Investigating Liquid Bulk Claims: An Eye for Detail
Most cargo damage, like damaged containers, contaminated fruit or wetted corn, is easy to visualise. Yet identifying damage to liquid bulk cargoes is not so clear-cut. And if damage such as contamination is not identified at an early stage, the consequences can be far-reaching.
With so many different types of cargoes, vessels, cargo operations and parties involved, each case is different. To fathom the origin, cause and extent of any damage, thorough practical knowledge is indispensable. We can describe a case in great detail, but if you can’t imagine the situation on board, it’s difficult to understand to what factors the damage can be attributed. Schematics of a tanker only tell half the story.
Cargo Manipulation
Any manipulation, like discharging into a shore tank or barge, or blending can aggravate the damage, while obscuring the cause. It’s highly unusual for the exact cause to be known at the time of discovery. This means that all possibilities must be ruled out before damaged cargo can be manipulated. After all, if the cause and extent are unknown, so are the potential consequences.
Tank Conditions
Prior to loading, the tank is inspected. However, in most terminals it’s no longer allowed to enter the tank. And what may seem a clean tank, may hide residue in corners. Or there may be a small leak in a heating coil at the bottom of the tank. Without a thorough inspection, it’s impossible to know whether the tank really is clean.
Arrangement of Lines
If a sample shows small droplets, the arrangement of lines, and the location of the common line connecting the tanks, is very important. It makes more sense that water is collected in the common line if it’s at the bottom, rather than on top of the lines. But the schematics don’t show this.
Limitations of Samples
The level of contamination may differ widely, depending on the location in the tank. In one case, some particles were found in the cargo. But only after the tank was empty, did it become clear that the tank floor wasn’t covered entirely. So depending on the sampling point, samples might not have shown any particles at all. The contamination was found purely by chance.
Off-Specification Cargo
When finding irregularities, the cargo inspector will declare the cargo off-spec. But samples are not always representative of the entire cargo. At this point, we don’t know the extent, the cause or the consequences of the damage. Without a thorough understanding of what’s going on, it’s easy to act and drive up the costs for all parties involved.
Complications
Let me illustrate just how complicated liquid bulk surveys can be with a relatively simple example: oil contaminated by water. The water is clearly visible in the sample.
If water is found in the manifold sample, operations can be stopped immediately. We can then investigate whether water is present in the shore tank. Unfortunately, more often than not, we’re involved after discharge when the vessel is blamed, rendering investigation of the shore tank impossible.
The location of where the samples are taken, changing waterlines as a result of trimming: it can all distort the picture. In addition, all the shore and shipboard systems and processes can contribute to contamination. Not all of them are logged and a thorough investigation is the only way to determine the cause.
Best Practice
Attention to detail makes all the difference. Particularly when the contaminant cannot be seen and doesn’t show up in standard checks or analysis.
Witnessing and inspecting all the samples is essential, as is taking manifold samples for the vessel. In addition, all correspondence and every step of the operations must be recorded. And finally, involve mariners and chemists right from the start. Their joint expertise will help uncover the details that might otherwise go unnoticed.