ACCELERATED RESTORATION OF PRIMARY BOILER FOLLOWING MAJOR CRITICAL FAILURE

AT PLANE Creek Mill on 17 November 2012 a low water level incident occurred during the operation of the primary boiler. This resulted in exposure of some critical boiler pressure parts to above normal temperatures (in excess of 500°C) for a period due to insufficient circulation, evaporation and steam flow. The boiler was temporarily repaired and the remaining two weeks of the crushing season were completed. As a result of the damage, an emergency project was established to restore the boiler to its operating condition prior to the start of crush on 28 May 2013. This left six months to plan, order, schedule and implement a $10M+ major boiler re-tube project. A project of this magnitude would normally have been conducted over a number of years. To establish the extent of work required, while the November repairs were still being conducted, Wilmar Sugar, together with EDMS Australia and Aurecon Australia, conducted a number of inspections of the boiler to determine the scope of work and to comply with AS3788 (Inspections of pressure equipment). Within three weeks from the date of the initial incident, a detailed scope of work was established and a contract to AS4902 (design and construct) was formally agreed to between Wilmar Sugar and EDMS Australia (assigned principal contractor). Aurecon Australia was engaged to formulate a scope of work for all non-destructive testing (NDT) to determine in further detail the extent of damage to all critical boiler components. A number of NDT techniques were used including 3D scanning, metallurgical replication, radiographic testing and penetrant testing. To meet the critical timeframes, boiler tubes of over 10 different sizes were sourced from Australia, Singapore, Japan and Germany to achieve the required quantities of over 18 km of combined tube length. Tubes were manipulated and delivered in five different stages to maintain a continuous installation process. Over 70 personnel were on site at any given time dedicated to the restoration of the boiler. Most work was conducted with teams of personnel on 12-hour shifts on a continuous basis. Through immediate action, defined key-tasks, vigorous schedule monitoring and encouragement of open dialogue between all parties, the boiler was completely restored and ready for operations on 28 May 2013 within hours of requirement. The entire project was completed in less than six months without any medical treatments or lost time injuries and it was delivered both under budget and on schedule.