Periscope Spirals

[Rokket]

I found this interesting..while doing some research on the Colins class sub, I found that there was a problem with the periscopes originally:

"The first was that they were not streamlined; raising a periscope while moving would create vibrations and water turbulence that could shake the entire submarine.[91] As with many elements of the submarine, there were disagreements as to who was responsible for the problem.[91] It was solved by fixing a spiral wrap around the head of each periscope, which redirected the water flow around."

The spirals on the Type VII - I think they've been referred to as "strengtheners" - never understood what they were or how they worked, but maybe (just maybe) they were for the above... either way, interesting.

[Bad Karma]

I can`t remember where this article came from,but it says at all.




 

[Rokket]

wow, thanks mate! Cool in one way, bad in another - 50-60 years later, no one learned from history! GRRRR! Why don't we learn and remember?!!!

[Bad Karma]

A few months ago someone ask the same question on another forum about these wires,
back then I made a scan of this article,well  :-[I had to look it up where this came from.

It comes from the book ''ubootwaffe,marine-kleinkampfverbande 1939-1945''(Waldemar Trojca) page 54.

[Rokket]

ahhhh.  It's interesting, I can't get over the point that modern sub designers HAVENT LEARNED! weird huh?  Bu thanks for the info, it was driving me crazy (I know, shirt drive)

[Pat]

Funny that sub designers haven't learned but automobile designers have.

Have you noticed the same sort of spiral on many car radio antennas these days?

[Jan]

Hehe...right now i`m thinking about putting a spiral around my car-antenna, too

[Rokket]

ahh, interesting!