Uboat binoculars and carrying straps, thoghts on developement and choise of materials

[Mikedenmark]

That is one thing that I wonder about: Why did they use leather for straps, why not cotton?, or even steel chain with hooks at the ends?

A leather strap torn has no redundancy, meaning once something snaps, the bino is in for a short drop and a sudden stop, (to quote pirates of the caribean referring to a somewhat different snapping exercise)

And why did the 8x60 fat model not have rubber protection?

Did they run out of rubber?

I think we still need to figure out what happened with uboat binoculars during the war.
Prewar was Leitz porroII unprotected.
then came the rubber protection
Then the leitz 8x60 porro II with rubber protection ( ever seen in an unrubberised version anyone??)
Then the Zeiss 7x50 Uboat Bino, but still early on, un rubbered.
Then that one with rubber.
And last, the 8x60 Commanders glass, again without rubber covers.

OR, do someone actually have a commanders 8x60 with rubber protections
It seems to have the needed edge around the upper prism housings to keep a rubber protection on.

Either zeiss archives might have something..like a drawing of the rubber covers for the 8x60, or, someone should look through old reports from the uboats and see what they said about binoculars during the war.
Each crew was going through an extensive interview after each active trip. They constantly systematically gathered as much intel as possible to improve performance. And developements of binoculars are likely to have originated here.

[phild]

That is one thing that I wonder about: Why did they use leather for straps, why not cotton?, or even steel chain with hooks at the ends?

A leather strap torn has no redundancy, meaning once something snaps, the bino is in for a short drop and a sudden stop, (to quote pirates of the caribean referring to a somewhat different snapping exercise)

And why did the 8x60 fat model not have rubber protection?

Did they run out of rubber?

I think we still need to figure out what happened with uboat binoculars during the war.
Prewar was Leitz porroII unprotected.
then came the rubber protection
Then the leitz 8x60 porro II with rubber protection ( ever seen in an unrubberised version anyone??)
Then the Zeiss 7x50 Uboat Bino, but still early on, un rubbered.
Then that one with rubber.
And last, the 8x60 Commanders glass, again without rubber covers.

OR, do someone actually have a commanders 8x60 with rubber protections
It seems to have the needed edge around the upper prism housings to keep a rubber protection on.

Either zeiss archives might have something..like a drawing of the rubber covers for the 8x60, or, someone should look through old reports from the uboats and see what they said about binoculars during the war.
Each crew was going through an extensive interview after each active trip. They constantly systematically gathered as much intel as possible to improve performance. And developements of binoculars are likely to have originated here.

All interesting questions to think about. I agree that on the surface leather does not seem to be ideal choice for KM heavy bino straps. I can say however that when new and even a few years old the leather was very strong and short of being soaked in sea water for many months..and maybe some were, it would have held them fine during the period. I have not seen a strap on a 8x60 that I knew was period...but some out there probably are period...but the ones on the 7x50 U-Boot glass that I have seen and own that I KNOW are the orginal ones for those heavy glasses are of a thicker leather than normally found on Heer large binos...maybe 2X as thick.....I could guess that the Fat 8x60 straps were at least that thick and maybe wider as well....as the eyelets were wider .

As for why the fat 8x60s were not rubber armored.....well they were built like a tank to begin with, also they were for the Cdr use only and kept in a case except when in his use...not handed off and passed around the deck of the U-boot for hours on end by watch crewmen.