WEBVTT - How do torpedo engines work if they're underwater? 0:00:00.040 --> 0:00:02.920 Audible dot com is the leading provider of digital audio 0:00:02.960 --> 0:00:05.800 books and spoken word, with over one thousand titles to 0:00:05.880 --> 0:00:09.840 choose from. Audible lets you listen to your favorite books anywhere, anytime. 0:00:10.039 --> 0:00:13.119 Go to Audible podcast dot com slash stuff brain to 0:00:13.119 --> 0:00:15.400 get a free audio book download of your choice when 0:00:15.400 --> 0:00:18.640 you sign up today. Welcome to brain Stuff from house 0:00:18.640 --> 0:00:29.440 stuff works dot com where smart happens. Hi Am Marshall 0:00:29.480 --> 0:00:33.879 Brain with today's question, how do torpedo engines work if 0:00:33.880 --> 0:00:38.000 they're under water? A torpedo is essentially a guided missile 0:00:38.040 --> 0:00:42.159 that happens to fly underwater. A torpedo therefore has a 0:00:42.200 --> 0:00:46.080 propulsion system, a guidance system, and some sort of explosive 0:00:46.120 --> 0:00:49.640 device that's gonna blow up the target. Torpedoes can travel 0:00:49.720 --> 0:00:52.560 several miles on their way to the target, and therefore 0:00:52.680 --> 0:00:55.440 they need a propulsion system that can run for ten 0:00:55.520 --> 0:00:59.240 to twenty minutes. Most missiles that fly through the era 0:00:59.440 --> 0:01:02.720 use either rocket engines or jet engines, but neither of 0:01:02.720 --> 0:01:06.360 these work very well. Underwater torpedoes use one of two 0:01:06.400 --> 0:01:10.840 techniques for propulsion. Batteries, and an electric motor is one option. 0:01:11.319 --> 0:01:14.720 This is the same technique that any non nuclear submarine 0:01:14.800 --> 0:01:19.200 must use when it's running underwater. Engines using special fuel 0:01:19.400 --> 0:01:22.680 is the other option. Most engines that were familiar with, 0:01:22.800 --> 0:01:26.240 like car engines and jet engines, draw their oxygen from 0:01:26.280 --> 0:01:28.720 the error around the engine and use it to burn 0:01:28.800 --> 0:01:32.279 the fuel. A torpedo can't do that, so it uses 0:01:32.360 --> 0:01:36.000 fuel that either does not need an oxidizer, or it 0:01:36.080 --> 0:01:41.000 carries the oxidizer inside the torpedo. Auto fuel spelled O 0:01:41.280 --> 0:01:44.800 t t O has its own oxidizer mixed in with 0:01:44.880 --> 0:01:49.640 the fuel. Hydrogen peroxide doesn't need an oxidizer. It turns 0:01:49.680 --> 0:01:52.960 the steam when it hits a catalyst. We don't encounter 0:01:53.040 --> 0:01:56.240 too many fuels that contain their own oxidizers in our 0:01:56.280 --> 0:01:59.480 normal lives for two reasons. When a fuel has its 0:01:59.520 --> 0:02:04.160 own sidizer, it tends to make it explosive. Dynamite, for example, 0:02:04.200 --> 0:02:08.600 has its own oxidizer and it's quite explosive. Rocket engines 0:02:08.639 --> 0:02:11.880 have to carry their own oxidizer. But because we normally 0:02:12.000 --> 0:02:14.680 run engines in the error, which has a good supply 0:02:14.760 --> 0:02:18.680 of oxygen, carrying the oxidizer means extra weight and hassle, 0:02:18.720 --> 0:02:23.040 which is unnecessary. For more on this and thousands of 0:02:23.080 --> 0:02:29.760 other topics. Because it has staff works dot Com audible 0:02:29.800 --> 0:02:32.560 dot com is the leading provider of digital audio books 0:02:32.560 --> 0:02:35.679 and spoken word, with over one titles to choose from. 0:02:35.720 --> 0:02:39.120 Audible lets you listen to your favorite books anywhere, anytime. 0:02:39.360 --> 0:02:42.400 Go to Audible podcast dot com slash stuff brain to 0:02:42.440 --> 0:02:44.680 get a free audio book download of your choice when 0:02:44.680 --> 0:02:45.560 you sign up today.