Signaling

 

Intl. Code of Signals

 

The International Code Flags

Numeral Flags

 

1

 

 

6

 

2

 

 

7

 

3

 

 

8

 

4

 

 

9

 

5

 

 

0


 

Substitutes and Answering Pendant

 

1st

 

 

 

 

2nd

 

ANSWERING

 

3rd

 

 

 

 

 

 

 

 

 

Alphabetical flags

A

 

N

B

 

O

C

 

P

D

 

Q


 

E

 

R

F

 

S

G

 

T

H

 

U

I

 

V

J

 

W

K

 

X

L

 

Y

M

 

Z

 

Purpose of the International Code of Signals

The Code was primarily intended for use by ships and aircraft and via coast radio stations, between ships or aircraft and authorities ashore.

A certain number of signals were inserted for communications with ship owners, agents, repair yards, etc.

The code is intended to cater primarily for situations related essentially to safety of navigation and persons, especially when language difficulties arise. It is suitable for transmission by all means of communication, including radio telephony thus obviating the necessity for a separate radiotelephone code. The code embodies the principle that each signal has a complete meaning.

Today with the advancement of communication – AIS and DSC VHF etc, the contents of the code are still relevant. To give advance information on a situation by hoisting flags pertinent to the issue. Also in radio telephony the language barrier exists more so accent is difficult to understand in such cases the Code is of invaluable help.

The two letter and the three letter (medical section) codes are complete message by themselves and in an emergency are the best messaging means available.

The purpose of the International Code of Signals is to provide ways and means of communication in situations related essentially to safety of navigation and persons, especially when language barrier difficulties arise.

Provision has been made in the Code where plain language may be used where language difficulties are not present.

The signals used consist of:

Single letter signals allocated to significance, 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

The code follows the basic principle that each signal should have a complete meaning. This principle is followed throughout the Code, in certain cases complements are used, where necessary, to supplement the available groups.

Complements express: a Variations in the meaning of the basic signal, like:

‘CP’                 “I am proceeding to your assistance”

‘CP 1’              “SAR aircraft is coming to your assistance”

Thus ‘CP’ was a general statement with no information about what is expected, when the signal ‘CP 1’ is sent it means a definitive statement an SAR aircraft is coming to the assistance.

Again a question may be as:

‘HX’                Have you received any damage in collision?

Here the answer may be specific:

‘HX 1’             I have received serious damage above the water line

Also instead of just informing:

‘IN’                 I require a diver

Which may be a vague request – for what type of work or damage control

It would be better to add a complement and send a complete picture:

‘IN 1’              I require a diver to clear propeller.

So the assistance is geared up accordingly to bring material and equipment required to clear a propeller.

The material is classified according to subject and meaning.

Extensive cross-referencing of the signals in the right hand column is used to facilitate coding.

Significance of the arrangement of the Code different types of signals

The Code is divided into chapters and into sections. Whereas the sections deal with signals for specific signals, the chapters deal with the methods and use of signals in general.

The Chapters include:

Explanation and general remarks

Definitions

Methods of Signalling

General Instructions

Flag Signalling

Flashing Light signalling

Radiotelephony

Signalling by hand flags or arms

Sound signalling

Morse symbols

Single letter signals

Single letter signals with complements

Single letter signals between Ice breaker and assisted vessels

Identification of Medical Transports

The sections include:

General, which is divided into many parts dealing with all aspects of general messaging including distress

Medical – this section deals exclusively with medical response and queries that would flow between the ship and the shore and vice versa.

The Table of contents deals with the Medical section and details the human body, medicines and the diseases.

These are specific signals and are exclusive and should not be mistaken for any other signals.

The meanings are very straightforward.

May be made by any method of signalling, except as stated in italics – care to be exercised when deciding to make the signal by sound.

A:         I have a diver down; keep well clear at slow speed

B:         I am taking in, or discharging, or carrying dangerous goods

The above signal ‘B’ when made by sound should comply with the COLREGs

C:         Yes (affirmative or “The significance of the previous group should be read in the affirmative”).

D:         Keep clear of me; I am manoeuvring with difficulty.

The above signal ‘D’ when made by sound should comply with the COLREGs

E:         I am altering my course to starboard.

