(www.MaritimeCyprus.com) The pinnacle step of tank cleaning operations is verifying the condition of the cargo tanks after cleaning. A physical tank inspection is the most common approach. This may be accompanied by analytical testing by completing a wall wash test (WWT) or using the technique of wash water analysis (WWA), which is becoming increasingly more popular due to benefits it holds over traditional tank inspections.
Tank Inspection
If an enclosed space entry is to take place, all tanks must be gas free prior to entry and enclosed space entry procedures followed.
During the tank inspection, the tank and all other equipment that was in contact with the cargo must be inspected. Inspection of the internals of the cargo lines is almost always impossible, but the cargo manifold can be opened and inspected. Inspections should be carried out jointly with a representative of the vessel present along with a charterer’s representative and sometimes a cargo owner’s official as well.
During the tank inspection the following must be inspected:
- Entire tank surface for visible cargo residues
- Entire tank for smells and wetness or moisture
- Bulkheads should be touched to check for cargo residues and IG soot
- Shadow areas of cleaning machines
- Underneath heating coils
- Heating coil supports
- Pump suction well (pitting and residues)
- Loading line outlet
- Tank internals: ladder, pump stack, purge pipes, sounding pipes, striking plates, tank cleaning machines, level indicators etc.
- Condition of tank coating
- Stainless steel tanks should be inspected for discolouration and pitting
Although tanks must be inspected as per Class requirements as part of the vessel’s planned maintenance, it is good practice to note any defects or deficiencies during any tank inspection, such as indentation in plating or weld cracks so progressive worsening of these can be noted. Additionally, any mechanical defects can be noted and repairs made if necessary, prior to the commencing of cargo operations. This can save a mechanical issue occurring during cargo operations which is far more complex to repair when the vessel is in a loaded condition.
For complete details, click on the below image to download the Loss Prevention bulletin from West:
Source: Emma MacCarthy, West
