S-Boat battery recharge rate

[Sniper297]

Worst trouble is what info you can find often has the internet factor - it's not all accurate.

http://en.wikipedia.org/wiki/United_...lass_submarine

P class was the first experiment with 4 diesels in two engine rooms, using the diesel-electric instead of direct drive with clutches. This source;

http://www.valoratsea.com/boats.htm

Lists all classes before Gato as having;

Power 2 Diesel engines/2 electric motors

Which is wrong for the Porpoise and Salmon/Sargo. Someone using that as a source and assuming all the data is correct would propagate that, then someone else uses HIS incorrect numbers as a source, Abandon Hope All Ye Who Enter Here.

I actually met a WWII submariner at a VA hospital several years ago, he served on an S class before the war and a Sargo during the war. That was several years ago and he mostly talked about the Saury, but one thing he mentioned about the S class was the depth limit - there was no way to take it down near test depth since they leaked at all the outboard flanges, the periscope flanges leaked even at periscope depth, the propeller glands leaked even on the surface. Down below 100 feet the bailing pumps had to be kept running full time and the water came in like a hydrant thru stuff like the diving planes shafts and sonar connections. A dive to 150 feet was the furthest they ever went, and after surfacing they needed several hours to drain and dry out the engines before they could start them since the main induction and exhaust valves all leaked.

As for charging rate, I can't find any info either, but even with a WWI design you would expect to be able to have at least 12 hours submergence for 6 hours charge. IIRC the fleet boats did a lot better than that, 1 hour of charging for every 6 hours at minimum speed submerged when the batteries are new.

[aanker]

"Valor At Sea" is an excellent website and mostly about the game SH1 & SHCE - with some real history added. SHCE was a great sim considering it was made in the mid 90's when most people were using MS-DOS without Windows but sadly it was already outdated when it was released.

You are absolutely correct about sources.

Lucky you to have had contact with 'real' WW II submariners. I was fortunate to have met some when I was young because almost everyone had a Dad or Uncle etc that served in WW II - but as kids I didn't fully appreciate it like I would now. They were the greatest generation!

[Sniper297]

It was actually one of them serendipity deals, the nearest VA hospital is in Tomah, WI, 90 miles away. When my son is out of town I take the VA van, which is usually loaded up at 0600 and doesn't return until 1800 or so, whatever time your appointment is for you end up spending the entire day in Tomah. He had finished his appointment around 0900 and had to wait til 1600 for his ride back to where he was going, my MRI wasn't until 1430, so we ended up trading sea stories in the cafeteria for 5 hours. I was an Aviation ASW tech in a heavy helicopter anti-submarine squadron, so he was as interested in my MOS as I was in his.

[TorpX]

Originally Posted by aanker

Maybe there is hope. Which specific RFB version are you using? I assumed RFB and TMO were accurate.

I'm using the latest RFB, 2.0.



Something else I (and others) have noticed, the S-boats don't turn half as well as they did in SHCE. At least when submerged. I don't really know if that is realistic or not. I tend to think the SHCE version is the more accurate.

Ruhe, in the previously mentioned book says quite a bit about the S-37. He made two war patrols on it. Almost everything would break down or leak, but apparently the batteries gave little trouble. It could be that the batteries were of recent manufacture. He did mention that most of the water obtained from the stills went into the batteries, leaving little for the crew.

I can only mod enough to get myself in trouble, but we shall see... lol

On those rare occasions when I give in to the temptation to try modding, I open up a game file in S3D, stare at the digital bits and pieces for awhile, then shut it down in disgust, thinking --well, that's not getting me anywhere. --

[aanker]

We're almost out of luck. Searching the forum the past few days and trying to make a 'nice' RFB install to work from, I became sidetracked... lol

What did you guys do about the NARWHAL? I wanted to include the 'donation' NARWHAL .....

It is almost sacrilegious to touch the/any RFB files because they worked so hard to keep it real. Apparently what I thought of as an agile boat because of its small size, the S-class did not have a fast turning time.

