VietNamNet Bridge – The massive blackout in 22 southern provinces and cities on Wednesday raised concerns over the security of the national power grid.

Workers of the Power Transmission Company No4 clear trees along power lines in southern Dong Nai Province. Concerns over the security of the national power grid were raised after a massive blackout in 22 southern provinces on Wednesday.

The two-hour blackout occurred when a truck driver was moving a tall tree from the garden of a new urban area in southern Binh Duong Province. The tree accidentally collided with a 500kV transmission line linked to the national power grid.

Representatives from Electricity of Viet Nam confirmed the outage was the result of violating distance regulations pertaining to safety corridors near power lines.

It was not the first such incident on the 500kV transmission line, which transmits electricity from the north to the south and vice versa.

Figures from the National Power Transmission Corporation revealed there had been seven cases of safety corridor violations along power lines that affected the national grid. They were chiefly caused by activities such as kite flying or use of vehicles which were taller than permitted levels.

The 2005 Government decree on protecting the safety corridor along power lines requires local authorities to inspect and handle violations.

However, Deputy Director General of Electricity of Viet Nam Dang Hoang An told Lao Dong (Labour) newspaper that in some localities, protective measures were not effective.

There were 342 guard stations with 1,500 security guards along the 500kV line. However, security guards at many stations were found to be leaving their posts, while firefighting equipment had been stolen from some stations, An said.

Meanwhile, many local authorities complained that they should not be held responsible for protecting the electricity works.

Three men who caused the massive blackout in the south on Wednesday are expected to be prosecuted, according to Binh Duong Province's Police.

The suspects are a truck driver, his assistant and a farmer working at a nursery for young dau (Dipterocarpus alatus) trees in the province.

Police said the incident caused severe economic damage and negatively affected the national security.

Police said that while the suspects were on low incomes and it was hard for them to pay damages, it was still necessary to prosecute them.

"Under regulations, the nursery garden must be seven metres far from the 500kV transmission line," said Trinh Dinh Chinh, deputy director of the Mien Dong Power Transmission Department.

In reality, it was about 14 metres away from the line, he said, but the tree being moved was about 17 metres in length.

Source: VNS