Lets say I’m rich and I can pay someone to build me a submarine. We want to be as self sufficient as possible, stopping to take on food and other consumables only.
How many people would we have to have?
I want to be able to stay underwater for a month or more so we’ll need a nuclear reactor I think. That’ll need a good deal of attention.
We only need the bare essentials of life; food, cleaning and sleep. We’ll play with hand-held games consoles and packs of cards to entertain ourselves.
We’ll need the ability to carry out minor repair and maintenance but we’ll go into port for anything big.
This is a leisure craft so there’s no need for weapons but we’ll need a periscope and a full array of communications.
Would we need sonar? Does it have applications other than hunting other subs?
Lets assume the crew we hire are smart guys and can be trained in more than one job.
How big would such a sub need be? How big would the crew need to be?
Hmm…How can you call your operation self-sufficient if you’re picking up supplies every month?
You’d definitely want sonar, otherwise you may find your journey cut short when you either run aground or run into something.
You can get (or will be able to get) zero-maintenance nuclear power generation units like Hyperion, so you don’t necessarily need a big engineering staff.
You could probably computerise most of your other systems.
Looks like you’re on your own.
You’d just need to refit your nuke every 5 years or so.
Typical U.S. nuclear submarines have crews numbering about 130 officers and sailors.
However, U.S. subs have traditionally eschewed automation, preferring to do as many tasks as possible manually. This is because you need lots of crew members for damage control efforts. Also, you have lots of crew members available for preventive and corrective maintenance.
You could get by with far fewer people if you automated many of the systems. I’m betting you could run a small nuclear sub with as few as 10 people.
Unless we’re going to recycle everything and grow food with hydroponics, I don’t see any other way to get food. But we can try and get more supplies on-board than a months worth I think. Especially if it’s just me the wife on-board.
Refiting every 5 years doesn’t sound too bad. Just haul that Hyperion out and drop in a new one! Very low maintenance.
So maybe with enough automation I could run a sub by myself. That’s great. I’ll have the thing built with enough room for six people so I can take friends on underwater cruises and with the space I’ve saved by cutting out a crew we’ll add in a computer room with satellite internet access.
In addition, if our hypothetical submarine is to be used for peaceful purposes, then it won’t need any crew to maintain and operate weapons. That knocks off a pretty significant percentage right there.
311 feet long, 27 feet wide, 16 foot draft, 1500 tons surfaced, 2400 tons submerged displacement, 4 diesel engines driving the ship at 20 knots on the surface (and/or recharging batteries). 48 hours battery charge submerged at creeping speed. Carried enough food and fuel for 75 day patrols. Crew of 60.
If you take out the weapons and their crews, and with more modern automation and machinery designs, I imagine that you can reduce the ships length considerably, or, alternatively, carry even more food/fuel/ammenities. You could get by with much fewer crew, as well.
I imagine you will need some positions manned at all times. (The helm, the trimsman, engineering, sonar, radio.) Some jobs, like galley duties, could be “co-lateral duty” assignments, I suppose.
You could use spare power from your power plant to run grow-lights, and if you make the power plant really big (and the crew small), you could conceivably desalinate the seawater and use that for watering the plants & people. Mushrooms could be grown in a dark cargo area, feeding on the plants that the crew have eaten. Between beans and mushrooms you could probably get enough protein to subsist on a purely vegetarian diet, but having a few egg-laying hens might be worthwhile.
Just remember that every life-form in the food chain takes a cut of the available energy and nutrients, and consuming that life-form doesn’t ever recover all of the energy that it consumed – the more animals you add to the submarine (including crew!) the less efficient you are overall.
I’d say that equipment to make fresh water is considered close to essential on any vessel that plans to be at sea for more than a week or so, let alone a submarine gone for months. Such devices certainly consume power, though not vast amounts. They are common on offshore yachts, and not actually all that expensive (examples here).