Spy Story-2

[Dileep]

Spy Story – 2

Prologue

July 26, 2009
Visakhapatnam, Andhra Pradesh

“I am honoured to be present here today on the occasion of the launch of India's first indigenous nuclear powered submarine.”

The soft voice from the man, in his neatly folded turban, and almost white facial hair, echoed around in the huge building. The dark lumbering object behind him, which had just been lifted from the supports on which it was resting for the past few years by the first embrace of salt water, gave a menacing contrast to the almost frail figure of the leader of the biggest population of free people. The feet of the proud sailors standing atop the object gave the impression of a curtain behind him. Three cameras, manned by operators from the armed forces, recorded the proceedings. The audience, consisting of the defense minister, top ranking officers of the armed forces, and selected journalists sat, mostly in awe of the sight in front of them, rather than the speech being delivered by the man. A nation waited impatiently, while the top secret function was underway inside.

“We do not have any aggressive designs nor do we seek to threaten anyone. We seek an external environment in our region and beyond that is conducive to our peaceful development and the protection of our value systems. Nevertheless it is incumbent upon us to take all measures necessary to safeguard our country and to keep pace with technological advancements worldwide. It has rightly been said that eternal vigilance is the price of liberty.”

The soft voice of the man continued to echo. The capitals of the world powers, especially the ones in the neighbourhood, would be listening to the tone, diction and cadence of each of his words, and reading between the lines and even words will be undertaken. There is no mistaking in the importance of the event. The lumbering elephant that is the world’s largest democracy is taking another confident step forward. It is not simply a matter of pride. It was a vital pillar on which the economic power of the nation rested. At the same time, specific care has been taken not to project an un necessarily aggressive image. The nation did not believe in that, just like the man standing behind the podium.

Earlier, not deviating too much from the established naval traditions, the wife of the man had broken a coconut, instead of a more widely used Champagne bottle, on a steel rail mounted in front of the sail of the ship, naming it the destroyer of the enemy. In order to help the feeble hands, the hard shell of the coconut was nicely scored all around. A simple hit broke it open, and let the sweet water inside flow, and wet the neatly mounted anechoic tiles on the body.

“The years of hard work, dedication and perseverance that have gone into today's launch are an example worthy of emulation. They show that no task is difficult and that there is no greater power than the power of self-belief. I am confident that the lessons learnt this launch will enable the ATV Programme to achieve even better results in the coming years.”

What the man left unsaid was that during all those years, the ATV project was literally a black hole. It did not exist in any records. Every question about it in the media was vehemently denied, or given the silent treatment. Drastic measures were alleged to be taken against people who suspected of making anything public. No one, except the enthusiasts who flock to the defense forums talked about it in the open. Those were waiting with baited breath, constantly online, for any piece of the news.

Journalists, stripped off any kind of imaging, recording or transmitting devices, gaped at the bulky mass, trying to estimate its dimensions. Their position, which is rather close to the immense object, prevented them from making accurate judgements of the size. Some smart ones among them were seen furiously sketching the various features. They knew that a huge audience is impatiently waiting for any information they could provide. Articles, sketches, and artists impressions will fill the media and blogs in the coming days, and pages and pages of web forums will be spent discussing about each piece of real or imaginary information.

At the same time, there were another set of people, whose work was even more secret than that of the scientists and engineers who built the boat. Those who tried to gather any piece of information, or prevented others from doing so. Their years of work, just like those who does the building, were not going to end today.

Public media talked about satellites hovering above, trying to get a glimpse of the boat. Nothing could be far from truth. Of course satellite images of this location are ALWAYS subject to extra attention, but the launch itself was not a big event for those people. It was just another day.

The game had been on for a long time, and it is going to continue.

[Dileep]

I am starting a new story. I prefer to run it in a seperate thread from the current "Scenarios" thread, because:

1. This story is not really military.
2. The current authors there are doing a stellar job there.
3. I don't want to distract them (and be distracted).

Since this story deals with submarines and associated naval stuff, I have sought the expert help from Chair Admiral Austin Joseph, BRVSM. Thank you Austin for the help.

Disclaimer: This is a work of fiction. The only link to reality is the prologue. None of the rest exists to the best of my knowledge, except in my imagination.

Enjoy.

[andy B]

^^^ Oh yes the Grand Pooba is back with a zing a ling ging onlee Danke' Dileep saar looking forward to some good ol espionage!

[Raja Bose]

^^^ Aha! Is this Dileep saar's plan B for racking up them post counts towards that Oldie status *ducks for cover*

[Dileep]

Snake’s Ruby.

The Legend

Naga Manikyam is believed to be a magical precious stone that is a ruby, which forms within the head of a snake. Snakes are believed to be magical creatures. The magical powers of a snake comes from the ruby it carries in its head.

A snake creates the ruby by ingesting a grain of sand and moving it into a cavity in its head. By years and years of effort, the grain of sand is converted into a ruby. A snake with a ruby can take any serpentine form. It can extend its life forever, and also gets the capability of vision across boundaries of space and time. When a snake decides that it has completed a meaningful life, it will remove its ruby from the head and discard it at a suitable location, so that no one will find and misuse it. The snake will then burn itself in a spontaneous fire.

