What is INTERCO or International Code of Signals and its contents in details ? |

What is INTERCO or International Code of Signals and its contents in details ?

INTERCO
Written by Vikrant_sharma
Interco is published by her majesties stationery office  –  London

CONTENTS OF INTERCO:

SECTION I:
CHAPTER 1: Explanation and general remarks

1. The purpose of the INTERCO  is to provide ways and means of communication in situations related essentially to safety of navigation and persons, especially when language difficulties arise  in the preparation of the code, account was taken of the fact that wide application of radio telephony/telegraphy can provide simple and effective means of communication in plain language whenever language difficulties do not exist.

2. THE SIGNALS USED CONSISTS OF

  • Single letter signals allocated to significations which are very urgent, important ,or of very common use;
  • Two letter signals for the general section;
  • Three letter signals beginning with ‘m’ for the medical section.

3. COMPLIMENTS EXPRESS

  • VARIATIONS IN THE MEANING OF THE BASIC SIGNAL.

Examples:

  1. ‘CP’ =   ‘I Am ( Or Vessel Indicated Is ) Proceeding To  Your Assistance’.
  2. ‘CP 1’    =  ‘Sar  Aircraft Is Coming To Your Assistance’.
  • QUESTIONS CONCERNING THE SAME BASIC SUBJECT OR BASIC SIGNAL.

Examples:

  1. ‘DY’ =  ‘Vessel ( Name Or Identity Signal ) Has Sunk In Lat….. Long…..’.
  2. ‘DY 4’   =  ‘What Is The Depth Of Water Where The Vessel Sunk?’.
  • ANSWERS TO A QUESTION OR REQUEST MADE BY THE BASIC SIGNAL.

Examples:

  1. ‘HX’ =  ‘Have You Received Any Damage In Collision?’.
  2. ‘HX 1’   =  ‘I Have Received Serious Damage Above The Waterline’.
  • SUPPLEMENTARY, SPECIFIC OR DETAILED INFORMATION.

Examples:

  1. ‘IN’ =  ‘I Require A Diver’.
  2. ‘IN 1’   =  ‘I Require A Diver To Clear Propeller’.

4. COMPLEMENTS APPEARING IN THE TEXT MORE THAN ONCE HAVE BEEN GROUPED IN THREE TABLES. THESE TABLES SHOULD BE USED ONLY AS AND WHEN SPECIFIED IN THE TEXT OF THE SIGNALS.

Example:

  1. An Alternative Eg. : ‘…(Or Survival Craft)…’.
  2. Information Which May Be Transmitted If It Is Required Or If It Is Available, Eg.: ‘…(Position To Be Indicated If Necessary)’ ;
  3. An Explaination Of The Text.
CHAPTER 2: DEFINITIONS
CHAPTER 3: METHODS OF SIGNALLING

     Methods of signalling:

  • Flag signalling.
  • Flashlight signalling, using morse symbols.
  • Sound signalling, using morse symbols.
  • Voice using a loud hailer.
  • Radio telegraphy.
  • Radio telephony.
  • Signalling by hand flags or arms. Semaphore/morse.
CHAPTER 4: GENERAL INSTRUCTIONS

   Signalling Numbers Using Interco:

  1. Signalling A Decimal:
    • Flag Signalling: By Inserting The Answering Pendant Where It Is Required To Express The Decimal.
    • Flashlight And Sound: By The Decimal Point Signal Aaa.
    • Voice : By The Use Of The Word ‘Decimal’ As Indicated In The Figure Spelling Table.
  2. Signalling Azimuth And Bearing:
    • They Are To Be Denoted In Three Figure Notations From 000 To 360 Measured Clockwise.
    • They Should Be Preceeded By The Alphabet ‘A’.
  3. Signalling Course:
    • Course Is To Be Denoted In Three Figure Notations Clockwise From
    • It Should Be Preceeded By A Single Alphabet ‘C’.
  4. Signalling Date:
    • Dates Are To Be Signalled By Two, Four Or Six Figures Preceeded By The Letter ‘D’.
    • The First Two Figures Indicate The Day, Month And Year Subsequently Follow If Signalled.
  5. Signalling Latitude And Longitude:
    • Latitude Is Expressed In Four Figures Preceeded By The Alphabet ‘L’, Subsequently ‘N’ And ‘S’ May Also Be Denoted.
    • Longitude Is Expressed By Four Or Five Figures.
    • These Are Preceeded By The Single Alphabet ‘G’.Subsequently The Letters ‘E’ Or ‘W’ May Be Used.
  6. Signalling Distance:
    • Figures Precedeed By The Letter ‘R’ Indicate Distance In Nautical Miles.
  7. Signalling Speed:
    • If Speed Is Indicated By The Figures Preceeded By The Letter ‘S’ Then It Indicates Speed In Knots.
    • And If It The Letter ‘V’ Then It Is In Kilometres Per Hour.
  8. Signalling Time:
    • Time Is To Be Expressed In Four Figure Notations Out Of Which The First Two To Denote The Hour And The Last Two To Denote The Minutes.
    • The Letter ‘T’ Indicating The Local Time And The Letter ‘Z’ Indicating Greenwich Mean Time.
CHAPTER 5:   FLAG SIGNALLING

