navigation manual ch. 08 bridge...

NAVIGATION MANUAL

Ch. 08 BRIDGE EQUIPMENT

Rev.No. 6

Date 28-Oct-16

of 14

8.1 GENERAL

It is essential that the performance and efficiency of all Navigational Equipment is constantly

monitored and checked.

The Master is to be advised immediately of any suspected malfunction of Bridge Equipment.

8.2 CHRONOMETERS (if available)

The chronometer must be treated with great care and no adjustment of any sort is to be attempted.

Particulars of battery renewal-dates must be recorded, and preferably attached to the chronometer.

The Master must ensure that fresh batteries are available in good time before the due renewal date.

Chronometer errors are to be checked daily and the findings recorded in the Chronometer Rate

Book.

8.3 CLOCKS

At Sea, Bridge and Engine Room clocks must be checked and synchronised daily. They should also

be checked and synchronized when engines are put on standby for manoeuvring. No further clock

alterations may be made during periods when engines are on standby.

8.4 RADARS/ARPA

Radar is a valuable aid to navigation, but its use is subject to important limitations which must be

thoroughly understood by every Deck Officer. Correct interpretation of the radar picture is of extreme

importance.

Full use of radar equipment is to be made at all times. X-Band Radar must be kept “ON” at all times

while at sea. Radar must not be regarded as a substitute for a good all round look-out. The

OOW must ensure that range scales employed are changed at sufficiently frequent intervals so that

echoes are detected as early as possible. It should always be borne in mind that small or poor

echoes may escape detection.

The angular width and bearing of any shadow sectors should be recorded and displayed on a

diagram adjacent to the radar display and kept up to date following any change that might affect

shadow sectors.

The heading marker is to be checked each watch for accuracy within 1 degree of the vessels

heading and must be aligned as soon as practicable whenever it is found to be substantially

misaligned.

When an Automatic Radar Plotting Aid (ARPA) or Radar with electronic plotting is used, the

limitations of electronic plotting must not be overlooked and this method must not be used to the

exclusion of other plotting methods. For collision avoidance information to be accurate, vessel’s

speed must be ‘through the water’ and not ‘over the ground’. In areas of strong current or tidal flow

these errors can be significant. In vessels where the speed log cannot provide speed through the

water at all times a warning poster is to be posted pointing out the potential errors.

Uncontrolled when Printed

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The ARPA alarms must be appropriately set. The CPA/TCPA alarm limit has to be in accordance

with the CPA/TCPA limit as given in the Masters Standing orders.

Radars performance to be checked as per makers recommendations. Performance of the radars

must be checked before the vessel proceeds to sea and at least once every 4 hours whilst the

vessel is at sea. Performance checks may be either by using a performance monitor built into the

equipment or by utilising known targets. Brief details of these checks are to be entered in the Deck

Log Book. Reference Values to be obtained from the maker’s manual such as attenuation value of

transmitter and receiver should be entered in the Deck Log book for checking the performance of the

Radars on board.

Officers must be aware of the dangers of using excessive sea or rain clutter which can obliterate

small or weak targets. When in use, regular checks must be made to ensure that the use of anti-

clutter is not excessive.

Brief details of all maintenance carried out should be entered in the Radio and Radar Maintenance

Log.

8.4.1 Radar Mapping

Company discourages use of radar mapping on board vessels due to high probability of errors while

making manual inputs and due to other inherent limitations. However, on board vessels without

ECDIS, if radar mapping is used, it should be used with extreme cautions.

The following are the general guidance on the use of radar mapping and procedures.

1. Only the 2nd Officer or navigational officer in charge of passage planning should make these

maps.

2. The Master or Chief Officer should re-check the map before putting it in use.

3. Plan the passage according to established practice and lay off tracks on the chart accordingly.

4. Highlight Margins of Safety either side of the planned track.

5. Highlight major navigational items such as buoys, shoal areas, etc. that you want to map.

6. Highlight any routing lines you wish to include in the map.

7. Decide on a mapping key which will be used for all maps constructed on your particular ship.

8. This cannot be made more formal as different radar installations offer different selections of lines

and symbols and colours.

