Question 58 OSV01 - Master/Chief Mate - Offshore Supply Vessels

The Correct Answer is C ### 1. Explanation for Option C (Galleys) being Correct The question asks what **can NOT** segregate enclosed spaces containing sources of vapor ignition (like accommodation spaces, which include galleys) from cargo tanks on a modern vessel carrying high-flammability cargoes (Grades A, B, C, or D). Regulations (specifically those derived from SOLAS and USCG/IMO codes concerning chemical and oil tankers, like 46 CFR Subchapter D or related IMO Codes) require that cargo tanks must be segregated from accommodation and service spaces (including galleys) by two vertical, contiguous steel bulkheads which are separated by an intervening safe space, such as a cofferdam, pump room, or inert space. * A **Galley** is an integral part of the accommodation and service area. It is considered an "enclosed space where sources of vapor ignition are normally present" (due to electrical equipment, open flame cooking, etc.). * A **Galley itself cannot act as a segregation measure**; rather, it is one of the spaces that **needs** to be segregated from the cargo tanks. Placing a galley directly against a cargo tank bulkhead would violate safety requirements because the galley is a potential source of ignition. Therefore, a galley is the space that needs protection/segregation, not a method of segregation. ### 2. Explanation for the Other Options being Incorrect Options A, B, and D are incorrect because they represent approved methods or structures used for segregating cargo tanks from ignition sources or machinery spaces, as required by regulation. **A) Pump rooms:** A pump room, when properly ventilated and constructed, serves as a barrier space (a type of cofferdam) between cargo tanks and adjacent machinery or accommodation spaces. It is designed to safely contain and manage leakage and provides the required two-bulkhead separation. Therefore, a pump room **can** segregate these spaces. **B) Tanks used to carry liquids having a flash point of 150°F or above (e.g., fuel oil or clean ballast tanks):** Tanks containing non-hazardous or low-flammability liquids (like fuel oil with a high flash point, usually considered non-volatile, or segregated ballast water) can be used as segregation spaces between highly volatile cargo tanks (Grades A, B, C, D) and ignition sources (like the engine room or accommodation). These tanks fulfill the requirement for a safe intervening space. Therefore, these tanks **can** segregate these spaces. **D) Cofferdams:** A cofferdam is specifically defined as an isolating space between two bulkheads or decks, designed to prevent the passage of heat or liquid. They are the primary and most common structural method used to segregate cargo tanks from accommodation/service spaces and machinery spaces, providing the mandatory two-bulkhead separation. Therefore, a cofferdam **can** segregate these spaces.