Four Desperate Hours

A Prelude

          "You know Bhatia, when I was at ANU last year, David Weisser told me about an old incident at ANL. You know, they have an old FN Tandem there --- a 9 MV HVEC machine, which they have recently upgraded to a Pelletron. It's basically a horizontal machine; so, like us, they don't have a moving service platform inside the tank. They use an aluminum ladder to access the column for maintenance.”

“ So? Just what are you getting at?“  asked Bhatia impatiently.

“Well, one day they had about half a dozen people working in the tank for routine maintenance, you know. After finishing their work, they filed out one by one, shut the manhole cover and tightened all the bolts to seal the tank. Then, they all went for lunch leaving behind one man inside the tank. They had not gone very far when, they suddenly heard what at first sounded like a distant church bell, but they soon knew the sound was actually coming from inside the tank. It was then that they realised, to their horror, that they had locked one of their chaps in the tank, who was now frantically banging on the tank walls to draw their attention. All rushed back immediately and opened the tank to find the man had gone almost mad with rage, naturally.  Thank God, luckily for him, they had not started the evacuation of the tank! Now, as a rule, they carry a key whenever they get into the tank and they can’t start the pumps unless it is returned to its key-switch in the gas room."

"But, why did you remember it now?"

"Well, I was just reminded, probably because we are now in an almost similar situation." 

*******************

          It was a pleasant Sunday morning in December 1989 and as we had done for the past few months, we were working on Sundays and holidays. It was only a few days since we had successfully done the acceptance tests for the Pelletron accelerator and now, we were literally racing against time to get the machine ready and in full shipshape for the formal ‘Inaugural’, which was just one week away. Our Project Director, Dr. Kapoor, in his characteristic enthusiasm, had invited the Prime Minister to inaugurate and formally ‘dedicate’ the machine to the nation. It was going to be a big gala affair, which we had been planning for several months in minute detail.

        As the PM turned a key-switch in the Control Room, the Faraday Cup in the main beam line would quietly move out of way to allow an intense 28 MV proton beam to fall on a tiny quartz plate making it shine in all its glory like a brilliant star in the sky, even as the VIP visitor watched it all in awe on a CCTV monitor!  The ion beam would then be brought to a staggering halt in an acrylic cube, where it would leave in its wake an outline of a beautiful, minuscule “tree”!!  Later, the acrylic piece would be ceremoniously presented to the P.M. as a priceless memento.  We had been taking regular trials for the past several days to ensure nothing went wrong in the last minute.  But, as luck would have it, two days back we found to our great dismay that a “Faraday Cup” in the Terminal, which was used to intercept the ion beam for measurements, had got stuck in its position and no matter what we did, it just refused to budge!  Under the circumstances, we had no other option but to open the tank and enter it for investigation and repairs.

Pelletron accelerator is a gigantic machine, called Tandem Van-de-Graff accelerator in our parlance. It normally operates at a maximum potential of 14 Million Volts(MV) on its “Center Terminal” and it is housed in a huge, 100 ft. tall, steel tank filled, during operation, with a pure, high pressure, insulating gas called Sulphur-Hexafluoride(SF6). The accelerator itself is a tall, modular structure of steel and ceramic that stands like a Kutub Minar inside the steel tank. Each of the thirty modules, stacked on top of each other, is made from a pair of circular aluminium boxes separated by six, two feet high, alumina ceramic insulators. Centrally along the axis of the stack runs the so-called ‘Accelerating Tube’ which, so to say, is the heart of Pelletron.

The accelerating tube is basically made as a chain of several annular titanium disk electrodes separated by small, ceramic insulators. The high DC voltage, applied between the successive electrodes, helps to accelerate the atomic charged particles, such as protons, alpha particles or other heavier ions, which move along the tube axis in the form of an ‘ion beam’, very similar to a beam of light. This is the main function of the particle accelerator. About midway in the Pelletron stack is situated the so-called “Center Terminal”,  which is housed within a pair of large, highly polished, stainless steel spinning. Inside the Terminal, we have a number of remotely controlled, beam line devices that help focus or steer the ion beam to maintain it strictly along the axis. If any one of these devices malfunctions or even if it is just a minor problem like a ‘blown-up’ fuse or a loose screw, we have no other option but to open the tank and physically enter it to carry out the necessary repairs. The entire process of in-tank repairs can easily take a full day or two. We normally enter the tank through two access ports, which we call as ‘manholes’, one provided at the top and the other near the bottom of the tank. Once inside the tank, you can go up or down the entire length of the column riding on a movable deck, called the “Annular Service Platform” or simply “ASP”.

          By the time I arrived that morning, our two electronics engineers, Bhalerao and Vaze had already entered  the tank and they had traced  the root cause of  the trouble to a blown up IC(integrated Circuit)  in the FC-Control PC(printed Circuit) card. They had replaced the defective PC card with a spare one which they had in stock to meet just such an eventuality. Later, they had also taken a quick survey of all the rest of the electronic instrumentation in the Terminal and tested its operation. Bhatia inspected and checked the working of all the UHV pumps and other components in the tank and cleared the tank for final “button-up” prior to its evacuation and pressurising with the gas.  

           As part of our “button-up” protocol, the cleaning crew entered the tank for a thorough precursory clean-up procedure to render it absolutely dust-free. For this purpose, all the aluminium castings were rendered dust-free using a portable vacuum cleaner and all the stainless steel rings were polished using a special, waxed cloth called “tack rag”. We go through this elaborate procedure of cleaning the tank every time we open it because even a single dust particle suffices to trigger a spark breakdown at the several million volts at which the machine normally operates. This is then followed by the final drill of testing by actual operation of all electronic and other systems in the tank.  It was lunch time when the tank crew had finished all their appointed tasks except for closing of the Centre Terminal, which was postponed until after lunch break, as everyone was so hungry and tired.

****************

         After lunch, I usually relax a little trying to steal a wink or two, but today was an exception as there was hardly a week left for the Big Day and I had to get few things off my hands by then. So, I was just browsing through a draft of the Inaugural Souvenir, when there was a faint knock on the door followed by Bhatia. He came in and settled down in the chair before me with an expression of anguish written all over his face. “What’s the matter, Bhatia?” I asked. ”Is everything alright?” “Yes, everything’s okay” he sighed.”The boys have cleaned up the tank and finished all other work in the Tank before lunch. But, it’s already 2:30 pm now and they have not returned still.” When you work on a Sunday, it’s but natural to take things a little easy, I thought.  “At this rate, we won’t close the Tank before evening” continued Bhatia. “So instead of just waiting for them, why not we both go in the tank and finish closing the Terminal ourselves? That way, we could save some valuable time and by this time tomorrow, we should be back in business. Okay?”  “Okay. Let’s go.” I said, cheerfully.

         Deciding to enter the Tank through the ‘Lower Manhole’, we proceeded directly to the Pelletron tower, at the 12-meters level.  Before entering the tank, however, we quickly changed into our white ‘boiler suits’ and pulled over a pair of plastic  covers on the shoes; it’s  a precautionary measure, that we take meticulously to keep unwanted dust etc. from entering the tank. The manhole was already open. So, squatting in the access porthole, I gave a light push on the steel flange and  shoved myself in to land directly on the annular Service Platform (ASP),  Mr. Bhatia quickly following suit.  In the beginning, getting in all of my eighty kilogrammes of weight through the two feet diameter hole used to pose quite a problem.  But, after some practice, I found I could manage myself pretty well without help, physical or otherwise. However, no sooner you enter the tank, you get amply rewarded for the ordeal by the beautiful sight of a majestic Pelletron, standing there in all its glory like a tall, Egyptian belly dancer swaying with so many hula hoops around her waist!  Like a stunned admirer, I stood there looking up in awe, when all of a sudden I felt the stack began sinking fast into the ground!! 

Actually, I soon realised, it was the ASP which had started moving upwards as our friend Bhatia had set it in motion and not before long, we were face-to-face with the Lower Terminal Spinning which had been previously parked at the lower Dead Section during the recent Terminal maintenance.  The huge, shining, stainless steel shell, weighing some quarter of a tonne, was supported on four wooden blocks perched in the recesses of the aluminium castings of the Dead Section.  By now, both of us knew very well the Terminal closing routine; so, we silently proceeded to pick up the four, special Terminal Support stands that were lying lazily on the ASP floor and clamped them firmly in place over the inner rim of the ASP and lugged forward the Tower Bolts provided, in a manner in which you normally cock a rifle, so as to engage them in the four respective holes provided in the Terminal spinning.  I then picked up the ASP Control Switch box and gave a smart
tap on the “UP” button so that the ASP lunged upwards a tiny bit clearing the supporting blocks. We then slowly pulled out the four wooden supports, one by one, from underneath the thick, steel inward flange on the spinning. The entire half-ton weight of the spinning was thus smoothly transferred from the wooden blocks to the tower bolts.  We could now use the ASP to carry the spinning to its rightful place in the Centre Terminal.  I just happened to look at my watch: it was already 3:00 pm! I knew it was going to be a matter of just another few minutes before we were finally ‘done’ with the job and called it a day. How terribly wrong I was, for little did I know then what ordeal was awaiting us!

