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G.O.D. bends laser beam!

A mere thirteen years after Theodore Maiman developed the first workable laser, George Octavious Dalby (known to his friends as G.O.D), local to Broken Hill, was bending lasers around corners at the New Broken Hill Consolidated and Zinc Corporation mines in 1973.

George Dalby worked as a chief surveyor at the Zinc Corporation mine where he had been using lasers in the mine for long straight drives since 1971.

George Dalby’s innovation used a mirror system that allowed the laser beam to continue around a moderate bend in the drive of the mine.

The Zinc Corporation mine’s Ore-Bits publication (Nov, 1973) explained that this was understood to be a new development in underground laser surveying at the time.

“Dad always told the story that he didn’t want to blast straight away. He instead wanted to find out how close he could get to the target by bending the lasers around a corner in the drive,” George’s son Ian Dalby said.

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They calculated the target using conventional surveying methods, and then Mr Dalby made similar calculations for the laser beam.

He and his team calculated the angles of the mirrors and made the necessary adjustments to the mirrors so that the deflected beam would hit the same target in the new heading using the laser.

“The first time they used the laser in the mines, they came within three inches of the target. Then they blasted,” Mr Ian Dalby said.

Jim Daly, who worked as part of the Fire and Rescue team for the mine (Emergency Services) said he remembered the set-up and how it was the first of its kind.

Mr Daly remembers the system they made and said it streamlined the surveyors needing to go back and forth in the mine.

The invention also allowed production to continue in other parts of the mine without too much disruption said Mr Daly.

What George Dalby and his team were doing was remarkable considering the atmospheric pressure and conditions that also existed in the mine.

The path of the laser’s light through the mirror system was developed by the mines personnel and led by George Dalby, who tested the system before installation.

Cyril Clare of the Rock Mechanics Laboratory helped George Dalby by manufacturing the necessary mountings for the mirrors and ratchet mounting used for adjusting the laser and the mirrors.

The fitters and turners constructed other cradle mountings at the Zinc Corporation workshop.

The beam was reflected through a horizontal periscope system from one mirror to the second mirror, where it was again reflected.

Each mirror was 2.5 inches (the imperial measurement system was used in those days) in diameter and was made from optically flat half-inch thick glass coated with aluminium on the front surface.

The laser was mounted near the start of the drive with its beam directed 700 metres along the drive to the mirrors, the beam was deflected and projected for a further 280 meters along the drive using the mirror system.

By reflecting the laser beam, George Dalby changed the laser’s direction by 25 degrees through a 46 metre radius curve.

Three lasers were installed in the mines, one on No. 17 level, one on No. 19 level south of the No. 3 Airway at the New Broken Hill Consolidated mine and the third one at the No. 21 level exploratory crosscut at the Zinc Corporation mine.

Ian Dalby remembers his Dad being invited to a symposium in Leoben, Austria, to present a paper on his work about bending lasers around corners.

Last week in Europe, there happened to be a symposium on the applications of lasers. Unfortunately, they could find no literature on George Dalby.

Don Mudie remembers George Dalby being an active member of the Vintage Sport Car Club, he crewed for Neville Webb at the South Australia Hill Climb at Collingrove in 1957 and raced cars out on the hill near Silverton.

He was given the nickname G.O.D due to the initials of his name (his father, grandfather and great grandfather all had the same name).

Jim Daly remembers one friend phoning him and saying, ‘is that G.O.D, I’ve got the archangel messenger who wants to talk to you’.

The word ‘laser’ is also an acronym for Light Amplification by Stimulated Emission of Radiation.

The laser was developed from a theory rather than from an applied solution to solve a particular problem, this gave people the freedom to find uses and applications for the laser like George Dalby did.

It would be a shame for G.O.D’s work to fall into obscurity, particularly when he found a new application for laser technology by bending the actual laser beam itself.

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