If a human gets possession of the Naaga Maanikyam, it is believed to give him immense powers, including snake like agility and reflexes, trans sensory vision, and a very long life. But the only way to get hold of one is in the form of tribute by defeating a snake in combat, or as a gratuity by rendering the snake a remarkable service. The legendary ayurvedic physicians Aalathiyoor Nambi’s family is believed to be in possession of one, gifted by a snake in gratitude of curing it of an illness.

This legend has caused harm to a lot of snakes, especially cobras, which are killed in search of the ruby. Charlatans have swindled the gullible by copious amounts of money by selling them normal rubies, or even just red grains of sand.

Quest for such real and imaginary objects of value had always been the part of history. Anything that provides you with an advancement in your cause is always an object of desire. People would take drastic steps, make elaborate plans and execute them and take unimaginable risks to themselves and the people associated with them.

[Dileep]

The Science

Submarines are practically blind creatures. The suns rays doesn’t penetrate deep into the sea water. It is perennial darkness after a few tens of metre of depth. Light, or other forms of electrimagnetic radiation doesn’t go far in the sea water, so they are practically useless.

But sound does. Water is an excellent conductor of sound. A man lying in water with his ears submerged, can hear a drop of water falling on thr surface of the water even several metres away. Like a snake senses vibrations, submarines senses the sound waves that come over water to find its way, and detect enemies.

Any object that moves in the water is bound to make some sound. A fish, a turtle, a ship, or a submarine, all makes sound. A smart listener, often a computer, can obtain lot of information about the source of the sound in water, including what kind of object that is, what is its location, and even how fast it moves. You can listen to the sounds produced by the objects, or send your own sound waves out and listen for echoes.

But that will show your own position. So, it is better to do what you want to do without making a ‘sound’. So, it becomes a game between making the submarine generate the least amount of sound, and detecting the feeblest sound from the farthest distance.

Just detecting the sound isn’t enough. It should be analyzed. Computer algorithms help in weeding useful information from the feeblest of sound. Information from sensors places at different points on the body of the submarine are simultaneously processed for the purpose of identifying and tracking targets. The better you do this, the better your submarine is as a weapon.

At the same time, producing the least amount of sound is another key area. Sound and vibration isolation is made on all pieces of machinery, and even the crew walk around on soft-soled shoes. There are also techniques to cancel the sound going out, by sending out an exactly opposing sound wave. If you build a submarine that sends out no sound, that is undetectable by the enemy.

There are physical phenomena other than sound that are affected by the presence and operation of a submarine. These are also exploited in the detection and tracking of submarines.

The techniques and technologies used in these areas are the prized possessions of any country, and targets for others who want to get it. Tremendous amounts of effort has and being put into the intelligence, espionage and counter measures in this area.

And some people make fantasies about it as well.

[Dileep]

The Discovery

INS Agatti (nicknamed agathi, ie destitute by the nerds who used her) had taken a shape of a spider. It was an old rusty craft. The navy would have decommissioned it long ago, but the miserly babus up in Delhi has found a use for the old hag. When the need for the new additions came up, many thought that it was in fact better to build another ship. But the bean counters did not agree, and the customers were not ready to wait.

Since the ship repair yard at the naval facility expressed helplessness to finish the work in the allotted time, the shipyard was roped in to help. The deck of the old craft is strengthened, and six derricks made of space frames are mounted all around. Hydraulic actuators and controls bought from the local service centre for JCB were mounted to make them a bit articulate, albeit clumsily. New pipes were installed for the fluid network, and also conduits for the cable harnesses. Ropes, pullies, guides and the motorized capstans came from Mumbai. The work was completed in a few months, well in time for the trials in the calm months of December-March.

The new coat of light blue paint, and the white lines which were added as a courtesy by the painter czar at the shipyard, only helped to make the old craft look more awkward. The rear admiral who was the man of honour on this voyage thought it was a bit below his rank even to get aboard. He even made a bad joke, copied from a hollywood movie, about getting a tetanus shot. But duty is duty. He was required to see something new that the NRE (Navionics Research Establishment) guys has rigged together, and the poor Agathi is what they use to run their voyages.

NRE was considered more of a parasite by the elites in the Navy. Most of them did not understand technology beyond the knowledge that his commands made the ship move, guns missiles and torpedoes fire etc. Some, who are part of the technology side, didn’t like them because they themselves were not permitted to be involved with the NRE.

The building where NRE operated was nestled among the other naval buildings well inside the protected inner perimeter of the naval base. However, a tall chain link fence separated it from the rest of the facility, and within it was out of bounds for the naval officers and the sailors. This arrangement has pissed off the officers to no bounds. They couldn’t find a reason to place this supposedly DRDO unit within the naval facility, while a huge campus was available elsewhere on landside.

And the fact that the landlubbers who worked there got accommodation in their colony, that too on priority, and heavens forbid, getting canteen facilities at par with them was the clincher. None of the naval folk liked the NRE folk. They even made jokes about them, and used the shared expansion “Non Resident Expatriate” to refer to them.