The above signal ‘E’ when made by sound should comply with the COLREGs

F:         I am disabled; communicate with me.

G:         I require a pilot. When made by fishing vessels operating in proximity on the fishing grounds it means: “I am hauling nets”.

H:         I have a pilot on board.

The above signal ‘H’ when made by sound should comply with the COLREGs

I:          I am altering my course to port.

The above signal ‘I’ when made by sound should comply with the COLREGs

J:          I am on fire and have dangerous cargo on board: keep well clear of me.

K:        I wish to communicate with you.

The signal ‘K’ has a special meaning as a landing signal for small boats with crews or persons in distress.

L:         You should stop your vessel instantly.

M:        My vessel is stopped and making no way through he water.

N:        NO ( Negative or “The significance of the previous group should be read in the negative”). This signal may be given only VISUALLY or by SOUND. For voice or radio transmission the signal should be :NO”.

O:        Man overboard

P:         In harbour: All persons should report on board as the vessel is about to proceed to sea.

            At sea: It may be used by fishing vessels to mean: “My nets have come fast upon an obstruction”.

Q:        My vessel is ‘healthy’ and I request free pratique.

S:         I am operating astern propulsion.

The above signal ‘S’ when made by sound should comply with the COLREGs

The signal ‘S’ has a special meaning as a landing signal for small boats with crews or persons in distress.

T:         Keep clear of me; I am engaged in pair trawling.

The above signal ‘T’ when made by sound should comply with the COLREGs

U:         You are running into danger.

V:         I require assistance

W:        I require medical assistance.

X:         Stop carrying out your intentions and watch for my signals.

Y:         I am dragging anchor.

Z:         I require a tug. When made by a fishing vessel operating in close proximity in the fishing grounds it means: “I am shooting nets”.

Two‑letter signals

The two letter signals are for the General section – most of the signals are two letters however the answer to a query may be by three letters the last being a complement or a more specific signal.

For example:

Query: AM       (Have you a doctor)

Answer: AN 2  (I need a doctor; I have radiation casualties).

Three‑letter signals beginning with ‘M’ for the Medical Section

The Medical section have three letter signals, the first letter is always ‘M’

Thus from the above arrangement we see that there is little to confuse a recipient of a message by the InterCode since the categorization is done according to the related message.

If a message starts with ‘M’ it relates to the medical section

If it is a two letter then it belongs to the General sections

And a single letter signal is usually a general message to all vessels.

Use of complements and tables of complements

‘K’                   I wish to communicate with you

More specifically

‘K 9’    I wish to communicate with you using ‘VHF Radiotelephony Ch. 16’ from the Table of Complements I

Again

‘XX 2’             True wind direction is …EAST… (Complements Table III)

The table of complements are three in number.

Table I – methods of signalling – communication

Table II – Requirements – water, survival craft, towing etc.

Table III – Direction of the weather – East, west etc

Using substitute flags

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.

The first substitute always repeats the upper most signal flag of that class of flags which immediately precede the substitute.

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 precedes them. No substitute can ever be used more than once in the same group.

The Answering pendant when used as a decimal point is to be disregarded in determining which substitute to use.

Example: The signal ‘VV’ would be made as follows:

Flag position (1)           V

Flag position (2)           1st substitute

The number ‘1100’ would be made by numeral pendants as follows:

Flag position (1)           1

Flag position (2)           1st substitute

Flag position (3)           0

Flag position (4)           3rd substitute.

The signal ‘L2330’ would be made as follows:

Flag position (1)           L

Flag position (2)           2

Flag position (3)           3

Flag position (4)           2nd substitute

Flag position (5)           0

In this case, the 2nd substitute follows a numeral pendant and therefore it can only repeat the second numeral in the group.

How to spell

Names in the text of a signal are to be spelt out by means of the alphabetical flags. The signal ‘YZ’ = ‘the words which follow are in plain language’ can be used if necessary.

Other use of code pendant (by ships of war)

When a ship of war wishes to communicate with a merchant vessel she will hoist the code pendant in a conspicuous position and keep it flying during the whole of the time the signal is being made.