9. Keep a hard copy of the map for checking purposes. This should contain information that

includes:

a. Draft and UKC criteria used for setting the safe water limits.

b. List of co-ordinates of left and right safe water limits.

c. List of buoys or navigational mark positions.

d. Intended track waypoints.

e. Routeing limit positions.

The following are the generic limitations of radar mapping and additional constraints may exist in

individual radar equipment.


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1. The waypoint must be carefully input i.e.Lat/ Long or range and bearing. Datum shifts would

apply to the former.

2. Some Radars may receive direct NMEA inputs correctly from the GPS and will hence be

corrected for datum shifts if any, and already programmed on the GPS. On other radars, it will

have to be manually input since the position input will be uncorrected.

3. All officers must know the different types of stabilisation (ground/sea) and the method of

alignment, should the map overlay shift position. This is particularly true of touch screen radar

displays, which must be calibrated prior use as per the radar manual.

4. The fact that the vessel is on the track as per the radar map does not free the officer from his

obligation to plot positions at regular intervals as defined in the company procedures. The

officer should abandon the radar map should the possibility arise that clutter settings need to

be increased to keep a map stabilised and thereby erase small targets or decreased to catch

small targets and subsequently lose the map stabilisation.

5. Most radars have a restricted number of lines, marks and waypoints per map. It is

recommended that radar mapping be used only for critical areas such as straits, TSSs, etc. If

the entire stretch cannot be accommodated in one map, there must be an overlap between

maps with a common waypoint.

6. It is possible in some sets to identify a key or code to lock the map for editing and this must be

used to ensure inadvertent erasures to the map.

7. In some systems, deleting an intermediate way point will just make the route skip to a new one

joining the previous and next waypoint. Waypoints must be deleted only by the Second officer

and in the planning stage.

8. Some radars further may have a provision for data card input with pre-loaded navigational

charts which integrate with the radar display. The Company strongly discourages the use of

such chart integration in vessel's radars.

8.5 ELECTRONIC AIDS TO NAVIGATION

The Master and Deck Officers are to recognise the known limitations of all navigational aids. Watch

keeping Officers must always be conscious of the possibility of error in the ship’s navigational

equipment. Constant checks and counter checks are essential. Significant errors can occur in

electronic systems due to manual input of inaccurate data e.g. Speed

8.6 AUTOMATIC PILOTS

Hand steering & NFU is to be tested and logged each Watch. All changes of steering mode are to be

supervised by the Officer of the Watch who will also ensure that control has been established in the

relevant mode by alternating the course setting or helm +/-5 degrees and observing rudder

response. Any changes of watch on the bridge must be accompanied by a positive report on the


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status of the steering systems. Any subsequent change of steering systems or their status must also

be reported by the Officer of the Watch to the Master when he has the con.

The Officer of the Watch must take into account the need to station the helmsman and to put the

steering into manual control in good time to allow any potentially hazardous situation to be dealt with

in a safe manner. With a ship under automatic steering it is highly dangerous to allow a situation to

develop to the point where the Officer of the Watch is without assistance and has to break the

continuity of the lookout in order to take emergency action.

Hand steering must be utilised in all circumstances of close quarters and when manoeuvring.

It should be noted that in some areas the use of auto-pilots is forbidden on certain vessels. Masters

are required to ascertain local regulations prior to arrival and comply accordingly.

The use of auto-pilot is not recommended when navigating in areas with high traffic density, narrow

channels and traffic separation schemes and other restricted waters. The auto-pilot may not be

efficient enough to turn the vessel spontaneously while navigating in such areas demanding swift

alterations and manoeuvres to avoid collision or close quarter situations.

When the automatic pilot is used in areas of high traffic density, conditions of restricted visibility, or

any other hazardous navigational situations, the master shall ensure that:

It is possible to immediately establish manual control of the vessel’s steering;

A competent person is ready at all times to take over steering control; and

The changeover from automatic to manual control of the vessel’s steering and the

reverse is made by, or under the supervision of, the master or officer of the watch.

Clear Instructions are to be posted at the steering console describing the changeover procedures

from auto to manual steering and additionally to all follow up systems and vice versa. Master to

ensure that all Bridge Team members are aware of this switch over procedure.

