The Defence Minister has approved land acquisitions between the existing training area and Iron Knob.

This land, in addition to the current 48,000 hectares, would make Cultana one of Australia's largest military training areas.

Just how much land was acquired would depend on negotiations with leaseholders of nearby stations.

However, the defence department proposed to acquire all of Tregalana Station and all or part of Roopena and Katunga stations.

According to a defence department spokesperson, all proposed acquisitions were dependent on negotiations with leaseholders and sale prices would be in accordance with the Lands Acquisition Act 1989.

The stations surrounding Whyalla have significant historical value for Whyalla and its residents and this would have to be safeguarded if the expansion went ahead.

The defence department claimed it was sensitive to the need to make "appropriate management arrangements for historic and heritage sites".

It would consider allowing access so that the non-pastoral uses of those sites, such as historic tours, could continue, as long as they were compatible with defence department activities.

The expansion project would see the larger training range ready to use by 2009, according to the defence spokesperson.

The total number of troops training at any one time would depend on the eventual outcome of the acquisition, however much of the training would involve mechanised formations, which were heavy armoured vehicles and tanks.

Although it was too early to predict the economic benefits for Whyalla, it was envisaged that by 2009, with the increase in army training activity, Whyalla would receive a significant economic benefit.