I am a fan of the saying that those who don’t know history are doomed to repeat it. After all, humans have been building things for a number of centuries and we should learn from the engineers of the past. While you can learn a lot studying successes, sometimes — maybe even most of the time — we learn more from studying failure. The US Navy’s Mark 14 torpedo certainly has a lot to teach us.
The start of the story was the WWI-era Mark 10 torpedo which was fine for its day, but with faster destroyers and some additional data about how to best sink enemy ships it seemed necessary to build a new torpedo that would be faster, carry more explosive charge, and use a new method of detonation. Work started in 1931 with a $143,000 budget which may sound laughable today, but that was a lot of coin in the 1930s. Adjusted for inflation, that’s about $2.5 million.
From the Age of Sail through to the Second World War, naval combat was done primarily in close quarters and with cannons. Naturally the technology improved quite a bit in those intervening centuries, but the idea was more or less the same: the ship with the most guns and most armor was usually the one that emerged victorious. Over the years warships became larger and heavier, a trend that culminated in the 1940s with the massive Bismarck, Iowa, and Yamato class battleships.
But by the close of WWII, the nature of naval combat had begun to change. Airplanes and submarines, vastly improved over their WWI counterparts, presented threats from above and below. A few years later, the advent of practical long-range guided missiles meant that adversaries no longer had to be within visual range to launch their attack. Going into the Cold War it became clear that to remain relevant, warships of the future would need to be smaller, faster, and smarter.
It was this line of thinking that lead the US Navy to embark on the Littoral Combat Ship (LCS) program in the early 2000s. These ships would be more nimble than older warships, able to quickly dash through shallow coastal waters where adversaries couldn’t follow. Their primary armament would consist of guided missiles, with fast firing small-caliber guns being relegated to defensive duty. But most importantly, the core goal of the LCS program was to produce a modular warship.
Rather than being built for a single task, the LCS would be able to perform multiple roles thanks to so-called “mission modules” which could be quickly swapped out as needed. Instead of having to return to home port for a lengthy refit, an LCS could be reconfigured for various tasks at a commercial port closer to the combat area in a matter of hours.
A fleet of ships that could be switched between combat roles based on demand promised to make for a more dynamic Navy. If the changing geopolitical climate meant they needed more electronic reconnaissance vessels and fewer minesweepers, the Navy wouldn’t have to wait the better part of a decade to reshuffle their assets; the changeover could happen in a matter of weeks.
Just about everything the US Government publishes is available to the public. Granted, browsing the GPO bookstore yields a lot of highly specialized documents like a book on how to perform pediatric surgery in hostile environments. However, there are some gems if you know where to look. If you ever wanted to have a comprehensive electronics course, the US Navy’s NEETS (Navy Electricity and Electronics Training Series) is freely available and has 24 modules that cover everything from electron flow through conductors, to tubes, to transistors and integrated circuits.
There are many places you can download these in one form or another. Some of them are in HTML format. Others are in PDF, which might be easier to put on a mobile device. The Internet Archive has them, although sorting by title isn’t quite in numerical order.
Some of the content is a bit dated — the computer section talks about magnetic core and bubble memory, for example, even though the latest revision we know of was in 1998. Of course, there are also references to bits of Navy gear that probably doesn’t mean much to most of us. However, things like the shift register (from module 13) you can see above haven’t changed in a few decades, so you can still learn a lot. The phase splitter in the top banner is even more timeless (you can find it in module 8).
Here is a two-part Navy training film from 1953 that describes the inner workings of mechanical fire control computers. It covers seven mechanisms: shafts, gears, cams, differentials, component solvers, integrators, and multipliers, and does so in the well-executed fashion typical of the era.
Fire control systems depend on many factors that occur simultaneously, not the least of which are own ship’s speed and course, distance to a target, bearing, the target’s speed and course if not stationary, initial shell velocity, and wind speed and direction.
The mechanisms are introduced with a rack and pinion demonstration in two dimensions. Principally speaking, a shaft carries a value based on revolutions. From this, a system can be geared at different ratios.
Cams take this idea further, transferring a regular motion such as rotation to an irregular motion. They do so using a working surface as input and a follower as output. We are shown how cams change rotary motion to linear motion. While the simplest example is limited to a single revolution, additional revolutions can be obtained by extending the working surface. This is usually done with a ball in a groove.
[Daniel] sent us over to the blog for the Naval Academy’s Autonomous underwater vehicle entry for the AUVSI competition. You can follow along as they design, build, and test this years entry. It really looks like it would be fun to be the guy who gets to swim with them, like in the latest post in their blog. Their entry, named “Awkward turtle” can be seen above in orange, pictured with their 5th place winning previous entry.