Suggestion: Instability at Periscope Depth

derstosstrupp · 09-13-21, 01:13 PM

I think it would be great to make the boat a little more unstable at periscope depth, and well nigh impossible to hold over wind speed 9. The more I play with the wind speeds the more I am starting to think they approximate Beaufort scale winds based on the resulting waves I am seeing. And periscope depth was out of the question over about sea state 7 (where winds are often 9).

Many people complain that the dive officer does not have enough to do and that the role is too easy to learn/perform, and this would be a welcome challenge, the very same challenge that the chief engineer in reality faced when trying to hold periscope depth during an attack. I have read many accounts of skippers screaming down at the chief engineer for letting their scope pop up too high or dunk at a critical time.

The current ability to simply just dive and get a speed estimate even in very rough seas is a massive exploit and needs to change in my opinion.

Lignite · 09-14-21, 12:20 PM

I agree. It would seem a fairly common theme through memoirs of the guys that were there that holding exact depths was not an easy task and required constant attention. I too would like to see some slight changes to buoyancy (nothing crazy) that require some planes and/or trim tank work. Not easy for solo players, but hopefully the bots can make up for that (dive officer bot is not particularly necessary in the current state, I can set it and take care of it solo). Just my opinion.

mobucks · 09-28-21, 08:38 PM

Realistically, no sub Captain would ever even attempt a periscope attack with seas that high. It is just a game though.

Personally I don't even bother joining servers with high seas. Seems like a waste of time.

Fidd · 04-07-22, 07:06 PM

Trim-tanks to affect longitudinal balance, especially after torpedoes are fired, or with changes of depth, are I think the missing component here. From the little I've read - and I'm no expert - one of the chief causes of boats being forced to the surface, or deeper than they intended to go, was the boat becoming out of trim. This could occur from depth charges exploding beneath the boat, causing the front or aft end to decend rapidly into the aerated water beneath. The crude pitch changes required to regain control necessitating major trim changes. If this process got away from the dive officer, they could find themselves unable to cease a rise or descent of the boat.

A need to operate such trimming would make attaining and maintaining periscope depth harder and more time-consuming, and to potentially make vertical operation of the boat more demanding.

VonHoffman · 05-05-22, 06:54 PM

Does trim change that much with attitude? If you simply point the boat up/down using the planes and forward speed, then I can only see trim changing due to temperature differentials or even minor variation of pressure due to the different depth of each end of the boat?

If the tanks are not totally flooded, then I can also see the shift in mass making a small change, but surely not that much? Once the boat levels it will be back in trim again?

I do agree that near/on the surface the boat needs to rock a lot more with the waves. It's almost completely immune to the sea state.

derstosstrupp · 05-05-22, 07:47 PM

Quote:

Originally Posted by VonHoffman

Does trim change that much with attitude? If you simply point the boat up/down using the planes and forward speed, then I can only see trim changing due to temperature differentials or even minor variation of pressure due to the different depth of each end of the boat?

If the tanks are not totally flooded, then I can also see the shift in mass making a small change, but surely not that much? Once the boat levels it will be back in trim again?

I do agree that near/on the surface the boat needs to rock a lot more with the waves. It's almost completely immune to the sea state.

Trim for U-boats referred strictly to attitude changes. These were offset by transferring small amounts of water between the forward and aft trim tanks. This needed to be done daily as part of the trim dive, and became necessary due to any weight changes forward vs aft. Say carrying a sack of potatoes from end to end as a simple example. It’s also why, when submerged, moving about the boat was only by permission of the chief engineer because it would upset the trim (which is why the crew had “diving stations”).

I agree in terms of buoyancy being a function of many different factors including temperature, salinity, plankton content, own weight etc. That’s what the regulating tanks (what Wolfpack calls trim tank) were used for. However no significant changes were made here typically since weight changes were maintained in the dive logbook and the control room mate added the necessary water to compensate already on the surface. Different concept than trim though.

So the bulk of trimming (“einsteuern”) was shifting the water between trim tanks and also possibly adding/subtracting water from regulating tanks to make up for any miscalculations in weight, such that, at Kleine Fahrt and periscope depth, depth could be maintained with minimum hydroplane input on an even keel. But in rough seas this whole process was made exponentially more difficult because the sea churns on the surface and just below it, wreaking havoc on a submarine trying to maintain depth.

I advocate for true trim tanks in Wolfpack because the dive officer role becomes easy to master quickly. So some more complexity here I think would be welcome.

Now, that being said, there is an argument to be made for leaving that element out, because the assumption would already be possibly that the boat has undergone its daily trim dive by the time you spawn in, but regardless, it would be a nice touch to have to do a quick trim dive before you go about your engagement.

