Blog 114 == Of 'Sukhanis' and Auto Pilots == Of 'Maccha Yantra' and Sextants == Of AIS and GPS

Steering Console – Auto Pilot

The ‘Quartermaster’ or ‘Sukhani’ of decades ago, who awaited helm orders to steer the ship at all times, even in mid sea, was replaced by an ‘auto pilot’ in which a series of parameters can be input into the equipment, which then does the job of steering the ship.

Helmsman - sailing ship

Helmsman 1960s

The Helmsman / Quartermaster / Sukhani of Today

In the immediate future

The ‘ Auto Pilot’ has eased the strains of steering a ship, taking out the human handler and replacing him with a ‘closed loop’ computing system that keeps the ship on a steady course.

However good, the guiding human hand is incapable of steering a faultless course at sea, because of external influences such as waves, wind, weather. Realisation that the vessel is off the intended course takes a bit of time and, after correction is applied, the vessel resumes her intended course, only to go astray again. Thus she follows a zig zag course.

The initial ‘auto pilots’ were, mostly, to relieve the helmsman of the strain of continued course corrections in the open sea. The initial autopilots used a bit of hydraulics and manual cables to regularly adjust the course on the basis of the rough 'feedbacks’ on the position of the rudder. The initial autopilots were crude and the vessel had to contend with an increased ‘yaw’ at all stages.

The introduction of telemotors into the closed loop was a huge advancement, solenoids and hydraulics assisting in converting the feedback of rudder positions into an electrical signal that was fed back into the auto pilot to automatically make the course corrections needed.

The progression to increased reliability, efficiency and sophistication of the auto pilot came in quick stages.

Stage 1 : Synchronised with the gyro compass

Stage 2 : Rudder limits were introduced. When the set limit of rudder angle was reached, a feedback would correct the course. As technology developed, electronic sophistry made available parameters such as ‘deviation control’, ‘proportional control’, ‘rate of turn’ ‘speed’ etc.

Stage 3 :The latest autopilots are also connected and interfaced to the Rate of Turn Indicator, GPS and ‘ECDIS’.

Fiction now - Fact later?

Rate of Turn Indicator

Telegraph

The age old telegraph communicated the signal from the Bridge to the Engine Room, the acknowledgement of the telegraph order coming from the responsive movement of the Engine Telegraph. When the indicator on both the telegraphs coincide, both parties are aware of the communication having been passed and the bells stop ringing.

Most ships were equipped with ‘Chadburn’ telegraphs.

There were no Engine Control Rooms. The Engineer of the Watch would stand at a desk provided for resting the Engine Room Log Book when filling in all engine parameters. A branch ducting of one of the main Engine Room blowers - mostly the port aft blower - would be blowing air on to the engineer. Close by would be a small table with coffee pots, mugs, milk etc.

When he turns around to face the engine, he would be within a metre of the Main Engine manouvering handle, the reversing handle, the Engine Telegraph and the two telephones, one connected to the ship’s telephone exchange and the other to the sound powered telephone.

With the advent of electronics into merchant ships, the printed circuit boards needed to be protected from the engine room heat. An air conditioned Engine Control Room came into vogue.

A scaled down version of the telegraph was fitted on the Control Room console, initially a ‘stand alone’ unit, later integrated with the Main Engine manouvering controls.

Pedestal mounted Bridge Telegraph

All integrated into one unit, including fuel and rpm adjustment

Engine Control Room console on a recent ship

Automatic Identification Systems or AIS

AIS was developed by the IMO technical committees as a technology to avoid collisions among large vessels at sea that are not within range of shore-based systems. The technology identifies every vessel individually, along with its specific position and movements, enabling a virtual picture to be created in real time.

“AIS is intended, primarily, to allow ships to view marine traffic in their area and to be seen by that traffic. This requires a dedicated VHF AIS transceiver that allows local traffic to be viewed on an AIS enabled chartplotter or computer monitor while transmitting information about the ship itself to other AIS receivers. Port authorities or other shore-based facilities may be equipped with receivers only, so that they can view the local traffic without the need to transmit their own location. All AIS transceivers equipped traffic can be viewed this way very reliably but is limited to the VHF range, about 10–20 nautical miles.”

Interfacing the AIS with the ARPA has helped in identifying each and every ship on the screen. On the AIS screen or ARPA screen, just by clicking on a target, a lot of information about the target vessel can be seen.

At the same time, all vessels within the range of a shore monitoring facility are tracked, identified and guided. Although this unit is supposed to be tamper proof, smuggling vessels find ways of switching off the AIS, in order to avoid detection by a country’s Coast Guard.

