The formative years anywhere are very important in one’s life but all the more so in the Navy. What one sees, as a cadet, midshipman or even as a watchkeeping officer goes a long way in the make-up of an officer. As a cadet on the training ship INS Krishna, I learnt firm lessons on how not to handle a ship. Our Captain was a terrible ship handler. On the other hand, when one comes across a competent captain the lessons that can be imbibed go a long way in shaping an officer’s subsequent conduct. That is how I was initiated in the submarine world. After the completion of the basic submarine course in Nov 1975, I was lucky to have been appointed on a brand new submarine INS Vagli (Foxtrot Class) based at Mumbai. Lalit Talwar was the Captain. He was rather particular to conduct the formal calling on by an officer joining in. In that call as was usual, he did indicate what he expected of an officer but what struck me was his intrinsic belief in the competence of an officer just by virtue of being one. His statement “An officer is an officer unless he proves otherwise. With me you start with a score of 9 unless you decide to work yourself downward”, was a refreshing one and inspired one to strive and put his best foot forward always and every time. That it was not a facade was soon proved in my first dive al sea.
We had sailed out after the President’s Review in Jan 1976 (Fakhruddin Ali Ahmed reviewed the fleet) and after reaching the diving position the boat was prepared for diving. The XO was soon to go for the COQC (Commanding Officers Qualifying Course) and the Senior Engineer Officer (SEO) had just been awarded a dive watchkeeping ticket. The Captain thought it fit to let the XO and the senior engineer work out the trim and carry out the Trim Drive (which was my first in a sub). A trim dive usually is the first dive at sea and is carried out in two stages. The first is when the end groups of ballast tanks are flooded and the submarine goes down up to the level that it’s casing or the outer hull is just about underwater. At this point of time, all the compartments are inspected for any leaks and the boat’s list and trim are checked. The trim should be zero but should not exceed half a degree aft bubble and the list should be zero. Only after ascertaining that all this is in order, the second stage of the dive is initiated wherein the centre group of the ballast tanks are flooded in stages and the propulsion is ordered half ahead. The trim dive is initially up to 9 metres and once there, fine adjustments to the trim are carried out using forward and aft trim tanks to control the nm and with compensating tanks to adjust the weight of the boat so that a neutral buoyancy is achieved. Once that is done the sub is free to manoeuvre freely at any depth and all subsequent dives are only urgent dives wherein all the ballast tanks can be flooded simultaneously.
I have been a bit elaborate for the benefit of those to whom the submarine diving and surfacing is Greek and Latin. So when we were ready to dive, the OOW (officer on watch) was ordered to shut the upper lid (hatch) and come down. Lalit Talwar sat in the control room as a spectator (I was standing next to the WC door under the ladder coming down from the conning tower) and all the orders were being given by the XO and the senior Engineer as also the reports that had to be monitored. Once the end groups had been flooded, the compartments were inspected and the list and trim were checked. The senior engineer reported “End Groups flooded; compartments inspected correct. List zero bubble slightly more than half a degree aft, depth 1.5 metres, request permission to flood centre group in stages.” At this point, the SEO himself should have realised that the bubble was slightly more than half a degree and that it was prudent to check the reason but he felt satisfied. Lalit Talwar asked him and the XO if they were satisfied, though knew fully well that it was not so but chose not to intervene. The XO answered in the affirmative and gave the go ahead to flood centre group in stages. Accordingly, the SEO proceeded to do just that and as soon as the centre group main vents were opened and water entered the tanks, the bubble started moving aft. When the main vents were opened a second time the bubble just shot aft and the sub developed a steep forward angle and with the motors going half ahead the boat started going down like a stone gaining depth. In all this Lalit Talwar just sat unmoved giving the XO the chance to react, who was trying to reduce speed and pumping out compensating tanks but it was just not enough. The total depth in the area was about 80 meters and when the boat had reached a depth of about 50 meters , Lalit Talwar intervened and ordered all groups blown in the sequence of centre first followed by forward and then aft. The blowing takes a short while to take effect and by the time the boat started recovery and coming up we had reached 70 meters. When all the tanks are blown like that the boat shoots up to the surface. On reaching the surface, he turned to the SEO and the XO and said, “Your trim calculation was not correct. I think you need to rework on it” and walked off to his cabin in the second compartment with the same expression as he had throughout. No shouting, no yelling, just calm disposition.
I was very impressed because what we had seen was an actual emergency and anything could have happened. Now an explanation is necessary. In F class boats, on the surface, to create one degree of trim, the Lever or the moment required is about 3200 Ton Metres (Means that over the length of the pressure hull- about 80 metes if 40 tons are moved from aft to forward then a degree of forward trim or aft bubble would be created). This lever is only 1100 TM when the sub is in trim down position with end groups flooded end only 11TM in the dived state.
Therefore the difference in the moment for one degree of trim between trim down position and dived state is 100 times. A ‘Half Degree Aft’ in trim down position could become 50 degrees in the dived state. Why even a slightly more than half a degree aft bubble indicated that the forward end of the boat was very heavy and the trim dive should not have been proceeded with and the trim calculations should have been rechecked. This was one reason why submariners take their stability very seriously.
However, the lesson I learnt that day was the extreme confidence of the CO so much so that he was willing to take a risk to teach his XO and SEO without in any way letting panic creep in. To stay calm in an emergent situation instils faith and confidence in the crew and it comes with professional competence alone. I dare say that it was a lesson well imbibed by me and it stood me in good stead throughout my naval career. I was also fortunate to have served with very competent Commanding Officers, which shaped my growth in the Navy.