Question: This question applies to added container weight. “We mounted a mixer and some other equipment to our tank container. This added equipment also added weight, so now the markings on the tank are incorrect. What should I do?”
Tank Guru: Now that the International Maritime Organization (IMO) has introduced the Safety Of Life At Sea (SOLAS) regulations for Verified Gross Mass (VGM) of containers, there will continue to be increased scrutiny of container weight — especially when loaded, but also when empty.
It is key to have an accurate starting point, knowing what the empty weight of the container is before cargo is added. If you have reason to believe that the actual weight of the container doesn’t match the tare (empty) weight that is stenciled on the tank, then we recommend re-weighing the tank. First ensure that it is completely emptied of product, then have it weighed at a certified truck scale or comparable. Once you know the weight, grind and re-stamp the data plate to correct both the tare weight and net payload, and replace any corresponding decal markings as well.
There are a lot of reasons that the tare weight on a tank container can change from its originally declared weight. More common reasons include the installation of baffles, or the addition (or removal) of insulation and jacketing. It is important that when changes are made, the markings are also updated accordingly. People will make assumptions based on a container’s markings, and improperly declared weights have been a factor in previous incidents involving ship safety.
Thanks for the question!
More info on SOLAS