Deep Dives: Torpedo Data Computer

[@SantiagoArraga]

Thank you very much for the informative video. I remember reading Edward L. Beach's Submarine! and wondering as to how the TDC worked - mind, I knew the overall purpose of it, but *how* it looked like and how it would be used operationally has been beautifully illustrated.

[@EdwardCzajka]

Thank You for putting together this video. I learned quite a lot. One of my ancestors served on the USS Bowfin as the Fire Control Officer, so he operated the ships TDC Mark3. Watching this video helped me understand what he had to do, and how critical he was to the success of the ships missions.

[@paralleler]

I'm currently reading Thunder Below which led me to finding out how the Torpedo Data Computer worked. Many thanks! p.s., Blind Man's Bluff is another great book as is Soldier, a biography about Colin Powell. "History makes you smart, heritage makes you proud."

[@McsMark1]

Bruce, that's exactly how I ended up here! Great Book!

[@emilyelizabeth4180]

Love the Deep Dives segment. Bring it back Greg! NOW!

[@tomtrenter3208]

Overall a good description. One small correction, speed of sound in seawater is closer to 4800 feet per second +/- a few feet per second depending on water temp.

[@mackfisher4487]

Best description of how a TDC works, consider revising Wikipedia. Analog computers are amazing craters, hats off to the technician who rebuilt the Poppa Nido TDC

[@raylouis]

How does the information get transferred to the torpedo? I seen on the USS COD site, The Torpedo tube has round hole in the side of tube. Is that where the torpedo instructions are loaded? (GYRO SETTINGS)

[@independenceseaportmuseum]

Yes, there are several spindles that extend into the torpedo tube and interface with the torpedo that are used to set the torpedo’s depth, speed, and gyro. Setting the gyro can be done individually by tube or you can set all tubes at once using the indicator-regulator located between the torpedo tubes.

[@FrancSchiphorst]

Thanks, a very nice look at a lot of the elements invoved!

[@roxy_badass]

How interesting! I was watching Hell under the Sea by Natgeo, when I first had in touch with this technology. Thank you for explaining so well about the history of this wonderful tech. Likes and subscriptions.

[@mikem5043]

I've always found the TDC to be just a marvel of electro mechanical engineering. Fascinating piece of equipment

[@storerestore]

Awesome overview!

[@DrSchor]

excellent explanation.

[@barryolson3998]

Very interesting!

[@chazzatheninja]

Very cool!

[@mikehurricane5767]

Thanks ! Enjoy learning of war history . Saw you on the 571 in another video . Admire the knowledge you share .

[@johnnyellis4499]

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[@aressantino2382]

@Johnny Ellis Instablaster =)

[@johnnyellis4499]

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[@johnnyellis4499]

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[@aressantino2382]

@Johnny Ellis You are welcome :D

[@skovner]

I note the angle solver is divided into two similar parts. Is one for the aft and one for the forward torpedo tubes?

[@DGQ1Q2]

Amazing.

[@danielmkubacki]

Cool!

[@edwardpate6128]

An area where the US Navy was leaps and bounds compared to either the Axis or our allies.

[@carlweiss8942]

does the tdc also set the torpedo dept?

[@dan319611]

I am so overwelmed with the info, I never thought that Albert Einstein would be on every Sub in the Pacific. My hat goes off to the men that manned the Silent Service and a special thanks to the torpedo officer! Wow they had a job! How does Hollywood portrayel of " Bearing Mark" from the Captain and "Rang Mark" fit into this computer?

[@independenceseaportmuseum]

Bearing and range are inputs into the TDC. "Mark" is a term of indications so if someone said "bearing mark" they want the bearing measurement at the time mark is called but the TDC eliminates the need for any of that since it continuously updates the variable information.

[@tomtrenter3208]

"Bearing mark, Range mark" give the info to the plotting party that does a manual plot on paper using the DRT (Dead Reckoning Tracer). This gives a visual display of the engagement to backup the TDC

[@stevenikazy2943]

Another mystery solved. Thanks!

[@stevelewis7263]

Hollywood makes this look so simple

[@sdcoinshooter]

I tried to understand what he described… but my head exploded. One question i don’t understand is how could they get the range from the periscope? By the height of the target? That would be too variable.

[@DrSchor]

by the width. once you recognize which ship it is by it's silhouette, you look up in a book how long it is. it is then a very simple trigonometry calculation to know how far away it is. all artillery range finders use this method.

[@sdcoinshooter]

@@DrSchor I believe you and of course they knew what they were doing, but it’s a good thing I was never a submarine commander, the enemy would have less to worry about then my own boat.

[@elindsey357]

how was that information transmitted to the torpedo

[@independenceseaportmuseum]

There are little spindles that extend from the walls of the torpedo tube and fit into slots on the torpedo to adjust the relevant variables.

[@LexieAssassin]

I'd be interested in see someone create a computer program that replaces similar functions to the Mk 4 TDC, but in a more generic manner. I'm currently playing through a Japanese campaign of War on the Sea and I think having a TDC to look at would be immensely useful in determining if a torpedo launch is worthwhile. Particularly useful would be a Time-to-Impact calculator as I often fire torpedoes at enemy vessels, only to blow them out of the water long before the torpedoes reach the intended target. I try to torpedo from very close range to minimize this, but even at only a few klicks, this is a problem. Also, as I understand it, you have a seperate TDC unit for homing torpedoes, and that would be very interesting to have explained as well. Esp. as AFAIK, the Germans never had a seperate TDC for their acoustic homing torpedoes.

[@paulloveless4122]

Bruh. Your level of Operational knowledge is sjilii8x5lllkkkkkk

[@elye3701]

How did the Germans target their torpedoes?

[@jaywinters2483]

too much face