Tick tock: Martin Tower’s final moments

Martin Tower’s demise is drawing near.The 21-story skyscraper’s skin has been scored to ensure the concrete crumbles as desired on implosion. A total of 485 pounds of explosives will cut the steel columns on preselected floors. The public has been informed of the road closures and other restrictions near the west Bethlehem site. Police are expected to provide an overnight vigil, and infrared drones will scan the property during the final hours. A blasting activity permit, approved by the Pennsylvania Department of Environmental Protection, provides a peek into the final moments of Martin Tower, once Bethlehem Steel’s world headquarters:At 6:45 a.m. Sunday, officials will confirm that the security area is clear.At 6:58 a.m., two five-second sirens will signal that the implosion will take place in two minutes.A minute later, a blast signal of three, one-second sirens, will sound. If there is a safety problem, the countdown will hold for a minute, and then continue after the issue is resolved.The contractor, Controlled Demolition Inc., will perform an audible 10-second countdown over its radios, and then the explosives will be detonated by a certified contractor.The explosive force comes from a linear-shaped charge placed inside a copper tube that is bent into the shape of a chevron, or an inverted “V.” The explosive force is calculated to just touch the top of the steel columns, cutting through them more cleanly than a blow torch.Gravity then will take down Martin Tower in 13 to16 seconds, sending a cloud of dust in the air that will dissipate in up to six minutes. The rubble of 6,500 yards of concrete and nearly 16,000 tons of structural steel will pile up to about 45 feet high. It’s expected to fall within 200 feet of the building’s cruciform footprint and slant slightly southeast.Five minutes after the implosion, Controlled Demolition will inspect the area and sound “a prolonged audible signal” to designate an “all clear.” That’s when crews will begin cleaning up the dust and removing any protection provided to adjacent property owners.Roads will reopen after being checked. All restrictions are expected to be lifted by midmorning.Morning Call reporter Nicole Radzievich can be reached at 610-778-2253 or at nmertz@mcall.com
Source: Morningcall