Battery while Surfaced?

[Schlageter-JG26]

Is there any way to make use of battery power while surfaced? My theory being that we could squeak out greater patrol range this way by saving fuel and using the battery to gain faster speed on the surface.

Is this possible? Or would this be a mod?

[valpospe]

How exactly would this save fuel? I'm no thermodynamic expert but I would guess that the energy expeneded to recharge the batteries is more than the energy you get out of them. In other words, even if you could link the two systems to get greater speed or power or whatever, your batteries would eventually need to be recharged expending at least (and probably more) enegery (fuel) than just running diesel on the surface.

[Rykaird]

Yes, it couldn't possibly be more efficient.

But, it would be realistic. In Werner's Iron Coffins they pretty much always pull away from the dock on electrics. He never says why, but it does come up a number of times.

[Cakewalk]

It depends how they would have the diesels hooked up to the generators. If the diesel shafts simply ran through the electric motors and turned them while the diesels were running, then there would be no loss in effeciency.

In Silent Hunter 3, one of your engines would switch to turning over an electric motor inside the sub, leaving you with only one screw, thereby making it less effecient.

In SH4 though, both props keep turning while recharging, so it may be the case I stated above.

[valpospe]

I haven't had enough time with the game to do in game testing. However, the fact that you can select to not charge the batteries while on the surface implies that it does take away power from the main diesels (like pto in a tractor or some kind of clutch) even thought both screws are turning (which I haven't verified). Either way, nothing regarding energy is free. I doubt they had the system set up turn the generators for recharging the battieries even when they didn't need to. It wouldn't make sense simply due to the resulting loss of efficiency it would create.

[GoldenRivet]

there needs to be a mod for this in SH3 as well.

I have read in a few books that type VII skippers would often conduct surface attacks using the electric motors as they were quieter than diesels when stalking close in on a ship.

[valpospe]

"I have read in a few books that type VII skippers would often conduct surface attacks using the electric motors as they were quieter than diesels when stalking close in on a ship."

Agreed. You should be able to choose to run batteries on the surface. If they could do it in real life, then we should be able to also.

I have no idea whether mechanically they could run both at the same time like the original poster suggested, though I doubt it. I was mainly addressing the theory that doing this regularly would somehow save fuel. Two different questions.

Happy Hunting....

[ccruner13]

batteries recharge without fuel. i know this because well...i ran out about 2000km from base. dive run on batteries surface and they recharged. took forever at less than 20k a dive. also....being damaged kills you efficiency. i get from midway to sea of japan on roughly 1/4 tank and i had more than 1/2 a tank left on my way back when i ran out....travelling at 1/3 speed.

solar power? wind? lol

[XanderF]

batteries recharge without fuel. i know this because well...i ran out about 2000km from base. dive run on batteries surface and they recharged. took forever at less than 20k a dive. also....being damaged kills you efficiency. i get from midway to sea of japan on roughly 1/4 tank and i had more than 1/2 a tank left on my way back when i ran out....travelling at 1/3 speed.

solar power? wind? lol

What, you mean you didn't notice all the bicycle machines they get out on the deck?

[Drebbel]

Yes, it couldn't possibly be more efficient.

But, it would be realistic. In Werner's Iron Coffins they pretty much always pull away from the dock on electrics. He never says why, but it does come up a number of times.

Perhaps to keep smoke out of the eyes of the farewell party or not to fill the uboat penn with fumes

[hyperion2206]

Yes, it couldn't possibly be more efficient.

But, it would be realistic. In Werner's Iron Coffins they pretty much always pull away from the dock on electrics. He never says why, but it does come up a number of times.
Perhaps to keep smoke out of the eyes of the farewell party or not to fill the uboat penn with fumes

It's same reason why you must not let your car engine run in a garage, the fumes become deadly (at least when you're leaving a sub pen).

[Dowly]

And same applies to running electrics while stalking close ships. The diesels generate small amounts of smoke + they are noisier.

[Sgian Dubh]

Yes, it couldn't possibly be more efficient.

But, it would be realistic. In Werner's Iron Coffins they pretty much always pull away from the dock on electrics. He never says why, but it does come up a number of times.

Because there wasmuch less chance that electrics would arm an acoustic mine in the harbor.

[MP]

Hi All,

Basically my sub is crippled about 80 miles outside the harbor in the Jawa Sea (pwned by a task force). My electric engines are repaired a functioning fully. My diesel engines are caput!
I tried going to periscope depth and my electric engines come online, but even though I have repaired all damage to the sub (diesel engines excluded), she sinks like a brick, and my electric engines just drive me deeper into the ocean floor.

Has anyone found a way to enable electric engines while on the surface, so I can limp home? There is nothing in the MOD release section.

Thx in advance

[Ostfriese]

It depends how they would have the diesels hooked up to the generators. If the diesel shafts simply ran through the electric motors and turned them while the diesels were running, then there would be no loss in effeciency.

Oh yes, there would be. If you withdraw energy on one side of the system (to charge batteries for example) you must put (at least) the same amount of energy into the system on the other side.

[AVGWarhawk]

What we really need is the ability to shut down each diesel independanlty. Often the subs would patrol on one diesel to save fuel. Above and beyond that we need to be able to control speeds of each screw for tighter turning.

[joea]

What we really need is the ability to shut down each diesel independanlty. Often the subs would patrol on one diesel to save fuel. Above and beyond that we need to be able to control speeds of each screw for tighter turning.

We could do that in SH2. :nope:

[tater]

Most US subs were true diesel-electrics—the screws were truned by electric motors, there was no shaft turned by the engine. Switching between the generator and batteries should be flipping a switch.

Might also be useful if damaged on the surface, you run off batteries to egress if diesels are out of commission. Alternately, ahead 1/3 off the genrators is higher speed than 1/3 battery. There might be times you want to move slower (and we don't have individual engine control).

tater

[-Pv-]

My impression is there is some WWII US realism modeling going on with diesels in that setting the lower speeds takes engines offline and directs them to battery charging making that process a bit faster.

In my opionion, no modding is necessary if the captain just uses smarts and watches the fuel usage. At lower speed settings (slow and 1/3) you have a great amount of range (much more than the SH3 boats.) Although I can see it as attractive to be able to switch to batt on the surface (and I have read real historical accounts where this was done to make the boat quieter while passsing near the enemy and near coasts) in a more practical sense, anything that would make less than full battery available when you get jumped or forced under for extended periods is not a good practice. WWII commanders protected the battery charge like a glass of water in the desert.

On efficiency...
Careful observation of both SH3 and 4 behavior indicates there is a slight fuel extension to running on the battery even if submerged so don't worry you can't do it on the surface, just go ahead and do some battery-range extension submerged anyway. In a tough situation, it might mean the diff between getting home. I did that once in SH3. But again, if you are smart and reserve the amount of fuel you need to get home and don't let youself get distracted, the crew will appreciate getting their mail and you will have a better next mission with a rested crew, skilled replacements, and upgrades to the boat.
-Pv-

[SingeDebile]

as was said before in terms of physics (maybe game is wrong) it is IMPOSSIBLE to get more range by charging and using your battery's... (you would be creating energy.. end of story) Not to mention the battery's they used back then were probobly not very effeicient. if you really wanted to get ultimate range and you had used some of your battery, by shutting down the battery recharge (no one mentioned you could do this?) you would get a better range... this is your best bet (and might actually be an option if you barely run submerged).