Navigational instrument

Navigational instruments are instruments used by nautical navigators and pilots as tools of their trade. The purpose of navigation is to ascertain the present position and to determine the speed, direction, etc. to arrive at the port or point of destination.

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Charts and drafting instruments

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• Charts are maps of the areas to be navigated with details specific to the marine environment.
• Computing aids: used in the necessary mathematical calculations. Today electronic computers or calculators are used. Other traditional aids used included tables (trigonometric, logarithms, etc.) and slide rules.
• Dividers used for measuring lengths of lines and approximate lengths of non-linear paths on a chart.
• Nautical almanac used to determine the position in the sky of a celestial body after a sight has been taken.
• Parallel rules used for transferring a line to a parallel position. Also used to compare the orientation of a line to a magnetic or geographic orientation on a compass rose.

Direct measuring

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• Chip log and sand glass serve to measure the ship's speed through the water.
• Sounding line used to measure the depth of the water and to pick up samples from the bottom.
• Drift meter optically measures the effects of wind on an aircraft in flight.

Position finding instruments

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Celestial navigation instruments

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These instruments are used primarily to measure the elevation or altitude of a celestial object:

• Back staff, the best known of which is the Davis' quadrant. It could measure the altitude of the Sun without having the navigator directly observe the Sun.
• Cross staff, an older instrument long out of use.
• Kamal Very simple instrument used primarily by Arabian navigators. It consists of a small board with a knotted piece of twine through the center. The observer holds one of the knots in his mouth and extends the board away so that the edges make a constant angle with his eyes.
• Mariner's astrolabe Derived from the astrolabe, it was developed in late 15th century and found use in the 16th to 17th centuries. It was replaced by the back staff and later by the octant and sextant.
• Quadrant A very simple instrument which used a plumb bob.

These instruments are also used to measure the angular distance between objects:

• Octant, invented in 1731. The first widely accepted instrument that could measure an angle without being strongly affected by movement.
• Sextant, derived from the octant in 1757, eventually made all previous instruments used for the same purpose obsolete.

Bearing instruments

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• Pelorus used to determine bearings relative to the ship's heading of landmarks, other ships, etc.

Compasses

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• Bearing compass used to determine magnetic bearings of landmarks, other ships or celestial bodies.
• Magnetic compass used to determine the magnetic heading of the ship.

Timekeeping

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• Marine chronometer used to determine time at the prime meridian with great precision which is necessary when reducing sights in celestial navigation.
• Nocturnal used to determine apparent local time by viewing the Polaris and its surrounding stars.
• Ring dial or astronomical ring used to measure the height of a celestial body above the horizon. It could be used to find the altitude of the Sun or determine local time. It let sunlight shine through a small orifice on the rim of the instrument. The point of light striking the far side of the instrument gave the altitude or tell time.

All those mentioned were the traditional instruments used until well into the second half of the 20th century. After World War II electronic aids to navigation developed very rapidly and, to a great extent, replaced more traditional tools. Electronic speed and depth finders have totally replaced their older counterparts. Radar has become widespread even in small boats. Some Electronic aids to navigation like LORAN have already become obsolete themselves and have been replaced by GPS.

Electronic Travel Aid

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As technologies are developed, designers and engineers have also turned their attention to minority groups like people that are visually impaired. In this case, Electronic Travel Aid are developed to target the needs of visual impaired individuals for obstacle identification as well as navigation of the surrounding to enhance mobility.[1] Not only GPS systems, there are other approaches like infrared sensors, ultrasonic sensors as well as optical technologies like cameras that are developed/ developing to enhance the navigation of the minority group.[2]

See also

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References

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1. ^

   Li, Kun(LElectronic Travel Aids for Blind Guidanceinda). Sutardja Center for Entrepreneurship & Technology, Berkeley, California, 2015, pp. 1–10, Electronic Travel Aids for Blind Guidance.

2. ^

   Patra, Rusha, et al. “(PDF) an Electronic Travel Aid for Navigation of Visually Impaired Persons.” ResearchGate, Feb. 2011, https://www.researchgate.net/publication/224219996_An_electronic_travel_aid_for_navigation_of_visually_impaired_persons

Nowadays, sailors are well-trained to handle all modern navigation equipment to make sailing smoother and safer at sea. The vessel today is equipped with various advanced navigation systems that provide accurate voyage data. Thanks to modern facilities and automation.

This is an article which covers both old and new navigation equipment used by merchant ships.