A graphical display of AIS data on board a ship.- Wikipedia

Global Positioning System

Perhaps the single most piece of technological innovation that transformed a ship’s bridge procedures, was the installation of the GPS.

In the days of yore, boats - one really cannot classify them as ships - stayed close to the shore and proceeded with what one can humorously call ‘palm tree navigation’.

The more intrepid ones went out of sight of land and navigated using currents and wind as reference.

The next step was celestial navigation using the sun during the day and stars at night, once the stars had been identified and roughly plotted.

Simultaneously, the next step in the evolution of navigation was the use of roughly made instruments to aid in navigation.

In ancient India, calculated to be around 2500 years ago, the beginnings of what is today called a sextant was used as an aid to navigation, called Vruttashangha Bhaga.

Another was the Maccha Yantra, an iron fish floating in oil, which would point north at all times. The probable forerunner to today’s magnetic compass.

Ancient India’s more sophisticated knowledge of astronomy also played its part in navigation.

(I had written this portion about Vruttashangha Bhaga and Maccha Yantra around 26th Jan 2023. By a strange coincidence references were made to the very same objects in an article in the February 2023 Edition of ‘Marine Engineer’s Review’, which I read on 02nd Feb 2023).

The typical Chinese navigational compass was in the form of a magnetic needle floating in a bowl of water, sometime in the 11th century.

The first known use of a compass in the European maritime sphere was dated around 1200 CE. Quote “The sailors, moreover, as they sail over the sea, when in cloudy whether they can no longer profit by the light of the sun, or when the world is wrapped up in the darkness of the shades of night, and they are ignorant to what point of the compass their ship's course is directed, they touch the magnet with a needle, which (the needle) is whirled round in a circle until, when its motion ceases, its point looks direct to the north.” Unquote

From then on, improvements, innovations took place during each century, whether it was the dry compass or the wet compass and has arrived at what is seen today.

“The first sextant was produced by John Bird in 1759. This is a very early example of his work now in the Nederlands Scheepvaart Museum in Amsterdam. The frame is mahogany with an ivory scale. It is so large and heavy that it needed a support that fitted into a socket on the observer's belt.”

The older version

The Modern Sextant

A digital sextant

The ‘Noon Sight’ and the evening ‘Star Sight’ were the revered tasks of the navigating officer, the rituals almost bordering on mysticism to find out the ship’s present location and the miles travelled from noon to noon, all with use of the sextant, the sun and the stars.

A Deck Cadet’s, a Third Officer’s “Rite of Passage” into the realms of Navigation is completed only when he takes his first “Sight” and marks the position of the ship on the chart. It was a privilege that the deck juniors fought to gain till the year 2000. It was supplanted by looking at a GPS receiver, noting the digital display and plotting it on a chart, to locate the position of a ship at that time. Even that has given way to the automatic transfer of data from the GPS to the ECDIS, which takes place almost instantly, the period between updates being dependent on only the configuration that the GPS equipment provides and the contract that the company has with a satellite provider.

Many a Second Mate, who is responsible for the ‘Noon Sight’, has muttered under his breath, with clenched teeth, that the evening ‘Star Sight’ taken by the Chief Officer “He is totally wrong - he doesn’t know how to take a sight”, because there is a variance between where the ship was at noon and, going by the course steered, where it was in the evening. The mutterings and the strained, unvocal tussle between the Second Mate and the Chief Mate would become more pronounced in the event of bad weather, ‘dead reckoning’ having been introduced into the equation which, basically, was guesswork with some positive assumptions.

Just before noon or in the evening, were one to enter the Bridge, one would hear the ritualistic sound of ‘Standby’ and ‘Stop’ as the sights were taken.

At first, the calculations were done by hand in less than 15 minutes. Navigational calculators, costly in the 1960s and becoming cheaper year by year, made the calculations faster and faster.

The romance no longer remains.

Alas, in the modern world, the sextant has lost its mysticism and religiosity and is a mere instrument in a cushioned box, kept in one of the drawers on the Bridge, the GPS having made it obsolete.

For over 4 decades, the realm of satellite navigation on a commercial basis was the exclusive preserve of the United States of America, as they had the maximum number of satellites in space for different purposes, with the Russians coming a distant second. It was the height of the Cold War, with the USA and Russia jockeying for positioning themselves to influence the rest of the world.

Initially, the US satellites were only for their own military use. After nearly two decades they realised the commercial potential of a system, the technology of which was now spreading across the world.

Commercial shipping, by the 1980s, was paying a huge sum to the USA for connecting to their navigational satellites, starting from around 1980. It was as late as 2010 that Europe became a player with the deployment of satellites, with India following suit in 2013 in a limited fashion. From the 1990s, the number of navigational satellites grew manifold, as many private players entered the field to harvest the huge potential of communication and navigation satellites.

