46 C.F.R. § 32.56-5 – General—T/ALL.

(a) Except as provided in paragraphs (c) and (d) of this section, each category A machinery space must be aft of the cargo area and pumprooms.
(b) Except as provided in paragraphs (c), (d), and (e) of this section, each accommodation space, service space except isolated storage spaces, and control space and each main cargo control station must be aft of:
1. (1) The cargo area;
2. (2) All cargo pumprooms; and
3. (3) All cofferdams that isolate the cargo area from category A machinery spaces.
(c) Except as provided in paragraph (e) of this section, any pumproom may be recessed below accommodation, service, and control spaces and recessed into any category A machinery space if the distance between the deckhead of the recess and the underside of the accommodation, service, or control space is at least equal to the height of the recess.
(d) Accommodation, service, control and certain machinery spaces, such as spaces for bow thrusters, windlass, and emergency fire pumps, may be located forward of the cargo area and pumprooms if it is demonstrated to the Commandant that the overall degree of safety of the vessel is improved and that the degree of fire and life safety for these spaces is not less than the degree of fire and life safety for similar spaces located aft.
(e) On liquefied gas carriers:
1. (1) Main cargo control stations may be located in the cargo area;
2. (2) Accommodation, service, and control spaces may be located over cofferdams that isolate cargo tanks other than integral tanks from category A machinery spaces;
3. (3) Pumprooms may not be recessed into any space below deck.