46 C.F.R. § 167.40-7 Voice tubes, telephone, and telegraph systems.
Title 46 - Shipping
(a) Each nautical school ship shall be fitted with an efficient means of communication between the pilothouse and engine room. This may be by bell signals with voice tubes, telephone, or telegraph systems. (b) A voice tube or telephone system between the radio room and the navigating bridge shall be provided when the nautical school ship is equipped with a radio installation. (c) A voice tube or telephone system between the pilothouse and emergency steering station shall be provided when the nautical school ship is equipped with an emergency steering station.
Title 46: Shipping
PART 167—PUBLIC NAUTICAL SCHOOL SHIPS
Subpart 167.40—Certain Equipment Requirements
§ 167.40-7 Voice tubes, telephone, and telegraph systems.