And the officers and men assigned to run the Agathi were a pitiful lot. Everyone considered it to be a punishment to be put on those missions. It was no different this time either. The Lt. Commander who was in command of the vessel received the Real Admiral with the smartest salute he could muster, and took him to what could be called a cabin. He shook hands with the two gentlemen who accompanied the RA, ignoring their self introduction as some Director of Something of DRDO. He led the RA and the other two to what could be called a cabin, and ordered a sailor to inform the NRE team that the guests are on board.

The NRE team had already boarded well in advance. Their leader, a man in his early fourties, sporting a thin beard, and a pair of deep set blue eyes peering from behind thick glasses, was busy helping his staff to setup the equipment when the information came to him. He nodded, and followed the sailor to the cabin.

“Yasser Ayoobi, Director of NRE, Sir”. He shook hands with the RA.

The other two men smiled wide, and after the handshake, pulled him close in a half embrace and half pat on the back. They were clearly excited, but they made do with a simple “Good to see you Yasser”.

“Good to see you too Sir”, came the reply. The older men noted the same honesty and humility they are used to from their younger, brilliant colleague.

[ramana]

Thanks Dileep. I still relish your first story!

[Dileep]

INS Agatti was loitering at around 20 NM north of west of the harbour. The shipping channel went in an east-west direction, around 5 NM to the south. All the spider legs are now extended out. One forward, directly in front of the bow. Another aft, jutting out of stern, and two each on port and starboard, at the quarter points. Each went around 20 ft beyond the hull, and suspended out, around 30 ft above the water. Something was suspended from the pulleys at the end, and a thick yellow jacketed cable came up from under water, and routed around through the newly installed cable raceways, going a deck below where the bug stack of instruments were kept. The racks had a number of flashing LEDs, and cables criss-crossed them in a complex mesh of interconnect. A pair of monitors with keyboards and mouse was setup on a small aluminium table in front.

The RA was standing there with an “I would like to be somewhere else” face. The other two were a bit excited, but they were trying to subside it in the intimidating presence of the RA. No other naval officer was in the room. A couple of younger guys were working on the consoles, busily typing and working with the mouse. Yasser stood there, just looking on, but the lines on his forehead, and the little perspiration there indicated that he is a bit tense.

“OK, we are getting some readings Sir”, said one of the engineers. He expanded a window on his console, and in an obvious inviting gesture, stepped aside.

All four bent forward, and looked closer. The window was showing a few lines of text

Code: Select all

S# ID      Distance   Bearing  Mag      Type    Attr
1  UNK     23         260      23.8     HULL    None
2  UNK     23         260      4.8      SCREW   6
3  UNK     8          130      48.3     HULL    None
4  UNK     8          130      8.5      SCREW   6
5  UNK     8          130      2.4      SCREW   4

“It doesn’t make any sense to me. Are they targets?”, snarled the Rear Admiral.

“I will explain Sir” offered Yasser.

[Rahul M]

relishing it !!

[Dileep]

“Yes, they are targets. We have limited the number to five for now. The identification algorithms are not yet ready, so it says Unknown. You can see the distance and bearing there. Right now the type identification is limited to the hull and the propeller. The blade counting algorithm is working now, so you can see the count displayed. When ready, the hull size also would be displayed.”

The admiral knitted his brows, looking at the numbers, of which the decimals kept changing. He was thinking hard to find something intelligent to say, but apparently, he couldn’t.

One of the other men solved the problem. “Why do we see two screws at 4 and 5?” he asked.

“Right, right!! Why two, and that too, with different blade counts” The RA asked excitedly.

“I don’t know..” Yasser said frankly.

“How accurate is the blade counting algorithm, Yasser?” asked the other man.

“Pretty Accurate, sir. We haven’t seen a false reading for a long time”.

“But I haven’t seen a vessel with two dissimilar screws in my career”, boomed the RA, somewhat satisfied with himself.

One of the young engineers, who was standing silently, cleared the throat and suggested. “It is close to the harbour, sir. It must be a Tug pulling the ship”.

“That is likely, Soman. Maybe you should call the port traffic and find out.” Yasser smiled.

“Don’t you have a graphics view?” Asked the RA.

“It is getting ready, Sir”. Yasser Said. “You should have done the demo after that. Old salts like me are not good with numbers”. The feebly attempt of humour by the RA didn’t make much effect on the others.

A shimmer of red, a ray of the lusture of the ruby hidden deep inside the head of the great snake, has come out through the lidless eyes.

[Dileep]

Snake's Ruby. Section 2.

The Origin

14th April, 1998

Yasser Ayoobi was floating on his back in the swimming pool, immersed in deep thought, just like his body in the rather warm water. It had been an overly dry spring, and the customary pre-monsoon had not shown up. The days were unbearably warm, and the cloud cover made it doubly uncomfortable. Today being a holiday for the Vishu, that his family didn’t celebrate, he has decided to take a dip in the pool in the apartment complex.

Another reason for him being in the pool is that his father, Hussein Rawther, was visiting. Despite his ample love and respect for the old man, Yasser always felt uncomfortable in his presence. Hussein was a typical patriarch seen in the wealthy muslim families. He rarely had time or inclination to socialize with his children. Running and growing the timber business itself was a full time job, and top of it he was involved with the religious and political organizations of his sect. He was a leader of the Sunni group of Muslims. This group propagated the extreme conservative wahabi sect of Islam. He enforced the same principles with his family as well. That is the very reason why Yasser was forbidden from celebrating the Vishu.

