battery recharge question:historic

[brett25]

I noticed in SH3 that I am able to recharge the battery without moving the sub, as long as the engines are running and im in recharge mode. Does anyone know if this is historically correct? Did the uboats have a gear that disabled the propeller shaft allowing the engine to stiull spin the shaft to recharge the batteries withput having to be in motion?

[Task Force]

Originally Posted by brett25

I noticed in SH3 that I am able to recharge the battery without moving the sub, as long as the engines are running and im in recharge mode. Does anyone know if this is historically correct? Did the uboats have a gear that disabled the propeller shaft allowing the engine to stiull spin the shaft to recharge the batteries withput having to be in motion?

I belive when U boats are rechargeing they use one engine to spin one prop and the other to recharge. so, i believe if the were stopped, they would have 1 engine rechagreing and running and the other stopped.

[ryanglavin]

Task force is correct. they would also run extremely fuel efficient-like, by running 1 diesel through both electrics to run the boat. that was a solid 4 Kts.

[brett25]

ok thanks that makes sense. do you know of any good books covering the engineering and mechanics off the uboat?

[Jimbuna]

Recharging batteries whilst stationary is not realistic...but simply a glitch in the game that has not been addressed thus far.

[ryanglavin]

Originally Posted by brett25

ok thanks that makes sense. do you know of any good books covering the engineering and mechanics off the uboat?

One book, a biography on Wolfgang Luth goes into detail about the IXD2. Clay Blairs' Books go into alot of detail, if you read both front to back, (done that 4 times here )

[brett25]

Recharging batteries whilst stationary is not realistic...but simply a glitch in the game that has not been addressed thus far.

@jibuna , do you know if this was because the crew typically did not do that, or is it because its not possible mechanically speaking.

@ryanglavin thanks for those suggestions

[Task Force]

I would think its mechaniacly possiable... running one engine while while not turning the prop shaft... Abit like a car in park I guess, its still rechargeing the battery by turning the alternator but isnt moveing the wheels...

[ryanglavin]

Originally Posted by Task Force

I would think its mechaniacly possiable... running one engine while while not turning the prop shaft... Abit like a car in park I guess, its still rechargeing the battery by turning the alternator but isnt moveing the wheels...

The thing is, that I learned from my research on a Honors Lit paper in 9th grade (I write alot about submarines), that the diesels were directly connected to the electric engines which were connected to the Propeller shafts. Keeping it stopped wouldn't work because you would need the diesel engine to power the electric engine to get it recharged... Unless you found a way to cut a line to the propellor shaft, and i don't think you would want to do that.

[Jimbuna]

Originally Posted by brett25

@jibuna , do you know if this was because the crew typically did not do that, or is it because its not possible mechanically speaking.

See below....

Originally Posted by ryanglavin

The thing is, that I learned from my research on a Honors Lit paper in 9th grade (I write alot about submarines), that the diesels were directly connected to the electric engines which were connected to the Propeller shafts. Keeping it stopped wouldn't work because you would need the diesel engine to power the electric engine to get it recharged... Unless you found a way to cut a line to the propellor shaft, and i don't think you would want to do that.

[Sailor Steve]

The problem I have with that is that it also means that you would never see one prop not turning while you recharged. If they disengaged one engine from the propellor shaft while recharging, then it follows that if one was recharging and the other shut down then you could indeed be sitting still while recharging (if you so chose).

[Jimbuna]

Originally Posted by Sailor Steve

The problem I have with that is that it also means that you would never see one prop not turning while you recharged. If they disengaged one engine from the propellor shaft while recharging, then it follows that if one was recharging and the other shut down then you could indeed be sitting still while recharging (if you so chose).

Sorry Steve but you've lost me here (might be experiencing one of my rare sober moments).

Do you mean the game should always show at least one prop turning?

[brett25]

I found this manual covering recharging protocols: http://www.uboatarchive.net/BDUOrder2.htm (this article needs some deciphering from some of you who can)

and this more general article which seems to indicate the boat needed to be in motion during a recharge: http://www.uboataces.com/uboat-type-work.shtml

At greater depths, the U-boat is driven by electric motors using electricity drawn from giant internal batteries. When these are depleted, they must be recharged. This is done by traveling on the surface, or while snorkeling at periscope depth. The diesel engines are used to turn the electric motors so that they act as dynamos (generators) to recharge the depleted batteries. For rapid recharge, both diesel engines would be clutched onto the electric motors. For maximum range, one diesel engine would be clutched to an electric motor – which in turn acted as a generator to drive the other electric motor. Both propellers were turning in this way with only one diesel running.

here is a good article on uboat batteries: http://www.uboat.net/articles/id/54

[Sailor Steve]

Well, I spent 20 minutes researching and typing a long post explaining what was just said above, including links to both u-boat sources and US sources (US boats had the diesels connected directly to generators, which provided electricity to either run the motors or to charge the batteries) only to find that I had been logged off by the system and the whole thing was lost.

Sometimes I hate this server.

Anyway, the US stuff is all here.
http://www.maritime.org/fleetsub/elect/chap2.htm#2A

[Jimbuna]

Which takes me back to my post @#5....the propellor would be moving which would mean the U-boat should not be stationary........but the game allows for recharging of the batteries to take place whilst the boat is at a standstill.

I think....not really sure anymore.....what was the original point again?