8.7 GYRO AND MAGNETIC COMPASSES

8.7.1 Gyro Compass

The gyrocompass is to be run continuously. Should it stop for any reason, it must be restarted in

accordance with manufacturer’s instructions then checked before use to ensure it has “settled” and

is reading correctly.

Latitude and speed corrections must be applied, where necessary by a designated officer.

Repeaters are to be checked for synchronisation with the gyro at least once a watch. The gyro alarm

is to be checked daily. As a safeguard against the gyro and gyro repeaters wandering, frequent

comparisons should be made between the magnetic and gyrocompasses. Care should be taken to

monitor errors induced by the ship’s manoeuvring as such errors can reach 5 degrees or more.

Should the Gyrocompass be found to be malfunctioning or unreliable, the vessel must immediately

revert to hand steering using Magnetic compass and a helmsman assigned until such time as the

fault is remedied and the gyro fully settled and tested. Errors shall be checked prior to reverting back

to automatic pilot.


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The gyrocompass is to be serviced according to the recommendations in the maker’s instruction

manual.

8.7.2 Magnetic Compass

Vessel shall be swung once a year by the master and a deviation card prepared. The Magnetic

Compass adjustment must be made by a duly authorized compass adjuster. Magnetic Compasses

shall be adjusted when:

a) They are first installed or replaced,

b) They become unreliable,

c) The ship undergoes structural repairs or alterations that could affect its permanent and

induced magnetism,

d) Electrical magnetic equipment close to the compasses is added, removed or altered,

e) A maximum period of two (2) years has elapsed since the date of the last adjustment and

record of compass deviations has not been properly maintained or the record of deviations

are excessive or when the compass shows physical defects,

f) Deviation exceeds five (5) degrees taking into account the variation of the place and the

method used.

Observation should be made, every watch when conditions permit, to determine and record

compass error and deviation. This may show the need for repair, testing or adjustment or if the

records are not correctly carried out.

If vessel has a spare magnetic compass the same should be stowed in an inverted position

8.8 ECHO SOUNDER

The echo sounder is a valuable navigational aid and is to be used whenever appropriate, and in all

cases when making landfall.

Echo Sounder must be switched on and depth must be recorded when in depths of less than 50

meters. The echo sounder recorder paper is to be clearly marked with the date, time, range and

initialled by the OOW at the instant of starting and stopping. Used recorder rolls are to be retained

onboard for a minimum period of two years. Whenever the ship’s position is established or verified

with the aid of soundings, the particulars are to be recorded in the position / echo sounder Log Book.

Sufficient paper rolls and spare Stylus to be carried on board at all times. If the vessel is fitted with

digital echo sounder, sufficient backup arrangement shall be available as per maker’s

recommendation.

Performance of the echo sounder should be tested on all ranges and scales and also verified

against depths shown on the chart. The depths obtained from Echo sounder and the depths shown

on the chart shall be recorded in the position / echo sounder log book.

Alarm setting on the Echo Sounder should be in accordance with the Passage Plan UKC

requirements. The value of anticipated Dynamic UKC as obtained from UKC calculation should be

used as the grounding line on the Echo Sounder and alarm set at that value. During the passage, if

there is an alarm, master should immediately reduce speed and investigate the reason for same and

take corrective action


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8.9 EMERGENCY NAVIGATION LIGHT AND LIGHT SIGNAL SYSTEM

Emergency Navigation Lights and alarms are to be checked daily while the signal systems and

navigational shapes are to be checked weekly.

8.10 SPEED LOGS

If possible speed logs are to be in operation at all times. During operation they are to be regularly

checked for errors.

Readings of distance through the water are to be entered in the deck log at the end of each watch

and at times of establishing and logging of the ship’s position and when the course or speed are

changed.

8.11 COURSE RECORDERS

Course recorders where fitted are to be run continuously while the vessel is underway and at

anchor. Where the paper is marked with a time scale, this is to be set to UTC. The Navigating

Officer is responsible for ensuring that the course recorder is properly set up. After carrying out the

checks, Paper is to be marked with date/time initialled by OOW each day at noon and at the

commencement and end of Sea passage. Sufficient spare paper rolls to be carried on board at all

times.

