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

February 2, 2006: The joys of early morning
Loading D-24 with Mickey and his ABS team

Learning Links

Wikipedia: About detonators
The History of Explosives and Blasting
From Dyno Nobel: Shock Tube concepts
From SP ELectronics: Detonator Systems
Presentation: The evolution of detonators
Shock Tube Surface Systems

Mickey and Ken loading (24 Mb quicktime video)
Tie in the ignition lines (12 Mb quicktime video)
Tie in the ignition lines (13 Mb quicktime video)
Filling, measuring and loading (64 Mb quicktime video - be very patient)

Sunrise and unbuilding

During the building of the Ravenel bridge I discovered that between December and late February, the sun is sufficiently south that the early morning light reflects gold off the Ravenel edge girders

Joe Duffy and his phone + Mickey and his coffee

I just can't get enought of the early morning golden sun

Mickey's team

with the Pearman and Grace skeletons in the background

and on our way to the worksite - more golden Ravenel Bridge

and early morning reflections

It all starts with a hole - top (left) and bottom (right) 36' deep that will be loaded with explosives and gravel. (Sometime, try to focus on the bottom of a 36 ft hole.)

The ABS team has been drilling using a John Henry (right) with a 4" cross-bit and a smaller drill (left)

I met John Henry - a drill on steroids mounted on an excavator

Meet John Henry

The drill that avoids steriods

Looking toward Mt. Pleasant - the drilling site with early morning continuing its elegant beginning

Sparky caught a nice shot of what is happening

Ken, Mickey and Brett laying out what I refer to as the ignition system but these red and yellow tubes are known as shock tubes developed in Sweden in 1967.. Shock tubes are long small plastic tubes that are coated with a thin film of explosive material. When ignited at one end, the shock wave generated by the explosive material travels about about 2000 m/sec or about 1 mile/sec. Delays can be incorporated into the shock tube system in order to control the detonation sequence.

Loading the first hole - Mickey holding the shock tube:
A nice image of "who's boss today, Mickey (right) or Ken (left). Brett, kneeling, knows that it doesn't matter - and I smile.

After Ken measures the depth of the hole Mickey is ready to drop a dynamite cylinder into the hole

down it goes

then pouring in some gravel between loads

Ken makes another measurement

down goes the next charge

Mickey with the iginition line

more loading and filling

Mickey tamping the explosives and gravel

Next Mickey ties in the shock tubes which establishe the detonation sequence. Today, the ignition will start at each end (north and south) and move inward toward the center. See the single frame video images: for visual confirmation