This paper presents the outcomes of a joint project carried out by Glencore Ulan Surface Operations and Orica, to reduce total mine cost by optimising overburden blasts. Typical overburden blasts are 60 m wide and 1000 m long with the blasts designed to cast. Ulan Surface operations has a Marion 8050 dragline operating using the traditional Key-Low wall combinations, High Wall Chopping and Extended Bench according with spoil profile balance with a dragline production rate of 2000 bcm/hr.The objectives of the project were to: optimise post blast muckpile profile to improve dragline advance; improve cast percentage (%); reduce coal roof damage and edge loss; and control blast emissions and their impact on neighbours. The aim of these objectives is to reduce the total cost of mining. The use of Orica’s advanced blast modelling software, Distinct Motion Code (DMC), was essential in this as it allowed the analysis of alternative blast designs using the results from previous blasts in Strip 5 as the baseline. The results of the modelling indicated that there was scope to improve the cast % from a baseline of 23% to a range of 25-35% to final. In addition, the coal model was validated using touch coal and gamma logging data for each strip. From this information the blastholes were designed to stand-off from the coal seam and QA/QC approaches in the backfill and redrill tolerances were implemented. This paper also presents outcomes of this validation work.