Hotel+New+World+Collapse

//Raffi A. Kayat, BAE/MAE Structural, Penn State, Fall 2012.// toc =Introduction=
 * The Hotel New World Collapse ( ** March 15, 1986)

Singapore, located in South-East Asia, has as population of over four million people. With rising skyscrapers and a booming economy, its population has spread quickly to its neighboring towns to support the metropolitan area. There are a variety of towns that reside in Singapore, one in particular named Little India. A six story building called the Hotel New World, located in Little India, housed multiple local institutions and establishments such as offices, a branch bank, and a nightclub. On March 15, 1986, the Hotel New World on 305 Serangoon Road collapsed in less than 60 seconds at approximately 11:30 am (See Figure 1). The result was the entrapmentt of fifty people, seventeen of whom were eventually rescued, and thirty-three who were killed. After the collapse, all emergency response units as well as the Singapore Army and Air Force helped in rescuing the victims buried under the rubble. (Neale, 2001, p.128-p.131)

Following the collapse, various theories were offered as possible reasons for the failure of the building. The president at the current time, Wee Kim, ordered a full investigation into the cause and demanded the installation of measures to prevent a recurrence. The head commissioner of the investigation, Justice L.P. Thean, ultimately declared that no particular impact had triggered the collapse. However, the main cause of failure was the poor structural design which was inadequate for the building’s use; it was only a matter of time before it would have failed. After the Hotel New World collapsed, building codes and standards were improved throughout Singapore as well as the implementation of engineering ethics (How to avoid another Hotel New World disaster, The Straits Times, p.14-15, 1987). Disasters do not just randomly occur; there is always a chain of critical events. This wiki case study will unravel the clues and detail the reasons behind this collapse.

=History and Description=

The Hotel New World, built in 1971, was located in Little India about six kilometers from the prosperous downtown of Singapore. It had thirty six reinforced concrete columns that supported six concrete floors, totaling a weight of 6,000 tons. A parking lot was composed of the underground while a bank branch took up most of the ground floor. The next floor was a popular nightclub that attracted many tourists and locals from the metropolitan area. The remaining floors were occupied by a budget hotel named The Hotel New World, which eventually became the name of the entire building. All the mechanical equipment such as water tanks and air conditioning units, which were used to cool off the building in the hot climate, resided on the roof. The total height came to be twenty four meters. It was small compared to the skyscrapers in downtown, yet it was one of the tallest in Little India for its time. (The National Geographic documentary entitled “Seconds from disaster: The Hotel New World”, 2005)

The building experienced no severe impact or structural damage during its lifetime. In 1975 however, there was a gas leak in the building that poisoned thirty-five people. In a positive light, everyone recovered from their ailments and the Hotel New World escaped any sort of damage. The gas pipes were checked following the incident and the building was given approval for reusage. (Gas Leak made news 10 years ago, the Straits Times, 1986, p.4)

=Day of Collapse=

On March 15, 1986, eleven years following the gas leak, the Hotel New World collapsed in less than sixty seconds at approximately 11:30 am. The following events and timeline were taken from The National Geographic documentary entitled “Seconds from disaster: The New World Hotel” (2005), The Straits Times news article "Chronology of events" p.2 (1987) and The National Library Board Singapore article "The New World Hotel" by Lim Tin Seng (2011).

__March 14th__ At 7pm, the hostess of the nightclub hears a noise and witnesses a crack in one of the columns while setting up for the evening.

