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.

September 12, 2005:
A buffet of Pearman roadway and girder unbuilding

Here is the boundary between the roadway removal and open spans - as seen from the Grace Bridge

Another view of the boundary

And there is always clean-up going on - Pio is a hands-on supervisor

A week ago I was puzzled by the work at the eastern end of the superstructure. Testa was placing the vertical channels and welding angle irons. Well here, it seems they were making what I would call a tiedown - brackets that bind the bridge girder structure to the concrete pier.

Ken Canty and I talked about this and Ken helped me to understand what is going on. If you look at the right side of the concrete support, you will see a pin the couples the steel superstructure to the concrete support. As the concrete roadway is removed the entire bridge structure loses weight - sort of a Testa-diet. The tendancy, then, is for the concrete support to rise - since for all the time since the bridge was built the concrete support has had the weight of the bridge on it.

So, if enough weight is removed from the bridge, all the stresses will be concentrated in the two coupling pins. To assist the bridges integrity, the steel superstructure is couple via the tiedown cables (see the beam that link the short beam resting on top of the transverse girder (on either side) with a similar beam under the concrete cross member.

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C. Frank Starmer