Macmahon Holdings has been contracted for the project which involves the construction of a 2.2 km decline to a depth of 400 meters.
The A$120m ($123m) Ranger 3 Deeps Exploration Decline project will see underground exploration drilling work of the Ranger 3 Deeps ore body that hosts an estimated 34,000t of uranium oxide, including exploration of areas adjacent to the resource.
Energy Resources of Australia chief executive Rob Atkinson said, "the construction of the exploration decline marked the start of a challenging and exciting transition for the company".
The exploration decline will also allow an entrance and a tunnel that will extend between 2,000m and 3,000m, extended nnearly 250m and 450m below surface, following the alignment of the known ore body.
The work will also allow underground exploration drilling towards the north of the ore body, where it is open.
ERA is also conducting a surface drilling program for A$40m ($41m) on prospective and under explored areas of the Ranger Project Area until 2014.