To Answer Signals:

  1. All Stations To Which Signals Are Addressed Or Which Are Indicated In Signals Are To Hoist The Answering Pendant At The Dip As Soon As They See Each Hoist.
  2. Close Up The Hoist After They Understand It.

To Complete A Signal:

  1. The Transmitting Station Is To Hoist The Answering Pendant Singly After The Last Hoist Of The Signal To Indicate That The Signal Is Completed.
  2. The Receiving Station Is To Answer This In A Similar Manner To All Other Hoists.

To Act When Signals Are Not Understood:

  1. If It Can Distinguish The Signal But Cannot Understand The Purpose Of It, The Foll. Signals May Be Hoisted:
  2. If The Receiving Station Cannot Clearly Distinguish The Signal Made To It, It Is To Keep The Answering Pendant At The Dip.
  3. ‘Zq’ =  “Your Signal Appears Incorrectly Coded. You Should Check And Repeat The Whole”.
  4. ‘Zl’ =  “Your Signal Has Been Received But Not Understood”.

Use Of Substitutes;

  1. The First Substitute Always Repeats The Uppermost Signal Flag Of That Class Of Flags Which Immediately Preceeds The Substitute.
  2. The Use Of Substitutes Is To Enable The Same Signal Flag-Either Alphabetical Flag Or Numeral Pendant, To Be Repeated One Or More Times In The Same Group, In Case Only One Set Of Flags Is Carried On Board.
  3. The Second Substitute Always Repeats The Second, And The Third Substitute Repeats The Third Signal Flag, Counting From The Top Of That Class Of Flags Which Immediately Preceeds Them.
  4. No Substitute Can Ever Be Used More Than Once In The Same Group
CHAPTER 6: FLASHING LIGHT SIGNALLING

Signal Made By Flashing Light Is Divided Into The Foll Parts:

  1. The Identity: The Transmitting Station Makes ‘De’ Followed By Its Identity Signal Or Name. This Will Be Repeated By The Receiving Station Which Then Signals Its Own Identity Signal Or Name.This Will Also Be Repeated Back By The Transmitting Station.
  2. The Call: It Consists Of The General Call Or The Identity Signal Of The Station To Be Called. It Is Answered By The Answering Signal.
  3. The Text: This Consists Of Plain Language Or Code Groups. When Code Groups Are To Be Used They Should Preceeded By The Signal ‘Yu’. Words Of Plain Language May Also Be In The Text, When The Signal Includes Names, Places Etc.Receipt Of Each Word Or Group Is Acknowledged By ‘T’.
  4. The Ending: Consists Of The Ending Signal ‘Ar’ Which Is Answered By ‘R’.
CHAPTER 7: SOUND SIGNALLING
CHAPTER 8:  RADIO  TELEPHONY
CHAPTER 9: MORSE SIGNALLING BY HAND FLAGS OR ARMS
CHAPTER 10: MORSE SYMBOLS-PHONETIC TABLES- PROCEDURE SIGNALS

Procedure signals:

