night and day

Sledgehammer427 · 03-26-08, 10:01 PM

after playing in my career under command of a type VIIB in 1939-1940, i had a sudden urge to start a new career commanding a type XXI, which isnt available until 1944

holy cow....its like night and day, thank heavens i have the ability to stay under but its so tempting to surface to recharge the batteries....

and theres the ASW....
but it helped me realise that the type XXI is a very desirable boat...
first patrol, however, i sank a bogue CVE in a task force with a southampton cruiser, as well as a couple less notable freighters, and two unescorted fast tankers....
totaling 39,400 some tons...
and i made it home without taking any notable damage!

anyone else have this kinda fun?

Torplexed · 03-26-08, 10:16 PM

Yeah it's a nice sub. Be careful you don't get spoiled.

The one in the game probably functions far better than the real ones that were built under onerous wartime conditions and had quite a few teething problems. Assuming German sub design had been pushed a bit more by some visionary in the pre-war years it does make you wonder what might have been.

Sledgehammer427 · 03-26-08, 10:23 PM

yeah, i read that even though the sectioned building methods were revolutionary, they were held back by bad welds, and other problems, but they are still fun

Tessa · 03-26-08, 11:19 PM

The underwater speed is intoxicating, even at silent speed. So easy to ditch destroyers amidst a convoy and escape untouched.

finchOU · 03-27-08, 08:39 PM

Got a question on the above post. What is nosier...higher speed or RPMs? I've heard that you have to stay under 2 knots to be quiet..or 150 RPMs (about 3-4 knots in a VIIC)....well the 150 seems to be Bull casue they seem to hear me as soon as I break the 2 knot rule....so with a XXI....ahead slow gives like what 5-6 knots?...and Low RPMs?

I've been up 100% "attemped" realism since the start...so I have not tried tinkering with the Stealth O meter...whats the word on the street?

kurtz · 03-28-08, 06:32 AM

I believe the noise comes about through cavitation on the propellors so should change from boat to boat assuming different propellors but will ultimately depend upon rpm.

_Seth_ · 03-28-08, 07:14 AM

IIRC, in a scene i "Das Boot" (at the beginning, the LI told the Kaleun that one of the screws had been replaced, something that made the Kaleun very happy, since they "got rid of that whining noise.." (Please correct me if this is wrong, mates). Considering this, i could only imagine what importance the sounds of the screws must have had.

Brag · 03-28-08, 10:10 AM

If you go above 2 knots, your RPM will be over 100,

Jimbuna · 03-28-08, 11:41 AM

Quote:

Originally Posted by _Seth_

IIRC, in a scene i "Das Boot" (at the beginning, the LI told the Kaleun that one of the screws had been replaced, something that made the Kaleun very happy, since they "got rid of that whining noise.." (Please correct me if this is wrong, mates). Considering this, i could only imagine what importance the sounds of the screws must have had.

Your quite correct mate. A screw/propellor blade with damage to one of it's blades could quite possibly create a cavitational noise.

_Seth_ · 03-28-08, 12:31 PM

Quote:

Originally Posted by jimbuna

Quote:

Originally Posted by _Seth_

IIRC, in a scene i "Das Boot" (at the beginning, the LI told the Kaleun that one of the screws had been replaced, something that made the Kaleun very happy, since they "got rid of that whining noise.." (Please correct me if this is wrong, mates). Considering this, i could only imagine what importance the sounds of the screws must have had.

Your quite correct mate. A screw/propellor blade with damage to one of it's blades could quite possibly create a cavitational noise.

Could such failures be fixed during the patrol (divers, maybe?), or did they always have to go to a port with repair facilities? I know that during such repairs in Norway in WWII, German uboats used to flood their forward tanks. Together with the help af a small crane, the repair crew could lift the stern above water (Not much, but enough) to let a small boat get in under the screws to fix them. This saved a lot of time, since the boats didnt have to go to ports that had dry docks.
I can imagine the terror if a uboat had to dive to escape enemy DD's, knowing it had a broken screw that was making noise...
*"Yes, men, we are diving to get away from them..But they will find us anyway.."*

P_Funk · 03-28-08, 02:30 PM

Quote:

Originally Posted by _Seth_

I can imagine the terror if a uboat had to dive to escape enemy DD's, knowing it had a broken screw that was making noise...
*"Yes, men, we are diving to get away from them..But they will find us anyway.."*

Unless they chose not to use that side of the engines. I'm sure they could have done that.