__March 15th__ At 10:10 am, another crack was heard which resulted in falling debris. Workers from the previous night confirmed that everything was fine. Meanwhile, at the hotel reception area, staff saw cracks and fissures spreading across the walls. However, these concerns were never reported. Cracks continued to spread in the walls and columns. At 10:45 am, the receptionist heard a “loud bang” from somewhere in the building and a bellhop was told to collect timber to shore up the cracked columns. At 11:10 am, a passerby claimed to have felt an earthquake and the receptionist heard another loud noise. At 11:21 am, one the workers attending to the cracked column saw debris falling from the ceiling to the ground. The worker then felt vibrations all throughout the room. At 11:26 am, the whole building started to vibrate and shake as it was on the verge of collapsing. More columns cracked, walls began to cave and concrete and steel fell onto the occupants. In less than one minute, one of the tallest buildings in Little India transformed into rubble and dust. At 11:27 am, the landmark of Little India was completely destroyed with all its occupants still in it. A cloud of dust visible from miles away loomed over the area where the building once stood as its staff and residents remained buried under concrete slabs and columns. At 11:35 am, emergency and medical crews arrived at the disastrous scene. At 12:30 am, the first two survivors were rescued. However, what used to be the ground floor was now ten meters below ground, trapping the entire bank’s staff. From 1:00 to 5:00 pm, government officials, Prime minister Lee Kuan, and family members arrived at the scene.

__March 16th__ The rescue operation continued as seven were found dead and eleven were rescued. The president arrived at the scene.

__March 17th__ At 11:00 pm, Instead of using heavy machinery which would further endanger lives due to caving, rescuers created a series of tunnels and saved the last survivor of the collapse. In total, only seventeen people were rescued in the catastrophe.

__March 21st__ The rescue operation was halted while heavy equipment arrived to clear the site. The final death toll was thirty-three.

=Rescue Mission=

Minutes after the collapse, the first two fire engines were dispatched from the Central Fire Station and police arrived at the scene. They were followed shortly by members of the Singapore Civil Defense Force (SCDF) along with medical personnel of the Singapore Armed Forces (SAF). By late afternoon, government officials and relatives of the trapped victims assessed the situation. (Chronology of events, Straight times, 1987, p.2)

However, rescue operations were at a disadvantage because rescue personnel were not trained or equipped to deal with such a dire situation. Initial attempts to clear the rubble created problems for the firemen who were tunneling beneath to reach survivors. The authorities then called in tunneling experts from Britain, Ireland and Japan who at the time were stationed in Singapore for the construction of the Mass Rapid Transit (MRT) subway. The courage of three volunteers, Terry W. Hulme, Russell Black and Dave Stewart brought hope to the people. The rescue operation gathered momentum with the arrival of specialized equipment such as aqua-jet cutting tools, life detector devices and infrared imagers provided by private organizations and the SCDF. (Seng, 2011)



The rescue mission composed of several stages. First, large debris such as beams and columns were cleared. Next, tunnels were dug for rescue personnel to reach the buried occupants (See Figure 2). The rescuers used life detectors to search for survivors and the aqua-jet and other mechanical tools to cut through debris. The entire process, the tunneling in particular, was carried out with extreme care to prevent cave-ins. A shop selling pianos opposite the collapse site was used by authorities as the command center for the rescue operation, while helicopters were stationed in a nearby Park to fly the injured to hospitals. Authorities also set up a center for the relatives of the trapped victims at a nearby coffee shop. A once peaceful neighborhood was turned into an extensive rescue operation. On March 19th at mid-day, the tunneling operation was called off after it was clear that there were no more survivors. Workers then started to clear the remaining rubble. Finally, when the last bodies were discovered by the workers, heavy equipment came to clear the site. (Seng, 2011)

=Speculations and Forensic Study=

After the collapse, President Wee Kim ordered a full investigation to solve the mystery of what was perhaps the biggest tragedy in Singapore after World War II. He appointed Justice L.P. Thean as the head commissioner, who was also famous engineer at the time. This massive intervention was made due to the fear of much taller structures falling under the same risks. (Seng, 2011)

