Self-Trimming Bulk Carrier
What self-trimming means in a bulk carrier: hopper and topside tank geometry, the cargoes it works for, and why it does not remove the Code's trimming obligation.
A self-trimming bulk carrier has hold geometry that causes cargo to distribute itself close to level as it is loaded, using sloping hopper tanks at the bilge and sloping topside tanks under the deck so that there are no shoulders on which cargo can pile or shelves on which it can rest. Most modern gearless and geared bulk carriers are self-trimming in this sense.
The full article will cover the geometry and its structural role, since the hopper and topside tanks serve ballast capacity and hull girder strength as well as cargo distribution, and the hold shape that results. It will cover which cargoes the arrangement works for and which still need mechanical trimming despite it.
It will also address a persistent misreading. Self-trimming describes hold geometry, not a regulatory exemption: the IMSBC Code’s trimming provisions continue to apply, the master retains the right to require a cargo trimmed level where stability is a concern, and a free-flowing cargo in a self-trimming hold can still leave a surface that needs attention.