S-class and the TDC

[razark]

Originally Posted by Daniel Prates

Aren't analogic computers (specially manual methods as this mk viii) just a beauty?

I find old computational methods quite interesting. From a simple slide rule to a fleet boat TDC. Once I started learning about the TDC, but I was so surprised how amazing it was. Mechanical parts combined into a method of solving mathematical problems that most of us couldn't even begin to solve, and doing it in a continuous calculation to keep the firing solution up to date.

Originally Posted by Daniel Prates

Oh and since we're on the subject: did all sub classes carry this kind of manual calculators? I mean, this one for instance (the 'banjo' hehe) seems pretty reliable, portable and easy (?) to use. They would probably do just fine, should your TDC broke or didn't work for any reason.

Fleet boats did carry these, the one pictured in the link is from the Bowfin. The TDC was a complex mechanical device, and could easily break down.

Originally Posted by Daniel Prates

Anybody read anything about fleetboat captains having to use those?

I can't point you to anything off the top of my head, but I've read of them being used. The fire control party would use the TDC, while someone else was using the banjo to enter the same problem, making adjustments as new data was fed into the TDC. That way they could still carry out an attack if the TDC broke down in the middle of it. I've even read of cases where experienced users would beat the TDC to a firing solution.

[andqui]

I read something once about the Wahoo checking the TDC generated solution against the Banjo solution to make sure the soultion was 100% accurate, due to suspicions of torpedo troubles.

[Daniel Prates]

Originally Posted by razark

I find old computational methods quite interesting. (...) Mechanical parts combined into a method of solving mathematical problems that most of us couldn't even begin to solve, and doing it in a continuous calculation to keep the firing solution up to date.

Should anyone find this interesting, manual calculators (for the basic operations) exist since the 17th century!!! I am always humbled by the genius it took the inventors to develop machines that do math with nothing but dials and dented gears.

Gottfried Leibniz invented the Stepped Reckoner in 1694...



... also was the ARITHOMETER (1820)...




... and the most amazing, the CURTA, invented in 1948 by Curt Herzstark...



.... which is also portable.

[TorpX]

Very interesting thread here...............................


I'm amazed that anything so intricate could be built in the 1600's.

The S-boats would have used the Torpedo Angle Solver Mark VIII.

I'm still waiting for someone to make a printable version of it, though.

That would be sweet.

What would you suggest as a realistic compromise?

This is what I do:
I worked out the neccessary equations for the firing solution (for a zero gyro angle), and programed them into my TI-85. This reduces the amount of button pressing and last minute fiddling. I think it works quite well (as long as my data is good), but precludes course changes and attacking multiple targets at the same time.

Anybody read anything about fleetboat captains having to use those?

Normally, the XO would be on the TDC, with someone else, the Captain at the scope. But other arrangements were used as well. James Calvert talks about this some in his book, SILENT RUNNING. The XO was not good at operating the TDC, since he wasn't trained on it at the academy, so the skipper put Calvert on it, eventhough he was a junior officer. There were about 6 men in the group to plot and track, for an attack.

As Razark said, all boats had the mk VIII angle solver as a backup. It was often used to check solutions as the attacks were made. The reason the TDC came about, was that with the mk VIII, the time it took to generate the firing solution and set the gyros, often allowed the target to get by. I believe this was learned in prewar exercises.