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Sunday May 17, 2009

Land of lightning

Much can be done to increase public awareness of the dangers of lightning and experts tell us how and why.

ON Monday, 10 people on a squid fishing boat were injured when they were struck by lightning in waters off Kuala Terengganu.

A victim, Adnan Dolah, recalled the terrifying May 11 incident: “Next thing I know, everyone was lying face down on the floor and we were covered with wood splinters from the destroyed boat roof. Pain surged through my body, as if I had been drenched in hot water.”

Source: Malaysian Meteorological Department

On May 7, Mohd Fozei Saad, an ustaz (religious teacher) in Alor Setar, was riding his motorbike home from school with his son when he was killed by lightning.

“His body was smoking after it got struck,” recounted his son, Mohd Erdi, who survived with severe burns.

The newspaper archives reveal several lightning-related reports of deaths and injuries every year.

And then, there is property damage. On April 11, a fire broke out at the Putrajaya Hospital after it was struck by lightning. Staff evacuated all 14 patients in the orthopaedic ward before the ceiling collapsed.

In November 2007, two oil storage tanks at the Shell Malaysia refinery in Port Dickson caught fire after being struck by lightning. A year earlier in December, a lightning strike near the Ipoh Selatan exit of the North-South Highway fried the computerised systems. However, this act of God did not absolve motorists from paying tolls, which were then collected manually – resulting in a 8km-long traffic jam.

Apart from such dramatic incidents, lightning damage can also be very mundane yet maddening. When discussing this article during the StarMag desk meeting recently, many of us had our own little lightning encounters.

One colleague shared how her her television plug point actually popped out from the power socket (with a nail flying off too!) when her house was struck. Another grumbled how her electrical supply would always trip in a thunderstorm while yet another lamented how her cordless phones and computer modem got fried.

A lightning cauldron

The anecdotal evidence is backed up by hard facts – according to our Meteorological Department places like Subang (Selangor), Bayan Lepas (Penang) and Kluang (Johor) have a whopping 180 to 200 “thunderstorm days” (TDs) per year (the number of days that thunder can be heard at the weather monitoring stations there. See graphic Strike force, below)

In contrast, figures from the National Lightning Safety Institute (NLSI) of the United States show far fewer TDs in Japan (35-40), Australia (10-70), most of Europe (15-40) and England (a paltry 5-10). Even Florida, considered the “lightning capital” of the USA, has “only” 90-110 TDs.

Another NLSI measurement is that of “lightning density” where Kuala Lumpur is ranked fifth in the world with 48.3 lightning strikes (to the ground) for every square km of real estate. (The other top four lightning density sites are in Rwanda and the Democratic Republic of Congo.)

The bad news is that most of the freaky flashes happen in the most developed (and hence vulnerable to damage) part of the country, ie the West Coast of the Peninsula, whereas places like Sabah and Kelantan have less lightning activity.

So why is the West Coast such a “happening” place for lightning? Broadly, it is for the same reasons that Malacca became a great trading port – it is at the vortex of the changing monsoon winds.

Saw Bun Liong, director of the National Weather Forecast Centre, explains that lightning occurs when upward drafts of warm air (convection currents) carrying moisture interact against other water or ice particles high up inside thunderstorm clouds, generating static electricity until it reaches an explosive threshold.

This phenomenon, which requires rather still air conditions, occurs during the transition periods (March– April and October–November) between the North-East and South-West monsoons when the winds are light, thus allowing the convection currents to form thunderstorm clouds.

“Higher atmospheric humidity and more solar heating over the tropics also aid this,” adds Saw.

So, Malaysia is a lightning cauldron – which may boil over.

Take global warming. Malaysia’s average temperature has increased by 0.8°C (from 26.5 to 27.3°C) in the last 35 years. As the mercury rises, even more moisture feeds the storm clouds.

“Global warming will probably increase the severity and frequency of thunderstorms,” says Saw.

In addition, deforestation and land clearing for development will worsen the “heat islands” effect (especially in urban areas) and probably contribute to storm cloud formation.

As if all that wasn’t enough, Prof Liew Ah Choy of the National University of Singapore, a specialist in lightning protection and electrical engineering, predicts that 2009 will be another “hell year” for lightning.

“This is linked to the 11-year solar cycle. In 1996-1998, increased solar activity and the El Nino (hot) weather phenomenon resulted in lots of lightning. Now it’s 2009 and there will be disproportionately more lightning activity.”

To add to our woes, the Meteorological Department has recently warned that we can expect blistering weather (Subang recorded 35.6°C on May 8) right up till September.

Lack of awareness

Despite the high incidence of lightning strikes, Hartono Zainal Abidin, a local lightning expert and consultant engineer, bemoans the lack of awareness of the dangers.