VonHoffman · 05-05-22, 09:26 PM

Yes - I would certainly like to see more technical depth to the tanks.

I know some time ago there was discussion about adding the saddle tanks rather than the simplified trim tank we have now. I'd like to see that whole area improved (even make it an option for easy vs. realistic tank configuration).

How do you trim the sim? I flood both fore and aft ballast tanks then use the trim tank to obtain neutral buoyancy at 20-30 m below the surface in a level condition. I'm guessing the boat is "magically" trimmed given the tanks we have?

09-13-21, 01:13 PM	#1
derstosstrupp Grey Wolf Join Date: Aug 2008 Posts: 913 Downloads: 490 Uploads: 0	Suggestion: Instability at Periscope Depth I think it would be great to make the boat a little more unstable at periscope depth, and well nigh impossible to hold over wind speed 9. The more I play with the wind speeds the more I am starting to think they approximate Beaufort scale winds based on the resulting waves I am seeing. And periscope depth was out of the question over about sea state 7 (where winds are often 9). Many people complain that the dive officer does not have enough to do and that the role is too easy to learn/perform, and this would be a welcome challenge, the very same challenge that the chief engineer in reality faced when trying to hold periscope depth during an attack. I have read many accounts of skippers screaming down at the chief engineer for letting their scope pop up too high or dunk at a critical time. The current ability to simply just dive and get a speed estimate even in very rough seas is a massive exploit and needs to change in my opinion. __________________ Ask me anything about the Type VII or IX! One-Stop Targeting Shop: https://drive.google.com/drive/folde...WwBt-1vjW28JbO My YT Channel: https://www.youtube.com/channel/UCIJ...9FXbD3S2kgwdPQ

09-14-21, 12:20 PM	#2
Lignite Watch Join Date: Jul 2002 Posts: 19 Downloads: 4 Uploads: 0	I agree. It would seem a fairly common theme through memoirs of the guys that were there that holding exact depths was not an easy task and required constant attention. I too would like to see some slight changes to buoyancy (nothing crazy) that require some planes and/or trim tank work. Not easy for solo players, but hopefully the bots can make up for that (dive officer bot is not particularly necessary in the current state, I can set it and take care of it solo). Just my opinion. __________________ U-157

09-28-21, 08:38 PM	#3
mobucks Seasoned Skipper Join Date: Jan 2010 Posts: 713 Downloads: 209 Uploads: 0	Realistically, no sub Captain would ever even attempt a periscope attack with seas that high. It is just a game though. Personally I don't even bother joining servers with high seas. Seems like a waste of time.

04-07-22, 07:06 PM	#4
Fidd Captain Join Date: Apr 2005 Location: Blighty! Posts: 542 Downloads: 10 Uploads: 0	Trim-tanks to affect longitudinal balance, especially after torpedoes are fired, or with changes of depth, are I think the missing component here. From the little I've read - and I'm no expert - one of the chief causes of boats being forced to the surface, or deeper than they intended to go, was the boat becoming out of trim. This could occur from depth charges exploding beneath the boat, causing the front or aft end to decend rapidly into the aerated water beneath. The crude pitch changes required to regain control necessitating major trim changes. If this process got away from the dive officer, they could find themselves unable to cease a rise or descent of the boat. A need to operate such trimming would make attaining and maintaining periscope depth harder and more time-consuming, and to potentially make vertical operation of the boat more demanding.

05-05-22, 06:54 PM	#5
VonHoffman Seaman Join Date: Oct 2019 Location: Near crush depth. Maybe. Posts: 33 Downloads: 6 Uploads: 0	Does trim change that much with attitude? If you simply point the boat up/down using the planes and forward speed, then I can only see trim changing due to temperature differentials or even minor variation of pressure due to the different depth of each end of the boat? If the tanks are not totally flooded, then I can also see the shift in mass making a small change, but surely not that much? Once the boat levels it will be back in trim again? I do agree that near/on the surface the boat needs to rock a lot more with the waves. It's almost completely immune to the sea state.

05-05-22, 09:26 PM	#7
VonHoffman Seaman Join Date: Oct 2019 Location: Near crush depth. Maybe. Posts: 33 Downloads: 6 Uploads: 0	Yes - I would certainly like to see more technical depth to the tanks. I know some time ago there was discussion about adding the saddle tanks rather than the simplified trim tank we have now. I'd like to see that whole area improved (even make it an option for easy vs. realistic tank configuration). How do you trim the sim? I flood both fore and aft ballast tanks then use the trim tank to obtain neutral buoyancy at 20-30 m below the surface in a level condition. I'm guessing the boat is "magically" trimmed given the tanks we have?