First, many engineers who examined the rubble and the speed of the collapse thought of the incident as out of the ordinary and unexpected. This sentiment initially led to the belief that an internal explosion caused by a bomb or terrorist attack was responsible for the collapse. As any investigators would do, the engineers evaluated the building’s history. They concluded that a gas leak was the only incident that occurred. It was feared to have reocurred, resulting in an explosion that brought down the entire building. However, as investigations progressed, no evidence of an explosion was found, as this type of disaster has its own distinctive footprints. Evidence of explosions include shattered glass, small debris of walls and crushed rubble blown to tens, even hundreds, of meters away. (The National Geographic documentary entitled “Seconds from disaster: The Hotel New World” ,2005)

Secondly, the building failed suddenly and vertically. This vertical failure provoked curiosity amongst the engineers, so they investigated all the witnesses. The first sign of progress happened when they debriefed the rescuers. They reported that when drilling through the concrete, the drills were very smooth and quick like a knife cutting butter. This result can come from the following two theories: one is that the concrete was badly mixed and caused the strength of the concrete to decrease or that softness of the concrete was due to the fractures of the collapse. Samples were brought into labs for strength and consistency testing. The concrete met all of the international safety standards, concluding that the strength of the material was not the problem. This theory of defective building materials was ultimately eliminated from the list.(The National Geographic documentary entitled “Seconds from disaster: The New World Hotel” ,2005)

Third, the investigators then turned to another dangerous hypothesis. They examined the land under the building and realized that it used to be a swampy flat plane drained since the 19th century. It was not an issue in the past as buildings were not as tall as the New World Hotel, but this scenario caused panic as it could have propagated to an island wide devastation. Nevertheless, engineers looked at the surviving foundation and basement walls of the structure. If movement had occurred, it could have been easily noticed as the walls would have had big cracks but nothing was found. The forensic team double checked by analyzing the composition of the soil and tested the strength of the surviving foundations. Hence, there was no failure in the foundation even though minor movements had occurred.(The National Geographic documentary entitled “Seconds from disaster: The New World Hotel” ,2005)

=Reason behind the failure=

Buildings don’t spontaneously collapse, therefore a critical clue or piece of evidence was missing to unveil the mystery of the Hotel New World building. The report and description given by the witness who reported the cracks in the column on the second floor the night before offered the first clue to determining the true cause of the collapse. In fact, all the witnesses’ reports together unveiled everything. Each report contained unique failures throughout the building. The investigators referred back to the plans and realized that each failure corresponded to different columns; they failed because they were stressed to their limit. This was proven by examining the concrete on the microscopic level. In fact, when concrete is stressed to the limit, tiny cracks-- also known as micro-cracks invisible to the naked eye -- in the particles are developed. (The National Geographic documentary entitled “Seconds from disaster: The New World Hotel” ,2005)

Furthermore, these micro-cracks that were found in laboratory testing explained the description of the cracking columns reported by the witnesses. Such cracks reduced the weight that is supported by the piers and initiated a progressive collapse. Hence, the loads on the building needed to be rechecked by the investigators to recognize the origin of the cracks. It could have been that either the supporting elements were under-designed in the construction phase, or the building saw extra and uncalculated weight throughout its lifetime.

As expected, the investigators found heavy equipment in the rubble that was not in the original design plans (See Figure 3). During its fifteen years of life span, the owner of the building had added extra weight:

(The National Geographic documentary entitled “Seconds from disaster: The New World Hotel” ,2005)
 * In 1975, the bank added a vault weighing twenty-two tons on the ground floor.
 * In 1978, the building owner added two additional cooling towers on the roof.
 * In 1982 for architectural reasons, the building owner fixed heavy duty ceramic tiles on each exterior face on every floor weighing a total of fifty tons.
 * In 1986 the owner installed an additional cooling tower on the roof.

