46 C.F.R. § 108.145 Hatches and tonnage openings.
Title 46 - Shipping
Each hatch, except a hatch between storage spaces and each tonnage opening closure, must be made of steel or an equivalent material of the same class as the bulkhead or deck where the opening occurs.
Title 46: Shipping
PART 108—DESIGN AND EQUIPMENT
Subpart B—Construction and Arrangement
Structural Fire Protection
§ 108.145 Hatches and tonnage openings.
