Falling trees not result of poor maintenance, says NParks

Hoe Pei Shan Straits Times 23 Jul 10;

THE recent spate of trees falling are the result of severe weather conditions, not poor maintenance.

The National Parks Board (NParks) said it had, in fact, stepped up its 15,000 tree a month inspection to include an additional 2,000 large, mature trees in the past two months, when unstable weather first hit Singapore.

Meeting the media yesterday, NParks director of streetscapes Simon Longman said there was no emerging pattern as to what sort of trees or areas were more prone to such accidents.

'There was no trend in the species, the size or the location of these recent cases, and it really boils down to the individual circumstances like wind and rain,' said Mr Longman, who added that the recent severe weather conditions have made the work of NParks particularly challenging.

'For the tree that fell in Yio Chu Kang, it had a well-formed root system, and yet was completely uprooted by the microburst.'

Thunderstorms and microbursts, which are powerful gusts of air, contributed to 240 incidents of fallen trees or branches in June alone.

This week, two instances of trees falling on cars were reported - one in Ang Mo Kio yesterday and another in Yio Chu Kang on Tuesday, when a man was crushed to death.

And in the light of more severe weather expected at the weekend, the intensified maintenance regime - which targets trees along roads with high vehicular traffic - will continue.

Mr Longman also gave the assurance that NParks has been carrying out a 'very rigorous and systematic' tree care programme, with regular tree safety inspections for signs of poor health, disease, pests or structural defects performed since the 1980s.

NParks has 120 officers certified by the International Society of Arboriculture who go around inspecting each of the estimated two million trees along Singapore's roads, in parks and protected nature areas at intervals of 12 to 18 months.

A visual examination - to look out for decay, cracks or entanglement - may be followed up with secondary checks with the use of high-tech equipment if necessary.

For example, the PiCUS sonic tomograph is used to detect the internal condition of the trees by measuring the velocity of sound passed through the wood in a cross-section of the tree to assess if there are cavities.

Inspection details are then recorded in a computerised database which enables NParks staff to identify trends and take preventive action to minimise the risks of tree failure.

For instance, once NParks identifies trees in areas with public access that are deemed vulnerable during rainstorms, they are replaced with stronger species like the angsana, rain tree, broad-leaf mahogany and yellow flame.

Addressing questions about trees in urban areas possibly having insufficient space to develop their roots, Mr Longman explained that a 2m-wide road coast designated for tree planting is allocated whenever new roads are built - and that is sufficient.

Trees 'will maximise the available space below the ground', even creeping under nearby drains, as the tree in Yio Chu Kang did.

When asked whether the age and size of roadside trees should be capped to ensure they are not safety hazards, Mr Longman said: 'It is not so much about the size of the tree, but about the management - even smaller trees can cause extensive damage. Big trees like rain trees are just well-adapted to this tropical region.

'As for ageing trees, we take it very seriously when it comes to assessing the decline of trees and in anticipating the point when a tree becomes a liability under normal conditions.'

Noting that older trees will eventually be replaced in the long-term streetscape master-plan, he said: 'We can't give 100 per cent assurance that nothing will happen...but we have a duty of care owed to people to keep trees safe and well-maintained.'

Another tree falls, damaging car
Driver and two passengers unhurt; he plans to seek redress from NParks
Carolyn Quek Straits Times 23 Jul 10;

Mr Steven Lee standing next to his damaged two-year-old Chevrolet with its shattered rear windscreen. A sea apple tree fell on the car while he was driving it along Ang Mo Kio Street 22 yesterday morning. -- PHOTO: SHIN MIN DAILY NEWS

ANOTHER falling tree hit a car on the move yesterday, the second such incident in three days.

The impact shattered the rear windscreen of the two-year-old blue Chevrolet, which was on Ang Mo Kio Street 22, but its three occupants escaped unhurt.

Although they were not trapped, the shocked trio stayed put in the car until the Singapore Civil Defence Force came to their aid.

The incident echoed what happened to Mr Chua Loong Wai, 32, on Tuesday - except that he was killed by the rain tree that fell on his car as he drove down Yio Chu Kang Road.

Yesterday's mishap took place at about 7.40am near Block 226, Ang Mo Kio Street 22, shortly after a heavy downpour.

The tree in question has been identified as a sea apple tree that is 15m tall and about 25 to 30 years old. It was last pruned in November.

The driver of the car, Mr Steven Lee, 48, told The Straits Times that he had just picked up his brother and 20-year-old niece from their home and was taking them to work and school when the tree came crashing down on them.

The IT company manager said: 'The tree covered the whole car. Thank God nothing happened to us, but the car is badly damaged.'

His brother Edward, 52, a manager in the food and beverage industry, was in the front passenger seat. He said he saw the falling tree heading their way but it happened so fast that he could not warn his brother in time.

Mr Lee, the driver, said he hit the brakes, which threw his niece Rebecca, a Ngee Ann Polytechnic student, forward.

She said of the smashed rear windscreen: 'I was saved because my uncle slammed on the brakes.

'If I had been leaning back, it would have shattered on my head, and it would have been much worse.'

She added wryly: 'The first thing that came to my mind was, the trees are falling a bit too much.'

She said she was shivering while waiting for help to arrive.

'I never expected this would happen so soon after the other accident - and certainly not to me.'

Her uncle said he intends to seek compensation from NParks as his car insurance policy does not provide coverage for incidents like this.

NParks declined to elaborate on its compensation policies, but said it had contacted Mr Lee and given him some information.

General Insurance Association president Derek Teo said that if a driver had bought a comprehensive motor insurance plan, he would be covered for mishaps of this kind.

Recent incidents
Straits Times 23 Jul 10;

# July 20: A projects manager and father of a two-year-old, Mr Chua Loong Wai, 32, suffered spinal injuries and died at the scene when a rain tree fell on his Honda Freed at the junction of Thomson Hills Drive and Yio Chu Kang Road at around 2pm.

# June 25: Two people were hurt when a khaya senegalensis tree fell across four lanes of traffic on the Central Expressway.

The woman suffered bruises, while the man's left hand was injured.

# June 24: A 59-year-old cabby escaped with only a minor abrasion on his chest after a tree branch broke off and pierced the windscreen on the driver's side of the taxi.

The driver was alone in the cab when the incident happened at the junction of Depot Road and Depot Close that morning.

NParks has structured approach to tree care programmes
Imelda Saad/Alvina Soh Channel NewsAsia 22 Jul 10;

SINGAPORE: The National Parks Board (NParks) has said it takes a structured approach in the way it cares for its trees.

It uses high-tech equipment to ensure that trees across the island are sturdy.

It gave this assurance on Thursday in the wake of a series of accidents involving fallen trees.

The latest incident happened on Thursday morning when three people were trapped in their car by fallen branches during an early morning downpour.

The Singapore Civil Defence Force (SCDF) said it received a call about the incident in front of Blk 226, Ang Mo Kio Ave 1 at about 7.40am.

SCDF personnel cleared the tree branches and manually opened the door of the vehicle to let the occupants out.

A spokesman said that the three occupants of the car had no visible injuries and were not sent to hospital.

Fallen trees have come under public scrutiny during the recent rainy spell.

NParks has stepped up its inspection and pruning of trees around the island.

Besides deploying manpower, it is also leveraging on technology to check the trees for signs of poor health, disease, pest or structural defects.

A tomograph (PiCUS Sonic Tomograph) is used to assess the internal condition of a tree, for example, if it is filled with cavity or not.

NParks director of Streetscape Simon Longman said: "It introduces sound waves into the internal wood of the tree and (from) the rate at which the sound waves travel through the wood, we can determine whether the wood is sound, whether it's solid and well grown or whether it is decayed.

"The sound travels well through well-formed hard solid wood and it travels not so well through cavities or decay.

"So based on the overall extent to which the sound travels through the wood, we can build up a picture of cavities or decay within the internal wood of the tree.

"This helps us a lot in our inspection. We can determine if the tree has internal weakness or not."

Another instrument to assess the internal condition of a tree is the Resistograph which uses a microdrill driven into the wood to detect any defect.

Results are recorded in a computerised database to identify trends and take preventive action.

NParks said there is no particular area which is prone to tree failures.

Fallen trees are the result of several factors.

They include intense weather conditions and the direction of strong winds and storms.

NParks said its approach has always been to plant hardy trees around Singapore.

On whether tress are less stable if planted along pavements and drains, NParks said there is a tree-planting strip reserved along the roads.

Mr Longman said: "After this strip, it's usually occupied by buildings or people's properties.

"This is the road reserve where the planting strip is set aside for tree planting so we have to maximise this space.

"We've set it back as far as we can. But, really, the tree must occupy this space near the road."

The authorities have warned of more wet weather ahead as typhoon Chanthu makes landfall in southern China.

