What does 121 in compartment 2-121-1-L indicate?

The designation of 121 in compartment 2-121-1-L indicates the forward most frame within that compartment. In damage control terminology, the first number (in this case, 2) refers to the deck number where the compartment is located. The next part, 121, signifies the specific compartment’s frame number, with the digits denoting its position along the length of the ship. When compartment numbering follows this system, the lower numbers typically indicate locations closer to the forward part of the vessel. Therefore, 121 being a lower number signifies that it is located at the forward end of the compartment, reinforcing that it represents the forward most frame in that designated area.