TSM Orion in the magnetic treatment facility at HMAS Stirling in Western Australia during the successful trial of the new demagnetisation technique developed at the School of Physics, UNSW.

Perhaps the least conspicuous, but most serious, threat to naval (and civilian) vessels during conflict is their vulnerability to magnetic sensing marine mines. To guard against this the Royal Australian Navy (RAN) regularly bulk demagnetises their ships and submarines.

Researchers at the Advanced Electronics Materials Laboratory in the School of Physics have been working with the Defence Science and Technology Organisation of Australia to analyse the way this has traditionally been done. We have spent four years looking at what happens to the magnetism of a vessel while it is being demagnetised and this year we have succeeded in designing a more efficient demagnetising method capable of saving the Royal Australian RAN millions of dollars.

In previous years a physical model was established for simulating and investigating the process and, using this, alternative demagnetising procedures were explored. Several theoretical approaches were also developed to describe the magnetism of naval vessels during and after a magnetic treatment — with very positive results.

It is one thing to make physical and theoretical models and quite another to apply this research to a full-scale 90m submarine. In June 2002 we were presented with the opportunity to test our theories and an alternative demagnetising treatment on TSM Orion in the Magnetic Treatment Facility at HMAS Stirling W.A. It was to the great satisfaction of all concerned that the trial on the real vessel demonstrated the improved efficiency of the methods advanced in the laboratory.

According to the Australian Defence Science Magazine, the more efficient technique will save the RAN at least $12 million over the lifetime of the Collins Class submarines. In fact, the savings from first time that the new method is used will pay for the entire PhD project that developed it.

Tim Baynes