Merchant Submarines

Necessity is the mother of invention – so when your port is blockaded and you still need to get supplies in, you need a plan. Normally, you’d build a fast ship to run between the enemy ships. But what about under them?

Enter the merchant submarine – a wacky concept that came out of World War I. The submarine was coming into its own, and as a new technology, it wasn’t covered under the Geneva Conventions. However, merchant ships were covered, so the Germans came up with a clever plan to exploit this. You build a merchant ship, you dive under the blockade, then once you’re in open water, you just sail on the surface like anybody else – protected by the same rules.

If you know anything about merchant ships, you’re already starting to see the problem. There’s a limit to how much stuff you can put into a submarine. Remember just how big freighters are. That’s on purpose–they’re trying to move the maximum amount of stuff for the minimum cost. Considering it takes a month to move stuff from America to Europe, it could only be profitable if you snuck in high-value cargo, such as medicine.

As a result, the Germans only ran the SS Deutschland twice, before they gave up on the idea, and converted it to a regular submarine. It also didn’t help that the Lusitania was sunk around the same time, so they didn’t have America or other former “neutrals” to run to. Believe it or not, this particular ship made it to the end of the war, and was surrendered and dismantled.

The Russians actually used regular submarines to run supplies into Sevastopol during WWII, but there’s always been lots of ideas to use submarines for other things. Take, for example, the submarine aircraft carrier. It’s one of those things that sound better than it is. The point of a submarine is stealth. The second you surface and launch an jet aircraft–which is loud as hell–you’ve just announced to everyone where you are. Sneaking an oversized submarine at that point is very difficult. So although you’ve launched your pilots in a successful first strike, there’s nowhere for the pilots to land. Better to just fire missiles and disappear.

But that’s the problem with any new technology–working out what works and what doesn’t. Nowadays, “merchant subs” are only used by drug smugglers, but there is an idea to make a submarine tanker to pump oil under the Arctic ice sheets. What do you think? Is there a cool sounding tech you’ve heard of that is actually impractical? Let me know in the comments below!