                     Taking charge of the ASP Control pendant, Bhatia pressed the “UP” button and the service platform started moving up again. Then, all of a sudden, before we could realise what was happening, there was this deafening, booming sound reverberating all through the tank: “DHUM-DHUM-DHUDDHOOOMMMMmmm”, that sent an uncanny chill down my spine! “Come on, STOP IT for Heaven’s sake!” I cried out almost in panic and the ASP obediently came to a dead halt. “What’s the matter?” asked Bhatia quite alarmed.  We had both at once realised what the source of that terrific bang was: it came from the Terminal Spinning slipping out from all but one of the four tower bolts and now it was precariously hanging on a single bolt! “Hell! I know what has happened” said Bhatia.”The Stabiliser Arms are not in place and so, the platform wobbles to and fro when we try to move it.”  I was too stunned to respond. For, from where I was standing on the platform, I could see clearly that the spinning was just about a quarter-inch in from the edge of the bolt! There are four ‘Stabilizer Arms’ provided on the outer periphery of the platform for the very purpose of keeping it from wobbling. But, they are normally kept folded on the inner side of the ASP when parked during operation at the top, hemispherical end of the tank. The first time you enter the tank, it is the normal practice to unfold and lock in position the Stabiliser arms, such that the small rubber wheels on the outstretched arms press firmly against the tank walls. Thus, the service platform remains quite steady when it moves up and down the column length.  Obviously, someone had missed the important protocol that fateful morning and we too, on our part, had failed miserably to cross-check it before moving the ASP. 
“I think I will try to engage the Arms now” said Bhatia, but, I stopped him before he could move. “NO! No Bhatia, SIT DOWN!!” I shouted at once and then continued in a more restrained tone: “Bhatia, you see, the platform’s swaying like a big pendulum and I can see from here the Spinning is already just a few mm from edge of the bolt. If it moves out now even a tiny bit, it will fall freely to the tank bottom.” Without a word, Bhatia squatted down obediently on the floor, obviously sore at my shouting. So, I explained to him, now in a more soothing tone, as to how we were both caught in a very critical situation and how the Spinning was in fact hanging over our head like the ‘Sword of Damocles’’!  If, by any chance, it were to slip out from the single bolt it was hanging on, it was going to experience a free fall under gravity from a height of about fifty feet culminating in a terrible impact as it hits the bottom with a terminal velocity of about 100 km per hour! Such a large impact of about 80,000 Newtons could easily damage the ceramic insulating posts supporting the modular structure of the Pelletron stack, which could come down in a heap like a pack of cards!! But, Bhatia did not seem to be fully convinced of the gravity of the situation that we had so unknowingly let ourselves in.   “But, NEC says that their Insulating Posts are strong enough to withstand even an Earthquake!” he pointed out.  “True. Maybe their posts can withstand 6000 kg of tensile force, but it’s probably in a lab experiment, where the load is increased gradually in steps. But, here it’s going to be a sudden impact, which is quite different. Materials like even steel are known to become brittle under sudden impact. We really don’t know what will happen in this case.” I said. “But, I know one thing for sure. We are not going to take any risk what-so-ever. No, not with the Inauguration Day just one week ahead! ”

          There followed an eerie silence which pervaded the whole of the tank and neither one of us spoke even one word.  In our mind, though, search was on for a feasible solution to our present predicament which, however, was eluding us.  After a while, it was Bhatia who broke the silence: “What are we going to do, then?”   

“I really don’t know, Bhatia. It’s a million dollar question for which I have no answer.” I replied.  “But, there’s one thing we should remember. Whatever action we take, it mustn’t lead to any major mishap or setback of any kind to our project, because we just can’t afford one right now.  God, we’re in real soup!  Tell me Bhatia, you have some brilliant idea?”     