Actions to take when signals are not understood

If the receiving station cannot clearly distinguish the signal made to it, it is to keep the answering pendant at the dip. If it can distinguish the signal but cannot understand the purport of it, it can hoist the following signals:

‘ZQ’ = ‘Your signal appears incorrectly coded. You should check and repeat the whole’ or

‘ZL’ = ‘Your signal has been received but nor understood’.

End of a signal is indicated

The transmitting station is to hoist the answering pendant simply after the last hoist of the signal to indicate that the signal is completed. The receiving station is to answer this in a similar manner to all other hoists.

How to answer signals

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 and close up immediately they understand it; it is to be lowered to the dip as soon as the hoist is hauled down in the transmitting station, being hoisted close up again as soon as the next hoist is understood.

Purpose of identity signals

Identity signals may be used for two purposes:

1.         To speak to, or call a station

2.         To speak of, or indicate, a station.

Examples:

‘YP VWXP’    ‘I wish to communicate with vessel VWXP by …. (Complements table I)’

‘HY 1 VWXP’ ‘The vessel VWXP with which I have been in collision has resumed her voyage’

Signalling: Azimuth or Bearing, Course, Date, Latitude, Longitude, Distance, Speed, Time

Azimuth

They are to be expressed in three figures denoting degrees from 000 to 359, measured clockwise. If there is any possibility of confusion, they should be preceded by the letter ‘A’ (for Azimuth). They are always to be true unless expressly stated to be other wise in the context.

Examples:

‘LT A023 T1548                     ‘Your bearing from me is 023 degrees at (Local Time) 1548’.

 

 

Course

They are to be expressed in three figures denoting degrees from 000 to 359, measured clockwise. If there is any possibility of confusion, they should be preceded by the letter ‘C’ (for Course). They are always to be true unless expressly stated to be other wise in the context.

Examples:

‘GR C240 S18             ‘Vessel coming to your rescue is steering course 240 degrees, speed 18 knots’

 

 

 

Date

Dates are to be signalled by two, four or six figures preceded by the letter ‘D’. The first two figures indicate the day of the month. When they are used alone they refer to the current month.

Example: ‘D15’ transmitted on the 15th or any other date in April means ’15 April’. The two figures which follow indicate the month of the year.

Example: ‘D1504’ means ’15 April’. Where necessary the year may be indicated by two further figures.

Example: ‘D181004’ means ’18 October 2004’

Latitude

Latitude is expressed by four figures preceded by the letter ‘L’. The first two figures denote the degrees and the last two the minutes. The letters ‘N’ (for North) or ‘S’ (for South) follow if they are needed, however, for reasons of simplicity they may be omitted if there is no risk of confusion.

Example: ‘L3740S’      ‘Latitude 37˚ 40’ S’

Longitude

Longitude is expressed by four figures or if necessary, five figures preceded by the letter ‘G’. The first two (or three) figures denote the degrees and the last two the minutes. When the Longitude is more than 99˚, no confusion will normally arise if the figure indicating hundreds of degrees is omitted. However where it is necessary to avoid confusion the five figures should be used. The letters ‘E’ (for East) or ‘W’ (for West) follow if they are needed, however, for reasons of simplicity they may be omitted if there is no risk of confusion.

Example: ‘G13925E’    ‘Longitude 139˚ 25’ E’

Distance

Figures preceded by the letter ‘R’ indicate distance in nautical miles.

Example:

‘OVA080 R10’            Mines are believed to be bearing 080˚ from me, distance 10 miles.

The letter ‘R’ may be omitted if there is no possibility of confusion.

Speed

Speed is indicated by figures preceded by:

The letter “S’ to denote speed in knots or

The letter ‘V’ to denote the speed in kilometres per hour.

Examples:

‘BQ S300’       ‘The speed of my aircraft in relation to the surface of the earth is 300 knots’

‘BQ V300’      ‘The speed of my aircraft in relation to the surface of the earth is 300 kilometres per hour’

Time

Times are to be expressed in four figures of which the first two dente the hour (from 00 to 23) and the last two denote the minutes (from 00 to 59). The figures are preceded by:

The letter ‘T’ indicating Local Time or

The letter ‘Z’ indicating Greenwich Mean Time.