“People often continue playing football in the field even though there is thunder.”

According to the US National Oceanic and Atmospheric Administration (NOAA), 27 and 45 people in America were killed in lightning accidents in 2008 and 2007 respectively (89% were male!)

Hartono estimates that Malaysia has a similar number of fatalities.

“But when you consider that America has about 300 million people while we have only 27 million, that means our lightning death rate is actually 10 times more than theirs,” he adds.

“Even though they have less lightning than us, they take it very seriously. The public is taught from young to seek shelter inside buildings once they hear thunder. Some years ago, a man was arrested by the police for fishing with his two sons during a thunderstorm for recklessly endangering them.”

A person inside any metal structure (called a “Faraday cage” in physics) is safe because lightning will move along the metal but not into the cage.

Hartono Zainal Abidin

That is why the first safety rule during a thunderstorm is to run into a large building as its metallic “re bars” (reinforcement bars inside concrete), water pipes and electrical wiring will form a sort of protective Faraday cage.

Similarly, a car (with doors closed please!) is also a safe metallic cocoon – but not small open structures like bus stops, park gazebos and food stalls.

Hartono is concerned that outdoor events in Malaysia such as fairs, jogathons or family days could be sitting ducks for lightning strikes.

“Other than a golf tournament, it is normal to see events continue in drizzling rain despite thunder in the background. They only stop when the downpour becomes too heavy. Even then, participants would just stay in the tents or even under the trees where they risk getting struck.”

Hartono notes that Singapore also has much better awareness about lightning safety (see Shielding public spaces).

Hartono became fascinated with the constant drama of the skies when he was living in a government-run training centre surrounded by jungles in Pertak (on the road towards Fraser’s Hill).

“There was no TV reception,” he laughs in a recent interview.

Hartono Zainal Abidin says lightning strikes often damage masonry corners and he says 80% of high-rise buildings in the Klang Valley suffer from such damage.

What is less amusing is when the authorities give wrong safety advice. In May 2006, after a student was killed by lightning while sheltering in a gazebo in a field, the Subang Jaya Municipal Council announced that it would tear down the zinc roofs of gazebos and replace them with tiles. Council officials were also supposedly “shocked”, claiming “there had never been reports of people being hit by lightning” inside gazebos and such.

In contrast, Hartono points out that it is standard lightning safety procedure to avoid such small shelters.

“Lightning will slice through them like a hot knife through butter,” he stresses.

In fact, to make such shelters safer, Hartono says that it is better to maintain the metal roof and make sure that it is “earthed” with thick metal strips to the ground.

In Singapore, small park gazebos have been earthed in just such a manner.

“It is not practical to tell people to stay away from small shelters unless you provide them with an alternative,” says Liew.

“People will also automatically assume that a shelter will provide ‘shelter’ (in all ways). Hence, we should make our shelters safe.”

KL’s hot rods

The normal way to protect a building is to have metal lightning rods (called Franklin rods after its American inventor Benjamin Franklin) on the roof which are then properly earthed. If lightning hits the rods, the power can then be safely channelled to the ground.

However, Hartono can recount several cases of public low cost apartments (where the grounding wires went down through the lift shaft.

“That’s the wrong place for the grounding wires. When lightning strikes, things inside can get fried. This is one reason why the lifts in such places break down often.”

Hartono, who says he has been doing a “detailed survey” of lightning damage since 1990, estimates that some 80% of high rise buildings in the Klang Valley have ben hit.

“It’s easy to spot: Look for top corners of buildings that are missing small chunks of masonry or concrete. Lightning strikes the exposed concrete corners but does not go deeper. Once the lightning reaches the steel ‘re bars’ inside concrete, the power from it will be diverted along the metal (and safely to the ground).”

Jimmy Lim, managing director of local lightning protection company Tokai Engineering, worked on the landmark KL Tower in the early 1990s.

“At 245m high, it would be THE lightning rod of KL, so we had to do detailed studies,” he recalls.

To safely dissipate any lightning that hit it, he connected eight chunky “downward conductors” (50mm x 6mm strips of copper) to the metal lightning arrestors atop the tower.

Only such thick metal can safely carry the immense amount of lightning current to the ground.

“The most powerful strikes can be up to 200,000 amperes. That’s enough to light up half a million 100 watt light bulbs!” says Lim.

(Electricity is measured in terms of amperes (power) and voltage (volts). If a live wire was a water pipe, amperes would gauge the amount of flowing water while volts would reflect the water pressure.)

Arrest the surge

However, Lim emphasises that external lightning rods and downward conductors are just part of the story.