Bhatia shook his head. "Nope!  But, how long can we go on waiting like this? Damn it, we can't even call someone for help. The Intercom’s not working and we have no telephone line here in the tank." 

"Yeah, in any case, there’s no one at the Control Desk, right now. Moreover, even if someone wants to help, how the hell is he going to get in here, in the first place, with the damn ASP stuck like this?”

“I guess, the fellow will have to jump down fifty feet thru the top manhole!” 

“Don't get disheartened, Bhatia. Let’s pray to God. Only He can save us!"

**********

Prayer!  God knows how long ago it was since I prayed last. While not exactly an atheist, I am not an ardent believer either; at best, you could say, I am an “agnostic”. Many people believe that most scientists are atheists, but, that’s not really true. As a matter of fact, if at all there’s anyone on earth who sincerely believes in God, it has to be the scientist. For, who else but a scientist would be able to appreciate the ethereal beauty and splendour of this ever expanding Universe; the grandeur of His creations from the farthest reaches of space to the architectural masterpiece and engineering marvel, that we all know the human body is; the natural wonders of the world and above all, the precision Laws of the Nature and its intricacies of design in the structure of matter, that keep the physicists overwhelmed with awe and busy discovering a new elementary particle almost every other day? Thus, God is a necessary and sufficient precondition a priori  to the very existence of the universe and the mankind.  Moreover, I think for a miserable person like me, He is a psychological mentor who you can depend on to show you the way out of unexpected calamities like the present one.   
I firmly believe that God, if at all He exists, must be a pretty busy person, like the CEO of some big corporate body like the Tatas, with his own daily share of worries what with looking after such a vast universe and petty quarrels amongst His children! So, just as the CEO may not know personally each and every one in his own organisation, so also I cannot expect God to be even aware of my existence, let alone my petty personal problems!  I am just a small man among billions, like a small grain of sand in the big desert.  It follows, therefore, that if I need His attention or help, I must needs to make a special request for it by way of prayer. So, right from my childhood, whenever I wanted  His divine assistance in overcoming some such perennial, serious problem, as facing the school exams or the boss in the office, I would always resort to a prayer with full faith that He would somehow do the needful! So, I closed my eyes and opted for the only thing I could do under the  circumstances: I said my most sincere prayer in years.

“ God, I know only You can help us now. I have always come to Your doorstep for succour whenever I have felt a need for it and You have always stood up by me. I know for sure that You won’t let me down this time either. But, Lord, this time I am not praying just for myself alone, but also for my fellow workers. I have always believed that a prayer's most effective when one prays for others rather than for oneself. You know very well that we have all been slogging day and night for the past two years and it’s our collective hard work and aspiration that is at stake now,God. At the very fag-end of our project comes this bleak prospect of a terrific disaster looming large before us which, if it ever occurs, will shatter us all to no end. So, God, please help us! You know the situation I am facing today. I just don’t know what to do. I am not asking for a miracle --- all I’m asking is to please give me the peace of mind and strength necessary to face the situation squarely and boldly. Please guide us and give us the wisdom to understand and tackle the problem. Enable us to patiently await your exalted benevolence and please tell us what we should do in the meanwhile. Once again I beseech You,God,to help and indulge us. Amen!”

             A sort of serene calmness soon descended upon me and for the first time I knew very clearly what needed to be done.  Suddenly, I felt confident that we would be able to somehow surmount our difficulties because I could see a feasible way out. I had this strange feeling of the certain presence with us, in the tank that day, of a third ‘being’ to give us tacit support in our efforts.  We must have been sitting there in muted silence, worrying incessantly and praying fervently for, God knows, how long.  Finally, I broke the silence.

“Yes. You said something, Bhatia?”    

"I was just thinking ----- Well, you know we have that big, twenty inch long screw driver; it’s right there behind you in the toolbox. See if you can you reach it by leaning backwards. Just try."   

 "OK, I'll try. But, I must take care not to move the service platform or else, we are doomed!"

