Earlier quoted context omitted.
Do you happen to have a link to the "Basic Hand Tools" version?
https://archive.org/details/UseOfTools1945/mode/2up
Thanks for posting the link. What a great book.
Basic Mechanisms In Fire Control Computers (1953) [video]
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Re: Basic Mechanisms In Fire Control Computers (1953) [video]
#92Earlier quoted context omitted.
WW II American torpedoes didn't have inertial guidance. They used gyros for directional control and just ran in a straight line after making a single turn onto the set course. Occasionally the torpedo would get stuck in that turn and run in a circle. Towards the end of the war the Navy also started introducing homing torpedoes, but those didn't use inertial guidance either.
> Occasionally the torpedo would get stuck in that turn and run in a circle. Well that's not a great failure mode, if it can come right back at vessel which launched it ... imagine trying to implement a self-destruct failsafe with that tech back then ...
At least two US Navy submarines were sunk by their own torpedoes making circular runs. The main failsafe mechanism disabled the detonators until the weapon had run out a certain minimum distance but obviously that wasn't effective in circular runs.
https://www.usni.org/magazines/naval-history-magazine/2011/j...
Re: Basic Mechanisms In Fire Control Computers (1953) [video]
#93The US Navy's old training materials are fantastic for learning about various technologies. I think their masterpiece is "Basic Hand Tools" a handbook written in plain English that describes the use of practically every hand tool ever invented. "Basic Hand Tools" on the hammer: >Whoever conceived the idea of cracking a nut with a rock unknowingly invented a tool. When a later genius tied a stick to the rock, he inven…
Not just military training videos, older ones in general are often superior to what gets made today. My favorite is probably this one on vehicle differentials: https://m.youtube.com/watch?v=yYAw79386WI
I've never been a car guy. While I've heard of differentials, I never understood what it was. Thanks to you posting this video, I now understand what a differential does and how it does it.
(I found playing it at 120% speed to be a good balance between comprehension and engagement)
Re: Basic Mechanisms In Fire Control Computers (1953) [video]
#94Earlier quoted context omitted.
My uncle was on the Wisconsin and operated the big guns during the first Gulf war. I never really had context as a kid for how large that ship is, and was just astounded by the distances they would shell.
This was right before the gulf war so I may have met him! Assuming he was a gunners mate, that crew had a lot of moments of touching history. Besides mechanical computers, it’s a really dangerous place since they had to handle massive bags of flash powder. My ship was near the USS Iowa when turret two went up. A sobering experience when you think how much risk the turret crews are in just by doing their jobs.
For those like me who didn't get this reference:
"On 19 April 1989, an explosion occurred within the Number Two 16-inch gun turret of the United States Navy battleship USS Iowa (BB-61) during a fleet exercise in the Caribbean Sea near Puerto Rico.[1] The explosion in the center gun room killed 47 of the turret's crewmen and severely damaged the gun turret itself."
Re: Basic Mechanisms In Fire Control Computers (1953) [video]
#95Great video! I love the simple straightforward presentation, it explains the concepts so well. The many applications of cams continue to impresses me. The fundamentals of mechanical computers go back much further, well into the 1800s and possibly even earlier. Much of it has its roots in clockwork.
> it explains the concepts so well.
Indeed. Watching the video I found the practical and visual illustration of math concepts when implemented in mechanical gears to feel intuitive in a way I never felt from chalkboard math instruction. As a person who's always struggled with traditional algebra and up math education, seeing it presented in this physical way really felt fundamentally more accessible to me. Like I strangely felt far more 'connected' to concepts in a way I never have before. Has anyone ever tried to teach algebra and higher level math concepts this way?
I suspect if back in high school and college, math classes had geared machines I could touch and turn a crank on to see the "math work", maybe my life would have been different. I basically dropped out of college due to falling behind in high school on algebra fundamentals and never being able to catch up in college. When I found I loved computers in the college's BASIC 101 class, yet found any access to computers beyond that class requiring a transfer to the math dept (this being the early 80s), and not being able to pass the prereq classes for that transfer, I dropped out. Strangely, I immediately bought an 8-bit computer with 4K of RAM and became an entirely self-taught programmer (which ended up working out very well for me in the end), but what might have been...
