Technology and Operations  
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RE: Periscopes
Posted by: Antonio Veiga ()
Date: August 19, 2001 06:02PM

Hi Fridolin

I think you mean all type VII german submarines had two periscopes.

Yes the type VII u-boat had two periscopes.

\"The ATTACK PERISCOPE was the larger (longer) and the aftermost of the two periscopes that protruded from the control room of a type VII U-boat.
Unlike the smaller (shorter) SKY PERISCOPE (and the attack periscope on US submarines of this period), the eyepiece of the ATTACK PERISCOPE did not rise and fall as the height of the periscope was adjusted.Rather, the eyepiece was sited at a fixed height in the small conning tower located directly above the control room.
Conventional periscopes, such as those used by the US Navy and by the Germans for the SKY PERISCOPE, used a simple prism arrangement.One prism in the periscope´s head bent incoming light 90 degrees downward and a second at height of the eyepiece bent the light another 90 degrees back to the original direction.The distance between the two prisms was fixed, making range calculations simple, based on image focus.
The type VII ATTACK PERISCOPE used the two prisms of a conventional periscope and added another adjustable double prism.
Light that entered the head was directed down to the bottom of the periscope and reversed 180 degrees in direction back up to the eyepiece by the double prism.
The configuration of the double prism was controlled by mechanical linkage to the
height adjustement mechanism of the periscope, (thus) compensating variances in periscope height....
... .The commander´s position at the attack periscope was actually quite efficiently
laid out despite the limited space.The CO was provided with a simple metal bicycle-type seat facing the periscope and the eyepiece.
Seated, straddling the periscope, the Commander controlled the rotation of the
periscope with foot pedals on each side.His right hand rested on a knob which controlled the angle of the upper prism.This could direct the centre of his field of view vertically from 15 degrees below horizontal to 70 degrees above.
On the left side was a lever which controlled the heigh of the periscope.
Other levers controlled the magnification, either 1.5 or .6, and the sun filtering.
The eyepiece was threaded to allow the connection of a still or motion picture camera.\"
(source: \"Type VII U-boats\" by Robert C. Stern)

Best regards

Options: ReplyQuote

Subject Written By Posted
Periscopes Fridolin 08/17/2001 06:29PM
RE: Periscopes J.T. McDaniel 08/18/2001 04:05AM
RE: Periscopes Bram 08/18/2001 10:08AM
RE: Periscopes walter M 08/18/2001 07:15PM
RE: Periscopes Fridolin 08/25/2001 07:17AM
RE: Periscopes Antonio Veiga 08/19/2001 06:02PM
RE: Periscopes kurt 08/20/2001 02:53AM
RE: Periscopes Fridolin 08/25/2001 07:14AM

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