Red tape meant an engineer with vital rescue equipment had to wait two hours before being deployed to the Canterbury Television (CTV) building collapse, an inquest has heard.

The fourth day of a coroner's inquest in Christchurch today heard evidence into the deaths of Tamara Cvetanova, Jessie Redouble, Emmabelle Anoba, Ezra Medalle, Reah Sumalpong, Rika Hyuga, Chang Lai and Mary Amantillo, who were known to have been alive after the building collapsed in the February 2011 earthquake, but were unable to be rescued.

Christchurch City Council senior manager Jane Parfitt, who was Civil Defence controller for most of the afternoon on February 22, described the setup of the emergency operations centre at the Art Gallery.

Counsel assisting the coroner, Richard Raymond, said evidence would be heard from an engineer with listening equipment who spent two hours filling out forms at the headquarters before attending the CTV site.

Health and safety procedures had tightened after the Boxing Day 2010 quake, Parfitt said.

''I do accept two hours is far too long, if that's how long it took,'' she said.

Raymond said the engineer became frustrated his skills were not being used at the CTV site and returned to the emergency headquarters.

He ''got fed up'' after waiting another hour and headed back to Madras Street.

Parfitt said despite extensive Civil Defence training she could not have prepared for the scale of the disaster.

''Was I well-equipped? Of course I could have done it better. It was my job so I had to do it,'' she said.

Communication between the agencies would be improved with plans for a combined facility in the central city blueprint, Parfitt said.

Earlier, a rescuer told the inquest he urged authorities to source site plans to help locate a trapped woman communicating from under the rubble.

Douglas Watt, who supplied equipment to the CTV site and joined the rescue, said he was introduced to Alec Cvetanov, who had been in cellphone contact with his wife, Cvetanova.

Despite language problems, Watt said, Cvetanov told him his wife was in the building's reception area.

Knowing the high rise could have several reception areas, he asked for building plans to be obtained.

Watt said he was told that sourcing plans from the Christchurch City Council was unlikely.

The arrival of Urban Search and Rescue (Usar) was a "big help" because members brought a more professional and structured approach.

He had been "greatly concerned" by discussions before Usar took command of moving rubble, which he believed could endanger trapped survivors.

The inquest heard how Watt and other rescuers freed a trapped woman from the west side of the building after the earthquake.

He heard a beeping noise, like a computer, that became more high-pitched when debris was removed.

"At that point, I knew it had to be a person. I said, 'Quick, we've got someone'."

A small cavity was located where Watt found the woman semi-crushed. He grabbed her hand and assured her she would be rescued.

"It was all hands on deck. Everyone who was standing around was keen to help."

The woman was freed after about 15 minutes, which was a "great thrill".

She was Asian and he did not know her name.

Watt said the woman indicated at least 50 more people were trapped.

About 11 were recovered from that area, but not all had survived.

Watt worked on the rescue until about 4am on February 23 and spent the next week helping arrange food for the site through the Bretheren church.

The inquest, which is being streamed live on the Justice Ministry's coronial services unit website, runs for two weeks and reconvenes for a final week at the start of December.

- © Fairfax NZ News