8.12 MANOEUVRING CHARACTERISTICS

A “poster” showing the vessel’s manoeuvring characteristics shall be prominently displayed in the

wheelhouse to comply with IMO/USCG requirements for manoeuvring information.

8.13 ECDIS, ENC AND ECS

Refer Ch.10 of this manual

8.14 AUTOMATIC IDENTIFICATION SYSTEM (AIS)

Ships fitted with AIS shall maintain AIS in operation at all times except where international

agreements, rules or standards provide for the protection of navigational information.

Some port authorities may request that the AIS is kept on when a ship is alongside. The AIS

operates on a VHF frequency and transmits and receives information automatically, and the output

power ranges between 1 watts and 12.5 watts. Automatic polling by another station (e.g. by port

authority equipment or another ship) could cause equipment to transmit at the higher (12.5 watt)

level, even when it is set to low power (1 to 2 watts).

8.14.1 Security:

Please also refer to the Ship Security plan.

If the master believes that the continual operation of AIS might compromise the safety or security of

his/her ship, the AIS may be switched off. This might be the case in sea areas where pirates and


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armed robbers are known to operate. Actions of this nature should always be recorded in the ship’s

logbook together with the reason for doing so. The master should however restart the AIS as soon

as the source of danger has disappeared. However, in cases where piracy attacks are known and if

the vessel is following a convoy or where naval vessel’s assistances are available, the AIS may be

kept on for the tracking by naval vessels.

8.14.2 Collision avoidance

The purpose of AIS is to help identify vessels, assist in target tracking, simplify information exchange

(e.g. reduce verbal mandatory ship reporting) and provide additional information to assist situational

awareness. The data received via AIS will improve the quality of the information available to the

OOW. When used with the appropriate graphical display, the AIS enables provision of fast,

automatic information by calculating Closest Point of Approach (CPA) and the Time to Closest Point

of Approach (TCPA). The voyage related information, shall be manually updated during the voyage

and confirmed during every watch.

AIS information may be used to assist in collision avoidance decision-making. Once the ship has

been detected, AIS can assist in tracking it as a target. By monitoring the information broadcast by

the target, its action can also be monitored. Changes in heading and course are for example,

immediately apparent, and many of the problems common to tracking targets by radar, namely

clutter, target sweep as ships pass close by and target loss following a fast manoeuvre, do not affect

AIS. AIS can also assist in the identification of targets, by name or call sign and by ship type and

navigation status.

When using the AIS for anti-collision purposes, the following cautionary points should be borne in

mind.

1. AIS are an additional source of navigation information. It does not replace, but supports,

navigation systems such as radar target tracking and VTS and

2. The use of AIS does not negate the responsibility of OOW to comply at all times with the

collision regulations.

The OOW should not rely on AIS as the sole information system, but should make use of all safety

relevant information available. Short safety-related messages are only an additional means of

broadcasting maritime information.

8.14.3 Limitations of AIS

Ships, in particular leisure craft, fishing boats, warships and some coastal shore stations including

VTS centres might not be fitted with AIS.

Ships nearby fitted with AIS as mandatory carriage requirement might switch off AIS under certain

circumstances by professional judgement of the master of that vessel.

Transmission of erroneous information implies risk to other ships as well as own ship. The accuracy

of the AIS information received is only as good as the accuracy of the AIS information transmitted.

Poorly configured or calibrated ship sensors (position, speed and heading sensors) might lead to


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incorrect information being transmitted. Incorrect information about one ship displayed on the bridge

of another could be dangerously confusing.

It would not be prudent for the OOW to assume that the information received from other ships is of a

comparable quality and accuracy to that which might be available on the own ship.

8.14.4 Additionally for tankers:

All tankers shall change over to low power output while in port. When alongside a terminal or port

area where hydrocarbon gases may be present, either the AIS should be switched off or the aerial

isolated and the AIS given a dummy load. Isolating the aerial preserves manually input data that

may be lost if the AIS was switched off.

If necessary, the port authority should be informed.