It was Hussein’s wish that Yasser, his second son, become an engineer. Omar, the first born, was always the heir apparent, and the future boss of the family business. Yasser was expected to do good at studies and build his own life. But when Yasser wanted to join DRDO, Hussein was not exactly happy. Father and Son had heated arguments, and Hussein had to give in for the first time in his life.

Yasser had a role model then. The name, and the picture of the slender man with long hair and captivating smile had started to come in mainstream media. It was a time when a lot of young men started worshipping him as a hero. Even his rather long name was a hit.

And that name was Avul Pakir Jainulabdeen Abdul Kalam.

[Dileep]

After spending a couple of years writing DSP software at a unit in Bangalore, Yasser got an opening in the DRDO unit close to his home. His family was happy that he is going to be closer. Initially he stayed at their family home a bit far from the workplace, but after getting married, he moved into an apartment close to his workplace. It was comfortable and convenient.

Yasser was an avid swimmer. He learned it in the river close to his ancestral home. One added bonus he had at the current apartment is the availability of the swimming pool. Not many residents used it, so he could get it all for himself often. He used to joke that he thought best in water, and his colleagues used to counter that they themselves did. Only that “water” there meant alcohol and Yasser never partook it.

Floating on his back, with the water covering him everywhere, except the top of the chest, the eyes and the nose, Yasser was adjusting his buoyancy by adjusting his breath. If he inhaled deeply, his body will raise, and if he exhale too much, he will sink. Keeping the breath cycle within limits, he can float indefinitely.

It was something he was currently working at his workplace also. He was involved in the buoyancy management system in a submarine. The only difference is it is achieved by pumping water in and out of the hull, not by expanding and contracting like the chest did. He was thinking about improving the algorithms that ran the pumps.

Suddenly he felt dizzy. His head felt that he is rolling around, while body felt that it is staying afloat. He startled and recovered from the floating position. He had floated close to the edge of the pool, and he noticed that the water purification system had turned itself on. Water was coming out in a slow flow from the slot. He swam two strokes to reach the ladder, and climbed out of the pool.

He was a bit concerned about the experience. He knew that feeling dizzy might be perfectly fine, or it could also be a symptom of diseases.

He decided to consult a doctor.

[ramana]

Dileep when you write do you first develop a plot outline and fill in the details or it write as it just comes? Carry on regardless.

[Dileep]

Dileep when you write do you first develop a plot outline and fill in the details or it write as it just comes? Carry on regardless.

The honest answer would be "neither"

I set a target situation/event and go on thinking how that can be achieved. If it involves a conflict, I think from both sides alternatively, and take it forward. As each branch develops, there will be new opportunities to set targets.

If you still remember SS-1, it went like this:

Target: Someone smuggles a nuke into desh, and the good guys defeat it.
Almost impossible, unless someone want to do it and blame pakis. Only possible if unkil goes against pakland.
Target 1.1: Unkil becomes enemy of pak. Hence the ouster of Mushy and exile in US. I know Bay area, so he goes there.
Someone need to figure out Mushy was into doing something.
Target 1.2: High-Tech tracking of Mushy, ie how would someone get some info from him.
Mushy is under unkly control, it is fun to kick unkly ass
Target 1.3: Snoop on FBI.

It went on and on like that.

[Dileep]

As usual the doctor ran every test available at the lab that paid for his brand new flat screen TV, but could not find anything wrong with Yasser. His BP was normal. No sugar. Cholesterol under control. “Maybe it was water in your ear” the doctor joked.

“Can water do that?” asked Yasser.

“Do you know how we feel dizzy?” Asked the doctor.

“Well, I never liked biology anyway” Yasser said with a sly smile.

“There is an organ in the ear that has three tubes in the three directions. When you move your head, a fluid moves in this tubes and the nerves sense the motion. If the fluid moves by some other reasons, or the nerves are tricked into thinking that it moved, your brain will sense motion, and you will feel dizzy”

“Maybe the water pushed the ear?” asked Yasser.

“No. Normal pushing would not reach the inner year. You know that if you keep on going round, you will feel dizzy. Other than that, it is difficult to induce it by motion”. The doctor was impatient to dispense him and see the next patient.

Yasser left a bit confused. He was happy that nothing was wrong with him, but something about the incident made him uncomfortable.

[Dileep]

Soon after Yasser got an internal move into the group that dealt with underwater accoustics. This is the branch that dealt with receiving analyzing sounds produced underwater. A device called a hydrophone is used to receive the sounds. It is very similar to a microphone, but is designed differently, so that the sound waves coming through water gets received properly. Most of them works using the piezzoelectric principle, where certain objects, like quartz crystals, produced electric charges when subjected to mechanical deformation. Some polymers like Kynar (poly vinylidene fluoride) also exhibited this property, and hence used in hydrophones.

When working with hydrophones, Yasser observed that they were always working on the higher frequencies. More research shown that it was because of the nature of the transducers. It was tough to convert the low frequencies, and to analyze them.

Then his boss casually mentioned that if they had a reliable low frequency transducer, that could have been a fantastic tool to detect the silent submarines. Low frequencies are always produced by the propeller, and even the hull itself moving through the water. But the problem is two fold. One is the trouble of reliably detecting the signals, and the other is to analyzing and discriminating them from the natural sources like the waves.

