Submarine Scopes - Can they always be deployed?

[XenonSurf]

Could in WWII all submarines (German Type II, VII, IX, XXI, US Gato type etc.) always raise their scopes without them getting damaged? At all speeds and all sea conditions?
And what about on today subs?


Thanks.XS

[Aktungbby]

NO!...this has been discussed previously; the submerged speed for an extended periscpe needs to be 3 knots or less to prevent tube vibration. AND don't forget to drap your arm over the periscope hand for added steadiness https://www.subsim.com/radioroom//sh...d.php?t=201357

Draping one arm over the periscope handle was a common practice among German U-boat captains, but it wasn't specifically an "Erich Topp thing." This gesture served a few practical purposes:

Stability and Control: By resting an arm on the periscope handle, the captain could stabilize the periscope while making adjustments to its position or while observing. This helped in keeping the periscope steady, especially in rough seas.
Comfort: It provided a more relaxed posture during long periods of observation, which was important during tense situations when the crew was on high alert.
Visibility: The position of the arm could also help in maintaining a better line of sight and reduce fatigue, allowing the captain to scan the horizon for enemy ships or submarines more effectively.
While Erich Topp, a notable U-boat commander, may have been observed doing this, it was not unique to him. Many U-boat captains adopted this practice during their missions.

Also the other factor is going slow to reduce the scope's wake in the water to observant escort vessels : https://www.subsim.com/radioroom/sho...22&postcount=5 https://uboat.net/forums/read.php?20,64127,64136

Originally Posted by walsh2509

he 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.

[KaleunMarco]

Originally Posted by Aktungbby

NO!...this has been discussed previously; the submerged speed for an extended periscpe needs to be 3 knots or less to prevent tube vibration. AND don't forget to drap your arm over the periscope hand for added steadiness https://www.subsim.com/radioroom//sh...d.php?t=201357 Also the other factor is going slow to reduce the scope's wake in the water to observant escort vessels : https://www.subsim.com/radioroom/sho...22&postcount=5 https://uboat.net/forums/read.php?20,64127,64136

fogging of the tubes......

i hate when my tubes get fogged.

[Aktungbby]

Originally Posted by KaleunMarco

fogging of the tubes......

i hate when my tubes get fogged.

Worse yet, after the advent of Liberator 10-centimeter radar equipped Coastal Command aircraft, being on the surface to recharge or surface-approach a target vessel was hazardous, a fogged scope would practically entail a return to base ending the war patrol. One little-discussed facet of the U-boat war is that the repair backlog at the bombproof bases was abysmal. This actually encouraged a scheme to create remotely flown explosive-laden B-24s into the concrete base bunkers to wreak damage on idle U-boats. One such experimental aircraft exploded prematurely before the pilots could bailout, killing Ambassador Joseph Kennedy's eldest son, Joe Jr., and paving the way for #2 son, John, stepping up to a career in politics after his PT 109 Navy Cross winning adventures in the Pacific.

[XenonSurf]

Thank you both very much for your extended feedbacks, very appreciated!


I had a discussion about this question on another forum and my close guess was that sailing at 2 knots with the scope deployed in rough conditions should be a safe limit - but probably a useless action as for what you could actually see with all the splashes. My recommendation in the game UBOAT was: Go deck awash to increase your sight range a bit at the risk to be spotted.


My best greetings to you
XS

[Aktungbby]

/\....you only do a 'decks awash' approach at night...and never with the moon behind you!

[Kapitan]

To quote perisher teacher Commodore Jim Perks "we don't go around waving masts around"

higher the speed more of a wake the scope will leave meaning more likely to be detected.

even back in WWII & WWI scopes and other masts had speed limitations and the same is true of today's boats.