Chris Groves – Used to be different officer training for diesel and nuclear
There used to be a separate Officers Training Course for diesel submarines and a separate one for nuclear submarines and as the number of diesel boats reduced and the number of nuclear submarines increased, they decided to do a single Officers Training Course which included the Nuclear Training, no matter where you were going, so I was the only person on my Officers Training Course who went to a diesel submarine straight away. Which was a great place to cut your teeth.
No automation, or minimal automation, and so when you learnt your systems, the valves, pumps, gauges etc that were attached to those systems largely were operated manually, and you needed to know where they were and you needed to understand and how to operate them and in what order to operate them to get the submarine to do things that submarines should do.
And by that I mean … the submarine has to be the right weight when its dived, and so we call that ‘being in trim’, and so trim consists of being in the right state of bodily weight, so making sure that you’ve got the submarine ballasted correctly, so you’ve got the right amount of water in the various tanks so that the submarine is the right weight, and then you have to worry about how that weight is distributed as well, so what you don’t want to be is out of trim by having too much of that weight for’ard or too much of that weight aft, ‘cos you end up with a bow down or a bow up problem.
What you really want to try and do is trim that submarine so that you’re in the correct trim for the depth that you’re at, and that you’re generally at periscope depth.
You want to be trimmed by 1 degree down by the bow and there are good reasons for that at periscope depth because if you come across something which you need to avoid on the surface and you pick it up too late, then you may need to go deep, or to go deeper quite quickly, and so better to be pointing in the right direction than not, so bow down is always good.
The other piece that you really want to have to consider I guess in bodily weight terms, is that as the submarine changes depth, then it experiences more compression from the pressure of the water around it, and so the volume of the submarine changed and therefore being at the right weight at one depth is not the right weight at another depth, so you get heavier as you go down because your volume shrinks and so as you go down in the submarine, as you go deeper in the submarine, then you need to pump water out of the submarine to account for the fact that your bodily weight is getting heavier, to remain in trim. So, another complication of what we call ‘ship control’ in the submarine.
