Innovative technology developed by Ausdrill is opening up previously inaccessible salt lakes for exploration drilling. Custom-built drill rigs, nicknamed lake walking machines, allow drilling for potential mineral deposits to be carried out in lakes and other locations with deep mud covering. The lake walking machines are designed and manufactured by Ausdrill subsidiary, Drill Rigs Australia, at a facility in Canning Vale in Perth’s southern suburbs.

They are already in use on salt lakes in the Goldfields of Western Australia, with Ausdrill conducting drill campaigns for major clients such as Gold Fields and AngloGold. To date exploration has taken place at both Lake Carey and Lake Lefroy. To overcome the problems inherent in drilling in locations where there is substantial mud coverage, the lake walkers have been designed to “walk” on the surface of a lake. A key to the technology is the use of 2.2 m wide tracks which stop the rigs sinking in to the mud.

“The rigs weigh up to 25 t each,” said Eddie Banner, General Manager of Drill Rigs Australia (DRA). “A traditional drill rig would sink straight into the mud.” Ausdrill has been developing equipment over the past 15 years to access the salt lakes around Kambalda, in order to explore for gold deposits. A range of different technologies have been employed in the past to allow drilling to be carried out in the lakes. This has included the use of hovercraft platforms, and the construction of temporary causeways to move conventional drill rigs out onto the lake.

“If you build a causeway, you have to remove it later. These new machines eliminate the need for the whole process of building and removing a causeway, and they save the mining companies a lot of money as a result,” Banner said. DRA are leaders in the design and manufacture of these specialised machines. With growing demand, Ausdrill now has eight of the rigs available. “We are seeing increasing interest from our clients for exploration drilling in lakes and sandy areas,” said Ausdrill General Manager Brian Mann. “Our expertise in this field, combined with the specialised equipment we have developed, has put Ausdrill in a very strong position to deliver drilling programs in what would otherwise be fairly inaccessible locations.”

Riding on their super-wide tracks, the lake walking rigs have a footprint of 53 square metres in order to minimise the pressure on the lake surface. This is approximately 90 times the foot print that an average car has on the road via its four tyres. The drill rigs are accompanied by a number of support vehicles which carry drill rods and other equipment, fuel, water and personnel. “Once we’ve set up on site, the drill rig and the support vehicles must remain stationary for days or even weeks at a time to complete each hole, so it is vitally important that they do not sink into the muddy lake surface,” Mann said.