“Some people complain, ‘I have paid RM10,000 to my contractor Ah Meng or Ah Fatt to do lightning and earthing rods but why is my TV still getting damaged?’ What they don’t know is that a lot of damage to electrical equipment happens when lightning strikes power or telephone lines outside the building and a “power surge” travels along those lines and burns out stuff indoors.

Sometimes, lightning may strike the ground outside our buildings and the power surge can travel along the ground and then enter our homes through the building’s grounding wires. (see graphic Surge and destroy)

In other words, while a building may be protected inside a Faraday cage, any wires coming in are in effect “holes” puncturing that cage.

Lim cautions that a lightning bolt that hits 5km away can still cause damage because 500,000 volts of electricity carries a whole lot of power, sufficient to reach your home. (For comparison, the standard voltage supplied to households is 240 volts.) The solution is to have good “lightning surge arresters” which can deal with this massive tsunami of power coming through the telephone/power lines or our earth wires.

Lim notes that such power surges will usually affect corner terrace houses because that is where the electrical supply cables (for a row of terrace houses) are first connected to. So, in a way, the corner houses are “protecting” those in the middle.

“You are really paying the price for being a corner house,” Lim smiles. “The same argument applies to bungalows since they have their own power supply lines.”

Another common phenomenon in Malaysia is that of “nuisance tripping”. Even though lightning may not strike one’s home directly, lightning in the neighbourhood is enough to cause a surge of current that will trip the ELCB (earth leakage circuit breaker, located inside a home’s fuse box).

“I have encountered cases where people have to wake up three times a night to reset the ELCB after it trips. When people consult the electrical contractors, they will normally say, ‘Oh you need to do better grounding’. The real solution is to use heavy-duty surge arrestors before the power surge can set off your ELCB.”

Economic costs

Hartono recalls that when he was working with Telekom Malaysia in the 1990s, he found that lightning often damaged public phones and PABX call systems.

“Damage in the telecommunications industry was about RM30-40mil annually. When you factor in damage to fax machines, modems, computers, TV’s and other electrical equipment, the figures can easily exceed RM100mil,” he adds.

Hartono, who has done lightning safety projects at the Dallas-Fort Worth airport and the Taipei LRT system, reveals even major projects in Malaysia can lack proper lightning protection.

“In 2005, a strike knocked out one dozen passenger bridges to aircraft at the KL International Airport. When I was called in, I found that the lightning grounding systems were not done properly.”

Lim shares how his company got the job last year to install complete lightning protection for the PM’s Office in Putrajaya after lightning blew out several CCTV cameras.

While petrol stations are protected (externally) from lightning strikes by grounded Franklin rod systems, the electronic equipment inside are still vulnerable to power surges.

“In fact, this is one reason why you often see the ‘rosak’ sign at petrol pumps. The solution is to install lightning surge arresters at every pump,” says Lim.

Generally, most major corporations have wised up to the need for proper protection.

“Many companies have to protect millions of ringgit worth of equipment. Otherwise one bang and it’s all gone. Unlike homes, where we can afford to lose the use of our (computer) modem for two weeks, companies cannot afford a ‘system down’ for even five minutes,” says Lim.

Personal safety

While corporations have taken steps to protect their hard assets, the situation for people safety is less sanguine.

Prof Liew of NUS says companies may be protecting their equipment but not necessarily the people around it. “So when immense current goes to the ground and somebody is standing nearby, he will be injured,” he cautions.

Lim estimates that 90% of Malaysian homes do not have proper lightning safety measures.

“It is not compulsory for homes in Malaysia to have proper lightning protection, unlike in Britain and Singapore. We have asked the housing development authorities to make this mandatory for all housing projects,” he says.

Yes, the estimated 30 to 40 lives lost to lightning every year may pale in comparison to the 6,000 deaths annually from our infamous traffic accidents. But getting fried is still a real danger in Malaysia, the land of lightning.

Hartono suggests the authorities give short safety messages during weather forecasts on TV. In the US, he adds, the National Weather Service conducts a lightning safety programme at the beginning of every summer. That’s a programme American meteorologist Ron Holle is very familiar with.

Thanks to public education, he says deaths and injuries in the US have dropped significantly over the past decade but creating awareness is never-ending.

“We have been doing this for quite a while but several hundred reporters will call us (about lightning dangers) every spring and summer and it’s like they never heard any of it before,” he says in a phone interview. “We spend most of our time in the US educating children as that has the most benefit in the long run.

“But it’s a very long, slow process. It’s like talking to someone from the moon,” he warns.

Surely that is good enough reason to start the education process in Malaysia immediately. As Hartono puts it, “We shouldn’t wait until lightning strikes a VIP before we take strong action.”

Related Stories:
Bolts of disaster
Shielding public spaces
Wrath of God?
The weatherman tells why

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