Finding range with Periscope

[Rosencrantz]

Hello everyone!


After years of research I'm still looking for detailed info how they find range to target with attack scope. What kind of scales there were in the scope? Just marks like we can see them in the SHIII attack scope? I doubt this. I think what you saw when looking in the real attack scope was much more complicated.

Heinz Schaeffer tells in his book "U-977" how you could see different "marks" when looking through the scope. Color of "marks" were red, green, yellow, black or white depending on what was their purpose. So, what are those marks? Any ideas? Marks for different mast heights?

In the fleet boats of US Navy the assistant approach officer checked the range from a special table after the approach officer has given him the estimated mast height. What I have read about U-boats, it looks to me approach officer was able to determine range to target with the scope or UZO without any need for assistant with tables.

I appreciate if someone could give me more info or send me a link or something where to look for, or share with me a good picture about what you saw when looking through the U-boats attack scope.


Greetings,
-RC-

[seafarer]

The stadimeter does this for the periscope operatior. All he has to do is line up the periscope markings correctly, enter the "known" mast height from the recognition manual, and the stadimeter will instantly calculate the range.

The stadimeter was invented by an American naval officer, Bradley Allen Fiske, in 1800's, and was first used in naval gunnery trials in the mid 1890's. It was widely available by even the first world war

"...In practice, a sailor would identify a distant ship, adjust the stadimeter for its mast-head height (a figure available in published accounts), bring the image of the mast-head into coincidence with the water line, and read the distance on the instrument’s drum. Stadimeters were widely used in World War I and again in World War II."

You might also find the 1946 Fleet Submarine Periscope manual interesting to read:
http://hnsa.org/doc/fleetsub/pscope/index.htm

P.S. When you look at US fleet boat scopes, the stadimeter control is a small crank below the right periscope handle, and the range readout dial is a large dial at the bottom of the scope, angles so it can be read by just glancing down from the eyepiece - see the pictures from www.bowfin.org at
http://www.bowfin.org/website/bowfin.../periscope.htm
also - http://hnsa.org/doc/attack/img/plateiv.jpg

P.P.S. Image through a u-boat periscope at http://ww2wochenschau.com/ww2-video/...525-uboats.jpg
and http://www.usmm.net/images/periscope.jpg

[Rosencrantz]

Thanks alot for the pics!


What I wrote before about the fleet boats and assistant approach officer wasn't correct. Sorry for that. By "table" I meant the the stadimeter's table behind the scope.

I think also germans got few different scope models at least for the attack scope and maybe also for the observation scope or luftzielrohr like they called it. I think there wasn't stadimeter in the early attack scope but just the horizontal range finder which needed the AOB to be taken under consideration.

Greetings,
-RC-

[Hitman]

After years of research I'm still looking for detailed info how they find range to target with attack scope. What kind of scales there were in the scope? Just marks like we can see them in the SHIII attack scope? I doubt this. I think what you saw when looking in the real attack scope was much more complicated.

Heinz Schaeffer tells in his book "U-977" how you could see different "marks" when looking through the scope. Color of "marks" were red, green, yellow, black or white depending on what was their purpose. So, what are those marks? Any ideas? Marks for different mast heights?

That was the fixed attack scope or Standsehror. It had an integrated analogic "computer" or range and AOB finding system through wiz-wheels. The results were displayed in the ocular, out of the main field of view. AFAIK green and red were for the different AOB (Port/Starbord), yellow for the range, black for the bearing to target.

Could you post the whole text of Schäffers book when he talks about the scopes? I would be interested in reading it, may be I can find something new