  • Signals for voice transmissions (radiotelephony or loud- hailer).
Signal Pronounced as Meaning
Interco In-ter-co International code group(s) follow(s).
Stop Stop Full stop
Decimal Day-see-mal Decimal point
Correction Kor rek shun Cancel my last word or group.the correct word or group follows.
  • Signals For Flashing Light Transmissions:
    1. Aa Aa Aaetc: Call For Unknown Station Or General Call.
    2. Eeeeeeeeetc:   Erase Signal
    3. Aaa:  Full Stop Or Decimal Point.
    4. Ttttetc:   Answering Signal.
    5. T: Word Or Group Received.
  • Signals For Flags, Radio Telephony Or Radiotelegraphy Transmissions.
    1. Cq:   Call For Unknown Station (S) Or General Call To All Stations.
  • Signals For Use Where Appropriate In All Forms Of
    1. AA’ =  “All After…”,(Used After The ‘Repeat Signal'(Rpt)), Means,’Repeat All After…’.
    2. ‘AB‘ =  “All Before…” (Used After The ‘Repeat Signal’ (Rpt)), Means,”Repeat All Before”.
    3. ‘AR’ =  Ending Signal Or End Of Transmission Or Signal.
    4. ‘AS’ =  Waiting Signal Or Period.
    5. ‘BN’ =  ” All Between…. And….” (Used After The”Repeat Signal”(Rpt)), Means “Repeat All Between…. And ….”.
    6. C =  Affirmative – Yes Or “The Significance Of The Previous Group Should Be Read In The Affirmative”.
    7. CS =  “What Is The Name Or Idnetity Signal Of Your Vessel (Or Station)?”.
    8. DE =  “From….” (Used To Precede The Name Or Identity Signal Of The Calling Station).
    9. K =  “I Wish To Communicate With You” Or “Invitation To Transmit”.
    10. NO =  Negative – No. When Used In Voice Transmission The Pronouncation Should Be ‘No’.
    11. OK =  Acknowledging A Correct Repetition Or “It Is Correct”.
    12. RQ = Interrogative.
    13. R =  “Received”.
    14. RPT = Repeat Signal “I Repeat” Or “Repeat What You Have Sent” Or “Repeat What You Have Received”.
    15. WA = “Word Or Group After….”( Used After The ‘Repeat Signal’ (Rpt)) Means “Repeat Word Or Group After…”.
    16. WB = “Word Or Group Before….”( Used After The ‘Repeat Signal’ (Rpt)) Means “Repeat Word Or Group Before…”.
CHAPTER 11: SINGLE LETTER SIGNALS
CHAPTER 12: SINGLE LETTER SIGNALS WITH COMPLEMENTS
  • Complement tables include the single letter signal used for such common transmission of signals like course speed distance etc.
CHAPTER 13: SINGLE LETTER SIGNALS BETWEEN ICEBREAKER AND   ASSISTED VESSELS

Wm   =  Ice-Breaker Support Is Now Commencing. Use Signals According To Chpt Xiii Interco.
Wo   =  Ice-Breaker Support Is Finished. Proceed To Your Destination.

Code Letters Of Figures Ice-Breaker Assisted Vessel/S Or Figures
A Go Ahead (Proceed Along Ice Channel) I Am Going Ahead(I Am GoingAlong The Channel)
G I Am Going Ahead; Follow Me I Am Going Ahead; I Am Following You
J Donot Follow Me(Proceed Along Ice Channel). I Will Not Follow You (I Will Proceed Along Ice Channel).
P Slow Down I Am Slowing Down
N Stop Your Engines I Am Stopping My Engines
H Reverse Your Engines Reverse Your Engines
L You Should Stop Your V/L Instantly I Am Stopping My Vessel.
4 Stop. I Am Ice Bound. Stop I Am Ice Bound
Q Shorten The Distance Between V/L’s I Am Shortening The Distance
B Increase The Distance Between V/L’s I Am Increasing The Distance.
5 Attention Attention.
Y Be Ready To Take Or Cast Off The Towing Line I Am Ready To Take Or Cast Off The Towing Line.
CHAPTER 14: IDENTIFICATION OF MEDICAL TRANSPORT IN ARMED CONFLICTS AND PERMANENT IDENTIFICATION OF RESCUE CRAFTS
  1. Shape, colour and positioning of emblems for medical transports:
    • The following emblems can be used seperately or together to show that a vessel is protected as a medical transport under the geneva convention.
    • The emblem may be a red cross on a white background or a red cresent moon on a white background.
    • he emblem should be positioned on the vessels sides, bow, stern and deck.
    • It shall be as large as possible and on the vessels side the emblem shall extend from the waterline to the top of the ships hull.
    • On the bow and stern if necessary should be painted on a wooden structure.
    • On the deck the emblem must be  clear of the vessels equipment.
    • In order to provide desired contrast for infrared films; the red emblem must be painted on top of a black primer paint.    
  2. Flashing blue light for medical transports:
    • A vessel engaged in medical operations shall exhibit one or more allround flashing blue lights the visiblity of the lights shall be as high as possible and not less than 3 nautical miles. The lights shall be exhibited as high above the hull as practical and in such a way that atleast one light shall be visible from any direction. The frequency of such light shall be between 60 and 100 flashes per minute.
  3. Radar transponders:
    • It should be possible for medical transports to be identified by other vessels equipped with radar by signals from a radar transponder fitted on the medical transport.The transponder signal shall consist of the group  ‘yyy’ followed by the callsign of the ship or other recognised means of identification.
  4. Underwater acoustic signals:
    • It should be possible for medical transports to be identified by submarines. These signals shall consist of the callsign of the ship preceeded by the single group ‘yyy’ transmitted in morse on an appropriate acoustic frequency. Eg. 5 khz
  5. Rescue craft carried by medical transports:
    • Every rescue craft should be equipped with a mast on which a red cross flag measuring about 2*2 mts can be hoisted.
To remember the contents in the first section make note of the foll sentence: 