However, all this extra weight that was added to the structure fell under the live load category and was already accounted for. In detail, the calculations of the engineers proved that the one hundred and ten tons of extra weight was trivial to the collapse. (Neale, 2001, p.128-p.131)

Finally, the engineers returned to their blue prints and calculations. They pulled out the plans and calculations of the draftsmen and realized that the building’s dead load was not accounted for in the original design. This monumental mistake meant that the building was on the verge of collapse since its construction. The building columns were stressed to their limit from day one and their collapse was inevitable. (Neale, 2001, p.128-p.131)

In conclusion, the investigators traced the source of the collapse to the engineers responsible for the structural system and integrity of the building. The primary reason of the collapse was then proven to be the under-designed columns and foundations as the designers lacked consideration for dead load when sizing the members. In addition to the substantial live loads that caused an overload, the lack of proper maintenance and engineering contributed to the collapse. (Neale, 2001, p.127-129)

=Progressive Collapse=

Progressive collapse occurs when a local failure spreads throughout a structure from element to element, eventually resulting in the collapse of either the entire structure or a disproportionately large part of it. It is caused by an abnormal or extreme loading event, typically due to accidental impact, faulty construction, foundational failure, or violent changes in air pressure, such as blasts (ASI, 2010). In this failure, the progressive collapse was due to the poor design of the structural system. All the columns were stressed to their limit and on the verge of failure. Thus, it was a matter of hours until their collapse.

In addition, Column 26, shown in Figure 4, was the column that cracked first. The origin of these cracks was the result of micro-cracks for fifteen years within the concrete as it was stressed to its limit. The weakening caused a load to distribute to adjacent columns. Next to it, Column number 32 was not able to support the extra load and was the next to fail. In fact, these two columns were the only two stressed over their capacity because of the dead load, the additional live load and the original poor design. The same crack propagation happened to two other columns in the same corner. Finally, that damaged corner triggered the collapse and brought the whole building down. (How to avoid another Hotel New World disaster, The Straits Times, p.14-15, 1987) Progressive collapse in concrete construction has been an important issue for several decades now and has been mainly addressed by increasing the resistance of punching shear in flat plate construction. However, various building types in recent events such as the World Trade Center push the limits of thinking. Currently, the philosophy of design is to limit the amount of damage rather than eliminate it. This was inspired from the earthquake-resistant design philosophy. (Baldridge & Humay, 2003, p.1-7)

In addition, engineers are currently faced with addressing progressive collapse. Progressive collapse can be prevented by designing and detailing the building with redundancy, ductility and continuity in order to have an alternative load path following a loss of a member. For example, a continuous beam that is supported at 24’ intervals is actually designed at 48’. In fact, if a column supporting that beam at 24’ is no longer there, the beam will still be supported by the other two columns making the beam length 48’. Thus, deflection and serviceability criteria are not addressed in the design stage, strength is the goal. This method of designing a “missing” column or beam may seem expensive, but the slight increase in cost is insignificant when compared to the safety of the building and its occupants. (PCA, 2005, p.1-8)

Moreover, as many assumptions need to be taken for adopting the progressive collapse prevention method, some scenarios are difficult, uneconomical and unreasonable to design. It was proven in “Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions” (ASCE, 2007) that if the total internal energy of a building is lost during the crushing of one story exceeds the kinetic energy impacted to that story, collapse will continue to the next story. This is the criterion of progressive collapse trigger. Hence, what matters is energy, not the strength or stiffness. (Bažant & Verdure, 2007, p.308-319)

=Aftermath of The New World Hotel Collapse=

The result of the collapse was the entrapment of fifty people, seventeen of whom were eventually rescued and thirty-three of whom were killed. After identifying the main reasons behind the New World Hotel collapse, Justice L.P. Thean presented the report to the President, leading to several reforms in the construction industry. In fact, the root of the catastrophe was during the design stage. The structural engineer and draftsman neglected the weight of the building, a rudimentary and costly mistake. Thus, one of the reforms stated that all structural plans and calculations of a building prepared by a professional engineer for submission to the Development and Building Control Division should be checked by another professional engineer. This design stage involves all the crucial structural components such as columns, beams, foundations and shear walls. It is required that the engineer checking the calculations should be an independent consultant and have at least ten years of experience in the relevant areas of design and construction. (Neale, 2001, p.128)