When alongside terminal or port areas where no hydrocarbon gases are likely to be present, and if

the unit has the facility, the AIS should be switched to low power. If the AIS is switched off or

isolated whilst alongside, it must be reactivated upon leaving the berth.

8.15 MAIN PROPULSION CONTROL SYSTEMS, BRIDGE CONTROL SYSTEMS AND

ENGINE ROOMS OPERATING UNDER UNMANNED CONDITIONS

Several instances of poor understanding by OOWs and engine room staff of the operation of bridge

engine control systems have resulted in incidents. This includes:

Lack of understanding by bridge and engine room staff of the override mechanisms for

the bridge control programmes which limit or control rpm changes;

Lack of familiarity with the procedures to transfer control to the engine room in an urgent

situation.

The Master must ensure that all OOWs and Engine Room Staff are thoroughly familiar with the

operation of main propulsion machinery control systems including all overrides and emergency

operating procedures Manual Control etc. New joining deck and engine room officers must receive

this instruction immediately on joining from a senior officer as part of their familiarisation training and

shall not on any account to be involved in any manoeuvre until this has been completed.

The Master must also ensure that proper instructions for the operation of the main propulsion

machinery are posted on the bridge and in the engine control room. These instructions must include

procedures for all routine and emergency control of the main propulsion machinery. Where

operation of any control e.g. Emergency override of the main engine could have serious

consequences in the event of incorrect use, then this must also be clearly stated. These instructions

must be displayed on permanent plates, which if not fitted, must be arranged by Masters in

consultation with the management office.

Testing of emergency overrides, stops and local control machinery is to be logged.


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8.15.1 Shaft Alternators

Some vessels may be fitted with shaft alternators from which the vessel’s main electrical supply can

be generated. Officers must understand that the stopping of the engine (hence the shaft) upon

which the alternator is operating could result in the complete loss of power from all main engines

and some auxiliaries.

In vessel’s fitted with shaft alternators, all Officers should be aware that the action of changing from

shaft alternator power to diesel alternator power (or vice-versa) can occasionally result in total loss

of all power. The OOW should ensure, so far as practicable, that the vessel is clear of other traffic

and is down-wind / down-tide of other navigational hazards when the change of power source is

made. The ER will expect suitable notice for the change-over, which is to be affected in good time

(at least 30 minutes) before manoeuvring is requested.

8.16 LONG – RANGE IDENTIFICATION AND TRACKING SYSTEMS (LRIT)

The Long-Range Identification and Tracking (LRIT) system provides for the global identification and

tracking of ships.

The obligations of ships to transmit LRIT information and the rights and obligations of SOLAS

Contracting Governments and of Search and rescue services to receive LRIT information are

established in regulation V/19-1 of the 1974 SOLAS Convention.

Ships shall automatically transmit the following long-range identification and tracking information:

- The identity of the ship;

- The position of the ship (latitude and longitude); and

- The date and time of the position provided.

All navigating officers should be aware of the equipment location and operating principle.

8.17 VOYAGE DATA RECORDER

8.17.1 Introduction

The purpose of a Voyage Data Recorder (VDR) or Simplified Voyage Data Recorder (S-VDR) is to

store (in a secure and retrievable form) information concerning the position, movement, physical

status, command and control of a vessel over the period leading up to and following an incident

having an impact thereon.

Information contained in a VDR or S-VDR should be made available to both the Administration and

the ship-owner. This information is for use during any subsequent investigation to identify the

cause(s) of the incident.


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8.17.2 Definitions

Voyage Data Recorder (VDR) & Simplified Voyage Data Recorder (S-VDR) means a complete

system, including any items required to interface with the sources of input data, for processing and

encoding the data, the final recording medium, the power supply and dedicated reserve power

source.

Sensor means any unit external to the VDR or S-VDR, to which the VDR or S-VDR is connected and

from which it obtains data to be recorded.

Final recording medium means the item of hardware on which the data is recorded such that access

to it would enable the data to be recovered and played back by use of suitable equipment

Playback equipment means the equipment, compatible with the recording medium and the format

used during recording, employed for recovering the data. It includes also the display or presentation

hardware and software that is appropriate to the original data source equipment

Dedicated reserve power source means a secondary battery, with suitable automatic charging

arrangements, dedicated solely to the VDR, of sufficient capacity to operate it for a period of 2 Hours.

