[TEC] German UBoat optics

[Hitman]

Because I see many people making guesses or misinformed about a lot of technical matters regarding the optics in the german UBoats, I have uploaded here a document that covers the scarce info that is available, and which I have been collecting over several years from different sources:

http://www.mediafire.com/?izkokujdowf

Much of this info I have been giving in the SH3/4 mods forum, but it is understandable that many new modders who pour into SH5 as their first step here have no idea what a wealth of info has been acumulated over years on the other forums.

Happy hunting

[reaper7]

Thank you Hitman realy appreciated.

[Shigawire]

Wow. Very impressive and decisive facts.

[verte]

Superb, I didn't seen that in SH3 forum. Still waiting for new Hitman optics to start a NYGM campaign.

[Pandion]

Cheers,

That was interesting to read

[emtguf]

Thanks hitman! used this info to update my mod.

[The General]

Hitman, this is fantastic stuff! Thanks for sharing So, the UZO was not gyroscopically based?

[Hitman]

Gyroscopical? I'm not sure if I understand what you mean, maybe stereoscopical rangefinder?

No, the UZO wasn't normally capable of rangefinding. I have readed references to some late war models that had 10x80 zoom and that stereoscopic rangefinding capability, but I have not seen records of any being operational on an uboat. They certainly were developed, but probably as the surface attacks were no longer possible due to radar they were dropped.

[Sailor Steve]

I think he's asking whether it was stabilized.

As far as I know even battleship rangefinders weren't stabilized until after the war.

[Arclight]

Many thanks, send an E-mail requesting details on binocular reticle, but no repsonse yet. So the image is more then welcome.

[walsh2509]

I read this ..



The periscope consisted of a long steel tube which extended out to about five meters from the housing. It had prisms and lenses at both ends, for which there was a switch that allowed the commander to toggle the magnification level – either 1x or 6x. Periscopes suffered from two main problems, the most important was vibration. When fully extended, the long unsupported tube created turbulence on a moving U-boat. At 6 knots, it caused excessive vibration which rendered it almost impossible to use. This was dampened by using an extension bracket to reduce the unsupported length and the pointed end was redesigned to minimize the forward hydrodynamic resistance. Nevertheless, vibrations still occurred, but to a much lesser degree. The other problem was fogging of the lenses. Since the damp atmosphere of the U-boat caused fogging, it was especially important that the tube was not only watertight, but was airtight as well. Any fracture on the airtight casing caused by a depth charge attack would result in fogging of the tubes.



The attack and observation periscope were somewhat different in that the latter had a bicycle like seat and paddles, which were raised and lowered together with the periscope. The observation periscope also had better night vision capabilities.


Saying the latter , I take it they mean the Observation periscope, I am right in saying the Ob/Scope is in the Control Room and the Attack periscope is up the ladder above the Control Room.

If so have they not got the Seat and Paddles on the wrong one ?

Nope - the attack scope, located in the small conning tower room, was the one with pedals and seat. The observationscope was the one in the control room.

[Hitman]

There were two types of fixed heigth periscopes, one of them was the standsehrohr A1 which effectively raised and lowered the seat with the scope. Thus it only could be placed in the control room. IIRC only a few boats from the bigger IX class did ever mount them, as it was dropped in favour of the standing attack periscope in the conning tower.

Follow this link for an overview of the Zeiss archives: http://www.archive.zeiss.de/rech.FAU...&RPOS=1&AUFT=0

[Vanilla]

Just to clarify as it can be tricky to understand:

The seat and pedals were NOT moved up or down with the scope in the control tower, they were fixed (although they rotated with the scope however). The periscope was so designed as to have a FIXED eye-level while the head could be moved up or down. Quite simple and ingeniuos design on the behalf of German engineers that quite impressed British experts:
"... The main feature of the periscope is that it can be raised and lowered through a distance of approximately 17 ft. while in any position over that distance, the observer can view the target without altering his position vertically relative to the deck. ..."

Here is a historical source with pictures and explanation.
http://www.uboatarchive.net/U-570BritishReport.htm
Check page 30 there, section Zeiss Fixed Eyepiece Periscope
It has a lot of other details about U-boat optics and many other systmes as well. I strongly recommend to look through the whole site - a lot of very interesting information there!
And it can be clearly seen from the reports there that type VII, IX and XXI - all used the same periscope arrangement with the obesrvational scope down in the control room and attack scope with a fixed eye-level in the command tower.

Few interesting things to note from there:
There were only two color filters in the both scopes: bright orange and deep neutral ('smoked glass'). Both scopes and UZO had graticule night illumination with 'on-off' switch.
Another thing: the observational scope was binocular 'on demand', i.e. it had two eye-pieces so designed that an observer could switch from one eye-piece to binocular mode (at light power expense, that is with loss of brightness).
One more feature - one could see bearing scale while looking through observational scope: " The periscope is fitted with a bearings scale telescope, which is intended to make the indications of the bearings scale, visible in the main eyepiece. "
Finally UZO: the UZO had almost 2 times brighter view (67% of light transmission as opposed to 30-40 by the scopes).

PS My humble guess it is the fixed eye-level feature that did not allow to install stadimeters in the U-boats. There is no advantage without a drawback.