You’re thinking the opposite of the best solution. After the regular food runs out, you start in on cooking up the crew. That ought to stretch things out quite a bit.
Not really. The only way that people or materials generally get transferred to or from a submarine these days is by tugboat. For example, if you need to pick someone up (like an inspection team), you would meet a tug just outside of port, transfer the personnel, and head back to sea. Similarly, the same could be done in reverse if you needed to get someone off the boat.
There are two submarine tenders left in the U.S. Navy, but they are generally used as forward-operating depot ships nowadays, and not used for resupply at sea like similar ships were used in WWII. The big difference is fuel. Most surface ships (and diesel submarines like those used in WWII) need to be refueled at sea every few days. A nuclear-powered submarine gets refueled every 15 to 30 years. 
Theoretically, yes, but practically, no. In any event, what would be the point of doing this? :dubious:
For I am a cook, and a captain bold,
and mate of the Nancy brig,
and a midshipmite, and a bo’sun tight,
and the crew of the captain’s gig.
“…may I take this opportunity of emphasizing that there is no cannibalism in the British Navy. Absolutely none, and when I say none, I mean there is a certain amount, more than we are prepared to admit, but all new ratings are warned that if they wake up in the morning and find any toothmarks at all anywhere on their bodies, they’re to tell me immediately so that I can immediately take every measure to hush the whole thing up. And, finally, necrophilia is right out.”
Because sailors belong at sea, dammit!
" … and by right out, I mean we don’t allow any emotional attachment to the corpses we bugger, so the suffix -philia is completely and totally inappropriate! It’s a duty, not a pleasure, and any man caught enjoing it is flogged. Now flogging – that’s a pleasure."
AND twenty minutes.
The National Geographic article is pretty good, as are Beach’s non-fiction books about submarining (as well as the fictional Run Silent, Run Deep).
I remembering wondering as a kid how deep 20,000 leagues was, so I looked it up, found a league was more than a mile, and … light bulb moment!
Good point: for practical purposes, a sub is probably normally running with the minimum crew for safe round-the-clock operation. Adding more people wouldn’t help! That contrasts with the kind of skeleton crew you might be able to get by with out of necessity, reaching the closest friendly port. But one wouldn’t plan a trip like that.
It amazes me (if I’m to believe Foster and Obrien) that back in the 1700’s and 1800’s, when a naval ship captured an enemy ship, it would fit the enemy with a prize crew from its own complement, such a small number of people to get that ship back to port. However, men of war had huge crews, especially compared to merchants (for fighting battles, making fast sail changes, and of course the marines.)
Haha!
No, no, no… You eat the flesh off of the crew, and then you reanimate the bones to continue working. That way you get the best of both worlds.
There’ve already been some explanations on why it’s not safe to sail with a skeleton crew.
In Jules Verne world they actually had underwater farms harvesting seaweed and such. And of course their is always fish to eat.
I think the Russians used to use fishing boats as spy ships since they technically could be out to sea for a long period without the need for resupply.
BTW, nitpick:
A ship that is moving is under way.
To raise an anchor is to weigh the anchor.
So ships weigh anchor in order to get under way.
(One can find examples of “under weigh” in literature, but only from people who were confused by the homophones.)
I like the sound of that.
You mean that’s sounding good?
Come to think of it, I wouldn’t be terribly surprised of you could program a course into a nuclear sub and send it off with no crew at all, or just one to turn on the autopilot. I’m not sure what the odds of failure would be in a scenario like this.
The odds of failure are 100%. The real question is how long it’d run. Hours, days, weeks, or months?
If it could run for months, that’s pretty good odds it would succeed. I think navigation would be the biggest problem. I’m doubtful it could pick up GPS signals submerged, which means either going the whole way on the surface (and presumably going a lot slower), or periodic surfacing to verify it hasn’t drifted off course, or some other means of submerged navigation I’m not aware of,
You would be surprised, then, at how much is manually done on a nuclear submarine. This is intentional: every bit of automation is one more thing that can break, inevitably at the worst time possible.
For example, enlisted watchstanders are assigned to manually record dozens of gauge readings every hour. There’s no reason this couldn’t be automated. The reason for this is to force them to actually look at the readings and pick up on trends before they become a problem, rather than just wait for an alarm. For the roving watches, it requires them to manually inspect their assigned spaces and pick up on small problems before they become big problems.
(That being said, the newest class of submarine (the Virginia-class), is certainly more automated than previous classes. Not everyone agrees with this trend.)
In any event, the idea of sending off a nuclear submarine without a crew is laughable. For one thing, there is no autopilot worthy of the name. An unmanned sub could not submerge or surface automatically, and would be traveling blind with no one to man the sensors. Finally, you need a crew to oversee the reactor and steam plant. Steam plants are notoriously manpower-intensive. Do you think that civilian nuclear power plants are ever unmanned?
There are other means of navigation, but none of them are tied to you what you would term an autopilot. You need a crew, or the sub would just travel until it ran into something. I can assure you that it would not make anything close to 20,000 leagues before this happened.
So the automated system can only steer a straight course? How about a wide circle?
Work with me, man!
Also, presumably, nothing will actually shut down due to the failure ro take an instrument reading, will it?
And no, I don’t think there are automatic un-manned nuclear reactors around. I’m just trying think of way to make the OP’s question possible – the genera consensus was that it’s not possible to store enough food to make the trip.
Ok, so maybe the whole thing blows up – the good news is that with my idea the crew doesn’t die. 
OK, sure, you could set the rudder somehow and abandon the sub on the surface. It would keep going for a while in a wide circle, maybe even a long while.
No, it would shut down automatically when the steam plant got low on makeup water, or some other minor adjustment failed to happen.
On the contrary, I don’t think it would be all that difficult to store enough food for the crew for such a voyage, if one was determined to do this for some reason. As I stated above, we had enough food for our full crew for more than four months using conventional storage techniques in the forward compartment only. If we filled the whole sub with food, and cut down somewhat on the crew, we could probably double this. An SSBN with its missiles removed could carry even more food.
To set your mind at rest, there’s no way it would blow up. It would likely just shut itself down automatically. Depending on the power output prior to shutdown, there is a slight chance of a meltdown with no crew present. By design, however, if the sub were to sink, the ambient surrounding seawater would remove enough decay heat to avert this.