American and German TDC

[Iron Budokan]

How much difference is there between the American TDC and the German one? Any similarities? Was there ever a study done as to which computer system was more accurate? Maybe that's hard to determine since there's a lot of human error involved: putting in the speed, AOB, etc....

I was just wondering about the mechanics of each system....any one know? Thanks!

[Torplexed]

They were similar electro-mechanical devices. However, later German models had the edge over the US TDC because, once the speed and course of an enemy force or convoy had been ascertained, the aim-off calculator could be fed data on up to five separate targets within the force; it could hold these, transmitting different gyro angles to different torpedoes, which could then be fired one after the other within seconds at the five different targets. The U-Boats also enjoyed an advantage in the optics department. The German Zeiss 7x50 lookout binoculars used in the UZO were lighter and more waterproof than those in other navies.

The primary American advantages probably lay in having sonar and radar sets for range-finding.

[Gino]

Originally Posted by Torplexed

They were similar electro-mechanical devices. However, later German models had the edge over the US TDC because, once the speed and course of an enemy force or convoy had been ascertained, the aim-off calculator could be fed data on up to five separate targets within the force; it could hold these, transmitting different gyro angles to different torpedoes, which could then be fired one after the other within seconds at the five different targets. The U-Boats also enjoyed an advantage in the optics department. The German Zeiss 7x50 lookout binoculars used in the UZO were lighter and more waterproof than those in other navies.

The primary American advantages probably lay in having sonar and radar sets for range-finding.

Could you give me the source of this data? I was always under the impression that the German system could only calculate for one solution. The only thing the UZO did was adjust the Defelection Angle. Thus it might seem that the germans could track more targets, but that is not true. During the attack the input was changed according to the position, speed etc of each target, and thus one could attack more targets at once. That in itself is nothing special...all navies had a similar system at that time.

I'm curious where you got the info from.

groetjes,

[Torplexed]

Originally Posted by Gino

I'm curious where you got the info from.

In Peter Padfield's War Beneath the Sea. In the second chapter he compares all the strengths and weaknesses of the subs of the major combatant navies. He's pretty objective about it too. Being British, he still gives Britain poor marks for their sub problems.

[Sailor Steve]

Originally Posted by Torplexed

They were similar electro-mechanical devices. However, later German models had the edge over the US TDC because, once the speed and course of an enemy force or convoy had been ascertained, the aim-off calculator could be fed data on up to five separate targets within the force; it could hold these, transmitting different gyro angles to different torpedoes, which could then be fired one after the other within seconds at the five different targets. The U-Boats also enjoyed an advantage in the optics department. The German Zeiss 7x50 lookout binoculars used in the UZO were lighter and more waterproof than those in other navies.

The primary American advantages probably lay in having sonar and radar sets for range-finding.

I disagree. I've heard about the multi-target option for the Germans, but I can't find any books that talk about it in-depth. I'd love to be shown wrong on that one.

But I really disagree on the UZO. The Germans may have had better optics, but the UZO was taken down before every dive. The American TBT (Target Bearing Transmitter) was fully waterproof and spent its life on the bridge.
http://www.bowfin.org/website/bowfin...ms/TBT/tbt.htm

An examination of a U-boat captured in 1941 (the TDC is examined in section II-E):
http://www.uboatarchive.net/U-570ONIReport.htm

A discussion of the TDC:
http://www.fleetsubmarine.com/tdc.html

[Paajtor]

This scheme is great...I like to pretend my cursor is a car, and I go riding along the lines, having great adventures everywhere.
Just came at a point, where it suddenly says ->A/REM34 |sin A...wow, made a huge jump there, all the way up to IM35!



*hunk hunk* omg, another turn...heeeeeeeere we go again!...screw it, the magnetic clutch rofl.

[Torplexed]

And this is a simple computer relatively speaking. .

[Boris]

Um... yeah. I'm not even going to pretend to understand that

[Gino]

Originally Posted by Iron Budokan

How much difference is there between the American TDC and the German one? Any similarities? Was there ever a study done as to which computer system was more accurate? Maybe that's hard to determine since there's a lot of human error involved: putting in the speed, AOB, etc....

I was just wondering about the mechanics of each system....any one know? Thanks!

There is a LOT of difference between the two. But it mainly comes to the Position Keeper, which no other nation had.
This made it possible for the US submarine TDC to continuously provide the gyro angle order that will send the torpedo to the target if it is fired at this moment. If the tactical situation will allow the torpedo to reach the target, then a "Correct Solution" indicator is lit. If the light is not lit it means that, even though the gyro angle order is correct, the torpedo won't reach the target (or won't have time to arm). The decision as to when to actually fire is up to the captain, who makes the decision based on a number of factors, including optimum range and/or intercept angle, and things like how to handle multiple targets or how to better avoid escorts
Futhermore, the Position Keeper was fed with data from Radar, Sonar and Periscope. It basically is a computer which continuously calculates where the Target is with respect from the submarine. Thus the submarine only had to make regular checks if the target 'behaved' as set in the TDC. If not, a correction could be entered, at which the complete solution was adjusted. Even with no periscope, or radar sticking out of the water the torpedo could be fired with great accuracy.

Check here:

http://www.usscod.org/tdc-restore.html This the TDC from USS Cod.The only Mark 4 in the world that is actually working! At the bottom you'll find a schematic of the TDC.

Another document about Japanese (somewhat the same idea as the German TFC) Torpedo Fire Control:

http://www.fischer-tropsch.org/prima...ort%20O-32.pdf

groetjes,