Scaling the heights of the Burj Khalifa, Dubai – Otis Elevators
Otis Elevators have applied their innovative solutions and expertise to meet the technical and other challenges that the Burj Khalifa presented, a unique project that the entire world had its eyes on.
Otis has provided elevators and escalators to most of the World’s Tallest Buildings. Therefore scaling heights is familiar territory. The Empire State Building, New York held the title for the “World’s Tallest Tower” for the longest period (40 years) over the last century, and to this day, the building is fitted with Otis elevators, which is currently in the process of modernizing. Before the Burj Khalifa, Dubai, Otis had done the Shanghai Financial Centre and the Petronas Tower in Malaysia. Every high rise project brings with it new learnings and different design challenges for the elevator to overcome.
The Burj Khalifa is one of the most talked about architectural structure in modern times. The unique design and engineering challenges of building it have been featured in a number of television documentaries and have gone down in history books. Otis Elevators take pride in getting the opportunity to apply their innovative solutions and expertise to meet the challenges of this unique project. Not only was this a technical challenge that had never been attempted before, but it was also a project that the entire world had its eyes on.
The initial goal was to design the world’s tallest building that would be marginally taller than Taipei 101 in Taiwan (measuring 509 meters/1,670 feet), the previous tallest structure. The brief however kept getting more ambitious as the team discussed, debated and planned. Plans evolved and the teams including that of Otis Elevators, were faced with challenges that would push boundaries. The Burj Khalifa eventually ended up surpassing the world’s tallest tower at the time, by a considerable margin.
The taller the building, the higher the complexity of design; the Burj Khalifa standing at over 828 meters (2,716.5 feet) and more than 160 stories gave rise to questions like - how do we ensure smooth people flow and serve all floors such that wait times are no more than 30 seconds after hitting the call button, How do we gear up for an emergency like an earthquake or a fire? Other challenges included machine hoisting, rail installation and alignment, etc. Considering the massive height of the project, we had to consider how we would depressurize the cabin in less than 30 seconds and build a powerful braking system. Otis had innovative solutions that matched these stringent project requirements. The challenge was implementing them and that is where the Otis Team’s expertise came into play.
The Innovative Solutions
The building was segmented into zones. Each elevator zone served different audiences – from visitors to office workers, to hotel guests, to residents. The efficiency of the system was maximized, by the use of a sky lobby system. The sky lobby is an intermediate floor where residents, guests and office staff will change from an express elevator to a local elevator, which stops at every floor within a specific zone of the building. The elevators were strategically grouped to align with the floor layout, offering passengers a direct express service to their sky lobby destination by bypassing other floors.
Energy Efficient Elevators
The brief also factored in environment friendliness. Among the 73 elevators installed by Otis at the Burj Khalifa, there are 22 energy-efficient Gen2® machine-roomless units, which are up to 75% more energy-efficient than conventional systems, enabling the owners to manage the building more economically, as well as benefit from lower building costs and increased rentable space.
The compact Gen2® lifts, replace steel cables with coated steel belts. The patented polyurethane-coated steel belts are highly flexible, allowing Otis to design and utilize a highly compact and efficient gearless machine. As a result, the Gen2® system allows for energy-efficient performance while saving space and offering outstanding design flexibility. The Otis patented flat belts also mean smooth and quite rides. In addition, the Gen2® system’s flat, polyurethane-coated steel belts and gearless machine do not require any additional lubrication, making the system cleaner for the environment.
The Gen2® family of elevators is also fitted with a belt monitoring system, the PULSE ™ which electronically monitors the status of the belt 24/7, 365 days a year. This means that an issue can be pre-empted and attended to, before an actual break-down. This results in minimal downtime which is essential for a building like the Burj Khalifa and the clientele it holds.
The elevators were also fitted with Otis ReGen® drives which played a very critical role in this project. In a typical non-regenerative drive, energy is dissipated as heat when braking occurs, resulting in reduced efficiency and creating additional waste-heat load in the building. A plummeting elevator car and its hundreds of feet of supporting steel cable can descend as fast as 22 miles per hour. Stopping that much weight moving at that speed generates a lot of heat; this is when the ReGen® drive from Otis comes into play. ReGen® drives feed this energy back into the building’s electrical grid where it can be used by other loads or users connected to the network. ReGen® drives reduce energy usage by up to 75 percent compared to conventional drives.
Dispatch Management System
To effectively manage traffic Otis designed a system incorporating Compass™ a computerized dispatch management system. Using Otis’ patented advanced technology, the Compass™ constantly evaluates real-time passenger traffic to improve flow and travel time, in busy high-rise buildings. Instead of using standard hall call buttons, passengers register their specific floor in the lobby. The system assigns passengers traveling to nearby floors, to the same car. This minimizes the number of stops per trip and significantly reduces car crowding, as well as passenger wait and travel times. Lobby traffic flow improves, and lobby areas are more organized.
A Landmark Project
Mr. Sebi Joseph, currently the President of Otis India, was Otis GM, UAE operations when Burj Khalifa was opened. He had said on the magnitude of the project that “As the world’s tallest building, the Burj Khalifa is certainly a landmark installation for Otis both in the Middle East and globally. We are proud to have had the opportunity to apply our innovative solutions and expertise to meet the challenges of this unique project. Otis leveraged its vast expertise to meet the challenges that come with designing and installing elevators for the world’s tallest building, such as machine hoisting, rail installation and alignment, and ensuring optimal passenger traffic flow. For example, elevators are strategically grouped to align with the floor layout, offering passengers a direct express service to their sky lobby destination by bypassing other floors. Each elevator zone serves different audiences – from visitors to office workers, to hotel guests, to residents – maximizing their efficiency as a result, and saving time, by the use of a sky lobby system”.