Petronas Twin Towers are among the top 10 the tallest buildings in the world. They were the tallest buildings in the world from April 15th, 1996 until October 17th, 2003 when Taipei 101 (Financial Center) was topped out at 508m (1 676 ft). It consists of 2 identical structures rising 452 metres (1 483 ft) on the site of a former race track in Kuala Lumpur, Malaysia. Their style is Islamic, which makes them unique between buildings built in international style. Their ground plan is eight-pointed star, which has special meaning in Islamic architecture.
The Petronas Twin Towers consist of more than 8 million square feet of work place, 1.5 million square feet of retail and amusement services. Their parking space is for 4 500 cars positioned in basement. There is also symphony hall and multi-media conference center. Each tower was built by another company, and they competed who will finish first. Both towers were finished at the same time.
Foundation
The towers are framed with a structure of concrete core walls and columns. In Malaysia, the local contractors on the job were more familiar and comfortable operating with concrete than with steel. Construction had 4.5 m thick raft foundation made up of 13 200 m3 of reinforced concrete. It weights roughly 32 550 tonnes beneath each tower. It is supported by 104 barrette piles from 60 to 115 metres long.
Exterior
The Towers feature multi-faceted walls of 33,000 stainless steel and 55,000 glass panels. Vision Glass, specialised panels with light filtering and noise reduction properties, offer a comfortable internal environment. The glass is covered by stainless steel visors to further protect visitors from the tropical sun.
Technology
Each floor or couple floors in the towers has its own local area network for air conditioning and illumination, as well as a general-purpose control. The most significant systems used control vertical transportation, energy conservation, air conditioning, building control, building security, the fire alarm and the safety plan.
Skybridge
On the 42nd floor there is a skybridge linking both towers. That bridge, with angled support, creates so called ”portal to the sky”. The most challenging part was the positioning of the two-story skybridge, which was built on the ground and elevated to its location 170 metres high. After it was lifted into place, the legs which had been installed on the towers were swung down into place, and connected under the bridge on 28th floor. The skybridge was not planned, but during the construction 2 tower had to be connected in some way in the air. It links two sky lobby levels in both towers making crossing from one to another tower easier. On that floors there are an executive dining room and a Surau (prayer room).
Elevators
The Towers have 29 double-decker high-speed passenger lifts, six heavy-duty service lifts and four professional lifts. The floors are divided into zones: two sets of 6 double-decker lifts serve levels 1 to 23 and levels 1 to 37, while another set of the five double-decker lifts take passengers immediately to the Sky Lobby. Here, passengers take another lift to the upper areas. The professional lifts are the longest rise in any office building in Malaysia. It serves every floor from the basement car park to the top of the Towers in 90 seconds. Each passenger deck can carry 26 people or 52 in total, while the professional lifts can carry an average of 10. Its speed is between 3.5m/s and 6.0 m/s, based upon on the zones they are servicing.
Fire safety
The fire alarm system is designed using specific fire detection systems that include smoke and heat detectors, manual call points, sprinkler-system tracking and a firemen‘s telephone / two-way intercom system. Each tower has an individual fire alarm system but is networked via LAN to allow administration to be centralized at the central fire command centre (CFCC) which regulates the fire alarm. The fire safety plan of the towers is designed so that if a fire happens on a floor, the shuttle elevators will be available for use in evacuating residents. Other floors would be evacuated or residents relocated only if required. Each tower can be divided into two parts at levels 41 and 42, because of the elevator zoning arrangements and the sky bridge. Predicts time of evacuation of the top three floors varies from 40 seconds for floors eighty-five to eighty-six, and 69 seconds to 1.3 minutes for floors thirty-five to thirty-seven. If we consider sky lobby as a safe level for the floors above, the maximum total time to exit is from 5.9 to 17.8 minutes.
Timeline of construction
Jan 1992Start of project planning
Mar 1993Start of foundation works
Apr 1994Construction of the superstructure
Jan 1996Fitting out of the interiors complete with furniture
Mar 1996Jacking of the spires of Tower 1 and Tower 2
Jan 1997Moving in of the first batch of PETRONAS’ personnel
31 Aug 1999Official opening by YAB Dato Seri Dr Mahathir Mohamad,
the 4th Prime Minister of Malaysia