_Seth_ · 03-28-08, 04:46 PM

Quote:

Originally Posted by P_Funk

Quote:

Originally Posted by _Seth_

I can imagine the terror if a uboat had to dive to escape enemy DD's, knowing it had a broken screw that was making noise...
*"Yes, men, we are diving to get away from them..But they will find us anyway.."*

Unless they chose not to use that side of the engines. I'm sure they could have done that.

That's true, P_Funk mate, good thinking! * I didn't consider that..

*
But i don't think they could achieve the same speed (and maybe maneuverability) with only one screw...Anyway, one is better than none, though..

Keelbuster · 03-28-08, 05:30 PM

I love the torpedo reload time in the XXI. You can pace a slow convoy and fire off most of your payload in one attack....

Sailor Steve · 03-28-08, 11:24 PM

Quote:

Originally Posted by _Seth_

Could such failures be fixed during the patrol (divers, maybe?), or did they always have to go to a port with repair facilities? I know that during such repairs in Norway in WWII, German uboats used to flood their forward tanks. Together with the help af a small crane, the repair crew could lift the stern above water (Not much, but enough) to let a small boat get in under the screws to fix them. This saved a lot of time, since the boats didnt have to go to ports that had dry docks.

A Damaged prop would have to be replaced, or at least removed for repair in a machine shop.

Quote:

I can imagine the terror if a uboat had to dive to escape enemy DD's, knowing it had a broken screw that was making noise...
*"Yes, men, we are diving to get away from them..But they will find us anyway.."*

One account I read said that the destroyer that sank Gunther Prien's U-47 tracked them by the noise from a damaged propeller.

Graf Paper · 03-29-08, 12:17 AM

My own experience in-game with the IIA and VIIB boats is that "silent speed" does indeed vary from one type of u-boat to another.

My old IIA could do 2kts without detection, but my VIIB can barely make 1kt without detection. I've read elsewhere in the forum that the XXI could make 5kts and still remain quiet to enemy ears.

The "Stealth Meter" is a decent training aid when trying to determine the best silent speed for a given u-boat in the game. It can indeed tell you how detectable your boat is, but not the likelihood of actually being detected by the enemy.

The only two criteria the SM measures is how much noise your boat and crew are making while submerged near enemy escorts and how visible you are at a given distance from a ship when you're surfaced. Whether that poses a risk to you is a judgement call on your part as the u-boat commander.

03-26-08, 10:01 PM	#1
Sledgehammer427 PacWagon Join Date: Jun 2007 Location: Drinking coffee and staring at trees in Massachusetts Posts: 2,908 Downloads: 287 Uploads: 0	night and day after playing in my career under command of a type VIIB in 1939-1940, i had a sudden urge to start a new career commanding a type XXI, which isnt available until 1944 holy cow....its like night and day, thank heavens i have the ability to stay under but its so tempting to surface to recharge the batteries.... and theres the ASW.... but it helped me realise that the type XXI is a very desirable boat... first patrol, however, i sank a bogue CVE in a task force with a southampton cruiser, as well as a couple less notable freighters, and two unescorted fast tankers.... totaling 39,400 some tons... and i made it home without taking any notable damage! anyone else have this kinda fun? __________________ Cold Waters Voice Crew - Fire Control Officer Cmdr O. Myers - C/O USS Nautilus (SS-168) 114,000 tons sunk - 4 Spec Ops completed V-boat Nutcase - Need supplies? Japanese garrison on a small island in the way? Just give us a call! D4C!

03-26-08, 10:23 PM	#3
Sledgehammer427 PacWagon Join Date: Jun 2007 Location: Drinking coffee and staring at trees in Massachusetts Posts: 2,908 Downloads: 287 Uploads: 0	yeah, i read that even though the sectioned building methods were revolutionary, they were held back by bad welds, and other problems, but they are still fun __________________ Cold Waters Voice Crew - Fire Control Officer Cmdr O. Myers - C/O USS Nautilus (SS-168) 114,000 tons sunk - 4 Spec Ops completed V-boat Nutcase - Need supplies? Japanese garrison on a small island in the way? Just give us a call! D4C!