Gyro Compass Marine

It uses a gyrocompass to determine its direction. Unlike a magnetic compass, it is not affected by an outside magnetic field. Additionally, it supplies the accurate axis of rotation for the Earth, resulting in a reliable directional source. Typically, it is fixed to the steering platform.

Radar

To avoid collisions, marine vessels rely on S-band and X-band radar in Dubai to detect targets and display information on the screen such as distances from the ground or any floating objects (islands, icebergs, rocks, etc). With its rotating antenna, it detects the surroundings of a ship.

Magnetic Compass

To determine the planned route of a voyage, a magnetic compass is used. Along with Earth’s magnetic field, it operates simultaneously. Navigators use it as their primary direction indicator. On the bridge panel, the output signal can be displayed because the magnetic transmitting compass is fixed.

Autopilot

An autopilot assists the operator in steering by holding the wheel in autopilot mode. As a result, they can concentrate on the broad aspects of the operation. Thus, it is considered one of the most effective bridge navigation aids in our marine equipment suppliers in UAE.

ARPA

It is a feature on the radar that constantly monitors the condition of the ship. It automatically determines the number of targets for you, such as ships, boats, stationary or floating objects etc. and denotes their speed and course accordingly.

Automatic Tracking Aid

As with ARPA, the automatic tracking system displays information about the targets tracked, both in graphical and numerical systems. This enables the vessel to travel avoiding the risk of collision.

Speed & Distance Measuring Equipment

This bridge equipment on a ship is used to measure the speed and distance the ship has travelled from a given point.

Echo Sounder

There are many modern shipborne navigation instruments onboard and the echo sounder is one instrument that has been in use for nearly 100 years. With the principle of sound wave transmission, it measures the depth of water below the bottom of a ship.

Electronic Chart Display Information System (ECDIS)

The Electronic Chart Display Information System (ECDIS) is a navigation chart system used on ships. A ship’s location can easily be determined using this method.

Automatic Identification System (AIS)

AIS helps to accurately identify the position and other navigation statistics of ships. AIS sends and receives messages between ships using VHF radio channels.

Long-Range Tracking and Identification (LRIT)

LRIT is an international tracking and identification system incorporated by IMO in accordance with its SOLAS convention to provide a thorough tracking system for ships that make international voyages around the world.

Rudder Angle Indicator

It displays a ship’s steering angle. The ship’s navigator can adjust the steering speed and rudder angle thanks to the display’s location on the equipment console on the bridge. Both the engine control room and the bridge wings have indicators for them. The signal is also available in the engine control room and the bridge wings.

Voyage Data Recorder (VDR)

There is a voice recording system in the VDR that keeps a record of the last 12 hours of conversations. Any future investigation will be based on this information. VDRs are similar to black boxes mounted on aircraft in terms of their importance.

Rate of turn indicator

This navigation tool displays the degrees of turn, i.e, how fast the vessel is turning at a constant speed. The turn rate of a ship is calculated in degrees per minute. Also,  it helps the navigator to steer the course safely.

GPS Receiver

GPS receiver is a global positioning system (GPS) receiver is a display system used to display the location of a ship using a global positioning satellite in earth orbit. You can calculate the speed, the course it is taking, and the time required to cover the distance within two points.

Sound Reception System

This speaker system becomes vital for a fully enclosed bridge. The navigator will be able to hear audible signals (for instance, the horn of another ship). Also, it helps the navigator perform a watch for evading collisions at sea. Usually, it is installed in the ship’s equipment on the bridge.

Navigation Lights

According to the appropriate guidelines for the prevention of maritime accidents. All large/ small boats should have nightlights as part of their navigation systems.

Daylight Signaling Lamp

Daylight signaling lamps are used for conveying information between ships, or between ship and shore, by means of light signals, both by day and by night.

Voyage/Route Planner

Marine Digital route planner is used in ships to evade tough weather conditions and other hurdles. It helps you calculate the safest and most economical route to the port of destination.

Nautical Flags

Various types of flags with different colors and marks are used to indicate the position of a navigational vessel. Nautical flags are an International Code of Signals whose main purpose is to provide different ways of communication in different nautical situations. They can be used for communication between two ships or between the ship and the shore.

Conclusion

Being in the marine industry for more than 4 decades, we supply all types of navigational equipment that becomes necessary for any shipping company. For any queries regarding marine navigation in UAE. Contact Us.

Contact us to discuss your requirements of marine navigation equipment. Our experienced sales team can help you identify the options that best suit your needs.