- CNA/ir

A narrow escape after tree crushes car
Leong Wee Keat and Esther Ng Today Online 23 Jul 10;

SINGAPORE - Seconds after a 15-metre tall tree crashed onto his blue Chevrolet yesterday morning, all training manager Steven Lee, 48, could do was utter a silent prayer of thanks.

The impact smashed the front and back windscreens and left the driver shell-shocked, but he and his two passengers - elder brother Edward, 52, and niece Rebecca, 20 - were safe, barring some scratches.

Mr Lee had seen the tree coming down at around 7.45am, but said there was no way he could have avoided it even though he had jammed on the brakes. "It came down within a second," he said of the incident at Ang Mo Kio Street 22.

The father of three children aged nine, 12 and 17 instinctively thought of the tree which fell just two days earlier along Yio Chu Kang road, which killed projects manager Chua Loong Wai, 32.

The image of that mangled metal wreck also flashed across the minds of his passengers.

"I mean, that just happened a few days ago, right. What were the possibilities of a car being hit by a tree again?" Rebecca, a Ngee Ann Polytechnic student, said in disbelief.

Edward summed up the trio's feelings: "I feel fortunate to be alive."

Singapore Civil Defence Force personnel rushed one fire engine, one red rhino, two motorbikes and two support vehicles to the scene

Even before the SCDF arrived, residents went forward to help free the passengers, with Tuesday's incident fresh in their minds. After all, Mr Chua was killed just 1.6km away.

While the Chevrolet's front doors were jammed shut, the three passengers found a way out through the left rear door after around 15 minutes.

According to National Parks Board streetscape director Simon Longman, there was heavy rain and wind at the time.

The sea apple tree, which Mr Lee said has been in the estate since he moved there 30 years ago was last pruned in November.

While the uprooted tree was under NParks' care, Ang Mo Kio-Yio Chu Kang Town Council, which manages some 36,000 trees under a scheduled maintenance of once every six months, is not taking any chances.

"In view of the recent weather, we have intensified our inspection and maintenance of matured trees," a spokesperson told MediaCorp.

Maintenance aside, the two incidents in less than a week have sparked questions about trees planted along roadsides here.

Mr Longman disagrees with the notion, though, that too many trees had been planted in Singapore's early days.

"It's very purposeful to plant trees along the roads, and we've been doing that since the early '70s; it's part of the city in the garden vision," he said.

On major roads, a width of two metres is set aside on the verges as tree space. "The tree will maximise available space below the ground," stressed Mr Longman.

In the case of the "unfortunate accident" which killed Mr Chua, there was a tree space of 3.5m. The tree's roots had not only used the space up to the roadside drain but also underneath it, into vacant space, he said.

Arborists whom MediaCorp spoke to said NParks has been doing a "good job" in its tree inspections; tree failure, they said, occur for a number of reasons such as long periods of heavy rain, which causes the soil to soften.

However, urbanisation imposes a toll on trees. "A new building changes the wind direction or a tree could compete for space with a new road, restricting its growth," said Mr Veera Sekaran, managing director of arborist consultancy Greenology.

"No one really knows what's the life span of these urban trees, so we need a better study. The authorities should listen to local consultants than overseas consultants, as we're more familiar with the matter," he added.

When contacted, Mr Longman said the Board's 120 arborists were mainly Singaporean and trained by the Centre for Urban Greenery and Ecology, a joint venture between NParks and the Workforce Development Agency.

In the past two months, NParks has stepped up its inspection and pruning of trees, focusing on mature trees and where vehicular traffic is high.

In addition to routine maintenance operations, NParks inspected an additional 2,000 large mature trees and did crown reduction. "This intensified maintenance regime will continue," said Mr Longman.

In selecting which trees to plant, NParks chooses hardy species such as angsana, broad-leaf mahogany and yellow flame. It also plants rain trees - the same species as the tree that killed Mr Chua.

In the past three years, NParks has also removed storm-vulnerable species: 650 Albizia falcatarias.


Fallen tree branches trap 3 in car
Channel NewsAsia 22 Jul 10;

Singapore: Three people trapped in their car by tree branches which had fallen on their vehicle were rescued by SCDF personnel this morning.

SCDF said they received a call about the incident in front of Blk 226 Ang Mo Kio Ave 1 at 7.38am.

SCDF personnel cleared the tree branches and manually opened the door of the vehicle to let the occupants out.

A spokesman said that the three occupants of the car had no visible injuries and were not conveyed to hospital.