But like any engineer believing in DSP, Yasser believed that ‘if it can be digitized, it can be analyzed’

[Dileep]

The similarity of the sensing of motion by the body, and the sensing of very low frequency of events in water has suddenly came upon Yasser. The motion is sensed by flowing liquid, and the frequencies are in the range of the ones he is looking for.

But how to make a transducer for that was the question. He couldn’t let his hunches and ideas public at work, so he decided to conduct his research and experiments on his own. His primary means of experiment was the swimming pool. It went on for some time, even to the extent that his wife thought that he has gone a bit crazy. But breakthrough did come one day.

He has seen that he could ‘hear’ his waving the hand in water once, but lost it when he rose from water and tried it again. He realized that there was an air bubble in his ear that ‘heard’ the wave. Soon enough he had a crude setup, where a trapped air bubble in contact with a dynamic microphone, which could detect feeble signals when he moved a vane in the water.

He decided to talk to his boss about it.

[Dileep]

The challenges were enormous, and the hurdles were tall, but the little team fought on. The first hurdle was the bubble itself. How will you couple movement from a bubble? Without coupling the movement, it can not be converted to electricity. Without conversion, it is no use.

They had to go for a less ideal medium, even for demonstration purpose. They first used a party baloon, but that didn’t work. They even used inflated condoms, and that too didn’t work. Then someone saw the cylindrical balloons used to make shapes at a fair, and bought some. Those, coupled to the voice coil of a big woofer provided some useable signal. Good enough to sense a dinner plate moving at the other end of a swimming pool. But it was not at all reliable. It detected the signal only when the plate moved at a certain speed. Nothing registered if the speed is higher or lower.

Their boss suggested that they make a stable setup by rotating a boat’s propeller at a known constant rate. An old propeller that was lying around in the junk was obtained and hooked up to a motor-gear setup. A speed controller was rigged up to rotate it at a constant slow rate. If the rate was high, the water became turbulent, and they totally lost the low frequency component. The ideal case was for the propeller to rotate at one or two rotations per second.

There was an abandoned water trough in one of the labs. This was around 40 ft long and 3 ft square in section. This was repaired by fixing the leaks, and the rigged up propeller was mounted at the other end. The controller and the lab tables are setup at the other end on a platform. It took some time to obtain the pumps necessary to fill and empty the trough. Till that time, the team had to run flexible hose from the garden, and wait hours to fill the trough. Needless to say the gardener didn’t like it a bit.

They also built a wooden chamber lines with glass wool for the woofer. The woofer was mounted in the middle of the chamber, whose both sides are closed. A piece of acrylic stick served as the link to the voice coil. It was firmly glued to the voice coil, and projected out of a hole made on the front wall of the chamber.

The chamber itself was mounted on a hinge mechanism, which allowed it to be lowered into the trough, making the probe touch the receiving object, which normally was submerged just below the water surface.

A reasonably repeatable setup was thus made, and the experiments started in earnest.

The boss insisted that the activity be kept in strict confidence. He had reasons to advice so.

[Dileep]

The initial results were not at all encouraging. It was like groping in the dark. They got some signal sometimes, but none at all sometimes else. When they got it, the analysis of the available data has clearly shown components related to the rotational speed of the propeller. They could also see harmonics from the four blades of the propeller. But there were days where they didn’t get any received signal at all. It was frustrating.

It also became evident that they need better facilities to continue the research. The current setup was not going to make any progress.

Their boss asked them to summarize the work ad make a brief, which they obliged. Apart from the general description, they had included data that proved that:

1. There is unmistakable evidence of the reception of the signals.
2. The reception is frequency sensitive, like a resonating circuit.
3. The system worked only just below the water surface.

They gave the report to the boss, and continued their work.

Then the news came. The big man himself is visiting their facility.

[Dileep]

Things changed after the visit from the big man. Requests got magically approved, lead times got reduced for no apparent reason, and the team size also marginally increased. Instruction of strict confidentiality, even from their colleagues, was often repeated, despite the fact that it was the norm at the facility.

The first thing they have figured was that a voice coil was not a good transducer. They have experimented with many things, including capacitive and inductive probes, inertial detectors, and even a laser sensor using a HeNe laser borrowed from another lab. None worked well. Interfacing with the thin baloon was another problem.

Then someone brought in an inner tube from a motor bike. This was inflated and mounted underwater. A caliper like probe was made using steel wire and hooked to the coil assembly of an old galvanometer. That didn’t work either. But it gave some idea to Yasser.

He bought a bicycle tube and cut it into a foot long open tube. The ends are then tied off and sealed with rubber compound. When inflated, it formed a sausage like oblong object. He then would thin metal wire around it and sealed it with glue. This was mounted in the setup and tested.

They found that the wire worked like a strain guage, and its resistance changed. This change was thought to be more or less uniform across the frequency range. This was proven to be correct. When the sensor was kept very close to the surface of the water, they got a much wider response than the previous attempts. But any change in depth threw off the readings.

