Question on weather, history, and GWX

[theworldover]

Greeting fellow Kaleuns,

At what point on the way to the surface, would a Uboat crew have been aware of the weather on the surface? I’ve noticed in terrible storms in GWX that I give me some movement above 20m but I’d like a more historical perspective. Thanks in advance friends.

[Aktungbby]

...at periscope depth; when the exec would do a meticulous 360⁰ with the observation scope to look for any air/sea subhunting threats...

[theworldover]

Originally Posted by Aktungbby

...at periscope depth; when the exec would do a meticulous 360⁰ with the observation scope to look for any air/sea subhunting threats...

So that’s it? No idea whether it’s calm or a hurricane until you look at it in the periscope?

[Aktungbby]

Originally Posted by theworldover

So that’s it? No idea whether it’s calm or a hurricane until you look at it in the periscope?

...basically you look first, no matter the weather; particularly at the sky for inbound-low-level 10-centimeter radar equipped PB4Y-1 Liberators et al(like my late Uncle Bob did) using a weatherfront as cover with 4 depth charges set to straddle your boat.. set on shallow to damage crash diving subs. The weather is a distant secondary issue to mere survival. And, in real U-boat life, the use of the extended wider-view observation scope precludes exceeding 3 knots when submerged to avoid vibration(and periscope's wake) of the scope's tube risking moisture and fogging, forcing a probable trip back to base! https://www.uboataces.com/periscopes.shtml

Before a U-boat breaks surface, the skipper would scan the horizon at periscope depth, searching for hostile units which could pose a threat. Only when its clear, the U-boat would surface, led by the watch officer, the crew would rush into positions on deck.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.

https://warfarehistorynetwork.com/ar...bay-of-biscay/ https://en.wikipedia.org/wiki/Battle_of_the_Atlantic

[d@rk51d3]

Originally Posted by theworldover

Greeting fellow Kaleuns,

At what point on the way to the surface, would a Uboat crew have been aware of the weather on the surface? I’ve noticed in terrible storms in GWX that I give me some movement above 20m but I’d like a more historical perspective. Thanks in advance friends.

From what I've read in modern subs, real bad weather can still be felt by the crew at about 400' or 120m.

[Randomizer]

Captain Bill Toti, USN (Rtd) has said that during one Pacific typhoon, he had to take his USS Indianapolis SSN 697 down to 600' before the rolling from the surface wave action ceased. This in a Improved Los Angeles class SSN, which at some 6000 tons submerged displacement was some 5-times bigger than a Type VII and some three-times bigger than a Type IX.

-C

[Hooston]

oops! Finger trouble. Trying again...

[Hooston]

Of course it's a simple matter of solving the equations given by Airy wave theory Wikipedia is pretty good at ocean wave models. Well, better than I am at maths.

There's some more comprehensible but a tad less scientific stuff here (I think this reference is an approximation). This second reference says that in deep water waves should be "felt" down to half a wavelength, it gives an example of an ocean wave with a wavelength of 48m being detectable down to 24m. The amplitude obviously scales with the surface wave height and the motion of the boat should also get slower with depth as the short wavelength waves get filtered out. Wikipedia recons ocean wind waves can have wavelengths of 60-150m so therefore would be detectable at 30-75m.
i assume a sonar operator could hear rain and also tell if there were breaking waves - anybody got some hard info? It seems to me the SH3 GUI's which display the surface weather at all times are closest to reality.
Pity that the SH3 weather model is so poor. i think it's because the campaign mode was an afterthought late in the development.

[theworldover]

Great info as always gang, thank you!

[Captain Drastic]

I think if you use HSIE Hardcode Patch there's an option that prevents reloading internal torpedoes near the surface in a storm. Mine is set for 40m, which I seem to remember as a good depth to escape the battering of storms. So, there is some attempt to model storms below the surface. Also, I use Depth Charge Shake Mod which increases the pitching and rolling while standing in the compartments, so the action of the waves underwater is more noticeable... really noticeable if time compression is 4X.

[Fifi]

Originally Posted by Captain Drastic

I think if you use HSIE Hardcode Patch there's an option that prevents reloading internal torpedoes near the surface in a storm. Mine is set for 40m, which I seem to remember as a good depth to escape the battering of storms. So, there is some attempt to model storms below the surface.

On side note, believing Herbert Werner testimony in his Irons Coffin book, they could reload torpedoes while surfaced in huge storms … so I personally deactivated this option in Hsie

[Captain Drastic]

It has been a while since I have read Iron Coffins, what a great book! Anyway, talk about hazardous duty- loading torps in storm conditions!
On another note, Fifi, my latest problem is the sound of spraying water from burst pipes seems to have disappeared from my game, and so far I can't find a solution. Any help? Start a new thread?

[Fifi]

Originally Posted by Captain Drastic

It has been a while since I have read Iron Coffins, what a great book! Anyway, talk about hazardous duty- loading torps in storm conditions!
On another note, Fifi, my latest problem is the sound of spraying water from burst pipes seems to have disappeared from my game, and so far I can't find a solution. Any help? Start a new thread?

Have a look into your sound folder and find the Steam burst.wav…it should be playing when clicking on it, and it’s the sound file for when spraying water in the command room.

[Aktungbby]

Originally Posted by theworldover

Greeting fellow Kaleuns,

At what point on the way to the surface, would a Uboat crew have been aware of the weather on the surface? I’ve noticed in terrible storms in GWX that I give me some movement above 20m but I’d like a more historical perspective. Thanks in advance friends.

Having PM'd a long-term member from my friends list who served on nukes, he responded that on the way to the surface in heavy seas, the motion can be detected at 200 feet...particularly when perpendicular to or abeam the current. It can be masked if the sub is moving fast but readily becomes apparent when slowing for periscope depth. If serious rolling is at or above 150 ft, stowing and tying down loose gear is essential.