No TDC on Suger Boats

don1reed · 04-02-07, 12:43 PM

Just sank a 19k ton escorted Euro Liner NW of PI. As we know, Sugar boats didn't have a TDC so I used the horizontal reticules on the objective lens of the scope.

In high power, each small mark = 15' MOA; each large mark = 1°.Top to bottom and side to side, lens face = 8°.
In Low power, each small mark = 1°; each large mark = 4°. Top to bottom and side to side, lens face = 32°.

Acquired first range and bearing, down scope...made plot, 3 min. later, acquired second range and bearing, down scope...made plot. Dist. travelled converted to 13 kn.

Computed OAC via ASIN (( 13 tgt speed / 31 torp speed ) x SIN 80 aob ) = 24°. Therefore, I fired a spread of 4 at the liner as she passed in front of 336° travelling left to right. All hit and she sank within 1 min. leaving 4 liferafts (RB-15's) braving the sea.

edit: btw, I might add that the escorts paid little attention to the proximity of the liferafts as they attempted to do me in. Interesting.

PeriscopeDepth · 04-02-07, 12:46 PM

Most are not as hardcore and skilled as yourself, though to get firing solutions without a TDC. Good job!

PD

RickC Sniper · 04-02-07, 01:44 PM

WTG Don,

don1reed · 04-02-07, 02:16 PM

Hey, hey...its the, Frank Kulick, method from SH1

.

Jungman · 04-02-07, 02:39 PM

That works well, nice information. But in WWII they did not have a calculator to compute those fun conversions, arcsin, sin, even divide? I thought that is what they use the TDC for (as a calculator).

Though I do admit, I also make the same manual calculation without the TDC...except I stick into the TDC just for fun.

I think they would have had to use that nomograph, wizwheels and stuff (no TDC ). How did they do it without the power of a modern calculator, or a TDC? BTY what is a Sugar boat? the S-class?

nattydread · 04-02-07, 02:43 PM

I assume they had spread-sheets for the trig computations. I have one. They also had a another guy or two doing the computations and map plotting other then the guy looking through the scope to make it efficient time wise considering they couldnt pause real life

04-02-07, 12:43 PM	#1
don1reed Ace of the Deep Join Date: Dec 2004 Location: Valhalla: Silent Generation Posts: 1,149 Downloads: 910 Uploads: 0	No TDC on Suger Boats Just sank a 19k ton escorted Euro Liner NW of PI. As we know, Sugar boats didn't have a TDC so I used the horizontal reticules on the objective lens of the scope. In high power, each small mark = 15' MOA; each large mark = 1°.Top to bottom and side to side, lens face = 8°. In Low power, each small mark = 1°; each large mark = 4°. Top to bottom and side to side, lens face = 32°. Acquired first range and bearing, down scope...made plot, 3 min. later, acquired second range and bearing, down scope...made plot. Dist. travelled converted to 13 kn. Computed OAC via ASIN (( 13 tgt speed / 31 torp speed ) x SIN 80 aob ) = 24°. Therefore, I fired a spread of 4 at the liner as she passed in front of 336° travelling left to right. All hit and she sank within 1 min. leaving 4 liferafts (RB-15's) braving the sea. edit: btw, I might add that the escorts paid little attention to the proximity of the liferafts as they attempted to do me in. Interesting. __________________ [SIGPIC][/SIGPIC] During times of universal deceit, telling the truth becomes a revolutionary act. ~ George Orwell

04-02-07, 01:44 PM	#3
RickC Sniper Undetectable Join Date: Sep 1999 Location: Colorado Posts: 1,221 Downloads: 132 Uploads: 0	WTG Don, __________________ Support Subsim http://www.subsim.com/store.html

04-02-07, 02:16 PM	#4
don1reed Ace of the Deep Join Date: Dec 2004 Location: Valhalla: Silent Generation Posts: 1,149 Downloads: 910 Uploads: 0	Hey, hey...its the, Frank Kulick, method from SH1 . __________________ [SIGPIC][/SIGPIC] During times of universal deceit, telling the truth becomes a revolutionary act. ~ George Orwell

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04-02-07, 12:46 PM	#2
PeriscopeDepth Sea Lord Join Date: Jul 2002 Location: Pacific NW Posts: 1,894 Downloads: 6 Uploads: 0	Most are not as hardcore and skilled as yourself, though to get firing solutions without a TDC. Good job! PD

04-02-07, 02:39 PM	#5
Jungman Samurai Navy Join Date: Apr 2005 Location: Iowa, USA Posts: 596 Downloads: 0 Uploads: 0	That works well, nice information. But in WWII they did not have a calculator to compute those fun conversions, arcsin, sin, even divide? I thought that is what they use the TDC for (as a calculator). Though I do admit, I also make the same manual calculation without the TDC...except I stick into the TDC just for fun. I think they would have had to use that nomograph, wizwheels and stuff (no TDC ). How did they do it without the power of a modern calculator, or a TDC? BTY what is a Sugar boat? the S-class?

04-02-07, 02:43 PM	#6
nattydread Captain Join Date: Jan 2004 Posts: 498 Downloads: 2 Uploads: 0	I assume they had spread-sheets for the trig computations. I have one. They also had a another guy or two doing the computations and map plotting other then the guy looking through the scope to make it efficient time wise considering they couldnt pause real life