Devising A Plan



With an environmentally sensitive cove 500 feet to the south, active reservoirs 300 feet west, new administrative offices 250 feet north, and the existing power station just 50 feet east, there was literally no room to 'lay the stack out' without endangering or destroying one of these exposures. And unlike tall steel radio towers- which remain tethered to the ground via guy-wires during their fall- there was no way to safely 'guide' the structure down once the initial blast occurred. Even the smallest miscalculation would almost certainly result in severe consequences to the surrounding area.

After much brainstorming and consultation with independent engineers, Controlled Demolition Group decided on a revolutionary, yet totally unproven plan: They would blast the stack on two delays, and at two elevations.
 

First, a wedge blasted at the 350-foot elevation would start the top half of the stack moving towards the north. As it's center of gravity moved off-line, the base of this top section would 'kick back' (as all rigidly-reinforced structures are prone to do) and slide almost straight down, with the high end continuing in a slightly northerly direction. This would be followed quickly by a second, more powerful blast at the base of the stack on the opposite southerly side, which would cause the bottom half to 'sit down' and slowly pitch to the south. If all went as planned, the debris pile would be confined to the small open area between the stack's base and the cove.

The blast team knew that the success of their plan hinged on three things: The precise timing of the delays, an exact calculation of each section's load ratios, and a well-planned and executed drill pattern. If the top half were to begin it's descent even slightly off line, the high end could easily impact the adjacent power station or reservoir. In addition, if the bottom half failed to gain enough southerly momentum to counteract the top sliding down, it could 'squat', which would leave Brown & Mason with an unstable 300-foot tall safety hazard. The demolition team was well aware that although rare, both scenarios had been known to occur on various projects throughout the industry's history.
- The Land of Horizontal Rain -
High winds and rain coming off the Irish Sea are so consistent, the stack spent almost its entire existence half-wet and half-dry

CLICK ON A LINK BELOW TO CONTINUE

INTRODUCTION
DEVISING A PLAN
PREPARATIONS
BLAST DAY

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