Re: Basic Mechanisms In Fire Control Computers (1953) [video]
#96This is a great primer on one facet of the Navy and "technology". So much of early computing has some tie back to the navy. It isn't an accident that Grace Hopper was an admiral and not a General. Much of Cray's early work is littered with "Navy" (including his transfer from Europe to the Pacific). It's a fascinating bit of WWII and Post war history that is worth exploring.
Navigation and gunnery have always been driving forces for mathematical innovation so there are often naval connections to important discoveries and inventions. But don’t sleep on the importance of land-based artillery and military surveying and cartography as motivation too. Long range naval gunnery with these kinds of mechanical computers to take into account things like course, speed and rolling motion, was all bu…
This is the whole conceit behind Neil deGrasse Tyson's book "Accessory to War":
"Accessory to War: The Unspoken Alliance Between Astrophysics and the Military is the fifteenth book by American astrophysicist and science communicator Neil deGrasse Tyson which he co-wrote with researcher and writer Avis Lang. It was released on September 11, 2018 by W. W. Norton & Company. The book chronicles war and the use of space as a weapon going as far back as before the Ancient Greeks, and includes examples such as Christopher Columbus' use of his knowledge of a lunar eclipse and the use of satellite intelligence by the United States during the Gulf War. While speaking on the book, Tyson told National Geographic that he regards the collaboration between science and the military as a 'two-way street.'"
FWIW Tyson is quite critical of the application of astrophysics research to military ends.
Re: Basic Mechanisms In Fire Control Computers (1953) [video]
#97In 1989 I was a data systems tech on a Destroyer going through some overhaul at the shipyard in Pascagoula Mississippi. Moored right next to us was the battleship Wisconsin. Huge relic from WW2 but still going through modernization. A bunch of us that worked on combat systems got invited for a tour of their fire control systems. Wow. Just wow. All mechanical computers calculating fire control solutions for the big 16…
By the end of WW II American torpedoes were automatically programmed (direction, speed, fusing) before firing. The heavy calculations would be done by the shipboard firing computer while the parameters set would be used by the simple computer on the torpedo (which had inertial guidance). I struggle to imagine how people managed to design such things with just pencils and slide rules.
Yes, in fact even a Harrier Jump Jet was designed with pencils and a slide rule!
Re: Basic Mechanisms In Fire Control Computers (1953) [video]
#98This made me think of engines as computers- the crank shaft connected to the timing belt goes up to the camshafts to instantly calculate the positions of the valves.
Likewise, an automatic transmission is a hydraulic computer.
This is part of the reason why four speed autos stayed in use for so damn long. You can automatically shift a four speed transmission with a pair of solenoids that turn on/off based on the input values from a couple of basic sensors.
The solenoids control which pair of clutches in the transmission engage, which in turn, determines the gear the transmission is in.
Driveability wise, they were awful, and their overall efficiency was pretty bad. But the fact that it could automatically select the correct gear out of three or four with just one user input (throttle) is still marvelous.
They could also handle insane amounts of power for the era. The GM 3L series came out in 1964 and was the transmission people would reach for when they were putting WWII era plane engines into crazy automobiles.
Re: Basic Mechanisms In Fire Control Computers (1953) [video]
#99Earlier quoted context omitted.
For the fuel injection and ignition (spark) timing yes, but the camshafts to open and close the valves are still driven by a gear, belt or chain. Even variable valve timing is mostly controled by mechanical or hydraulic means, though I'm guessing some electronics may be involved.
This is about transmissions.
Upthread mentioned camshafts and valves, guess my reply is mostly to that.
Re: Basic Mechanisms In Fire Control Computers (1953) [video]
#100Earlier quoted context omitted.
Likewise, an automatic transmission is a hydraulic computer.
50 years ago that was true. Sometime ago though (I don't know when, but I'd guess starting in the 1990s) they changed to electronic computers. Using electronics makes some things simpler and puts the complex parts in standard hardware (a CPU is much more complex but it isn't custom designed for you), or software (easy to change if you get it wrong.
Yeah, but the electronic control in 4 speeds was basically replicating the mechanical control of the previous generation. So it was more of an incremental improvement over old tech.
Whereas modern 6+ speed transmissions are very different in design and control.