1. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Ship’s Interior Communications

2. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Introduction Interior communications deal with those forms of communication between a sender and a receiver aboard the same ship. Interior communications are carried out via sound and some visual methods. Communications by messenger, probably the most ancient of all methods, remains the most reliable system.

3. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Class Objectives 1) Define the purpose of interior communications systems. 2) Identify all types of interior communications systems.

4. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Purpose of Interior Communication Systems Various stations within a ship must be able to communicate with one another. For example: –The ship’s DC parties must be able to communicate with the DCC and bridge during an emergency –The bow lookouts must be able to report to the OOD what they see and hear –Primary flight control must be able to communicate with sailors moving aircraft on the flight deck The quicker a message moves through the ship’s interior the more efficient the ship will operate.

5. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Communications Equipment There are four basic types of interior communications equipment: –Voice Tube –Ship’s Service Telephone –Shipboard Announcing Systems –Sound powered telephone system

6. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Voice Tube Primary means of interior communications on most mine craft and patrol boats. Requires neither electrical or sound power. On large ships it is only used for short distances.

7. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Ship’s Service Telephone Similar to a regular telephone system in your house. Can communicate with any part of the ship just by dialing a phone number. When the ship is alongside, the ship can be connected with the shore to allow outside calls. One disadvantage: the number of talkers it can reach at a time is small.

8. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Shipboard Announcing System In the old Navy an all hands order was passed by word of mouth by the Boatswain’s Mate. Now the BM’s can pass the word over the MC Circuit while others can stay where they are. The basic MC circuit is the 1MC over which word can be passed to every space in the ship.

9. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Shipboard Announcing System Transmitters for the 1MC are found on the bridge, quarterdeck, and central station. Except for emergency no call may be passed over the 1MC unless authorized by the OOD, Executive Officer, or the captain. Some parts of the ship have independent MC circuits such as engineering (2MC) and hanger deck (3MC)

10. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Shipboard Announcing System 1MC, 2 MC, 3MC, and 6 MC are all one-way means of communication. MC circuits such as the 21MC (Captain’s Command) provide two- way communications also known as squawk boxes.

11. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Shipboard Announcing System CIRCUIT SYSTEM 1MC General 2MC Propulsion plant 3MC Aviators 4MC Damage control 5MC Flight deck 6MC Intership 7MC Submarine control 8MC Troop administration and control 9MC Underwater troop communication 18MC Bridge 19MC Aviation Control CIRCUIT SYSTEM 21MC Captain’s command 22MC Electronic control 23MC Electrical control 24MC Flag command 26MC Machinery control 27MC Sonar and radar control 29MC Sonar control and information 30MC Special weapons 31MC Escape truck 32MC Weapons control Abbreviated MC Circuit List

12. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Sound Powered Telephones Phones that operate on voice power, no batteries or external electrical power source. The mouthpiece and earpieces can be used interchangeably; you can talk into an earpiece and hear through the mouthpiece! Sound powered telephone talkers are found in the lookouts, the bridge, in CIC, and enginerooms to name a few.

13. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Sound Powered Telephones Typical sound powered headset consists of a headband, earpiece, breastplate, and a yoke that holds the mouthpiece. The headset has a wire which may be up to 50 feet long. Sound powered headsets plug into special telephone jacks. Never secure the headset until you have permission to do so. headband earpiece breastplate mouthpiece

14. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Summary 1) Define the purpose, use, and characteristics of interior communications systems. 2) Identify all types of interior communications systems.

15. United States Naval Sea Cadet Corps Region 7-1 – Recruit Training Questions???