Disposing of high-temperature waste via the incinerator can lead to unexpected issues, warns The Nautical Institute in a new Mars Report. The incident describes how firefighting measures were needed after burning oily rags in the incinerator on board a vessel.
The Nautical Institute gathers reports of maritime accidents and near-misses. It then publishes these so-called Mars (Mariners’ Alerting and Reporting Scheme) Reports (anonymously) to prevent other accidents from happening. This is one of these reports.
An engineer was charged with burning garbage and oily rags in the vessel’s incinerator. At one point, smoke emerged from the exhaust pipe, accompanied by excessive vibration in the draft fan. The engineer in charge used a dry powder extinguisher and the water mist system was automatically activated.
Crew members were alerted, and firemen stood by. Once the smoke was eliminated, a thorough inspection confirmed the exhaust piping, expansion joints, and gaskets were intact with no fire brick damage. However, the draft fan’s impeller sustained severe damage, causing imbalance in the unit.
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Flue gas temperature high alarm
It was later determined that during the burning of oily rags, the incinerator temperature increased significantly, triggering a flue gas temperature (FGT) high alarm, which led to the unit automatically tripping. The flue gas fan continued running to cool down the furnace until the temperature dropped to approximately 170°C.
During this cooling phase, excessive vibration in the fan reduced the furnace draft. This resulted in localised overheating of the exhaust pipes and furnace, causing insulation material to produce smoke, which subsequently activated the fire alarm and water mist system.
Advice from The Nautical Institute
- Disposing of high-temperature waste (such as oily rags) via the incinerator can lead to unexpected issues. Strict monitoring and controlled burning practices should be employed.
- For example, a controlled burning process for oily rags would ensure a small number of rags are fed and continuous temperature monitoring is employed to avoid rapid overheating.
Also read: ‘Cool heads, patience and proper technique key when fighting ship fires’
Mars Reports
This accident was covered in the Mars Reports, originally published as Mars 202535. A selection of the Mars Reports are also published in the SWZ|Maritime magazine. The Nautical Institute compiles these reports to help prevent maritime accidents. That is why they are also published (in full) on SWZ|Maritime’s website.
More reports are needed to keep the scheme interesting and informative. All reports are read only by the Mars coordinator and are treated in the strictest confidence. To submit a report, please use the Mars report form.
Picture: Someone using an incinerator on board a US Navy vessel (photo for illustrative purposes only, by US Navy/Picryl).
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