PM 595 | Project Risk Management | | | | |

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Introduction
After deciding on and obtaining a site for the Empire State Building the plan was to build a skyscraper as tall as possible without falling down. The logic of the plan was very simple. A certain amount of space in the center, arranged as compactly as possible, contains the vertical circulation, mail chutes, toilets, shafts and corridors (4). Surrounding this is a perimeter of office space 28 feet deep. The sizes of the floors diminish as the elevators decrease in number. In essence, there is a pyramid of non-rentable space surrounded by a greater pyramid of rentable space (4). In essence the taller the building, the higher the risk and the narrower the tip of the building became.

There are many risks to consider when starting a project especially if these projects are tied to high cost and high consideration for safety. One of the initial concerns for the Empire State Building project back in the early 1930’s was that because of its enormous height and weight that it would eventually collapse. Due to its height requirements the design was a critical component of this project. When completed the Empire State Building stood at 1,454 feet from ground level to the top of the lightning rod making it the tallest building in the world for 41 years until the World Trade Center's Twin Towers were built (1). Some of the risks associated with the possibility of the empire state building collapsing are as follows:
I. Design Frame Structure
Steel Frame
When one thinks of a skyscraper, the steel frame design comes to mind. The steel frame is the skeleton of the skyscraper and if this structure falls the project cannot proceed to the next step. The steel frame design is characterized by a large steel box, containing smaller steel boxes inside (2). This 3D grid is simple and efficient for most low-rises, but has its' drawbacks for high-rise structures. As the building's height increases, the space between steel beams must decrease to compensate for the extra weight, resulting in less office space and the need for more material (2). This is true with any building; as the building gets larger so does its circumference.

Shear Wall Design
In a shear wall design, the weight of the structure is distributed through the walls (2). These structures are often made of brick or cinder block--materials with high compressive strength. As the load exerted on the building increases, shear walls must increase in bulk, meaning skyscrapers would need considerably large walls (2). A failure in this area would mean that the structure of the materials would not be distributed evenly and part of the building would eventually fall as the materials would cause the weight to shift to one area of the building.

Concrete Core
This is the most common design for modern skyscrapers as it is fast to build and provides a strong center. All the utilities, elevators, and stairwells are centralized in this design, making it easier for building modifications and repair (2). This design can be dangerous. If a part of the core is damaged, everything above that section will be cut off from ground access. This happened in the WTC during the September 11, 2001 terrorist attacks, making it impossible for many people to escape the burning towers (2).

II. Fire Protection System
Stairwells
The other risks that were considered were that the fire protection system would fail in the event of a tragic accident. The stairwells were taken into consideration in the event that people needed to evacuate. Fireproof stairwells were required for all high-rise buildings in 1930. The fireproof stairwell in the Empire State Building saved the lives of hundreds of people during this near-catastrophe (Scott 2007).

Fire Spreading & Cooling Ducts
The building had a compartmentalized structure so that fire could not spread, each floor had its own heating and cooling ducts and each room was separated by fire partitions (2). This risk was identified early on in the planning phase of this project in order to prevent fire from traveling from one floor to the next. The cooling ducts are critical as they would be able to save the entire building from overheating and complete destruction which would eventually result in a collapsed building.

In conclusion, the creation of any skyscraper is of high risk not only due to cost, but also due to its safety risks. In the Empire State Building project there were many things that were considered which have resulted in a project that has withstood the length of time. The empire looks to be in great shape and appears safe after 80 years of being built.

References 1. http://failures.wikispaces.com/Empire+State+Building 2. http://www.allaboutskyscrapers.com/skyscraper_design.htm 3. Scott, Jeff. "Aerospaceweb.org | Ask Us - B-25 Empire State Building Collision." Aerospaceweb.org | Reference for Aviation, Space, Design, and Engineering. 17 June 2007. Web. 11 Nov. 2010. <http://www.aerospaceweb.org/questions/history/q0311.shtml>. 4. http://history1900s.about.com/od/1930s/a/empirestatebldg.htm