Birds the culprits in power cut?

Press, 17 December 1986, Page 9

Birds the culprits in power cut?

A short circuit at the Addington sub-station stopped power to much of Christchurch for two hours early yesterday.

Sub-station staff believe birds may have caused the arc, although they have found no feathers. “With that amount of power, they could have been vaporised,” said the area manager of the Ministry of of Energy’s southern region, Mr Bob Simpson.

The power, estimated at 250 megawatts, arced across about a metre. Mr Simpson believes at least two birds moving together may have been the cause.

A fireball would have appeared for about half a second at 4.55 a.m. before

the protection equipment at the main switching station at Islington tripped out the power. That closed the four 66,000-volt transmission lines from Islington to Addington, cutting the power supply to 30,000 consumers in the M.E.D. area, and all of Riccarton Borough.

The blast caused some damage to equipment and the power surge in the ground caused the substation’s telephone connections to fail. Staff had to communicate by radio as they worked to correct the fault. Meanwhile, a third of the M.E.D.’s consumers were without power. Areas not affected were New Brighton and Dall-

ington, which are served by the Bromley substation, parts of Halswell, Hoon Hay and Avonhead which have the Islington sub-station, and Merivale, Papanui and St Albans which have the Papanui sub-station.

It was just after 7 a.m. before all the power was restored.

The copper earthmat beneath the tower structure meant the power flashed to earth without causing much damage.

Mr Simpson was surprised by the distance of the arc. Staff have been investigating the incident, but he believes it was a freak accident and does not show a design fault.