Demystifying Ship Recycling - Issue 08
Cleaning of oil containing tanks onboard ships at HKC compliant Ship Recycling Facilities
Vessels are constructed with multiple tanks to store lube oils, fuel oils, and sludge. When a vessel is prepared for recycling, the minimum amounts of these oils are kept onboard. When the vessel is delivered to the recycling facility, it contains varying amounts of these oils, although in small quantities in different tanks. Before cutting permission is issued to the vessel, the remaining oils must be removed from the respective tanks as per GMB. Fuel oils and lube oils are sold to subcontractors for further treatment and reuse. The oils are transferred by portable pumps so that minimum unpumpable quantities remain in the tanks. The remaining oil is removed manually by draining the tanks. The oil spill containment kit is always kept on standby during the oil transfer and cleaning. All precautions are taken while performing man entry to these tanks. Thorough ventilation is carried out, and the atmosphere is checked with gas meters by a safety officer to check adequate oxygen (20.9%) and the absence of combustible/hazardous gases. The enclosed space permits are filled to eliminate any errors. The workers use adequate Personal Protective Equipment (PPE) in tank entry. The unpumpable oil is manually collected, and tanks are internally cleaned.
Finally, sand is used to absorb the stains of oils from the internal tank surfaces. The oil-drenched sand is collected in HDPE bags, and bags are handed over to Gujarat Enviro Protection and Infra Ltd. (GEPIL). Adequate infrastructure is developed at GEPIL facilities to dispose of the sand in an environmentally friendly way. The use of sand ensures that oil is completely removed, and ventilation ensures tanks are completely gas free. Furthermore, the application of sand ensures that the tank is not reused for any purpose. The yard owners have developed Standard Operating Procedures (SOPs) for preparing vessels gas free for hot work. The cutting permission is issued after the vessel is made gas free for hot work.