Signalman 1 & C - Historic Naval Ships Association

The International Morse Code and special signalsare used for this means of communication. Whentransmitting by whistle, siren, fog horn, or otherdevices in which the length of sound can be controlled,you use a short blast to represent a dot and a long blastto represent a dash. When transmitting with a devicethat is struck to create sound, such as a bell, gong, ordrum, use a single stroke to represent a dot and tworapid strokes to represent a dash.No heading or ending is used in sound signaling.The text is to be made twice, separated by a pause.LIMITATIONSThe use of sound communication is normallylimited to certain specified sound signals. The onescommonly used are those prescribed for vessels in theRules of the Road. When sound signals are used inspecial circumstances, care must be exercised thatthey do not conflict with the more commonly usedsignals and thereby confuse ships and stations notfamiliar with the special signals.Sound signals other than those included in theRules of the Road are not to be employed in pilotagewaters and are only to be used in an emergency whenshort range radio is not available, or for soundingvisual call signs on occasions when the OTC may wishto ascertain which ships are within hearing distance.Sound signals may only be used by the OTC or byan individual ship having vital information for theOTC. Signals made by any ship other than the OTCare to be followed by the call sign of that ship.RECEIPTINGWhen The OTC signals by sound, one ship usuallyis directed to repeat back or receipt for the signal.When sound is used by an individual ship, the OTC isalways to receipt for the signal with that ship's callsign followed by the prosign R. The OTC may directanother ship to receipt by making that ship's call signfollowed by the prosign K. The designated stationreceipts by making the prosign DE followed by theprosign R. No ship is to relay a sound signal.EXECUTIVE METHODThe executive signal consists of a 5-second blastimmediately following the repetition of the text. Theexecute to follow sign (IX) is not to be sent either inthe text or preceding the 5-second blast. The signal isexecuted on termination of the 5-second blast. Shipsare not to wait for any ship that may be ordered torepeat back or receipt. When ships are ordered torepeat back, they are to include the executive signal ifone has been used.IDENTIFICATION OF SHIPSOn occasion the OTC may wish to determinewhich ships are within hearing distance. This may bedone by the OTC sounding the appropriate signal onlyonce.On hearing this signal, ships are to reply bysounding their visual call signs once only as follows:1. If addressed to one ship, immediately on hearingthe signal.2. If addressed to more than one ship, the ships willanswer in alphabetical order of call signs. If no shipsounds within 30 seconds, the next ship in order is tosound.RADIOTELEPHONELEARNING OBJECTIVES: Define radiotelephone(R/T). Describe the procedures foroperating the radiotelephone and maintainingsecurity; list precautions that should beobserved when communicating byradiotelephone.Radiotelephone (R/T) is used for voice tacticaland administrative communication by ships andaircraft.The time will come when, as a Signalman, youwill need to use the R/T. Study this section to improveyour ability to use voice communication procedures.There can be certain drawbacks to using the R/T.Poor voice communications (whether because offaulty equipment, adverse atmospheric conditions, orinept performance by an operator) can createconfusion, reduce reliability and speed, and adverselyaffect operations. It is essential that all users observeestablished operating procedures.Basic guidance for voice radio communication iscontained in Communications Instructions RadiotelephoneProcedures, ACP 125. Various navalpublications prescribe procedures for specificenvironments.4-13