograph the entire bridge (above) and noticed that they were placing steel girders on the western approach (see left blur of a steel beam hanging from the crane). So I made a few photos of the crane hoisting the steel beams and placing them (see below). I updated the web page and sent Bill Mankin (part of the fabrication team at High Steel Structures) the link. He replied that if I looked carefully at the barge at the base of the below photos you could see the steel and cross members. I looked and sure enough, there they were. I suddenly remembered that in the morning batch of photos, I had taken a photo of a tug pushing a crane somewhere. I returned to this photo after reading Bill's email and noted that not only had I photographed the tug, crane and barge, but there were several other barges in the backgound with the steel beams and cross members. So here is that photo - below my digression.

    (A note about these bridge pages, the Internet and community. I was fortunate to be part of the early UNIX community (1975 - ) at Duke where we experienced the value of open exchange of information, ideas and insights via computer network connections. We started by exchanging seminar notices with UNC and over time, more was exchanged than notices. A new community arose from those connected to the computer network, a network which grew to become USENET - started by Jim Ellis and Tom Truscot at Duke and Steve Bellovin at UNC. For many person-to-person interactions, our computer network reduced geographical limitations to zero and new communities arose and network-centric collaboration became an informal and a continuously available way for dealing with the day's activities. We realized that something dramatic was changing - and that we were part of a major paradigm shift in collaboration, problem solving, communication and education.

    The software exchange model of the 70s within the Unix community has matured to the current open source software development paradigm and now is poised as a disruptive technology. That same disruptive technology is at work within the world of education. With Internet resources, I can often teach myself what is essential to solve a problem, without taking a special course in this or that. To solve a problme I use Google to locate information. I then test its believability and piece it together for use. These pages reflect this approach to continuous learning and the community that spontaneously arises when individuals encounter like minded individuals with intersecting interests. Education within this paradigm, where Google + Internet are learning tools and memory amplifiers are disrupting our current memory-based K-12 and university educational paradigms. Switching from just-in-case learning where memorization skills are essential to a just-in-time learning paradigm where Internet searching and problem solving skills are essential will be slow and resisted by those that continue to miss the information utilities that the Internet brings to the learning table. Disruptive technologys face great opposition as you can observe from these resources:

    What does open source have to do with the bridge photos? It seems to me that these photos have become an open library for those interested in tracking the construction progress of the new Cooper River Bridge. Moreover, these pages have become a tool for spontaneous learning and exchanging ideas. Preparing these photos each Sunday started as a project for my grandchildren. From time to time,people sent email commenting about various aspects of the bridge, the engineering and its construction. The folks at High Steel communicated with me and provided additional information. This started a conversation with several engineers who provide me much better insights into what I am photographing. Sharing the photos by the Internet thus evolved from a one-way show-and-tell into a two way conversation, exchanging my images with engineering and personal insights from members of our informal community. As an educator, I found the bridge photos evolving into a learning resource, with learners coming from a boundaryless community of curious folks - a university or engineering laboratory without walls. These experiences are very useful lessons for building learning opportunities for students here at MUSC. I really enjoy this interactions with folks in our new community that have taken the time to help me. With respect to the below photos, Bill's note reminded me that I saw what I was looking for and failed to see something much more interesting. This is a typical example of how the community of Internet users use web-asscessible resources to build new communities of folks with intersecting interests ).

    Placing fabricated steel on the approach piers

    Today (3pm) when I took my regular photos of the bridge and pylons, I noticed a steel beam hanging in the air between the last completed pylons of the west approach as I was leaving. Here is the sequence - the progress was very slow and I did not notice when the beam was finally planted - only that a person was walking about the terminal pylon doing something (difficult to tell from 1 km distance). Note that at the bottom of each photo, you can see the white steel beams and cross members (fabricated by High Steel Structures in Lancaster Pa.)

    3:00 pm

    Lifting the beam (time sequence is left to right)
    The suspended beam which I saw and the barges with beams and cross members underneath the beam which I did not see (click on the image to see the other barges).

    Placing right end on the pylon footing (next to the green port-a-potty)

    In perspective with the west pylon

    Final placement of the beam, lowering the left end. Note the workman (right most photo) standing between the green port-a-potty and the beam (click to see the full image).