03-28-08, 06:32 AM	#6
kurtz Seasoned Skipper Join Date: Oct 2006 Location: Leighton Buzzard,England Posts: 660 Downloads: 39 Uploads: 0	I believe the noise comes about through cavitation on the propellors so should change from boat to boat assuming different propellors but will ultimately depend upon rpm. __________________ War without Fire is like sausages without mustard-Henry V. http://www.myvintagelife.co.uk/

03-28-08, 07:14 AM	#7
_Seth_ Ocean Warrior Join Date: Dec 2005 Location: In Tromsoe, @Tirpitz' final resting place.. Posts: 3,277 Downloads: 94 Uploads: 0	IIRC, in a scene i "Das Boot" (at the beginning, the LI told the Kaleun that one of the screws had been replaced, something that made the Kaleun very happy, since they "got rid of that whining noise.." (Please correct me if this is wrong, mates). Considering this, i could only imagine what importance the sounds of the screws must have had. __________________

03-28-08, 10:10 AM	#8
Brag Navy Seal Join Date: Nov 2006 Location: Docked on a Russian pond Posts: 7,072 Downloads: 2 Uploads: 0	If you go above 2 knots, your RPM will be over 100, __________________ Espionage, adventure, suspense, are just a click away Click here to look inside Brag's book: Amazon.com: Kingmaker: Alexey Braguine: Books Order Kingmaker here: http://www.subsim.com/store.html For Tactics visit:http://www.freewebs.com/kielman/

03-26-08, 10:16 PM	#2
Torplexed Let's Sink Sumptin' ! Join Date: Dec 2001 Location: Seattle, WA Posts: 5,823 Downloads: 43 Uploads: 0	Yeah it's a nice sub. Be careful you don't get spoiled. The one in the game probably functions far better than the real ones that were built under onerous wartime conditions and had quite a few teething problems. Assuming German sub design had been pushed a bit more by some visionary in the pre-war years it does make you wonder what might have been.

03-26-08, 11:19 PM	#4
Tessa Grey Wolf Join Date: Feb 2007 Location: CG 96 Posts: 861 Downloads: 22 Uploads: 0	The underwater speed is intoxicating, even at silent speed. So easy to ditch destroyers amidst a convoy and escape untouched.

03-27-08, 08:39 PM	#5
finchOU Samurai Navy Join Date: Jan 2004 Posts: 571 Downloads: 77 Uploads: 0	Got a question on the above post. What is nosier...higher speed or RPMs? I've heard that you have to stay under 2 knots to be quiet..or 150 RPMs (about 3-4 knots in a VIIC)....well the 150 seems to be Bull casue they seem to hear me as soon as I break the 2 knot rule....so with a XXI....ahead slow gives like what 5-6 knots?...and Low RPMs? I've been up 100% "attemped" realism since the start...so I have not tried tinkering with the Stealth O meter...whats the word on the street?

03-28-08, 05:30 PM	#13
Keelbuster Ace of the Deep Join Date: Oct 2005 Location: BA 72 Posts: 1,092 Downloads: 43 Uploads: 0	I love the torpedo reload time in the XXI. You can pace a slow convoy and fire off most of your payload in one attack.... __________________

03-29-08, 12:17 AM	#15
Graf Paper Ace of the Deep Join Date: Jan 2008 Location: Pacific Northwest United States Posts: 1,146 Downloads: 41 Uploads: 2	My own experience in-game with the IIA and VIIB boats is that "silent speed" does indeed vary from one type of u-boat to another. My old IIA could do 2kts without detection, but my VIIB can barely make 1kt without detection. I've read elsewhere in the forum that the XXI could make 5kts and still remain quiet to enemy ears. The "Stealth Meter" is a decent training aid when trying to determine the best silent speed for a given u-boat in the game. It can indeed tell you how detectable your boat is, but not the likelihood of actually being detected by the enemy. The only two criteria the SM measures is how much noise your boat and crew are making while submerged near enemy escorts and how visible you are at a given distance from a ship when you're surfaced. Whether that poses a risk to you is a judgement call on your part as the u-boat commander. __________________ Still sailing the high seas, hunting convoys with those who join me.