Case Study: Emergency Cold-Cutting Response to the Manildra Silo Collapse, Nowra
Client: Illawarra Engineering
Service: High-Risk Abrasive Water Jet Cold Cutting
Silver Raven was engaged by Illawarra Engineering and arrived onsite 8 hours after initial contact, to execute emergency high-risk cold-cutting operations in response to the Manildra silo collapse in Nowra. The situation posed significant challenges due to the flammable nature of spilled grain and the proximity of flour silos, ruling out traditional cutting methods. The focus was on safely removing two critical structural members—large walkways and stairways still attached to the unstable silo structure.
To ensure the highest level of safety and precision, Silver Raven conducted extensive pre-planning and testing. Samples from the structure were transported to Illawarra Engineering’s workshop in Port Kembla, where tests were performed to simulate and refine the cold-cutting methodology. Through trial and error, the team tested and developed a system that was suitable for the task.
The first walkway was successfully cold-cut and craned off the structure without incident. The weight of the structural member to be removed was supported by a mobile crane while a Silver Raven specialist was positioned in a craned man box away from the structure to ensure safety. Two riggers were assigned to hold ropes to stabilise the man box that would be released in the event of a structural collapse. This setup was crucial given the sensitivity of the operation and the unstable environment.
The second walkway presented a unique challenge to its location where it could not be reached by the crane and the weight of the unstable structure was far greater. The cold-cutting technique involved attaching the cutting head to a long heavy beam, which acted as a stabilizer to counteract movement during the cutting process with the operator situated on top of a nearby silo. It was ultimately severed and safely pulled into the body water by Australia’s largest barge, owned by SMC Marine.
Key challenges during the operation included managing safety and stability issues with the man box while maintaining precision alignment of the cold-cutting head. Despite these difficulties, Silver Raven’s experience in high-risk scenarios, adaptive planning and specialized expertise allowed the team to complete the operation safely and efficiently, mitigating significant safety risks and preventing further structural failure.