             Then, keeping my fingers crossed, I slowly leaned backwards and lay down flat on my back while extending my right arm above my head. I tried hard to reach the toolbox, but, I could not. I could hardly even see it from my present position. So, pulling myself up a bit towards the box while   taking utmost care not to stir the ASP even so slightly, I could succeed after one or two attempts in touching the edge of the toolbox. Now, there remained the onerous task of lifting the box lid and groping inside for the big screwdriver.  After some trying, I could somehow manage to get hold of the screwdriver head and pulled it out through the small gap below the lid. Then, placing it on the ASP floor, I gave it a hard push to send it rolling towards Bhatia who was on my right hand side. He had to lean a bit forward to pick it up and then insert it in one of the holes in the spinning. Next, anchoring it on the inner steel rim of the platform, he tried to lever it up pushing the spinning slightly backwards to the tank wall. “DHUDOOMMMMM…….” Again, there was a big loud sound that reverberated through the tank like before forcing Bhatia to stop in his tracks. “Oops! What happened?” he asked almost terrified. The ASP must have swayed a little, but, all the same, I said, “It’s nothing. Go ahead!” Then, I too looked up and felt so relieved to find that nothing much had changed and everything was in its place as before ---if anything had moved at all from its position, it was the spinning which had moved in a little along the bolt towards safety.   

         "Very good, GOD IS GREAT!” I almost shouted in glee. “Yes. Bhatia, the shell has moved back further in by about quarter of an inch. I can clearly see the bolt’s now sticking out about half-inch. We are safer now. Bhatia can you keep pressing on the screwdriver so it doesn’t come out, while I go and engage the other arms, one by one? ".  So saying, I slowly got up on my knees and crawled towards the outer edge of the service platform. 

" No, no! Do it on the other side first. That will push the bolt more out thru the spinning, making it more safer." said Bhatia.

"Okay, I think you're right!" Then, I slowly moved back towards the opposite side, still crawling on fours and on reaching the outer periphery, I unfolded the stabiliser arm and locked it in position with its rubber-wheel pushing against the tank wall. Then, coming to my feet, I gently walked across to engage the diametrically opposite stabiliser arm, while Bhatia kept his pressure on the screwdriver. The platform had hardly swayed during all this time. I then proceeded to similarly engage the remaining two stabiliser arms, without further hassle. Bhatia could now withdraw the screwdriver from the spinning. He must have felt relieved a great deal after his ordeal. I remembered then, the legendary Dutch boy who had saved his village from flooding by the sea by sitting all night with his little thumb plugging a leak in the dyke.  We were now completely out of danger, totally safe and sound! In my mind, I silently thanked God Almighty, for without His timely help and guidance this would not have been possible. At last, we were back in business.
           So, we went ahead and completed the job we had originally set out to do, which was to transfer the Spinning back to its normal position in the Lower Terminal and close it. The service platform, with the full weight of the spinning now hanging from its four special stands, could be easily moved up to the Terminal without any further hitch. In the Centre Terminal, there are four height adjustable pads provided on four Support Arms that can be swung in and out of the Terminal. These four arms were duly swung out to move into position directly under the thick inward facing flange on the spinning and the screws adjusted so as to transfer the entire weight of the spinning onto the four supporting pads.  The level of the spinning and its axial alignment were then both checked with a plumb and once it was deemed acceptable, the service platform was lowered away. Whew, the job had been done, at last!

           Then, suddenly out of the blue, a booming voice filled the tank: “Hello! Need any help?” For a moment, I thought it was an “akashvani”, a celestial voice from the very heavens! I looked up and saw peeping through the top manhole was kind Dr. Prasad, who was making a concerned query. “No, thank you. Not now! ” I replied.

            “Congratulations, Bhatia” I said, as we got out of the tank."I think you deserve a medal for saving the country from a One-Million-Dollar loss!".  I casually glanced at my watch. It was 7:00 pm., which meant, we had been in the tank for nearly four desperate hours!

*************

             I was back at my desk writing a short summary of the day’s events in the Logbook. Just then, Bhatia peeped in from behind the door and asked, “Shall we go home, now? If you don’t hurry up now, you will miss the seven-thirty bus!” 

“Okay, you go ahead. I will come right behind you." I said. "Err, Bhatia, one more thing!  Let’s keep whatever happened today to ourselves, okay? We won’t tell the Boss even, right now. As it is, he’s very tense about the magnet chamber; he keeps asking me about its vacuum status, every day. Plus, he’s got his 'Inauguration Day' anxieties; so, let’s spare him other worries right now. Okay?”
 “Okay, boss, whatever you say.”

So, we kept it a closely guarded secret until now. I thought, now it can be told.

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