ted.com for engineers

We engineers these days need somewhere to get new ideas. One of the greatest sources one can utilize is the internet. While surfing the internet, one of the main sites I usually browse is www.ted.com. The site has many great ideas presented by notable people about interesting engineering topics. I love the website for its scholarly videos presented at no charge. "TED speakers are asking the big questions and offering some big answers. Autodesk believes that many of today's big questions can be answered through innovative design." (www.ted.com) Autodesk is a CAD program widely used among the engineering field. Using this program, you can design and explain things once thought unimaginable. Autodesk actually sponsors the website, helping them display some of their finest projects.  For example: A designer uses Autodesk or one of the related programs to collaborate digital inventions, to share with a global team. This allows easier innovation and more efficient management. If you'd like to learn more, see this website and click on the fourth video.

What is the best CAD program?

Many detonators use 3-D computer images to achieve the most accurate demolition plan possible. There are hundreds of CAD programs available for this purpose, but which is the best? To name a few; Autodesk, AutoCAD, SolidWorks, KeyCreator, TurboCAD, and Revit. The Silicon Valley AutoCAD Power Users (SVAPU), which is the world's largest local AutoCAD user group, presented Revit with their "Best of the Best CAD Software" trophy. Revit was tested among many of the leading software programs, and was given the reward based on ease of use and a "nice intuitive feel". The program is mainly used for 3-D structural, mechanical, electrical and plumbling (MEP) engineering. I personally have only had experience with KeyCreator in my Engineering Design class. I found it to be simplistic enough for a first-time user, yet complicated enough for the professional. My professor who was PE described it as being "just as useful as AutoCAD minus all the confusion". I'm looking forward to exploring new programs in the near future.

The Big Bang

All the hard work has come down to this. The blasters must prepare the people in the area for the blast, assuring local authorities and neighboring businesses that the demolition won't seriously damage nearby structures. Once the structure had been pre-weakened and fully loaded with explosives, the crew does a final check to insure the explosives are ready, and the building and surrounding areas are completely clear. Blasters can calculate the safety perimeter from the size of the building and amount of explosives used. On occasion, blasters may have misjudged the amount of explosives needed to bring down the building. Too much, and debris fly farther than predicted, possibly injuring onlookers or nearby structures. Too little, the building does not completely fall down, making it an extremely dangerous environment. Once the area is clear, blasters retreat to their detonator controls and begin the countdown. 3...2...1... Typically, the implosion only takes a few seconds. After the building has fallen and the smoke has cleared, the team surveys the scene and reviews tapes to make sure everything went according to plan. It is crucial to make sure all explosives have detonated, and remove the ones that haven't. Most of the time, experienced blasters bring buildings down exactly as planned. Damage to nearby structures, is usually limited to a few broken windows. And if something doesn't work out quite right, the blasters log it in their mental bank and make sure it doesn't happen again. In this way, job by job, the science of implosion continues to evolve.

What does it take to demolish a building?

The first step to successfully demolish a building is to remove any debris within the structure. Next, destruction crews begin to knock down any non-load bearing walls. This allows for a cleaner break at each floor: if these walls were left in tact, it would stiffen the building, negatively effecting the collapse. They may also weaken supporting columns with sledgehammers or steel-cutters. Sounds fun so far. Next, blasters (explosives experts) start loading the buildings columns with explosives. Different explosives are used for different materials, and more or less of an explosive is used depending on the thickness of the material. The two materials typically dealt with are steel and concrete. Concrete is loaded with traditional dynamite or similar explosives. The dynamite does its job by completely disentigrating the concrete. Steel is a bit more complicated, because of its high density. It is loaded with cyclotrimethylenetrinitramine, RDX for short. Instead of disentegrating the column, it actually slices right through the steel, cutting it completely in half.To ignite both RDX and dynamite, you must apply a severe shock. In building demolition, blasters accomplish this with a blasting cap, a small amount of explosive material (called the primer charge) connected to some sort of fuse. To control the sequence, blasters typically configure the blast caps with some sort of delay mechanism. Blasters determine how much explosive material to use based largely on their own experience and the information provided by the architects and engineers who originally built the building. But most of the time, they won't rely on this data alone. To make sure they don't overload or under-load the support structure, the blasters perform a test blast on a few of the columns, which they wrap in a shield for safety. After they conclude what the proper explosive amount is, they wrap the columns in a shield to avoid flying debris from damaging near-by structures. Its almost that time.

How Building Implosions Work

Explosive demolition is the preferred way to bring down large structures. When a building is surrounded by other buildings, it may necessary to "implode" the building onto its footprint. Engineers in foreign countries were showed the video of the World Trade Centers collapsing with no knowledge of the 9/11 attacks. They all stated that they were convinced the buildings were intentionally demolished. Yet when they were eventually told the real story, they were shocked. The World Trade Centers demonstrated a picture perfect controlled demolition in the way they collapsed. Yet, the fires from the fuel of the planes are still stated to have caused the steel to collapse in the buildings. The basic idea of explosive demolition is quite simple: If you remove the support structure of a building at a certain point, the section of the building above that point will fall down onto the part of the building below that point. The explosives are just the starting point of the demolition, gravity actually brings the building down. Demolition teams load explosives at multiple levels of the building to ensure the structure falls down on itself on multiple points. When a building is surrounded by other structures that need be preserved, the demolition must be laid out carefully. The lower floors are detonated first, then a floor in the middle and top of the structure usually follow. For example in a 20 story building, the 1st and 2nd floor would be detonated first, then following this explosion the 12th and 18th might be detonated. This formula usually causes the building to collapse on itself. Note that right before the WTC collapsed, there was a large explosion on the 1st floor of the building. Makes you wonder huh?

The 9/11 Conspiracy

Multiple researchers have put together a very notable video presentation about the 9/11 attacks on the World Trade Centers and the Pentagon.  They argue in this video that the attacks were in some aspect related within the government. I'm not stating whether I believe it or not, but the researchers seemed to look very deeply into the matter and have put together quite a presentation. The main part of the video that caught my eye was the analysis of the actual falling of the two world trade buildings. When the buildings were engineered, they were built to withstand being struck by the biggest plane of that time, the Boeing 707, at a speed of up to 600 mph. The plane that struck the trade center was a Boeing 727, a smaller plane than the 707, and was only traveling around 450 mph. The "main cause" of the collapse was a widespread fire caused on multiple floors by falling debris. Oddly enough, the 3 World Trade buildings were the only steel frame buildings in history to ever completely collapse from a fire. Many other buildings of similar size in history have caught fire with the same severity, and burned 3x, 4x  longer, but strangely did not fall down. The final point I will argue with is that no building can collapse onto itself in the way the World Trade Center did without having been purposely done so. Many eyewitnesses said they heard a series of explosions seconds before the building collapsed. The main idea of this video is to point a finger at the government and saying they knew about the attacks and were possibly even involved. I'm not saying I do or do not believe in the theory, but the writers really have some good conclusions. I'd urge you to look at the video here.

The part about the World Trade Centers start at 54:42