Every Day Must Go For Fun, Somehow Request Mother Mary  Send Some Sweets Immediately.

GENERAL SECTION: 

PART 1:     DISTRESS – EMERGENCY

Abandon, accident-doctor-injured/sick, aircraft-helicopter, assistance, Boats-rafts, disabled-drifting-sinking, distress, position, search and rescue, Survivors.     

PART 2:     CASUALTIES – DAMAGES.

Collisions, damages-repairs, diver-underwater operations, fire-explosion, grounding-beaching-re-floating, leak, towing-tugs.

PART 3:     AIDS TO NAVIGATION – NAVIGATION – HYDROGRAPHY.

Aids to navigation, bar, bearings, canal-channel-fairway, course, dangers to navigation-warnings, depth-draught, electronic navigation, mines-mine sweeping, navigation lights-search light , navigating and steering instructions and tide.

PART 4:     MANOEUVRES.

Ahead-astern, along-side, to anchor/anchors-anchorage, engines-propeller, landing, boarding, manoeuvres, proceed-underway, speed, stop-heave to.

PART 5:     MISCELLANEOUS:

Cargo-ballast, crew-persons on board, fishery, pilot, port-harbour, misc.

PART 6:     METEOROLOGY – WEATHER.

Clouds, gale-storm-tropical storm, ice-icebergs, icebreaker, atmospheric pressure-temperature, sea-swell, visibility-fog, weather-weather forecast, wind.

PART 7:     ROUTEING OF SHIPS.

PART 8:     COMMUNICATIONS.

Acknowledge-answer, calling, cancel, communicate, exercise, reception-transmission, repeat.

PART 9:     INTERNATIONAL SANITARY REGULATIONS.

Pratique messages.

TABLE OF COMPLIMENTS
To remember the contents of the general section use the sentence:

 “ Do Come And Meet My Mother, Report Certainly In Time “

PART III: MEDICAL SECTION.
Table Of Contents

Instructions:

I    Request For Medical Assistance.

Chpt. 1:   Request – General Information.
Chpt 2:   Description Of Patient.
Chpt 3:   Previous Health.
Chpt 4:   Localisation Of Symptoms, Diseases Or Injuries.
Chpt 5:   General Symptoms.
Chpt 6:   Particular Symptoms.
Chpt 7:   Progress Report.

II  Medical Advice.

Chpt 8:   Request For Additional Information.
Chpt 9:   Diagnosis.
Chpt 10:   Special Treatment.
Chpt 11:   Treatment By Medicaments.
Chpt 12:   Diet.
Chpt 13:   Child Birth.
Chpt 14:   General Instructions.

Table Of Compliments.

Table M1:   Regions Of The Body.
Table M2.1:   List Of Common Diseases.
Table M2.2:   List Of Common Diseases In Latin.
Table M3:   List Of Medicaments.

Medical Index
General Index.

APPENDICES:

APPENDIX I:      Distress Signals.
APPENDIX II:    Table Of Signalling Flags
APPENDIX III:  Table Of Life Saving Signals
APPENDIX IV:   Radiotelephone Procedures

manish-mayank

About the author

Vikrant_sharma

Leave a Comment