TV3 fears tunnel troubles

The television company fears viewers will hear rumbling both from construction vibration and then from trains. Photo / Dean Purcell

MediaWorks and receivers want to be bought out of studios above rail project.

Auckland Transport is resisting pressure from TV3's owners to buy them out of their studios above the city's underground rail project.

MediaWorks and its receivers will urge planning commissioners this week, at the continuation of a designation hearing for the $2.86 billion project between Britomart and Mt Eden, to support a plea to the council body to pay for new studios.

Their existing premises in Flower St, Eden Terrace, will be above southern portals of two tunnels and hard up against security fencing during construction - which Auckland Transport hopes to persuade the Government to allow to start in 2015 with early payment of half the bill.

The television company, which has a panel of experts ready to give hours of evidence to the council-appointed commissioners, fears viewers will hear rumbling both from construction vibration and then from trains emerging from the tunnels once the six-year project is complete.

But Auckland Transport lawyer Andrew Beatson submitted last week that his client was committed to managing vibration and noise, and as a responsible public organisation could not and would not buy property under the Public Works Act unless "reasonably necessary".

MediaWorks, which is understood to have considered moving studios since at least 2008, said in a pre-hearing submission that there was no market for such specialist facilities.

Auckland Transport initially listed them among surface properties needed for the project, but left them just outside a revised plan under which it expects to demolish almost 70 other buildings.

It still intends buying parts of MediaWorks' underground titles to tunnel 15m below the studios, but Auckland Transport vibrations consultant James Whitlock told the commissioners on Friday he was recommending rail tracks through that section be laid on a special "floating" concrete slab to dampen train noise.

Similar treatment should be applied under the council's Aotea Centre, and resilient fasteners or continuously welded rail should be laid below leading musician Neil Finn's Roundhead recording studios behind Symonds St.

Mercury Theatre and the Auckland District Court, where the Ministry of Justice is concerned about potential interference to digital recordings of evidence from excavations for trenched tunnel sections along Albert St, had also been added to a list of "notable receivers" entitled to extra consultation to manage noise and vibrations.

Mr Whitlock said that although more investigations were needed to set noise and vibration controls around the television studios, limits proposed by MediaWorks were tighter than levels already recorded there.

The nearest basalt rock to be blasted for surface connections between the underground project and the existing western railway line was 74m away.

But MediaWorks is also raising concern about the impact of dust on its sensitive equipment from the project's main work-site, just next door, and quoting a report in which council noise and vibration consultant Jon Styles says it is likely to be impossible to carry out proposed project works while maintaining successful studio operations.

Auckland Transport noise consultant Craig Fitzgerald said a blasting noise limit proposed by Mr Styles, who is also concerned about potential damage to other buildings, was over-restrictive. He acknowledged pre-stressed windows could crack at a limit of 150 decibels sought by his client, but said most could withstand up to 170dB and the trigger for structural damage was generally 180dB.