Cementation Shotcrete Accident May 23 rd 2011 Accident

Cementation Shotcrete Accident May 23 rd 2011

• Accident overview Cementation Shotcrete Accident 2 • Accident Timeline • Accident Causation • Recommendations • Safety Measures

A crew of 5 Cementation Employees arrived on 355 ml Service Rope Drift at the start of nightshift on May 23 rd, 2011 (2 mechanics and Accident Overview Events prior to the accident A crew of 5 Cementation Employees arrived on 355 ml Service Rope Drift at the start of nightshift on May 23 rd, 2011 (2 mechanics and 3 shotcrete crew members). The mechanics had to repair the vibrator on the shotcrete machine before the crew could start shotcreting the back and walls. Once the shotcrete machine was repaired, the scissor lift was moved into position, the area was cleaned up and a pre-op check was performed on the shotcrete machine. The nozzle operator positioned himself on the deck of the scissor lift and proceeded to wash the back and walls in the area that required additional shotcrete. The forklift operator positioned a bag of shotcrete above the shotcrete machine and the shotcrete operator filled the hopper of the machine. Once the nozzle operator completed washing, he connected the 1 inch water hose to the shotcrete hose. 3

Accident Overview ( Continued ) The shotcrete operator turned on the air valve to the feed hose and the nozzle operator turned on the water valve and adjusted the water pressure at the end of the shotcrete hose. The nozzle operator then signaled to the shotcrete operator (via cap lamp) that he was ready to receive shotcrete. The shotcrete operator turned on the feed valve to start sending shotcrete to the nozzle operator. The nozzle operator felt the shotcrete coming through the hose, the shotcrete operator saw the pressure gauge on the machine climb to 6 bar and he shut off the air to the machine (normal pressure is 2 – 3 bar). At this time the nozzle operator felt a violent jerk in the hose and lost his grip and was then stuck on the right side of his face and jaw by the shotcrete hose. 4

Accident Location 355 ml 355 Service Rope Drift 440 -150 Drift

Accident Time line Data Blocks 1. Crew receives line up at pre-shift huddle then proceeds to 355 ml via ramp in the Marcotte utility vehicle. 2. Two mechanics repair vibrator on shotcrete machine and leave the level with the supervisor. 3. Shotcrete crew do pre-ops and position associated equipment to begin shotcreting. 4. Nozzle operator adjusts the water flow to the shotcrete hose and signals for shotcrete. 5. Shotcrete operator opens air valve, shotcrete begins to flow, pressure builds to 6 bar, operator closes air. 6. Nozzle operator is struck on the right side of the face and jaw by the shotcrete hose. 7. Partners go to X-lift to check out and help the operator off the X-lift. Supervisor is notified and returns. 8. Injured worker is taken to surface, assessed by security and the ambulance was called to take him to TDH. 6

Equipment 7

Accident Causation Immediate Causes • Blockage occurs in shotcrete hose. • Failure to disconnect hose and nozzle to ensure there was no material build up. • The residual build up of shotcrete at the hose connections may have caused a flow restriction through the hose. 8

Build up at connections Nozzle connection Needle valve 9 Water ring connection

Accident Causation Personal Factors • Specific training does not include in-house license on the Aliva 252 shotcrete machine. Training to include proper cleaning of hoses and or equipment. • Procedure exists, however it does not include taking apart the hose and nozzle connection points during the cleaning cycle to ensure there is no material build up that could cause a blockage in the hose.

Recommendations • Modify Shotcrete procedure to include all hose and nozzle connection points must be disconnected and cleaned after each use. • Modify Shotcrete procedure to include all hose and nozzle connections to be checked before each use to ensure no build up of material has occurred. • Modify Shotcrete procedure to include checking the air flow resistance of an empty hose, ensuring pressure is less than 1 bar. • Modify Shotcrete check list to include the first three recommendations. • Review modified shotcrete procedure and checklist with all shotcrete operators. 11

Recommendations ( Continued) • Check condition of blow off valve to see if it can be adjusted to blow off at a maximum pressure of 4 bar. • Ensure all shotcrete operators are signed off on MTCU Module U 0086 “Perform Shotcreting” • Ensure all operators are signed off on the specific in-house license for each shotcrete machine. Additional Recommendations not directly related to accident • Full face respirator to be used by nozzle operator while shotcreting, this is to be included in procedure and checklist. • Whip checks are to be utilized on the shotcrete feed hose connections as well as the air feed lines. 12

Safety Measures • The procedure was modified to reflect the addition of dismantling connections, inspecting and cleaning connections after each use. • The procedure also details inspection prior to assembly and use at the beginning of the shift. • The pre-operational check outlines an airflow check that does not exceed 1 bar prior to operation. • The procedure now clearly reflects the use of a full face power respirator for the nozzle man during shotcreting operations. • The procedure clearly states that whip checks are required on material feed hose connections. • Training in the MTCU module U 0086 “Perform Shotcreting” and an in-house module on the specific shotcrete machine is required for all shotcrete operators. • The procedure and check list must be reviewed and signed off by all existing operators before further work. 13

Porcupine Gold Mines CANADA USA DOMINICAN REPUBLIC MEXICO GUATEMALA Safe Enough for our Family CHILE OPERATING MINES DEVELOPMENT PROJECTS 14 ARGENTINA Making Changes at the Hoyle Deep Project, Hoyle Mine as part of Porcupine Gold Mines working with Cementation to ensure we are building mines safely.