This video concerns the demolition of the 275’ x 21’10” base diameter concrete chimney at the Ohio Edison Mad River Power Plant demolished in Nov 10, 2010 by by Advances Explosives Demolition Inc. (AED).
On the Dayton dayily news we read Springfield Twp. Fire Chief John Roeder said in 2010 “It just started leaning the other way and I thought, ‘Holy cow.’ It was terrifying for a little bit,”.
On Engineering News Record (https://www.enr.com/articles/2583-tower-knockdown-scheme-does-not-go-as-planned
)we read “ AED believes there may have been an unseen crack that caused an unexpected weak point in the reinforced concrete stack, the diameter of which is 21 ft, 10 in. at its base. Lisa Kelly, president and owner of AED, told the Springfield, Ohio, News-Sun newspaper that an undetected crack in the tower caused it to topple in a different direction than expected. The tower was supposed to fall eastward into a cleared area; instead, it fell to the southeast, taking out two 12,500-volt power lines and damaging two oil-fired turbines that are still in use on a backup basis. … Eric Kelly, AED’s chief blaster and a co-owner, says the implosion company is working with the contractors to find out why the smokestack fell in an unexpected direction. Eric Kelly, AED’s chief blaster and a co-owner, says the implosion company is working with the contractors to find out why the smokestack fell in an unexpected direction. We [AED] think that there may be some information about structural deficiencies in the stack that would have been useful to know in planning the implosion but that we weren’t given,” he says. “During preparation of the stack, we weren’t given a condition report about the structure. But it’s not unusual for there to be no condition report for something this old,” says Kelly. He says that, after the implosion, a consultant on the project asked whether he had seen the condition-of-structure report. “If I had known there were deficiencies, I may have planned to drop the stack in a different direction,” Kelly says. Kelly says he planned to drop the smokestack right where the overall demolition contractor asked. “I did everything by the standard procedures. It was textbook. You establish a fulcrum point. Put the stack on ‘legs’ [by removing parts of its base], then blow it in sequence to lay it down in the direction you want,” he says. Kelly says it took just 17 lb of binary explosives detonated in blasts milliseconds apart to bring down the tower. He says that, in 31 years of imploding thousands of structures, this job is only his fourth that didn’t go as planned—and only the second in more than 25 years. “I just successfully ‘shot’ an 85-ft-tall building in Athens, Greece, with only 15 ft of clearance on two sides and 30 ft of clearance on the other two,” he says. FirstEnergy, and its sister company Ohio Edison, first filed a lawsuit in November of 2012, The lawsuit claimed the damage amounted to more than $19 million in losses. The lawsuit also alleges the three companies contracted for the demolition, which cost more than $4.7 million, violated parts of the project contract that says contractors will pay for any damages caused by their actions.
We can see here that there is a lot of confusion why the chimney fell the wrong way. First of all a lot of these people cannot or do not like to admit when they made a mistake, and more often than not, if they can, they will keep making the same mistake again and again until they have no choice but to change the way they are doing things. To us it is very clear why the chimney fell the wrong direction. We believe it was not because of a crack, lack of knowledge of the condition of the chimney, the absence of an inspection by a qualified chimney company though required, or some other reason. If the demolition was done correctly it would not have fallen the wrong way.
The reason for this catastrophe is twofold, neither of which has anyone proposed here. First, in a chimney such as this there has to be a piece meal dismantlement to take off 1/3 or more off the height of the chimney according to a chimney engineer. If there is something that could be damaged it is better to piecemeal dismantle the entire chimney until an excavator can reach it. After 1/3 of the chimney or more is dismantled piecemeal, the hinge at the base of the chimney can be engineered to support a much greater weight and a lean without a sudden collapse on the hinge. In this instance the whole height of the chimney was suddenly and by explosives brought to bear on just a few feet of the chimney base as it started to lean, where the concrete there gave way under the sudden and tremendous load.
Additionally, explosives should never be used in a demolition such as this. Rather, mechanical means would insure that there is no unexpected damage to the hinge. This would be done using a concrete saw and various other methods. When it is time to fell the chimney the hinge can be spread over a larger area with dense lumber that has been used to shore up the concrete that was removed. Tim Suter, FirstEnergy manager of external affairs admitted “(Explosives are) not without some uncertainty,” and “Fortunately no one was injured.” We would agree, we believe this kind of work need to be done without explosives and by first removing a substantial amount of weight off the base of the chimney.
Where the chimney fell off its hinge can be clearly seen in the two videos. On the video at the powerlines the chimney can be seen to move over to the right at the base horizontally while still vertical. Admittedly, “Lisa Kelly, the president and owner of Advanced Explosives Demolition Inc., told the Dayton Daily News that the explosives detonated correctly, but an undetected crack on the south side of the tower pulled it backward.” In the last video with a view down the rail tracks the chimney can be seen to move off its hinge and drop down in height.