Navy as such is in a unique siouatitn with respect to both the army and airforce.I am generalizing to some extent.In the army, if one had to repair something, say the tank in the middle of an operation, you can leave it at that spot for the time being and try to do get help later. In the airforce, if any airplane gets a snag, the pilot cant do much. That is both the airforce and army do not need to have the users (the persons doing the fighting) to do "more than cleaning level of repairs as a job requirement".whereas the navy in high seas, requires the sea men to do the repairs until they get back to the ship. i.e. the users need to be able to tinker with the machines, if need be. If say, the viraat is hit and a propeller gets damaged, you need the men operating it - not only to know control the siouatitn, so that the damage does not spread -"how to stem the flow of blood from a wound;" but also get the propellers to work , i.e. "they have to decent doctors".The analogy for the army would be say, a brigade hq was hit, what would the staff have to do? The ship for the navy is that level.and unfortunately for that, the officers should be able to decide which of the propellers can be rectified and most importantly, how it affect the future operational decisions, say do they want to get the propellers to work at maximum speed at for a very short or operate at only 60-70% of speed for a longer time. This requires them to have understanding of the technology.A tank operator like you, is an army officer, but I do not know whether the tank mechanic at your base is also an army officer from nda. For the navy, these mechanics are also at war and as such they require to be technologically competent.Ravi