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.
***************** x *****************
