Tank

Any ship that ranks on the OHS scale at a three or below classifies as a tank. Technically they have weapons, but in the case of anything larger than a corvette-weight ship, those weapons are more a formality than anything else, incapable of making an appreciable difference against anything more than small-time interplanetary pirates. In the case of corvette-weight planetary attack craft, such as might be carried by a fleet carrier, they usually have a single Tier 2 gun and several small Tier 0.4 detachable guns, intended to be gun emplacements or anti-personnel guns in the case that the ship’s crew embarks for crowd control or something like that. Many mining vessels fall under the tank classification as well, since mining weapons tend to fall above Tier 2.