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 Photo Gallery
 The Preparation Work
 Defying Gravity
 The Implosion
 The New Stadium
 Viewing the Implosion

Sunday, March 19, 2000

The preparation work

On the morning of March 26, the Kingdome will be reduced to a pile of rubble in a dramatic implosion lasting less than 20 seconds. The Dome has already undergone a stark transformation as work crews have stripped the building from roof to ramps over the past two months, leaving an empty concrete shell of the former landmark. At the same time, extensive plans have been made to protect the surrounding area during the implosion, and work has begun on the new stadium that will be built on the site after the Dome is history.

Removing roofing material Removing air-conditioning units Demolishing exterior ramps Wrapping and sealing nearby buildings Erecting protective walls and berms Establishing a restrictred zone and evacuating people and pets Dust control and repairs after the implosion Drilling holes for explosives Packing and wrapping explosives Stringing detonation cord and setting timing devices New stadium started

Stripping the Dome

Removing roofing material
Two backhoe-like machines, called mini-maxes, stripped approximately 400 square feet of the 6-inch-thick layer of roof surface and insulation so only bare concrete remains.

Removing air-conditioning units
The boxcar-size units were removed one at a time by crane and then stacked on the perimeter of the work site, forming a partial barrier for the implosion.

Demolishing exterior ramps
Using a combination of small excavators at the upper levels and larger machinery on the ground level, the ramps encircling the Dome were removed in portions. The concrete shaft and metal walls were removed from the top down, leaving the large supporting columns intact.

Demolishing lower-level seating sections
Labor crews, using loaders and mini-excavators, removed all non-concrete material from inside, separating recyclables from landfill debris. Concrete supporting the lower-tier seats was broken into rubble and spread over the field to help cushion the impact of the implosion.

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Cushioning the neighborhood

Wrapping and sealing nearby buildings
Nearby buildings will be protected in various manners depending on their structure and proximity to the Dome. Measures may include sealing air-handling units, taping seams on doors and windows, covering doors and windows with plywood, and draping reinforced polyethylene sheeting and geotextile fabric around the outside. Property owners will be provided with polyethylene sheeting to protect interiors.

Erecting protective walls and berms
Barriers were erected by stacking the air conditioning units and other materials on the perimeter of the work area. Rubble piles will also help absorb the impact.

Establishing a restricted zone and evacuating people and pets
An area extending roughly 1,000 feet from the Dome will be off-limits to people during the time of the implosion; a larger area will be closed to traffic. Accommodations will be provided for people and pets who live within the restricted zone.

Dust control and repairs after the implosion
Eight water trucks, eight sweeper units and more than 100 workers will be deployed immediately following the blast to clean up dust. Any larger repairs will be tended to as soon as possible.

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Rigging the explosives

Drilling holes for explosives
About 6,000 holes, each 1 3/4 inches in diameter and 5 to 6 feet deep, were drilled in the ribs of the roof and in the support columns. The rolling gantry originally intended for roof maintenance was used to drill holes in the ribs as well as to assist in stripping the roofing material.

Packing and wrapping explosives
Each of the drill holes is numbered and packed with a specific amount of explosive with a timing device set with a delay. Each hole is then wrapped in a layer of chain-link fencing covered with geotextile polypropylene fabric. The wrapping material is intended to expand with the blast and contain debris.

Stringing detonation cord and setting timing devices
100,000 feet of non-electric detonation cord, which burns at 24,000 feet per second, will run around the Dome's ribs and columns, connecting all of the explosives. A combination of surface delays in between the rows of detonation cords and timing devices will create the correct sequence of explosions to bring down the Dome.

New stadium started
Construction has begun on south walls and stairwells of new football stadium.

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Inside the Dome

Work crews have demolished much of the interior, including the lower seating sections. The upper sections will have explosives placed in supporting columns and will come down with the implosion.

The rubble from the lower sections and other areas of demolition has been spread out in berms across the floor of the Dome to absorb some of the impact of the falling roof.

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Graphics and text: Phil Loubere; Reporting and text: Whitney Stensrud; Reporting: Jeff Hodson / © 2000 The Seattle Times

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