8.17.3 Design Information

VDR or S-VDR should be capable of:

Continuous recording. The time for which all stored data items are retained should be at least

12 h. Data items that are older than this may be overwritten with new data.

Operating from the ship’s emergency source of electrical power. If the ship’s emergency

source of electrical power supply fails, the VDR or S-VDR should continue to record Bridge

Audio from a dedicated reserve source of power for a period of 2 hours. At the end of this 2

hours period all recording should cease automatically.

S -VDR should be capable of recording

Date and Time

Ship’s Position

Speed

Heading

Bridge Audio

VHF Communications Audio

Radar Data from at least one Radar

AIS Data


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In additional to above the VDR should be capable of recording:

Depth

Main Alarms (all IMO mandatory alarms)

Rudder Order and Response

Engine Order and Response

Hull Openings (Doors)

Watertight and Fire Doors

Wind Speed and Direction

The final recording medium must be in a protected capsule of either a fixed or float-free type. In both

cases, the unit must be of a highly visible colour and marked with retro-reflective material. The

capsule must be capable of being accessed following an incident but secure against tampering.

VDR OR S-VDR should be entirely automatic in normal operation. Means should be provided

whereby recorded data may be saved by an appropriate method following an incident, with minimal

interruption to the recording process.

To make effective use of VDR or S-VDR data after an accident, it is essential to be able to download

the stored data and playback the information without delay. To assist in achieving this aim, all VDR or

S-VDR systems installed on or after 1 July 2006 should be supplied with an accessible means for

extracting the stored data from the VDR or S-VDR to a laptop computer.

Manufacturers should provide:

- An output port providing data in an internationally recognized format, such as Ethernet,

USB, FireWire, or equivalent;

- Software, compatible with an operating system available with commercial off-the-shelf

laptop computers stored on a portable storage device such as a CD-ROM, DVD, USB-

memory stick, etc.; and

- Instructions for executing the software and for connecting the laptop to the VDR or S-

VDR.

The software should provide the capability to download the stored data and playback the information.

8.17.4 Ownership and Recovery

The ownership of the VDR or S-VDR information remains with the ship owner at all times. In all

circumstances, during the course of an investigation, the investigator should have custody of the

original VDR or S-VDR information. A copy of the VDR information will be provided to the ship owner.

There should be sufficient resources of the portable device on which the data will be stored during the

SAVE DATA Process.

VDR and S-VDR systems offer a convenient SAVE function for recording VDR data sets. The function

is accessed by either a process or a dedicated SAVE button on the VDR / S-VDR panel. When

initiated, the SAVE process should preserve and protect a 12-hour data set onto the VDR removable

memory module (portable storage device).The SAVE function does not interrupt or interfere with the

automatic recording and storing of data to the capsule.


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8.17.5 Operational Information

1. Master shall ensure that:

a. All duty officers are familiarized with VDR (as part of deck officers familiarization with

bridge equipment’s using Deck Officer's Handing / Taking Over report)

b. Ship specific procedure to save and download the VDR data in case of an emergency

is made and posted close to VDR.

c. Annual testing of VDR or S-VDR is carried out by the manufacturer or by a person

authorized by the manufacturer. The records shall be maintained with the Master.

2. During navigational watches, OOW regularly monitor the VDR status. If any alarm is present,

it should be attended to immediately. If the fault cannot be rectified, office should be informed.

3. VDR-linked radar should reflect the current navigation of the ship. In coastal waters and

during pilotage, this may be achieved through the use of VDR-linked radar by the person

conning the ship.

4. In the event of an accident, the Master should:

a. Within reasonable duration from the time of accident, save the data by initiating the

“SAVE DATA” process in the VDR or S-VDR.

b. Undertake recovery of VDR information, as soon as possible, after an accident to

preserve the evidence.

c. In case of abandonment of vessel, master should, where time and other

responsibilities permit, take necessary steps to preserve the VDR or S-VDR

information until it can be passed on to an investigator.