Furthermore, due to improper maintenance, the Building Control Act of 1989 was endorsed along with the Building Control (Accredited Checkers) Regulations 1989. The formation of the Accredited Checkers was the unique feature of the 1989 Building Control Act. The “accredited checker” aids in providing additional help and inspection of the work of the engineer in charge. Also, it is the owner's responsibility to conduct maintenance checks every five years by professional engineers. This higher degree of quality control is an early level of defense in the design stage to prevent disasters such as the New World Hotel. The accredited checker would be appointed by the owner of the project and must be registered with the Building Authority. (Neale, 2001, p.128)

Additionally, the legislation authorized the Building Authority to refuse any building plans that are not appropriate and to inspect any structural designs by appointing an accredited checker. The department that approves structural plans is now called the Building Engineering Division. During construction, the government forces the owner and the engineers to conduct spot checks and material testing on site for piles and other structural materials. These new laws are not perfect; however, they did stop much of the corruption that existed in Singapore's building industry. (How to avoid another Hotel New World disaster, The Straits Times, p.14-15, 1987)

For more examples of progressive collapse please refer to Ronan Point (May 16,1968), L'Ambiance Plaza (April 23, 1987) and World Trade Center Towers 1 & 2 (September 11, 2001)

=Conclusion=

The New World Hotel was a tragedy that hit Singapore in its budding prosperity. In fact, the collapse gave an awakening call to the nation and its building industry. Despite panic amongst the occupants, no one took action due to the reassurance of the construction workers. After the collapse,the president appointed a special thorough investigation of why and how the building failed. Many theories were brought to attention, yet nothing stood out at the time.

After heavy examination and study of the collapse, it was clear that the collapse of the New World Hotel was not caused by an explosion, nor by improper construction, material deficiency, swamp land or by the live load added to the building by the owner. The building failed because the engineers did not account for the building’s weight or dead load during the design phase. This monumental mistake meant that the building was on the verge of collapse ever since it was built. The building's columns were stressed to their limit since their construction and the collapse was a matter of time. Also, the substantial loads added to the building that caused an overload to the poorly constructed structure contributed to the collapse, as well as the lack of proper maintenance and engineering.

The progressive collapse, which is defined as the spread of an initial local failure from element to element, eventually resulted in bringing the structure down. The date was March 15th, 1986 and the time was 11:25 am when thirty-three people perished under the rubble of the New World Hotel due to negligence and professional misconduct of the engineers in charge. The government called on the owners of the 170 buildings designed by the same architects and engineers of the Hotel New World to examine their buildings as a precaution. (Chronology of events, The Straits Times, p.2, 1987)

New legislation was passed and the Building Control Act of 1989 was endorsed along with the Building Control (Accredited Checkers) Regulations of 1989. The formation of the Accredited Checkers was the unique feature of the 1989 Building Control Act. The “accredited checker” aids in providing additional help and inspection over the design of the engineers in charge. The government enforces that owners conduct maintenance every five years by professional engineers. They are also instructed to have all calculations and structural plans double checked by an accredited checker, conduct irregular spot checks at the site, and test piles and other structural materials. This higher level of quality control is an early level of defense in the design stage to prevent disasters such as the collapse of The Hotel New World.

