In the last couple of articles (part 1 & part 2), we looked at everything that is needed to prepare a building for implosion. In addition to these measures, we must prepare the people in the area for the drop, assuring local authorities and neighboring businesses that the implosion won't seriously damage nearby structures. The best way to calm down anxious authorities is by demonstrating our success with previous implosions and devising clear cut plans that demonstrate exactly how the demolition will go.
To work through this process, we will bring in an independent engineering/consulting firm, such as Applied Science Int’l, LLC. ASI uses portable field seismographs to measure ground vibrations and air-blasts during an implosion. The team can also inspect surrounding structures prior to the implosion, so that they can help assess any damage claims following the blast. Additionally, the team videotapes the blast from multiple angles so that there is a record of what actually happened. Using data collected from previous blasts, the company's Engineers can predict ahead of time what level of vibration a particular implosion may cause.
Once the structure has been pre-weakened and all the explosives have been loaded, it's time to make the final preparations. Our professional team of Blasters and Engineers perform a final check of the explosives, assuring the building and the area surrounding it are completely clear. To assure safety and with the level of destruction involved, it is imperative that all spectators be a good distance away. With our experience we are able to calculate the safety perimeter based on the size of the building and the amount of explosives used.
Once the area is clear, the team will retreat to the detonator controls and begin the countdown. We typically will sound a siren at the 10-minute, five-minute and one-minute mark, to let everyone know when the building will be coming down. In some cases we could even include pyrotechnic effects per our Change Maker Kit™ if the owner so chooses for Public Relations purposes. Toward the end of the countdown, a blasting team member presses the detonation button and the detonation process begins immediately. The equipment that we have creates a small spark and this spark initiates the detonation on the shock tube, which then initiates the blasting cap that initiates the explosives. Boom!
Typically, the actual implosion only takes a few seconds. To many spectators, the speed of destruction is the most incredible aspect of an implosion. It’s a true spectacle!
As a spectator, one will notice a cloud of dust billowing out around the wreckage. For this reason we use state of the art dust suppressors to minimize dust control during the blast. Proper dust suppression management will provide high-efficiency atomized misting equipment designed specifically to control the size of the dust cloud that’s anticipated. (For a good cast study on dust management click here). Some might say this cloud can be a nuisance to anyone near the blast site, but studies can show that it’s actually less intrusive than the dust kicked up by non-explosive demolition or mechanical demolition. When workers take down buildings mechanically using heavy machinery and wrecking balls, the demolition process can take months. In this time, a significant amount of dust is being kicked up into the air every day. When the building is leveled in one moment via implosion on the other hand, all the dust is concentrated in one cloud, which lingers for a relatively short period of time. With the help of dust suppression this cloud is relatively small and dissipates within in minutes. Additionally, nearby residents with allergies can leave the area for that one day and avoid the dust entirely, whereas if the demolition happens mechanically, they are susceptible to daily air born allergies for the life of that project. It’s a significant difference when you really think about it.
After the dust has settled, the FBUSA team surveys the scene and review the recorded videos to see if everything went according to plan. The hired Engineering team will also review their vibration and air blast data as well. Most of the time, experienced blasters bring buildings down exactly as planned. Further investigation goes into the perimeter of the project and to the surrounding buildings to assure no damage has happened to the surrounding areas. The team will assess the entire perimeter of the project and log it in their data base for future reference and future implosions. In this way, project by project, the science and art of implosion continues to evolve and only improve.