46 C.F.R. § 116.415
(2) Bulkheads and decks—Bulkheads and decks must be classed as A-60, A-30, A-15, A-0, B-15, B-0, C, or C' based on the following:
(i) A-Class bulkheads or decks must be composed of steel or equivalent material, suitably stiffened and made intact with the main structure of the vessel, such as the shell, structural bulkheads, and decks. They must be so constructed that, if subjected to the standard fire test, they are capable of preventing the passage of smoke and flame for 1 hour. In addition, they must be so insulated with approved structural insulation, bulkhead panels, or deck covering so that, if subjected to the standard fire test for the applicable time period listed below, the average temperature on the unexposed side does not rise more than 139 °C (250 °F) above the original temperature, nor does the temperature at any one point, including any joint, rise more than 181 °C (325 °F) above the original temperature:
| A-60 Class | 60 minutes |
| A-30 Class | 30 minutes |
| A-15 Class | 15 minutes |
| A-0 Class | 0 minutes |
(iii) B-Class bulkheads and decks must be constructed of noncombustible materials and made intact with the main structure of the vessel, such as shell, structural bulkheads, and decks, except that a B-Class bulkhead need not extend above an approved continuous B-Class ceiling. They must be so constructed that, if subjected to the standard fire test, they are capable of preventing the passage of flame for 30 minutes. In addition, their insulation value must be such that, if subjected to the standard fire test for the applicable time period listed below, the average temperature of the unexposed side does not rise more than 139 °C (250 °F) above the original temperature, nor does the temperature at any one point, including any joint, rise more than 225 °C (405 °F) above the original temperature:
| B-15 Class | 15 minutes |
| B-0 Class | 0 minutes |
(b) Bulkhead requirements. Bulkheads between various spaces must meet the requirements of Table 116.415(b).
| Spaces | (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) | (11) | (12) | (13) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Control Space (1) | B-0 | A-0 | A-0 | A-0 | A-15 | A-60 | A-60 | A-0 | A-60 | A-60 | A-60 | A-0 | A-0 |
| Stairway (2) | A-0 4 | A-0 | A-0 | A-0 | A-60 | A-60 | A-0 | A-15 | A-15 | A-15 | A-0 | A-0 | |
| Corridor (3) | C | A-0 | B-0 | B-0 | A-0 | B-0 | A-0 | A-0 | A-0 | A-0 | A-0 | ||
| Embarkation Station (4) | C | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | C' 1 | C | |||
| Low Risk Accommodation (5) | B-0 | B-15 | B-15 | B-0 2 | A-15 | A-15 | A-15 | A-0 | A-0 | ||||
| High Risk Accommodation (6) (≤50 sq. m.) | B-15 | A-30 | B-0 2 | A-60 | A-60 | A-60 | A-0 | A-0 | |||||
| High Risk Accommodation (7) (>50 sq. m.) | A-60 | B-0 2 | A-60 | A-60 | A-60 | A-0 | A-0 | ||||||
| Low Risk Service Spaces (8) | C | A-0 | A-0 | A-0 | A-0 | A-0 | |||||||
| High Risk Service Spaces (9) | C 3 | A-0 | A-0 | A-0 | A-0 | ||||||||
| Machinery Spaces (10) | C | A-0 | A-0 | A-0 | |||||||||
| Cargo Spaces (11) | A-0 | A-0 | A-0 | ||||||||||
| Auxiliary Machinery spaces, voids, fuel and water tanks (12) | C' 1 | C' 1 | |||||||||||
| Open decks (not safety areas) (13) | C | ||||||||||||
| 1 Boundaries of fuel tanks, auxiliary machinery spaces, and voids that contain a fire load in excess of 2.5kg/m 2 (0.5 pounds per square foot) must be minimum A-0 Class construction. | |||||||||||||
| 2 Toilet space boundaries may be reduced to C′-Class. | |||||||||||||
| 3 C-Class bulkheads may be used between two similar spaces, such as between two storerooms; however, an A-0 Class bulkhead shall be used between two dissimilar spaces, such as a storeroom and a workshop. | |||||||||||||
| 4 Separation is not required within a single stairtower. A-0 construction is required between two distinct stairtowers. |
(c) Deck requirements. Decks between various spaces must meet the requirements of Table 116.415(c), except that where linings or bulkhead panels are framed away from the shell or structural bulkheads, the deck within the void space so formed need only meet A-0 Class requirements.
| Space Above | (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) | (11) | (12) | (13) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Space Below: | |||||||||||||
| Control Space (1) | A-0 | A-0 | A-15 | A-0 | A-0 | A-15 | A-30 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 |
| Stairway (2) | A-0 | C | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 |
| Corridor (3) | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-15 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 |
| Embarkation Station (4) | A-0 | A-0 | A-0 | C | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | C' 1 | C |
| Low Risk Accommodation (5) | A-15 | A-15 | A-0 | A-0 | A-0 | A-0 | A-15 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 |
| High Risk Accommodation(6) (≤50 sq. m.) | A-60 | A-60 | A-30 | A-15 | A-0 | A-30 | A-60 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 |
| High Risk Accommodation (7) (>50 sq. m.) | A-60 | A-60 | A-60 | A-30 | A-15 | A-60 | A-60 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 |
| Low Risk Service Spaces (8) | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 |
| High Risk Service Spaces (9) | A-60 | A-30 | A-30 | A-30 | A-15 | A-60 | A-60 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 |
| Machinery Spaces (10) | A-60 | A-60 | A-60 | A-30 | A-15 | A-60 | A-60 | A-0 | A-0 | C | A-0 | A-0 | A-0 |
| Cargo Spaces (11) | A-60 | A-30 | A-30 | A-30 | A-15 | A-60 | A-60 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 |
| Auxiliary Machinery Spaces, voids, fuel and water tanks (12) | A-0 | A-0 | A-0 | C' 1 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | C' 1 | A-01 |
| Open decks (not safety areas) (13) | A-0 | A-0 | A-0 | C | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 | A-0 1 | C |
| 1 Boundaries of fuel tanks, auxiliary machinery spaces, and voids that contain a fire load in excess of 2.5 kg/m 2 (0.5 pounds per square foot) must be minimum A-0 Class construction. |
(d) Main vertical zones.
(1) The hull, superstructure, and deck houses of a vessel, except for a vehicle space on a vehicle ferry, must be subdivided by bulkheads into main vertical zones which:
(ii) Must be constructed to:
(iii) May have small horizontal steps, if the steps:
(f) On vessels with no overnight passenger accommodations, draft stops are not required above/around large public spaces provided all of the following conditions are met:
[CGD 85-080, 61 FR 900, Jan. 10, 1996; 61 FR 20556, May 7, 1996; 61 FR 24464, May 15, 1996, as amended at 62 FR 51348, Sept. 30, 1997; USCG-1998-4442, 63 FR 52191, Sept. 30, 1998]