=Bibliography=

The company Applied Science International (ASI) published this article of why progressive collapse is a must by analysing 2 different cases: The Minnesota I-35 Bridge August 2007 and The Oklahoma 1995 Bombing.
 * Applied Science International (ASI). (2010). Progressive Collapse Analysis is a Must: ASI has the Perfect Tool. Retrieved 10 3, 2011, from Applied Science International (ASI):** http://www.appliedscienceint.com/Services.aspx/ProgressiveCollapseAnalysis

This is a study published in Concrete International where they discuss seismically designed reinforced concrete buildings succeed in preventing progressive collapse.
 * Baldridge, S. M. & Humay, F.K. (November 2003). Preventing Progressive Collapse in Concrete Buildings. Concrete International, 1-5. http://www.baseengr.com/news-pub/white_papers/03.11_PreventingProgressiveCollapse.pdf**

In this article found in Journal of Engineering Mechanics, the authors discuss progressive collapse for tall buildings and for demolition purposes. They explain the importance of design and the reactions of buildings to this type of collapse. They use the World Trade Center as their main example.
 * Bažant, Z. P., & Verdure, a. M. (March 2007). Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions. Journal of Engineering Mechanics (p. 308 to 319). American Society of Civil Engineers (ASCE). http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/466.pdf**

This newspaper article retreived from the NewspaperSG cites in details the chronology of events from the day of the collapse to the day the investigating report was handed to the president.
 * Chronology of Events. (1987, March 15). The Straits Times, p. 2. Retrieved on December 5, 2011 from National Library Singapore, NewspaperSG.**
 * http://newspapers.nl.sg/Digitised/Article/straitstimes19870315.2.9.8.aspx**

This newspaper article retreived from the NewspaperSG talks about the gas leak that the Hotel New World experienced 10 years ago as it was the only incident that occured to the building before its collapse in 1985.
 * Gas Leak Made News 10 Years Ago. (1986, March 16). The Straits Times, p. 4. Retrieved on December 5, 2011 from National Library Singapore, NewspaperSG. http://newspapers.nl.sg/Digitised/Article/straitstimes19860316.2.4.8.aspx**

This newspaper article retreived from the NewspaperSG summarizes the new laws and requirements for the building industry as well as the events that happened the day of the collapse in brief.
 * How to avoid another Hotel New World disaster. (1987, March 29). The Straits Times, pp. 1, 14-15. Retrieved on December 5, 2011 from National Library Singapore, NewspaperSG. http://newspapers.nl.sg/Digitised/Article/straitstimes19870329.2.3.aspx**

This is a 48 min exculsive National Geographic documentary about the Collapse of the New World Hotel. They interview experts, witnesses and survivors of the collapse during that tragic day.
 * National Geographic. (Director). (Singapore Season 2 Episode 9. September 27, 2005). Seconds from disaster: The New World Hotel [Documentary]. Found on YouTube: http://www.youtube.com/watch?v=DtYKCu9XBDA**

This book discusses the causes and effects of certain building failures where progressive collapse is a big topic. Several cases were discussed among them Ronan Point.
 * Neale, B. S. (2001). Forensic Engineering: The investigation of failures. p.127-p.130. London: Thomas Telford publishing.**

The Company provides a free online full publication of the article dicussing progressive collapse (the basics) but focusing on concrete buildings only. They also discuss the codes as well as the use of previous historical examples such as the Oklahoma 1995 Bombing.
 * Portland Cement Assosiation, PCA. (2005 ). n Engineer’s guide to: Concrete Buildings and Progressive Collapse Resistance. Retrieved 10 1, 2011, from Portland Cement Assosiation, PCA: http://www.cement.org/buildings/security_progressive.asp**

This article found on the National Library Board summarizes the collapse, main events and the rescue mission. It was used mostly for the rescue procedure and investigation results.
 * Sen, T. L. (November 2011). Hotel New World Collapse. National Library Library Board Singapore 2009.**
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=Additional Resources=

This is a 144 page Book / Report writtin after the collapse that explains all the details about the Collapse.
 * Hon, J. (1987). Hotel New World Collapse. Singapore: Times Books International.**

This is a Report done following orders of the President of The Republic of Singapore right after the New World Hotel Collapse discussing all the reasons and consequences as well as future prevention to this kind of tragedy.
 * Thean, L. P. (February 1987). Report of the inquiry into the collapse of Hotel New World to the President, Republic of Singapor. Singapore: Singapore National Press Ltd .**