Today, the GPS is free to use. "GPS was built with military uses in mind during the Cold War. In 1983, Korean Air flight 007 was shot down by Soviet interceptors over Kamchatka when it went off-course. All passengers and crew aboard the civilian flight, including a sitting US congressman, were killed. Amid the ensuing controversy, President Reagan announced that GPS would be made available for free for civilian use to avoid such preventable disasters in the future. So in essence, it took the political momentum from a national tragedy for it to become freely available."

The US Government spends about $ 2 Million a day to provide this "free" service, but the revenue from the fallout from ancillaries of this service is in the trillions.

To give a science fiction perspective to satellites for communication, almost eighty years ago, in 1945, Arthur C Clarke, a science fiction writer, wrote two articles in which he proposed a satellite communication system using geostationary orbits. NASA made him a consultant much prior to launching their first satellite, Explorer 1, in January 1958 - all in response to the Russians having launched Sputnik 1 in October 1957.

(I would recommend two of his books for their far reaching vision and perspective. ‘2001, A Space Odyssey’ (written in 1968) and ‘Rendezvous with Rama (written in 1973.)

Initially, the launching of satellites by both nations, USA and the Soviet Union, were from a military perspective, with each nation flexing its muscles. No direct conflicts occurred, although subsidised confrontations took place in different parts of the world. The higher the level of confrontation, the faster were the technological developments being churned out by these two nations. Although these developments were, majorly, for advances in military armoury, the fallout from ancillary units became a source of commercial viability, which were eagerly seized upon by US corporations and, by going global, they influenced the path of a swathe of nations. It was the golden age of the USA.

The year 1975 and the year 1980 were watershed years for the ISRO (Indian Space Research Organisation). In 1975, the satellite ‘Aryabhata’ was launched by a Russian rocket. In 1980, India became the seventh country to have orbital launch capabilities, by sending its own satellite into orbit.

India launched its first navigational and communication satellite in 2013, followed by a cluster of 7, having regional influence only.

(Sorry, got a little carried away, discussing satellites).

Coming back to GPS on board, when installed on the ship, the GPS unit was a standalone, digital unit, fed from signals received by a rather large satellite dish. Over the years the size of the dish became smaller and smaller, till the present day size of a large dinner plate.

In the initial stages of the installation of GPS on board, the more elderly Masters used to instruct the Navigators to also use the sextant and take sights, as usual. In a couple of years, they had to bow down to the weight of technological innovations and use only the GPS.

The sextant, thus, died a silent death in commercial shipping. Only the navies of some nations use it to train their fresh staff in its use.

The first generation of these GPS units located the vessel to within 10 to 15 metres of the actual location, with it getting fine tuned over the years to place a ship within centimetres of its exact location. Time between Satellite fixes shortened from an hour or two, depending on which satellite the vessel is dependent on, to almost instant fixes. All at the touch of a button. The interference due to bad weather was also, mostly, resolved over the years, the satellites being only vulnerable to magnetic storms from erupting solar flares.

The interlinking and interfacing between the ARPA, ECDIS, AIS, Gyro Compass has interwound the important Bridge equipment to the extent that a failure of one unit can be calamitous, as everyone has started depending on them implicitly for their navigation purposes.

Navigation and communication have become so interlinked that US river pilots bring their own small satellite dish, clamp it on o the Bridge wing, tune it to acquire their Association’s satellite within a minute and navigate the ship using the input from the satellite into their hand held tablet.

I am introducing two aspects of a rather dark scenario, considering the over dependence on the sophisticated instruments being used during present day ship navigation.

What if a really massive solar flare develops into an electro magnetic storm of such a magnitude that it fries up all the circuitry on satellites, in spite of the present day level of shielding given to equipment by today’s manufacturers?

What if two powerful nations go to war and take down one another’s satellites, using actual powerful beams (which exist militarily), just like in ‘Play Station’ scenarios? I am certain that many such military mock drills have already been rehearsed.

{I am reminded of my cataract operation. All was okay till a couple of weeks later, when my vision deteriorated. Checks revealed the presence of water, edema. The surgeon used a computer, a ball tracker and shot a beam into as many globules of water that he could track to get rid of them. Three sessions spaced two weeks apart. Two more such sessions and I would have, likely, needed to go back to sea}.

Satellites are but droplets of mechanical and electrical parts floating around in the vast cornea of the universe.

And then there is the alien invasion —--------.

===== Continued Next Sunday in Blog 115 = = Possibly the Last =====