175mm FDC

I’m curious to know if  know if Fire Direction Control on the 175 Guns used FADAC or was it done manually. I know FADAC was not available for the 155 Guns because they were never converted to the metric system but I’m sure the Army was using FADAC with the 175 Guns in Vietnam. Did the USMC use FADAC with them as well?

3 thoughts on “175mm FDC

  1. I was in the F.D.C. when we tried FADAC with the 155’s as I remember it our team was faster than the computer when put to the test! It is,however very possible the conversion wasn’t made yet.I left in early January 1969 before 175’s were installed,and didn’t get to train on new guns due to being short .Sorry I can’t be of better help,perhaps the staff or officers could be asked.

  2. That would make sense that you would be faster computing manually because the FADAC was an “analog computer” and it took the entire flight time of a round to calculate the firing parameters.

    • Hi Bob and Bill;
      I operated the FADAC in the 3/12 FDC in ’68 at CaLu. The initial firing data was, as Bob points out, the entire flight of the round. This was mainly so all met data could be applied at the appropriate time in the flight. Also the memory was on a drum as opposed to RAM. At the time I didn’t know about access times and such so I can’t even guess what it might have been. However, after the initial round/calculation, adjustments could be “trigged” if they were under a certain distance. No chart op and computer ever got close to beating the machine during the adjustment phase. The S-3 in 3/12 at that time was a Maj. Westphal and he had been the officer in charge of fielding the FADAC prior to being assigned to 3/12. He was very knowledgeable of the device and was willing to explain it in great detail. YouTube has a video about the device at this address, there is some propaganda but what the hell:) https://www.youtube.com/watch?v=hJlPMSmmwZA

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