13 July 2000

The University of Canterbury wants to install another ring laser in the Cracroft Caverns in Cashmere.

Its installation is part of a research project involving German interests.

The Christchurch City Council’s Parks and Recreation Committee yesterday recommended that its construction go ahead as long as the necessary resource and building consents are obtained.

The Council owns the reserve, to the south of Princess Margaret Hospital, which includes part of the historic World War Two caverns. The caverns were designed to be the South Island’s defence headquarters for intelligence in the war.

The caverns were built in 1942 and closed two years later when it was apparent they were not needed.

The caverns came to media attention in 1987 and at that time the university’s physics and astronomy department started experiments with their ring laser gyroscope.

Two ring lasers were installed after the first and the latest will be a prototype of a ring laser to be installed in Germany after trials and refinement at Cashmere.

The university wants to place the whole device in the open air of the cavern, but fixed to the floor.

The committee was told that no building work would affect the cavern walls. However, 19 concrete piles will be fixed to the basalt rock floor.

"As far as the university is concerned, this is the ultimate project for Cashmere," said the Parks Unit's consents team leader, John Allen. "The university has discussed this project for a year with their German collaboration partners, who are extremely keen to see this machine become a reality.

"Its possibility was not dreamed of when the ring laser project was started but the various successes in each stage so far have exceeded expectations," Mr Allen said.

The project will take about 15 years and the Council will insist that when it is finished the cavern will be restored to its present stage, including putting back all rock excavated.