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-   -   The reduced positive boyance optional GWX mod (https://www.subsim.com/radioroom/showthread.php?t=117742)

Nuoz 07-02-07 12:17 PM

The reduced positive boyance optional GWX mod
 
I'm trying it. It's all good but my depth seems to depend on more than speed alone. I'm currently at 85meters having ordered 120, at 1 knots! wow. Anyone knows what gives?

Penelope_Grey 07-02-07 12:32 PM

U-Boat lacks the necessary inertial drive to push itself downward. You are going too slow.

Nuoz 07-02-07 12:37 PM

But shouldnt it mantain it's depth? If at one point i'm at 120 meters why should the boat ascend to 85 meters? It seems the deeper i go the more i will ascend. Oh boy :doh:

Penelope_Grey 07-02-07 12:38 PM

like I said 1 knot is too slow to maintain depth. If you had set 2 knots, you should have stayed put.

Thniper 07-02-07 12:50 PM

I always thought that an u-boat has zero buoyancy.:hmm:
In the book Das Boot it was said that the 'Regelzellen' were used for maintaining zero buoyancy.

Correct me if I'm wrong.

ichso 07-02-07 12:52 PM

The meters you will rise when going slower than 2kn seem to fullfit a certain rate. As I tested it some time ago here are some examples:
set depth....rised to
...15...............12
...90...............73
..140............115

Penelope_Grey 07-02-07 12:52 PM

No its not true, U-boats had a slightly positive bouyance. That is why GWX models a positive bouyancy in them.

Thniper 07-02-07 12:55 PM

Quote:

Originally Posted by Penelope_Grey
No its not true, U-boats had a slightly positive bouyance. That is why GWX models a positive bouyancy in them.

Well, what was the use of the 'Regelzellen' then?

Can you post a link where I can read about that buoyancy 'thing'?

Thanks in advance.

ichso 07-02-07 01:03 PM

The regelzellen are indeed for some fine tuning when submerged but aren't enough to eleminate every postive boyuancy.

http://www.weltderwunder.de/wdw/Tech...ten/index.html
sry, only in german :roll:

Brag 07-02-07 01:17 PM

In RL it is extremly difficult to achieve neutral bouyancy or perfect zero bouyancy.

Hadrys 07-02-07 01:23 PM

Quote:

Originally Posted by Brag
In RL it is extremly difficult to achieve neutral bouyancy or perfect zero bouyancy.

AFAIK they could only trim the boat not to "fall" with the bow or stern, just to keep it straight and when ascending/descending only pumping watter from bow/stern but not changing the trim volume. Also Das Boot book mentions about trimming every day to compensate food, water, diesel consumption. True.

However the deeper you go the smaller effect should it have. As I'm a diver it's very easy to keep 0 bouyancy at 40meter (especially using a wing not a "jacket") but you just take a deeper breath to start ascending quite fast when at 15-20m!

Nuoz 07-02-07 01:27 PM

Thanks for the info guys. Now i get it. Still one may think when the captain ordered a certain depth the crew would make sure the ordered depth was achieved and kept.. Nevertheless now this makes sense to me.

Hadrys 07-02-07 01:32 PM

Quote:

Originally Posted by Nuoz
Thanks for the info guys. Now i get it. Still one may think when the captain ordered a certain depth the crew would make sure the ordered depth was achieved and kept.. Nevertheless now this makes sense to me.

This was very hard, they needed to compensate non stop because in rough sea you can get in no time on the surface. Captain also needed to fight the scope up/down. When sub is moving with dive planes on dive a bit it's much easier because there is a constant force dragging down and it's better to go deeper than being shot to the surface in front of a DD :damn:

In game it gives some trouble but it's cool, I just set 14,5 meter periscope depth, not using P key.

Thniper 07-02-07 01:33 PM

I can remember a passage from the book where the LI says:

"Man kann ein gut getrimmtes Boot sogar am Periskop aufhängen."

Well, I'll try a translation (my english is not as good so don't laugh):

"You can hang up your u-boat by the periscope if it's well trimmed."

Consequently the book (or LI) must be wrong here, right?

Hadrys 07-02-07 01:45 PM

Quote:

Originally Posted by Thniper
"You can hang up your u-boat by the periscope if it's well trimmed."
Consequently the book (or LI) must be wrong here, right?

Yes, I can remember it and there was an explanation how to do it - periscope getting out of the water changes boat volume. In theory - dead flat sea it's possible I think :)

I had such a problem as diving in a thick drysuit in salty water. 40 kg of iron on my back couldn't drag me down, after breathing out all air from my lungs my head was hanging just below the surface of the sea. No matter of waves ets. Of course it didn't last for minutes. The only way was to bend down and kick my foot ;) After it I was like a rock. Maybe these examples are not that accurate but quite imaginable as they are reallife.


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