[Dileep]

By the time Yasser and his team was able to make reliably repeatable results with a sensor mounted just under water, and proceeded to evaluate the directivity of the various shapes of the transducers, the team has further grown with new members who were experts in the theoretical physics behind the devices. Till this time, they were mostly engineers, doing thigs by trial and error. Getting resources that could analyze the results theoretically, and provide suggestions was a great help. It was them who suggested to go back to the toroid shape of the motor cycle tube. They asked to make it small. In fact they wend and bought tubes used for scooteretes. These, coupled with better strain guages gave much better results.

Then they heard with pleasure about the formation of the Navionics Research Establishment. The entire team moved into a building obtained from the Navy. No reason was given for the move. Some more members were added to the team. One of them was an expert in piezo electric technology.

[Dileep]

Piezo electricity is a well known phenomenon. When force is applied to an object and it is deformed, electrical charges appear on the surface of the object. Opposite charges appear at opposite sides, and if they are connected through a conductor, the charges will flow through it, causing an electrical current.

This is a reversible phenomenon. If you apply a voltage across the object, it will deform as well.

Quartz is the first material that is shown to exhibit this property. A properly cut quartz crystal will produce an electrical charge across the two flat faces. These charges can be collected using electrodes. If a voltage is applied across the electrodes, the crystal will deform. If a cyclic waveform of voltage is applied, the crystal will vibrate. If the frequency of the waveform matches the natural frequency of the crystal, it will vibrate at resonance, and the effective electrical impedance will go to zero or a peak. Since the natural frequency is a mechanical feature, it would be very stable. So this effect is used to produce very stable oscillators. Almost every piece of electronic equipment have one.

The vibration effect can be used to generate or detect sounds. If you drive the crystal with a modulated waveform, it will vibrate in accordance to the waveform and produce mechanical movement. If these movements are transferred to the air using a voice cone, sound will be produced. On the contrary, the sound waves hitting the voice cone will cause the crystal to vibrate, and produce electricity as well. Hydrophones, which are the sound sensors used in submarines, are made this way.

Quartz is a ver hard material. It is difficult to deform, and hence it has limited use in sound sensing. Certain ceramics also display the phenomenon. They are easier to fabricate than quartz and offer much better response. However, certain polymer has revolutionized the piezo electric sensor technology. It is called Polyvinylidene Fluoride(PVDF), with trade name Kynar. This polymer, when stretched, or formed under an electrical charge, exhibits very high piezo electric property. The piezoelectric property is so large, that sheets of this material has been successfully used to generate electrical power from waves. A strip of this material, small enough to be embedded inside the sole of a shoe, can generate enough electricity while one walks to light a pair of neon lamps.

PVDF is a thermoplastic, which can be easily fabricated in any form. Making it piezoelectric is, however not easy. A lot of researches had gone into that from many companies, and several patents made. But when military needs are in question, patents do not matter.

Ram Kumar was an expert in this. He was originally from ISRO, where he was involved in the design and fabrication of piezo sensors for the space program. Some strings had to be pulled before the space agency agreed to let him go, and join NRE.

Probably that was the next best thing happened to the project, after Yasser’s original contribution.

[Dileep]

The first thing to try was to try replace the strain guage sensors with piezo sensors. Strips of the piezo material were made, and electrodes are screen printed on them. Before they went onto the toroid cell, they were thoroughly tested and characterized. They have obtained an order of magnitude better sensitivity with the iezo strip.

The strips are then glued onto the inner tube sensor. When they ran the test, they were surprised to see that no output came. It took a lot of work and brainstorming to find out why.

The screen printed electrodes were getting damaged when the rubber stretches. Many suggestions came, including a thin film metal coating, spring contacts, or even laminated cladding. Finally, the screen printer himself offered one.

He drew a complex pattern of thin lines perpendicular to the direction of the stretch. Those lines are connected by meandering traces. The surface was thus covered by a stretchable grid of electrodes.

That worked, with a 2dB loss of sensitivity. That was deemed fine for the purpose. The necessary quantity of strips were made, mounted on the tube and tested. It worked great. It gave good sensitivity. The frequency response was, however still with a narrow band.

[Dileep]

By this time, the NRE had an indoor pool that is 80 ft long and 10 ft in section. Overhead rails were installed with three gantries to assist equipment placement. At both ends, there were a set of vertical rails with hoists running on a rack and pinion. A new set of sound generators included a variable speed propeller, an oscillating vane system, and a cylindrical piston mechanism to push things into the water.

The other end had a similar set of rails onto which sensor cages could be attached. They primarily worked with an open frame sensor that dipped the toroid in water. It could be rotated in any direction to make polar plots of sensitivity. The toroids are made the old fashioned way. Tread rubber sheets are procured from a rubber company. Those are wound on a pre-form and pre cured. Those pre-forms are then inserted into a mold, and air is pumped into the preform to expand it into the mold. Heat is applied to cure the preform. This process gave sensor bases good enough for characterization work. They worked fine if kept at the same depth, and over a small band of frequencies.

Yasser, who had become the director of the facility by now, decided to divide the team into two. One team was to run characterizations and accumulate data on the current type of sensor, and start on the analysis software. Another team would work on improving the sensor so that it can be used for the useful purpose of serving on board a ship.

For the chagrin of many pen pushers and bean counters in the bureaucracy, as well as many in the naval facility, he requested for expanding the facility to twice its current size. One of the navy’s building had to be demolished, and a new one built. A lot of opposition came from various corners.

