1. Experience with Mining through Surface to Seam Large Diameter Boreholes. 26/11/14 Scott Dennis – Appin Mine

2. Location – Appin Area 9 Page 2 Appin Area 7 Current LW blocks Appin Area 9 Future LW blocks

3. Location - STIS holes Page 3 STIS 2 – Build Site STIS 2 – 3 x laterals STIS 3 – Build Site STIS 3 – Vertical boreholes STIS 3 – 2 x laterals

4. Mining in the vicinity of STIS 2 Additional inseam drainage As Area 9 development progressed it was soon identified that the STIS holes had not decayed to a level at which mining normally through these holes was acceptable. Before mining towards STIS 2 in 901TG it was decided that the following was to occur: Modify mining sequence to allow greater drainage time Set up and complete additional inseam drainage Page 4

5. Mining in the vicinity of STIS 2 Additional inseam drainage Page 5 2 x in-seam drill rigs set up, multiple flank holes drilled around STIS holes. Flow and pressure spread amongst multiple holes.

6. Mining in the vicinity of STIS 2 Planned drivage sequence Page 6 Panel Location 1 5 6 3 4 8 7 2 19 20 21 4 Undertook risk assessment, consulted workforce, check inspector and mines inspector before creating procedure and executing plan. Additional controls included: Maintain 4” flexible suction & brattice behind miner Minimum airflow requirements at face Monitor STIS hole water level and fluctuation of flow No undercut - ½ metre cut outs from roof to floor. Increased frictional ignition checks Red – Mining from remote location utilising two fans on suction. Blue – Normal Mining

7. Mining in the vicinity of STIS 2 Set up for mining from remote location with two fans on suction. Page 7 Restricted zone Two fans, two runs of 618mm vents. Remote operating station. Not to be confused with remote mining used at Appin for outburst risk. No requirement for 10 minute wait period and no fresh air base.

8. Mining in the vicinity of STIS 2 First intersection of STIS Page 8 Panel Location 4 19 20 21 First intersection of STIS 2 with continuous miner.

9. Mining in the vicinity of STIS 2 Following intersections of STIS 2 Page 9 1 23 4 5 67 8 Once inseam flow measurement of STIS below 70 l/s “normal” mining commenced. 9 10

10. Mining in the vicinity of STIS 3 Additional inseam drainage Similar philosophy adopted for STIS 3 Modify mining sequence to allow greater drainage time Set up and complete additional inseam drainage Page 10 In-seam drill rigs set up to flank STIS 3 from 901TG and 901MG.

11. Mining in the vicinity of STIS 3 Comparison of STIS pressures and flows 901MG drivages became critical path. Hole flows and pressure for STIS 3 were expected to be higher than that experienced with STIS 2. Brainstorming occurred for new mining method. Mining method utilising force ventilation designed and implemented. Page 11 Comparison of STIS pressures and flows for first intersections (Approximate numbers only) STIS 2 Surface gas flow (l/s)30 Casing Pressure (kPa)35 Downhole Pressure (kPa)117 Actual flow measured UG after intersection (l/s)~110 STIS 3 - Build site Surface gas flow (l/s)87 Casing Pressure (kPa)28 Downhole Pressure (kPa)Not available STIS 3 - Vertcial Well North Surface gas flow (l/s)Not available Casing Pressure (kPa)69 Downhole Pressure (kPa)207 STIS 3 - Vertcial Well South Surface gas flow (l/s)5 Casing Pressure (kPa)69 Downhole Pressure (kPa)241

12. Page 12 Additional controls included: Men excluded from face due to cutting from remote location. Maintain 85% incombustible content in face area Higher ventilation quantities at face. Fans always in fresh air, therefore ventilation continuously supplied to the face in the event of high gas make at face. Mining in the vicinity of STIS 3 Force ventilation whilst cutting from remote location – panel setup

13. Mining in the vicinity of STIS 3 Force ventilation issues Float dust left on miner and in wheeling road. Added controls to thoroughly hose down machine and wheeling road when accessing face after cut cycle High velocity ventilation  crews bolting on the RHS were sprayed with bolting water and fines from LHS. Poor vision for miner drivers using the remote cutting cameras due to dust make. Excessive set up time. Page 13

14. Mining in the vicinity of STIS 3 First STIS 3 intersection Page 14 First intersection of STIS 3. Hole flow only 26 l/s. Blockage at soft dyke approximately 30 m inbye.

15. Mining in the vicinity of STIS 3 Second STIS 3 intersection Page 15 STIS 3 intersected in 18C/T. Fans remained running enabling access to hole.

16. Summary of controls Page 16 ControlPositivesNegatives Cutting from remote location Removes all persons from risk when cutting Slow process Two fans in parallel on suction Additional air quantity No major change to existing practices Exposure to methane, trips can still occur Two pans in parallel utilising force ventilation More air quantity to face than fans on suction Fans in fresh air, no exposure to methane Dust make Visibility when cutting Fines and water spraying operators Excessive set up time

17. Questions / discussion Page 17