    The question for today is how is the suspended beam spiced to the beam that straddles the left pier? Seems to me the precision of the crane operation, combined with wind, swells in the water and just plain bad luck make it virtually impossible to spice these beams. Fortunately Tom Brodrick has provided some insights:

    "The splices that you are wondering about are made following these steps:
    1. lifting there are usually lifting points on the erection drawings that show where to place the girder dogs or chakers so that 
    when the girder is lifted the girder is either level or on the slope of the roadway.
    2. the barge is held in place with the spuds if it is in shallow water or by using anchors in deepwater. If the barge is moving in the 
    current/drifting then they will put the tug behind it to steady it. Most of the time if you are using spuds and they are dragging 
    then you shouldn't make the lift.
    3. As the crane takes the weight of the girder the front of the barge will begin to go down until the girder is completely held 
    by the crane. It is best to position the barge so that a heavy lift like this is done of the front of the barge and you do not 
    have to swing the crane any more then is absolutely necessary.Once the crane has the full weight and the barge is stable then 
    up she goes.
    4. Rope taglines are attached to each end to help control the spin of the girder. Once the girder reaches the connectors 
    (ironworkers on the top of the piers) then they control the signals and the girder.
    5. the splice plates that you can see bolted up are loose with some of them pushed out of the way.  I used to like to have the 
    web plates all bolted on one girder and those bolts real loose. I would take the bottom spliceplate (bottom flange underneath) 
    put one bolt in each side thru the bottom plate,bot.  flange, and the top plate of that flange. This would allow the girder to have 
    some thing to "rest on "while I worked the web plate around.
    6.This sounds a lot more complicated than it is. Yes, if a boat goes by (idiot power boater) the wake will rock the barge and 
    the girder but you get used to that after a while and learn where not to put you hands and fingers.
    7. Once you have the plates back in line you can wrench tight the bolts already in to get the girder and splice plates close. 
    Then start with "bullpins" (pins that taper to a point) drive some of these then start driving barrel pins(pins that are the 
    same dia. as the hole) . Start sticking bolts and you are home free. 
    8. It probably took me as long to type this as it did the ironworkers to get the girder in the picture from the barge and 
    entered in to the splices."
    If you have any questions please contact me I had such fond memories of 
    working in the "raising gang" that I think I deserve a cold one.

    And I agree - the cold ones are on me!

    [Jun 29, 2004 16:23] A hydraulic engineer with familiarity with bridge design has shed some light on stabilizing the barges. Here is his assessment:

    "Notice that on the barge there are several (brownish) vertical columns that can be seen between the crane. These are known as "spuds" and are steel columns that extend through the barge and into the river bed. They essentially anchor the barge in place.

    The number and placement depends on the river channel conditions - but there are typically four spuds for larger projects. In some instances, I have seen where the spuds actually jack up the barge itself - making a temporary platform. On the Mississippi River, sometimes you have to also add long cables and "anchor weights" to the barge. This is because the current may create a condition known as "scour" at the spud (the higher currents cause form vortices around these spuds, eroding out the channel bed and undermining the temporary foundation. You can experience "scour" yourself the next time your go to the beach, stand in the surf, and feel the waves remove the sand from beneath your feet and toes). [Note: this "scour" effect and the presence of shipping traffic is one reason there are those rock islands surrounding the towers.] While this is not an "official" answer, it seems to describe what is occurring in your photograph."

  • July 4, 2004 - placement of the steel beams and cross members is complete so the next question: How are the beams positioned in order to splice them with their predecessors? - For orientation - note the green porta-potty on the transverse beam (left photo), and compare with porta-potty from last week.

    July 18, 2004 Completing the east ramp and eastward platform

    July 21, 2004 Placing and attaching prefabricated steel units

    Dropping the crossbeam in place between the anchorage extensions

    Placing a cross beam - (before, left; after, right)

    Splicing the anchorage extension (left) and bolting the crossbeam (right)

    Attaching and splicing the beams is an interesting process. First a drift pin is inserted in a few key holes to align the beams. Shown here is the initial bolt tightening (left) and applying the final torque (right). Click the image for a quicktime video (15 Mb - be patient).

    Click for video of initial bolt tightening

    Click for video of final torque

    Bolts are then inserted and torqued to a final value and then lines painted on the top of each bold and on the beam to identify the position of each bolt.

    September 19, 2004 Building the final cap (East Approach)

    September 25, 2004 Building the final cap (East Approach)

    October 3, 2004 Placing steel on the final pier's cap (East Approach)

    October 17, 2004 Finished approach beams (East)

    Creative Commons License
    This work is licensed under a Creative Commons License.

    C. Frank Starmer