Example:

‘RX T0830’     ‘You should proceed at Local Time 0830’

‘RX Z0830’     ‘You should proceed at GMT 0830’

Signalling depths:

The following signals relate to depth – more are found in the Code book.

‘NK’                ‘There is not sufficient depth of water’

‘NL’                ‘There is sufficient depth of water.

‘NL 1’             ‘Is there sufficient depth of water?’

‘MA  ’             ‘The least depth of water in the channel/ fairway is. …(number feet or metres)’

More specifically:

‘MA 8’            ‘The least depth of water in the channel is 8 metres’

Cross‑referencing of signals

In the part dealing with Depth the codes start with ‘NK’ on the right column the cross reference is given as ‘MA’, this helps if transmitting the ‘NL’ code the reference may be seen at the ‘MA’ or ‘LZ 4’ etc.

Example:

‘NK’                ‘There is not sufficient depth of water’

‘NL’                ‘There is sufficient depth of water.

‘NL 1’             ‘Is there sufficient depth of water?’

‘The least depth of water in the channel/ fairway

is. …(number feet or metres)’                                                   ‘MA’

‘What is the least depth of water in the channel/ fairway?’          ‘LZ 4’

Significance of text in brackets

The text within the brackets help in understanding what to transmit after the alphabetical code.

Such as:

‘MA  ’             ‘The least depth of water in the channel/ fairway is. …(number feet or metres)’

More specifically:

‘MA 8’            ‘The least depth of water in the channel is 8 metres’

Time of origin

The time of origin may be added at the end of the text. It should be given toi the nearest minute and expressed by four figures. Apart from indicating at what time a signal originated it also serves as a convenient reference number.

Single‑letter signals for use between an ice‑breaker and assisted vessels

The following single letter signals, when made between an ice-breaker and assisted vessels, have only the significations given in this table and are only to be made by sound, visual or radio telephony signals.

WM     Ice-breaker support is now commencing. Use special ice-breaker support signals and keep continuous watch for sound, visual or radio telephony signals.

WO     Ice-breaker support is finished. Proceed to your destination.

Code letters or figures

Ice-breaker

Assisted vessel(s)

A

Go ahead (proceed along the ice channel)

I am going ahead (I am proceeding along the ice channel)

G

I am going ahead; follow me

I am going ahead; I am following you

J

Do not follow me (proceed along the ice channel)

I will not follow you (I will proceed along the 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 vessel instantly

I am stopping my vessel

4

Stop. I am ice bound

Stop. I am ice bound

 

Q

Shorten the distance between vessels

I am shortening distance

B

Increase the distance between vessels

I am increasing the distance

5

Attention

Attention

Y

Be ready to take (or cast off) the tow line

I am ready to take (or cast off) the tow line.

 

Special signal

 

Ice-breaker

Assisted vessel(s)

Stop your headway (given only to a ship in an ice channel ahead of and approaching or going away from ice-breaker)

I am stopping headway

 

 

 

Normal single letter signals – used in compliance with International Regulations for Preventing Collisions at Sea.

E

I am altering my course to starboard

I

I am altering my course to port

S

I am operating astern propulsion

M

My vessel is stopped and making no way through the water

 

 

Use of these signals does not relieve any vessel from complying with the International Regulations for Preventing Collisions at Sea.

 

Coding a distress message:

Vessel ‘VWXP’ is on fire and requests immediate assistance with fire fighting appliances. Her position is Latitude 05˚10’N, Longitude 130˚10’E.

VWXP decides send a distress call and follows up with a coded detailed signal, as follows:

‘CB 6’             ‘I require immediate assistance; I am on fire’

Following this signal she may send:

‘CC’ I am (or vessel indicated is) in distress in lat…long….(or bearing …. From place indicated, distance….) and require immediate assistance (Complements table II, if required)

VWXP                         Ship call sign

Latitude as ‘L’ followed by the figures ‘05˚10’ and the ‘N’ = L0510N 

Longitude as ‘G’ followed by the figures ‘130˚10’ and the ‘E’ = G13010E

‘4’                                Table II – fire fighting appliances

‘CC VWXP L0510N G13010E 4’

Decoding messages received.