This is typical of what I found - to further discourage me:
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Originally Posted by Hitman

I can't give you accurate data, but I can confirm that the Sclass certainly was phased out already by 1941! Crews hated them, and knew that their surviving chances were a lot slimmer than in more modern boats.

If you want to use the Sclass, you must exploit its strong points and not the weak ones ... try to engage in operations in coastal waters, where its smaller bulk operates to your advantage vs. enemy ASDIC, and make maximum use of the good underwater speed. Your best bet to escape the enemy ASDIC is not by outmaneuvering him, but by sprinting away from where it will search in the next turn after dropping.

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I guess the RFB crew are busy doing other things now.......

Originally Posted by TorpX

I feel the same way. For some reason, there seem to be 10 modders working on SH 3 for every one on SH 4. And God knows, there is plenty in SH 4 that needs to be fixed.

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Originally Posted by Hitman

RFB is a great mod but work on it stopped long ago, and sadly there are not that many fleet boat fans around . And many of those play Trigger Maru, which is also a great mod.

What you report is something related to RSRD, as the campaign should assign you the special missions. But that will depend on boat/date/command you are operating for.

The boats that get most special missions are the Narwhal/Nautilus class, because they were actually so fat, slow and outdated, that they were soon relegated to those tasks. Get one of those in late 1942 or 1943, and you will almost only do special missions.

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The recharge times could be hopeless too. We shall see. What a shame about NARWHAL not patching nicely into RFB though.

Happy Hunting!

[Sniper297]

Okay, after poking around in Silent 3ditor I found this;

\Data\Submarine\NSS_s18\NSS_S18.sim

9:unit_Submarine\unit_Ship



That's what the default values look like. Testing in game I ran submerged until the batteries were 50% discharged, then stopped and surfaced, timed how long to full recharge. 36 hours. In another copy of the game I hacked that file;



(Tripled the drag on the rudder just because it bugs me that you can't reverse one prop while going ahead on the other, that value increases the rate of turn.) The horsepower of the engines apparently increases the recharge rate, jacking it from 1200 up to 9600 reduces the 50% recharge time from 36 hours to about 17 1/2 hours. Near as I can tell it doesn't affect anything else, altho I haven't done anything other than quick tests for speed, range, fuel consumption and battery discharge rate.

[Sailor Steve]

Originally Posted by Sniper297

(Tripled the drag on the rudder just because it bugs me that you can't reverse one prop while going ahead on the other, that value increases the rate of turn.)

Just a note of reality here. Reversing an engine to increase the turn rate works fine when doing a pre-planned maneuver. In combat it's something that is almost impossible, simply because the order has to be given, the signal telegraph has to signal the engine room, one engine has to be brought to a complete stop and started in reverse. By the time all that happens the point is long past when it would have done any good. Also remember that with one engine reversed the speed loss is almost double. If you go into that maneuver making eight knots you're going to come out of it making two or three.

Yes, it's handy when maneuvering around a harbor. In combat not so much.

[Sniper297]

We're talking submerged here, electric traction motors, not engines. It's a matter of seconds to reverse an electric motor, and it was commonly done when trying to speed up the rate of turn without getting excess speed while trying to line up a shot.

[Sailor Steve]

Yes we are. You're absolutely right, and I apologize. I was doing something else entirely when I realized that, and was just coming back to fix it, but too late.

[aanker]

Originally Posted by Sniper297

Okay, after poking around in Silent 3ditor I found this;

\Data\Submarine\NSS_s18\NSS_S18.sim

9:unit_Submarine\unit_Ship

That's what the default values look like. Testing in game I ran submerged until the batteries were 50% discharged, then stopped and surfaced, timed how long to full recharge. 36 hours...............

(Tripled the drag on the rudder just because it bugs me that you can't reverse one prop while going ahead on the other, that value increases the rate of turn.) The horsepower of the engines apparently increases the recharge rate, jacking it from 1200 up to 9600 reduces the 50% recharge time from 36 hours to about 17 1/2 hours. Near as I can tell it doesn't affect anything else, altho I haven't done anything other than quick tests for speed, range, fuel consumption and battery discharge rate.