8.17.6 VDR Periodic Validation

To ensure complete operation of the system at all times, all vessels are required to Download the

VDR data and Playback onboard once every 3 months (i.e at Quarterly interval) and confirm the

operational status of VDR to Vessel’s superintendent.

8.18 BINOCULARS, SEXTANTS, TELESCOPES AND AZIMUTH CIRCLES

Binoculars, sextants, telescopes and azimuth circles, when not in use, are to be kept in the boxes or

racks provided in the wheel house for the purpose. These items are to be regularly cleaned to remove

salt deposits and examined to detect damage. On arrival in port they are to be locked away by the

Second Officer

8.19 BRIDGE NAVIGATIONAL WATCH ALARM SYSTEM (BNWAS):

New ships over 150 GT and all new passenger ships constructed after 1 July 2011 shall be equipped

with a Bridge Navigational Watch Alarm System.

BNWAS must be in operational condition at all times and shall be tested at least once in a week or as

per Flag requirements


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The BNWAS should be in use whenever the navigation bridge is being manned. The BNWAS should be operational whenever the ship’s heading or control system is engaged, unless inhibited by the master. The BNWAS should be used at all times when the vessel is underway or at anchor except when the ship is alongside, in Dry-dock or at a repair facility.

He shall ensure that the system cannot be tampered by the OOW. For example in some models,

Master has to set the system to “Manual ON” mode and remove the key. In such systems, it should

not be left on “Auto ON” mode as the system will turn off automatically when the vessels speed drops

below a certain value or when steering is switched to hand steering mode hence making the BNWAS

in operational when drifting at sea.

Interval for alarm shall be set by Master based on expected traffic density and visibility.

Master is free to activate the BNWAS alarm even when bridge is manned by additional watch

keepers.

The purpose of a bridge navigational watch alarm system (BNWAS) is solely to monitor bridge activity

and to detect operator disability that could lead to marine accidents.

The system monitors the awareness of the OOW and automatically alerts the Master or another

qualified OOW if, for any reason, the OOW on the bridge becomes incapable of performing duties.

Times of switching on and switching off of BNWAS to be recorded in the movement book or the deck

log book.

8.20 GLOBAL POSITIONING SYSTEMS (GPS)

This equipment is an accurate electronic position fixing device available for navigation of a vessel.

All vessels to have two working GPS onboard. Position displayed on one GPS to be compared

with the other for accuracy.

All users must be familiar with the equipment operating handbook and the guidance given in

ALRS.

It must be borne in mind that GPS positions are also not free from errors, and must not be fully

relied upon. The manufacturer's operating handbook shall be consulted to ensure that proper

corrections are applied.

Position fixing by GPS alone is not acceptable especially in coastal areas or areas of restricted

navigation. Ref to Navigation manual CH 5 Sec 5.1.1.

GPS is referenced to WGS84 and it is strongly recommended that the GPS receiver is maintained

referenced to that datum. Hydro graphic offices are gradually changing all charts to WGS84 and

these charts include the legend “WGS84 positions can be plotted directly on this chart”. Some

charts contain information on latitude and longitude shift values that should be applied to GPS

positions before they are charted. Occasionally these can be significant, and many charts still

show the land or obstructions in the wrong position when compared with GPS data


NAVIGATION MANUAL


Rev.No. 6

Date 28-Oct-16

of 14

In addition to the regular position fixing, it is a good practice to record the position at every change

of watch and at every alteration of course.

Upon joining the vessel the OOW should make himself well familiar with the operation of GPS

which include entering /storing waypoints, route planning, activating route, Alarm setting.

Limitations of Cross track alarm, Way point approach alarm and Anchor alarm should be clearly

understood.

Whenever the passage plan is amended, the new waypoints have to be re-entered in the GPS.

Position from one GPS should be cross checked with second GPS and logged down once every 4

hours in the Position / Echosounder log.

Records

OP-07 Deck Log book

OP-10 Compass Error Log

Radio and Radar Maintenance Log / file. ( Uncontrolled)

AD -09 Deck officers Handing Taking over checklist

Choronometer Rate Book ( uncontrolled)

OP-21 Position / Echosounder log

OP-08 Manoeuvring Order Book


navigation manual ch. 08 bridge...

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