Received the following:

‘BH T1045 L2015N G3840W C125’

Go to page starting with alphabets BE-BP

‘BH’    = ‘I sighted an aircraft at time indicated in lat. …. long…. flying on course

Here the time is indicated as ‘T’ thus it is the Local time of ‘1045’

‘L’ is for the latitude and ‘N’ for North, thus the Lat. is 20˚15’ N.

‘G’ is for the longitude and ‘W’ for West, thus the Long. Is 038˚40’ W

‘C’ is for course thus the course is 125˚ (T) since the course is always to be True.

So the message decoded would read as:

I sighted an aircraft at 1045 (LT) in Latitude 20˚15’ N and Longitude 038˚40’ West flying on course 125˚(T)

Medical Coding

Medical advice should be sought and given in plain language whenever it is possible but, if language difficulties are encountered this Code should be used.

Even when plain language is used, the text of the Code and the instructions should be followed as far as possible.

Reference is made to the procedure signals ‘C’; ‘N’ or ‘NO’ and ‘RQ’ which, when used after the main signal, change its meaning into affirmative, negative and interrogative (questioning) respectively. (See earlier topic on Procedure in Lesson 1)

Example:

‘MFE N’                      ‘Bleeding is not severe’

‘MFE RQ’                   ‘Is bleeding severe?’

Example of coding:

I have a male patient age 44 years, he has been ill for 2 days. Patient is delirious and has fits of shivering. Temperature in the mouth is 103˚C and pulse rate per minute is 110. The rate of breathing per minute is 30. Patient is in pain (chest). Part of the body affected is right (chest). Pain is increased on breathing. Patient has severe cough. Patient has bloodstained sputum. Patient has been given (penicillin Injection) without effect. Patient has received treatment by medicaments in last (18) hours. My probable diagnosis is (pneumonia).

Description of patient:

MAJ                 I have a male aged ….(number) years

MAJ 44

MAN                Patient has been ill for …. (number) hours

MAN 48

MCX                patient is delirious

MCX

MCM               Patient has fits of shivering (chills)

MCM

MBR                temperature taken in mouth is ….(number)

MBR 103

MBX                Pulse rate per minute is …..(number)

MBX 110

MCE                The rate of breathing per minute is ,,,, (number) (in and out being counted as one breath)

MCE 30

MDF                Patient is in pain …. (Table M I)

MDF 9 (Right)

MDQ               Pain is increased on breathing

MDQ

MIC                 Patient has severe cough

MIC

MIL                 Patient has bloodstained sputum

MIL

MAT                Patient has been given …. (Table M III) without effect

MAT 18

MAU               Patient has received treatment by medicaments in last …..(indicate number) hours.

MAU 18

MQE                My probable diagnosis is …..(Table M II)

MQE 68

Thus the total coded message would be:

MAJ 44           MAN 48          MCX               MCM              MBR 103         MBX 110 MCE 30      MDF 9 Right            MDQ               MIC                 MIL                 MAT 18  MAU 18       MQE 68

Decoding the answer to the above message:

MQT   MVK 18          MTQ 12          MVC   MVG   MUF    MUB   MVU 24

MQT

MQT                Your diagnosis is probably right.

MVK 18

MVK                You should continue giving  …(Penicillin injection)…(Table M III)

MTQ 12

MTQ                You should repeat every (12) (number) hours.

MVC

MVC                Put patient to bed lying down at absolute rest

MVG

MVG               Keep patient warm

MUF

MUF               Give fluid diet, milk, fruit juice, tea, mineral water

MUB

MUB                Give water very freely

MVU 24

MVU               Refer back to me in (24).(number) hours or before if patient worsens

Decoded and arranged the message would be:

Your diagnosis is probably right. You should continue giving (penicillin injection). You should repeat every (12) hours. Put patient to bed lying down at absolute rest. Keep patient warm. Give fluid diet, milk, fruit juice, tea, and mineral water. Give water very freely. Refer back to me in (24) hours or before if patient worsens.

The International Code Signal of distress

Distress:

‘NC’                I am in distress and require immediate assistance

For further assistance being more specific:

‘CB’                I require immediate assistance

Followed by:

CB 1                I require immediate assistance; I have a dangerous list

CB numerals start from 1 to 8 for various types of assistance required immediately.