But finally he got his way. His man who was his role model being the supreme commander at that time might have to do something with that, or not.

[ramana]

Man God's Own Country must be really that, for it makes you so creative!

[armenon]

Sorry to butt in the thread.. but I think you should take off from the work and finish this ASAP. Updates are too slow

[Dileep]

The first task of the new team was to take up the frequency response problem. It was seen that the frequency response if a function of the inflation pressure of the toroid. But that was not yet characterized. For that, a setup was made, where a linear motor drive moved a vane in the water at a precise sinusoidal pattern. But this did not serve the purpose, because the edges of the flat vane was creating turbulence, and the resulting pressure wave was not at all sinusoidal.

Then they tried to insert a channel in front of the vane. This was expected to filter out the higher frequencies, and leave the fundamental component intact. But the channel was found to another narrow band filter, so it was discarded.

The idea of pouring water in by varying rate was discarded in discussion stage itself. They even visited the nearby amusement part to check out their wave pool. It was good to produce stable surface waves, but that is not what they wanted. They need longitudinal waves in the water.

Finally they went back to a piece of equipment that was sparingly used. It was the piston plunger, which was hoped to simulate a torpedo launch later. It was never really used. They took it and installed it at the end of the new test pool.

As the plunger went back and forth, it did create the pressure waves, but the shape of the head was posing a problem. As the frequency changes, the curvature of the face must be changed to keep the harmonics away.

Finally, a ‘not-so-elegant’ solution was adopted. An empty cylinder was added to the head of the plunger, whose face is covered with a thick rubber membrane (fabricated from the same tread rubber material). Air is pumped into this chamber to bulge the membrane out. By carefully adjusting the pressure, they could create reproducible sinusoidal waves. A computer based controller was designed, which used a host of sensors, and pneumatic solenoids to drive the plunger and the air inflator together, so that the net effect is a clean sinusoidal pressure wave.

This formed the fundamental building block in the project.

[Dileep]

The frequency response being a function of the inflation pressure seemed obvious, but they could not really put a finger on how exactly they were related. So, once the wave generator was in place, they decided to attack that first. Data points were obtained by varying the inflation pressure and the frequency. The obvious thing was to look at the curve showing the plot of the pressure v/s the centre frequency of the band.

This was not linear, it was not exponential. No obvious curve did fit. In fact, no direct inference could be made from the volumes and volumes of data produced. Each sensor behaved differently, and on the same sensor, the data points were all around the place.

Months were spent on it, with no breakthrough in sight. The physicists also chipped in. Even the DSP algorithm experts tried to help.

All to no avail. A rare dullness fell on the whole NRE. Even the team that ran the characterization work started to go slow. Things are starting to look a bit on the hopeless side.

It was then the fate intervened in the form of a PhD student.

[Dileep]

I was a little bit concerned about going with the 'technology exploration' scenario. At some point I had realized that this too is very much like espionage work, so thought of giving it a try. But I still am not sure about what % of readers would enjoy such an endeavor. If it bores you, I apologize. The solace I can give is the promise that the espionage story that is upcoming is indeed related to this one.

This is not really new. We have done this a number of times in various mil-tech threads, be it missile, planes or radars. For the first time, it is being tried on a purely fictional basis.

Thanks Ramana and AR for the encouragement.

[Rahul M]

a techno-spy thriller, a first for BRF ! nice going !

[Prasad]

Dileep saar,
Its going great! Please keep at it

[jahaju]

Excellent technical buildup. Continue the good work.

[BajKhedawal]

I was a little bit concerned about going with the 'technology exploration' scenario....But I still am not sure about what % of readers would enjoy such an endeavor.....

This is good, carry on Dileepbhai.

Wrt to “Snake Ruby: The Legend” another belief: a king cobra that ingests the first drop of rain in a certain season (such as, but not: sharad; chaitar I am not sure which it is, and surely there’s additional criteria) transforms that rain drop into a pearl within the cavity in its head.

[Dileep]

Thanks for the comments.

The concept of snake's ruby is widespread in India. Some are like the production of pearls, ie involuntary. Some are mythical, like the use of it to get supernatural powers.

I have read an epic novel in a children's magazine long time ago. It deals with a prince who falls in love with the princess of the deposed king of Naaga Lokam. He helps the old king to regain his kingdom by fighting the firebreathing antagonist, with the help of the ruby gifted to him by the king. The ruby gave him "thrice the speed of a horse, thrice the strength of an elephant, an inexhaustible sheath of swords(ie, you pull out one sword from the sheath, another will appear in that instantly) and inexhaustible quiver of arrows. It also allowed him to track the other snakes.

I forgot which magazine (poompata, balarama, balabhumi) or the name of the novel. I just remember that the prince's name was Jayamaali and the princess was Naaga Mallika. The ending was that Naaga Mallika was allowed to marry the prince, and live with him in human form for the rest of his (prolonged thanks to the ruby) life. But he will eventually die, and Naaga Mallika will return to Naaga Lokam.

You might have figured why I mentioned the legend. If you didn't you will, eventually.

