Warning over Skyscrapers' Deadly Faults

    British scientists are completing a major study of the behaviour of World Trade Centre survivors in a bid to make Britain's growing numbers of skyscrapers safer and easier to evacuate.

    Key recommendations and suggestions include blaze-proof lifts, sky bridges linking high-rise buildings and curbs on mobile phones during evacuations. "It would add tragedy to tragedy if we did not learn from 9/11," said the study's leader, Professor Ed Galea of the University of Greenwich.

    Galea and his team analysed the written accounts of 250 survivors of 11 September, 2001, and found they show a startling variation in human behaviour. Almost half those working on floors below where the planes struck took more than five minutes to begin leaving the building. Incredibly, 5 per cent were still there more than an hour later.

    "They sat at their computers while the building blazed," he said. "It is astonishing. We also found most people had long mobile phone conversations to relatives during their evacuation. Such behaviour contrasts with the expectations of high-rise building designers. They assume people will exit in an orderly fashion in seconds of a fire alarm sounding."

    The 9/11 disaster had three zones: the floors where the two planes struck; the floors above, and the floors below. "Everyone on the impact floors ... was killed very quickly," said Galea.

    Nearly all those in floors below the impact survived, however, while all but a handful of those above died - because the crashed planes severed all lifts and each tower's three emergency staircases. The staircases were clustered together and made of plasterboard. Had they been widely spaced and made of concrete, one staircase might have survived and those above the impact could have got out before the towers collapsed.

 

 

    Using special software called Exodus, Galea also calculated how long it would have taken to evacuate the towers if they had been fully occupied. 'What happened on 9/11 was horrible, but it could have been a lot worse.

    "Each tower usually had about 25,000 occupants. However, 9 September was local election day and many people were voting, it was the first day of school term and many parents were late coming in, and it was quite early in the morning. The towers were struck at 8.45 and 9.03. As a result, there were only about 8,500 people in each tower. Had it been later on a normal day, about 13,000 people would have died as opposed to the estimated 2,700 victims who died that day."

    In fact, the people on floors below the impact zones only just got out, Galea's calculations revealed. There were only a few minutes between the last occupants reaching the ground and each tower's collapse. Many refused to leave their desks, a situation that could have been improved if senior executives, and other figures of authority, had been recruited as fire marshals. In addition, as people descended the narrow staircases, firemen were coming up, carrying equipment, causing delay though, according to simulations, not enough to cause loss of life.

    Galea's team has reported to the Office of the Deputy Prime Minister outlining key recommendations that need to be introduced. "High-rise buildings are currently not designed to have complete evacuations of occupants," he said. "We can no longer tolerate that attitude. That is the real lesson of 9/11. We have to find ways to all people out."

    In a bid to find out more about how people reacted to 9/11, Galea's team - plus groups from Liverpool and Ulster universities - have been awarded a 1 million UK grant for lengthy interviews with 2,000 survivors of 9/11. These will begin in New York in January and will be the largest study of 9/11 crowd behaviour undertaken so far.

    英国专家目前正在对美国“9·11”事件幸存者们遭遇危机时刻的反应进行分析,目的是总结经验教训,以便使英国正在增多的摩天楼盖得更加安全和易于人员疏散。

 

 

    据报道,英国格林威治大学教授加利亚领导的一个研究小组在研究了250名“9·11”幸存者的书面报告之后认为,未来超高层建筑的设计应该增设防火电梯、拓宽逃生通道、建设跨楼天桥,以便发生危机情况时有利于人员疏散,楼内人员则应该尽快逃生,而不是把时间耽误在用手机向亲戚朋友报信上。加利亚说:“如果我们不能从灾难中吸取教训,那将又是一种灾难。”

    加利亚研究小组的调查显示,在被飞机撞击部位下面楼层的工作人员中,有接近一半人是在撞击5分钟后才开始撤离的。令人难以相信的是,竟然有5%的人在撞击发生1小时后仍原地未动。“当时大火已经开始蔓延,可他们却仍守在自己的电脑桌前,”加利亚说,“我们还吃惊地发现,许多人即便在逃生途中还在通过手机跟亲朋喋喋不休”。

    在飞机撞击部位上面楼层工作的人员中,除了一小部分外,大都没能逃脱厄运。飞机的猛烈撞击不仅切断了电梯的运行,而且还使每栋塔楼中的3条逃生通道被阻断。由石膏板建成且过分集中的逃生通道系统在灾难中不堪一击。调查显示,如果逃生通道分布得更多些,且用混凝土建造,那么至少可能留下1条通道,在高层工作的人员就可以通过它在塔楼倒塌之前下到楼底逃生。

    调查显示,火灾发生时一分一秒对于逃生者都是重要的。在“9·11”事件中,从最后几人冲出大楼直到塔楼倒塌,中间只经过了短短几分钟。不幸的是,许多人因为拒绝离开工作岗位而耽误了逃生时机。如果当时各公司的高层领导能够振臂一呼,组织开展自救,那么惊惶失措的职员将可能更快地撤出。其次,狭窄的救生通道也是导致人员疏散缓慢的原因之一。

    研究小组提出的建议还包括:在紧急逃生运输工具中加装空气过滤器;研发可在火灾条件下运行的电梯;各公司高层领导能够组织职员自救,并告诫职员在安全脱险之前不要打电话;建设更宽敞、分散的逃生通道等。研究小组已经将上述建议上报给英国副首相办公室。

    报道说,另外,研究小组还将同来自利物浦和阿尔斯特地区多所大学的专家一道,对约2000名“9·11”幸存者进行访问。目前,该项目已经获得了100万英镑的资金支持,将于明年1月在纽约启动。这将是迄今为止针对“9·11”事件中群体行为开展的最大规模调查。