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Video | London’s exploding pavements, and what causes them

A series of pavement explosions in central London has led to Westminster City Council calling in a utility boss to explain what is causing the incidents.

The local authority has released CCTV footage showing the pavement at Piccadilly erupting in flames, with explosions lasting for over 10 minutes. A white van parked on the street was destroyed by the blaze, which occurred in July.

A statement from Westminster said the fire was caused by an electrical fault in a link box chamber, and that utility infrastructure operator UK Power Networks (UKPN) was investigating.

Some 64 explosions in the capital have been reported to the Health and Safety Executive so far in 2014, up from the 51 recorded during 2013.

This week, Basil Scarsella, chief executive of UKPN, appeared in front of Westminster City Council’s environment committee to explain what is being done to prevent the incidents and discuss whether the funding regime for investing in central London’s electricity infrastructure is fit for purpose.  Also present was Ofgem director of gas and electricity, Maxine Frerk.

The explosions can be caused by a build-up of gas or moisture entering cables and other fittings, according to Westminster. UKPN has blamed increased rainfall.

“There is some evidence that the age of the asset is a contributor, but more important is the increase in the amount of rain we have seen in recent years,” Scarsella explained.

“We have included £80M of expenditure over the next eight years on link box and cable pit inspections.

“These measures include introducing specially designed blankets which limit oxygen in the pits, filling underground chambers with sand, and in some cases replacing the boxes altogether.”

However, he added that eliminating the risk altogether was impossible.

Ofgem’s draft settlement for UKPN’s expenditure over the next eight years is currently open for consultation (which closes on 26 September). Under the current settlement, Ofgem has disallowed a proposed additional expenditure of £30M to improve the quality of electricity supply in central London.

UKPN has asked Ofgem to review a total of £110M of disallowed expenditure in London.

Ian Adams, chair of Westminster’s environment policy and scrutiny committee, said: “It is critical that we have reliable, safe and secure power supplies in central London.

“We are encouraging Ofgem to review their rules governing how much providers such as UKPN can invest in the network, and will be responding formally to Ofgem’s current consultation on this.

“Westminster Council is pleased that UKPN is now inspecting all its underground link boxes once a year and working hard to minimise the risk of explosions. However, the threat still remains.

“Given the need to maintain confidence in central London’s power network, we urge the regulator and UKPN to work together to unlock the additional investment required.”

Readers' comments (1)

  • The cable pits are not designed to be watertight. The problem is not rainfall but old and damaged cables and cable joints.

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