Trying to stick to real life practices: What is the purpose of the daily trim dive?

[Konovalov]

Having a great time having returned to SHIII with GWX 2.0. On my 9th patrol mid 1940 now operating out of Lorient, still using Type VIIb. :up:

Anyway I have started reading the book Iron Coffins by Herbert A Werner and I'm trying to implement as many real life procedures and tactics as I can into my in game experience.

I have noticed in the book constant reference to 'the daily trim dive' that was performed by the U-boat while on patrol. Can someone tell me why this was done on a daily basis and what was the point of this practice?

[Grayson02sept1980]

I think it was a daily routine to check if everything is ok for diving; check if the depth ruder and trimming tanks/vents... whatever worked

I am by far not an expert and I know little but I am just guessing.

[PhantomLord]

I think it was a daily routine to check if everything is ok for diving; check if the depth ruder and trimming tanks/vents... whatever worked

I am by far not an expert and I know little but I am just guessing.


Correct so far.

Boats behaviour under water is affected by many things

- water density and temperature - affects the amount of water to flood the tanks for a designated depth

- fuel and food consumption over the last day - it affects the weight

Chief engineer has to watch all these things and has to calibrate the boat every day. It´s all a matter of mathematics :know:

If the boat is trimmed wrong you´ll stay too long on the surface or go deep much too fast.

[Laufen zum Ziel]

For more realisim go to the below link under Authentic Photographs tab and you will see over 250 photos of U-boats and their crew, Chances are that your U-Boat will be there and is downloadable and printable. While your in that carreer you will have a photo of the actual boat and crew.

Wenn es mehr Waffen, dann laufen wie die Hölle

http://silent-hunter-addict.com

[Brag]

For more realisim go to the below link under Authentic Photographs tab and you will see over 250 photos of U-boats and their crew, Chances are that your U-Boat will be there and is downloadable and printable. While your in that carreer you will have a photo of the actual boat and crew.

Wenn es mehr Waffen, dann laufen wie die Hölle

http://silent-hunter-addict.com

That's an excellent site, I like the today in history page. :D

[PhantomLord]

I think it was a daily routine to check if everything is ok for diving; check if the depth ruder and trimming tanks/vents... whatever worked

I am by far not an expert and I know little but I am just guessing.

Correct so far.

Boats behaviour under water is affected by many things

- water density and temperature - affects the amount of water to flood the tanks for a designated depth

- fuel and food consumption over the last day - it affects the weight

Chief engineer has to watch all these things and has to calibrate the boat every day. It´s all a matter of mathematics :know:

If the boat is trimmed wrong you´ll stay too long on the surface or go deep much too fast.

I'd add that if the boat isn't trimmed properly it can be "heavy" on the bow or on the stern and thus very difficult to sail underwater

Right, thanks :D

[Jimbuna]

Initially it was also used as a means to check no sabotage had ocurred if the boat had been subject to shipyard maintanance.
As an example, it had been known for rope to be inserted in a seam to look like welding had been carried out.

[PavelKirilovich]

Other common forms of sabotage were "forgetting" tools or other hard objects in the ballast tanks and other sealed spaces after maintenance. This would create noise upon diving, helping ASDIC operators.

[PhantomLord]

...crosspost...

Yep.. some boats were lost without a clear reason. In some books i have you can read about many ways to sink a sub in the later years.
From bast shoes in the conning tower hatch, over to loose screws on the exhaust caps and flood tank caps and so on...
Afaik it was U123 (Hardegen) who returned to Lorient after one day. Boat was far away from being watertight! :o

[Jimbuna]

One of the better ones was discovering dead rats in the freshwater drinking tanks http://www.psionguild.org/forums/images/smilies/wolfsmilies/sickpup.gif

[Konovalov]

Ok, thanks guys for providing such great insight into this. :up:

By the way, I can't put this book Iron Coffins down unless the Mrs snatches it out of my hands. :lol:

[Avatar]

Is there a reason to do a daily Trim Dive in SH3?
I would think that you dont need to do this, asside from breaking up the monotomy.

[TomcatMVD]

Is there a reason to do a daily Trim Dive in SH3?
I would think that you dont need to do this, asside from breaking up the monotomy.
Just for fun and immersion.
Unless you're using SH3Cmdr, which includes failures and sabotage options.

[Avatar]

Thanks TomcatMVD.
I do it on occasion, also for hydrophone check.

[Kptlt. Siegmann]

Just for fun and immersion.
Unless you're using SH3Cmdr, which includes failures and sabotage options.

Would be nice to know if your boat had a leak or a wrench jammed in an unconvenient spot before getting too far from port:up:

[flag4]

Initially it was also used as a means to check no sabotage had ocurred if the boat had been subject to shipyard maintanance.
As an example, it had been known for rope to be inserted in a seam to look like welding had been carried out.

THAT is unbelievable - and believable too....

the people who did that sort of thing were brave beyond imaginable.

i think my only form of sabotague would be to not sweep up very well or dont empty the bins - drop litter, that sort of thing.

that example is really shocking - my god, you would test everything before heading out to sea. and then the thought of 'well, im probably not coming back anyway...'

[Jimbuna]

Initially it was also used as a means to check no sabotage had ocurred if the boat had been subject to shipyard maintanance.
As an example, it had been known for rope to be inserted in a seam to look like welding had been carried out.

THAT is unbelievable - and believable too....

the people who did that sort of thing were brave beyond imaginable.

i think my only form of sabotague would be to not sweep up very well or dont empty the bins - drop litter, that sort of thing.

that example is really shocking - my god, you would test everything before heading out to sea. and then the thought of 'well, im probably not coming back anyway...'

The Germans eventually introduced a tagging system whereby individual shipyard workers were made responsible for groups of workers or specific repairs.
Whilst this reduced the number of bouts of sabotage, it still resulted in numerous executions when a boat suddenly returned unexpectedly and reported faults.

[flag4]

[quote=jimbuna]Initially it was also used as a means to check no sabotage had ocurred if the boat had been subject to shipyard maintanance.
As an example, it had been known for rope to be inserted in a seam to look like welding had been carried out.

THAT is unbelievable - and believable too....

the people who did that sort of thing were brave beyond imaginable.

i think my only form of sabotague would be to not sweep up very well or dont empty the bins - drop litter, that sort of thing.

that example is really shocking - my god, you would test everything before heading out to sea. and then the thought of 'well, im probably not coming back anyway...'

The Germans eventually introduced a tagging system whereby individual shipyard workers were made responsible for groups of workers or specific repairs.
Whilst this reduced the number of bouts of sabotage, it still resulted in numerous executions when a boat suddenly returned unexpectedly and reported faults.

oh lord....it all sounds so hopeless :cry: