Unbuilding the Grace and Pearman Bridges

For Sparky and myself, curiosity drives passion which in turn fuels our life's engine. Our passion was capturing the story of both unbuilding the Grace (1929 - 2007) and Pearman (1966 - 2007) Bridges and discovering the unbuilders. It takes a lot of passion to track a project from July 2005 until April 2007 - rain, shine, hurricanes or moving to Singapore. We discovered the joy of discovery learning. Ken Canty opened the front door for us - then Steve Testa, Ponch Billingsley and Mickey Rogers opened many side doors. Below are the highlights of what we discovered, who we met and what we learned.

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

Home is where one starts from. As we grow older
The world becomes stranger, the pattern more complicated
Of dead and living. Not the intense moment
Isolated, with no before and after,
But a lifetime burning in every moment
And not the lifetime of one man only
But of old stones that cannot be deciphered.

Home Meeting St East Bay Drum Island Mt. PLeasant Pearman Stories Grace Stories Implosions Enginnering Insights Stories of unbuilders Learning Links Bridge Video Bridge Blog Unbuilding Archive All Unbuilding Segments Building the Ravenel Bridge Photo Essays About me

December 30, 2005: Micro-building and unbuilding: Happy New Year
About spider silk and its mechanical properties (stronger than kevlar)

Learning Links

Wikipedia: Orb weaving spidres
Wikipedia: About spider silk, synthetic spider silk and its mechanical properties
Wikipedia: Nephila clavipes
Wikipedia: About spider webs
Frank's observations: Natasha and our garden
Frank's observations: Male and Female banana spiders

Many of you know that my addiction to building and unbuilding started at the micro level. About 4 years ago, a banana spider, Nephila clivipes appeared in our garden. Usually when I walk to work, my curious eyes are still sleeping. Having never paid much attention to spiders before, I just walked by her web (about 12' between supports and about 4' in diameter). But as my curious eyes woke up, I noted that she was doing something each morning - and late in the afternoon, she was just sunning herself. What spiders have behavior? So I started watching her in the early morning and saw that she was weaving half her web - and then tomorrow, weaving the other half. Her weaving was like a dance. I named her Natasha because her movements were as delicate as that of a ballet dancer and each morning she was performing some sort of ballet - similar to what I had seen at the Bol'shoi in Moscow and at the Mali in St. Petersburg. Natasha's silk is special and is the strongest (in tensile strength) fiber known including kevlar.

My mother-in-law and sister-in-law live in Plant City Florida in an area called Walden Lake. There is a jogging path in the forest surrounding the lake, a perfect place to expect spiders to build their webs. So, early in the morning, I go looking for spiders and their webs - though I did not expect to find anything. Fortunately, my curious eyes are in their high state of curiosity and soon I found many small spiders and their webs. Some were building their webs, some webs were empty and some had caught the morning dew. Here are the results - a great way to start the new year, exploring building and unbuilding at a micro-scale.

The spiders that I found were all members of orb-weaving class of spiders. They all weave circular webs. While weaving, they build the radial elements first and then when all the spokes are built, they start weaving the circumferential elements - there is an example below.

This is a crab spider (Gasterocantha cancriformis). She is distinctive because of the small red spikes

and with her just-in-time dinner - a small bee or wasp

January 1, 2006 update: A better view of a crab spider (Gasterocantha cancriformis) weaving.

Here is another potential dinner candidate

Here is a morning web that caught dew as well as insects

My first encounter with such a tangle of webs

Here are two webs - one is obvious and if you have your curious eyes turned on, you can find the other web

Here, she is weaving her web and is building the 7th circumferential element.

Oops - I disturbed the web and she ran to the center - perhaps expecting an early tasty treat. Look at the 8th circle (counting from the outside) and you can see the remainder of what she was weaving as she ran for the center.

Here is a Leucauge venusta just chillin' a bit waiting for dinner - and there was not much of a wait. Here she is, preparing a small insect for breakfast

When finished, she left the insect attached to the perimeter of the web and resumed some weaving

Here is a close view

A January 1, 2006 update of her web. For each day that I have walked along the path, her web has always been in the same spot. So it is possible to update observations and improve characterization of her behavior