46 CFR §148.155

1. (a)A PDM must be stowed and segregated according to the requirements of this section and Table 148.155 of this section.
2. (b)When transporting coal—
   1. (1)Coal must be stowed separate from materials of Class/division 1.4 and Classes 2, 3, 4, and 5 in packaged form; and separated from bulk solid materials of Classes 4 and 5.1;
   2. (2)No material of Class 5.1, in either packaged or bulk solid form, may be stowed above or below a cargo of coal; and
   3. (3)Coal must be separated longitudinally by an intervening complete cargo compartment or hold from materials of Class 1 other than Class/division 1.4.
3. (c)When transporting direct reduced iron (DRI)—
   1. (1)DRI lumps, pellets, or cold-molded briquettes, and DRI hot-molded briquettes, must be separated from materials of Class/division 1.4, Classes 2, 3, 4, 5, Class 8 acids in packaged form, and bulk solid materials of Classes 4 and 5.1; and
   2. (2)No material of Class 1, other than Class/division 1.4, may be transported on the same vessel with DRI.
4. (d)Petroleum coke, calcined or uncalcined, must be—
   1. (1)Separated longitudinally by an intervening complete cargo compartment or hold from materials of Class/divisions 1.1 and 1.5; and
   2. (2)Separated by a complete cargo compartment or hold from all hazardous materials and other potentially dangerous materials in packaged and bulk solid form.