[Suraj]

I was a little bit concerned about going with the 'technology exploration' scenario. At some point I had realized that this too is very much like espionage work, so thought of giving it a try. But I still am not sure about what % of readers would enjoy such an endeavor. If it bores you, I apologize. The solace I can give is the promise that the espionage story that is upcoming is indeed related to this one.

I definitely like, and prefer, this line of storytelling to dishum-dishum right out of the gate scenarios. Great job so far!

[Dileep]

When Yasser reached home late in the evening Safiya told him that their uncle from Calicut had called. It was about a relative of him. The boy is studying in the university, and wanted to meet Yasser.

Yasser had been in a perennial bad mood for some time. He never discussed his work with Safiya. In fact Safiya had no clue about his work, other than that his office is ‘in the naval base’, but he is not ‘in the navy’. She also knew that he is a ‘scientist’. It was enough information for the girl who failed in the final year exam of her BA, and married the man chosen by her father. She was a good homemaker. She ran the household, keeping Yasser free to do his work. She never nagged him with anything. If she needed anything, she got it on her own. If Yasser needed anything, she got that too. She was happy with that. Her own family was run like that by her mother, but mother had to take the verbal, and sometimes physical, abuse by her father. She thanked god that Yasser was such a good husband, that he never even raised his voice to her.

Safiya had to tell him again, since no response came.

“For what?” Yasser asked, without really thinking.

“Something to do with his college it seems. He is going to come tomorrow evening”.

“You know that I come late” said Yasser.

“That is OK. He will be eating dinner here and staying back. He can talk whenever you are home”. Yasser didn’t say anything.

Yasser had forgotten all about it, till he saw the young man, with an untrimmed short beard, and a skull cap, sitting on the sofa when he came home the next day. He stood up, flashed a very warm smile from beneath the dark facial hair, walk towards Yasser, and embraced him, Arab style.

“Assalaamu Alaikum, brother. I am Mujeeb”

[Dileep]

Hassan Mujeeb Rehman Koya was a PhD student at the university. It was one among the very few universities in the country that offered coursed in naval technologies. Mujeeb was doing research in that department.

Mujeeb’s affection for stuff that deals with ships comes from his blood lines. His ancestors all were traditional navigators, building and operating boats that plied first between Arabia and Malabar, and then between mainland and the Lakshadweep islands. His ancestors originally came from Arabia for trade, and they settled down in the new land, where wood was a plenty to build boats. They made wood yards near the river, cut down the quality timber from the hills and transported them down the river. They built boat yards, and built big sea worthy ships using the expert carpenters available locally. The Arabs loved the boats. As time went by, it became a big business to built boats and operate them.

The Koyas were big at that.

By the time Mujeeb was born, the business was a bit down. The wooden boats were used only for recreational purposes. Rich Arabs bought them to be their personal yachts. Some still were built to be freighters to ply between the main land and the Lakshadweep. But it is no longer a flourishing business.

His father, Hassan Muthu Koya, had converted one of their traditional yards into building modern boats and yachts. He sent his son to study naval architecture. Since the father is still going strong in his fourties, the son was allowed to continue studies as far as he wants. Mujeeb enrolled into PhD in the university.

His subject was inflatable boats. And he thought his relative, who worked ‘with the navy’ could help with that.

After Yasser had the dinner, he and Mujeeb had a chat.

[Dileep]

Yasser instantly liked the young man. He looked like a religious student, with his beard and the skull cap. He could be easily mistaken for an instructor in a madrassa, or a student at the islamic college. No one might believe that he in fact carries an M. Tech in Naval Architecture, and is a PhD student. They mostly talked about Mujeeb’s project. He was planning to study the inflatable boats, with an idea to use them in the recreational boat building business of his dad.

Then the talk branched to the characteristics of the inflatable boat, and their interaction with the waves.

And a lamp flickered on in Yasser’s brain.

He instantly invented a scenario. He outlined a project, as if he was working on that. It consisted of a landing craft using inflatable base. There is a proposal to control its inflation to counteract the waves and stabilize it. What would be Mujeeb’s take on that?

Mujeeb realized the potential of that. It is related to his subject, and worth exploring. They went on to discuss various aspects of the project.

Before they parted, both had a pretty good idea on what the other wanted. Except that Mujeeb had absolutely no clue about the real application what Yasser had in mind.

Within a few weeks, Yasser got an e-mail from Mujeeb. It had a PDF file, which detailed the studies conducted by the worldwide research community on the interaction of inflatable bodies in water.

It also showed the value of original research that was somehow absent from his organization, even though the word ‘research’ was present in the name itself.

[Dileep]

From the articles found by Mujeeb, Yasser and colleagues realized that the characteristics of the sensor could depend upon various factors. What they really sense is the deformation of a membrane. This deformation is made against the combined elasticity of the membrane, and the compressed air within. The force for this deformation comes from the wave pressure in water.

With the new insights, they conducted more experiments. They used cells with very carefully calibrated thickness. They characterized their elastic properties by measuring that by stretching. They did the experiments under controlled conditions.

After a lot of effort and collection of data, they realized that if they made a cell with calibrated membrane elasticity, and the same size, it gave repeatable results.

He gave the findings to Mujeeb, who had done some good progress in his own research by this time.

Mujeeb got back within a week, showing that it was the radius of curvature of the membrane that mattered.