Absolutely ridiculous recharge times... that's definitely not right - as you've read. They charged overnight - and not all night either.

I'd like to find the discussion on trying to fix this so I don't duplicate work that's been done. Wonder why the S-class are so different.

[Sniper297]

You're probably thinking of U-Boats. It MIGHT apply to the S boat on the surface - I never did a full study of it, but I recall reading somewhere that the 1918 armistice surrendered a bunch of different U-Boats to various allied forces. The S boat was allegedly based on a 1915 U-Boat design which had a priority that it could be built quickly and cheaply, with all the compromises that go along with that. In other words the design was so bad the Germans didn't really want it, they needed it because they were running out of time and materials.

Best I recall WWII German, British, and all US boats up until the Porpoise class were direct drive, the Porpoise was the first diesel-electric design which used the electric motors at all times, with the diesels coupled to generators so all they ever did was create electricity for running the motors and charging the batteries. The direct drives came in several flavors, most had the motor-generator core wrapped around the propeller shaft so when the field control current was off, it was nothing more than a big copper flywheel. Turn one field circuit on and it became a motor, turn the other one on and it became a generator. The diesels had a clutch which could be disengaged, and most were designed without any kind of transmission, instead they had to be shut down and started in reverse to back up. If there was power in the batteries there was no real need for that since you could just throw out the clutch and back with the motors. Other designs had the motor-generator separate from the shaft with gears and sometimes clutches, but best I recall the U-Boats had to run at 9 knots minimum to charge the batteries. Which made snorkeling a real beast. Once they got the bugs out of it the diesel-electric was a much better design.

[Sniper297]

aanker, missed your post - see my previous, open the \Data\Submarine\NSS_s18\NSS_S18.sim in Silent 3ditor and try fooling with the horsepower numbers. Near as I can tell that's not actually used for anything other than recharging the batteries. Again I have no idea if the S-Boats had to be running at speed or could charge batteries faster while drifting, near as I can find the S-Boat was a direct drive rather than diesel-electric.

[aanker]

Okay Sniper297 - the recharge time bothers me. With ranges - I seem to remember the farther the submerged range, the longer the recharge time.

I'm going to play with ranges - different values to reduce the recharge time and try a lot of values to try to find a pattern.

Happy S3D-ing - err Hunting!

[Sniper297]

Yelling down the wrong voicepipe, it's the eng power. Stock game I submerge to periscope depth and run all ahead standard, about 7 knots, goes 10 miles before the battery is down to 50%. Stop and surface, takes 36 hours to recharge.



Change the eng power from 1200 to 9600 and it depletes the battery 50% over the same time and distance, but takes half the time to recharge. Another test I changed that value from 1200 to 49600.0 and it recharged from 50% in 10 hours. Again near as I can tell that eng power number doesn't affect anything except the recharge time. If we had an idea what the recharge time SHOULD be we could probably get it pretty close just by changing the eng power number.

[TorpX]

Originally Posted by Sniper297

Change the eng power from 1200 to 9600 and it depletes the battery 50% over the same time and distance, but takes half the time to recharge. Another test I changed that value from 1200 to 49600.0 and it recharged from 50% in 10 hours. Again near as I can tell that eng power number doesn't affect anything except the recharge time.

This is very interesting.

I thought the eng power affected acceleration. Did you notice if it got up to speed faster?

I seem to remember the farther the submerged range, the longer the recharge time.

I believe this is correct.

Apparently what I thought of as an agile boat because of its small size, the S-class did not have a fast turning time.

Someone posted a quote from a reliable written source to that effect, but it is hard for me to believe they were this bad. They were designed with underwater performance in mind. We should also keep in mind that turning time and turning radius aren't the same thing. It is possible that they were fast, but had a large turning circle (or vice-versa?). I have never seen anything specific with regard to their turning. You would think there would be some data about this.

When I played the S-class in SHCE, I could dodge ashcans very well (as long as the battery held out). In SH4 w/RFB, I don't even try to use these tactics.