Snorkel testing

MarshalLaw · 03-03-06, 08:34 PM

Hello all,

I had posted in a earlier thread about being detected with the snorkel up . A fellow mate suggested to try it at periscope depth. These are the results:

1.4b patched stock game no snorkel mods. Calm sea, clear conditions (as bad as it gets)

IXB boat

Ran at periscope depth at slow speed ( after dark) for half the night, was not seen or detected. Had periscope up as well at same level as Snorkel. Speed 4-5 KPH

Tryed it at 1/3 speed same results. Speed increased to 8 KPH
Went to standard was detected in 4-5 hours time speed increased to 11 KPH.

Finally at full I was detected within 2 hours. Not quite as fast as if I had been at snorkel depth. Speed was 13 KPH. Of coarse I found another bug. In real life u-boats could only travel around 8 KPH with the snorkel up. Any faster and damage would occur.

So the bottom line for you snorkel loving mates , drive at periscope depth and you should be fine for the most part. I plan to do more testing once the seas get rougher, see if at snorkel depth you are detected at the same rate as in calm seas.

Try it out for yourself to see if you get the same results.

andy_311 · 03-03-06, 09:05 PM

I thought ther was a mod for the snorkel so it wouldn't be detected easly?

MarshalLaw · 03-03-06, 09:11 PM

There is. I wanted to see if the Periscope deal would work. Sure enough it does. Once I go to RUB , I 'll have the fix. Just a FYI for those who don't have the mod.

Syxx_Killer · 03-03-06, 09:15 PM

Quite a while back there was a discussion about the snorkel. In it, I made a post about some of my findings when testing. This may be of some interest.

Quote:

I quickly tested the subs and their snorkels. I wanted to see how deep I could go and still be able to breath. I used the Scapa Flow single mission. The wind in that mission is 4m/s. Here are my results:

Type VIIB/C â€“ 12m
Type IXB/C â€“ 14m
Type IXD2 â€“ 15m
Type XXI â€“ 16.5

I then edited the snorkel depth in the appropriate cfg file in each submarine's folder.

Program Files/Ubisoft/SilentHunterIII/data/Submarine

Then choose the right folder for the sub and edit the cfg.

mike_espo · 03-04-06, 12:25 AM

KPH?? thats kilometers per hour.

Knots by defintion is nautical miles per hour.

Which is it? :hmm: It makes a huge difference.

1knot =1.853 kilometers per hour

MarshalLaw · 03-04-06, 08:34 AM

Knots... Sorry KPH is from my old Mech warrior days. Old habits die hard.

MarshalLaw · 03-05-06, 07:37 PM

Had the chance to test the snorkel in heavier seas. You are picked up faster , than in calmer seas, due to the fact that the snorkel is more exposed in the (valleys) of the swells. So for aircraft you are a intermittant target that they can still home in on. Just takes them a bit longer is all. I used both periscopes for visual spotting. Helped to get a few extra extra seconds.

Bottom line get the snorkel fix.

Bucketlung · 03-05-06, 08:39 PM

Exactly where is the snorkel fix? Is it in Rub?

VonHelsching · 03-06-06, 03:05 AM

It's all up to the type of radar the Allies have that given time. As a rule of thumb, the further you progress in 1943 and 1944 the lower your snorkel must be in order not to be detected. In late 1944 (?) and 1945 the radar catches everything 3 cm above the surface.

As for the patch, make a search for Jungman's snorkel fix.

mike_espo · 03-07-06, 02:40 PM

Something unusual I noticed. I have NYGM crew management mod and its great, but a serious bug exists.

It seems when you submerge and use the diesels and snorkel, that the crew in the diesel room does not fatigue. However, if you put them in the motor room, they do

In NYGM, the unused engine rooms are rest areas where no further fatigue takes place. Everything works as it should when you submerge below the snorkel depth.

Its too bad because NYGM is the best crew fatigue model I ran into.

snitzel · 03-07-06, 03:10 PM

I've been reading a book "Submarine design and development" by Norman Friedman. He writes about snorkels:

"The snorkel did not quite restore the U-boats' previous mobility, speed being limited to 5 or 6 knots. Thus a snorkelling Type VII still could not close a convoy."

"The germans were well aware of this limitation, and by the wars end they were experimenting with a new reinforced streamlined tube, good they hoped for 10-11 knots. Type XXI could snorkel at 10 knots from the start."

And about detectability: "Even relatively simple airborne radars were effective against surfaced submarines at tens of miles. By way of contrast, even the best existing airborne radar, the APS-20 could not detect a snorkel at more than 13 miles in smooth Sea State 2, it was useless in slight sea state 3 or more."

I think Sea state 3 is waveheight of 0,5-1,25m.

03-03-06, 08:34 PM	#1
MarshalLaw Navy Dude Join Date: Dec 2005 Location: Orlando Fla USA Posts: 174 Downloads: 0 Uploads: 0	Snorkel testing Hello all, I had posted in a earlier thread about being detected with the snorkel up . A fellow mate suggested to try it at periscope depth. These are the results: 1.4b patched stock game no snorkel mods. Calm sea, clear conditions (as bad as it gets) IXB boat Ran at periscope depth at slow speed ( after dark) for half the night, was not seen or detected. Had periscope up as well at same level as Snorkel. Speed 4-5 KPH Tryed it at 1/3 speed same results. Speed increased to 8 KPH Went to standard was detected in 4-5 hours time speed increased to 11 KPH. Finally at full I was detected within 2 hours. Not quite as fast as if I had been at snorkel depth. Speed was 13 KPH. Of coarse I found another bug. In real life u-boats could only travel around 8 KPH with the snorkel up. Any faster and damage would occur. So the bottom line for you snorkel loving mates , drive at periscope depth and you should be fine for the most part. I plan to do more testing once the seas get rougher, see if at snorkel depth you are detected at the same rate as in calm seas. Try it out for yourself to see if you get the same results.

03-07-06, 03:10 PM	#11
snitzel Swabbie Join Date: Apr 2005 Posts: 6 Downloads: 0 Uploads: 0	I've been reading a book "Submarine design and development" by Norman Friedman. He writes about snorkels: "The snorkel did not quite restore the U-boats' previous mobility, speed being limited to 5 or 6 knots. Thus a snorkelling Type VII still could not close a convoy." "The germans were well aware of this limitation, and by the wars end they were experimenting with a new reinforced streamlined tube, good they hoped for 10-11 knots. Type XXI could snorkel at 10 knots from the start." And about detectability: "Even relatively simple airborne radars were effective against surfaced submarines at tens of miles. By way of contrast, even the best existing airborne radar, the APS-20 could not detect a snorkel at more than 13 miles in smooth Sea State 2, it was useless in slight sea state 3 or more." I think Sea state 3 is waveheight of 0,5-1,25m. __________________ Werner Snitzel.

03-03-06, 09:05 PM	#2
andy_311 The Old Man Join Date: Apr 2005 Location: Oldham, Lancs,England Posts: 1,312 Downloads: 82 Uploads: 0	I thought ther was a mod for the snorkel so it wouldn't be detected easly?

03-03-06, 09:11 PM	#3
MarshalLaw Navy Dude Join Date: Dec 2005 Location: Orlando Fla USA Posts: 174 Downloads: 0 Uploads: 0	There is. I wanted to see if the Periscope deal would work. Sure enough it does. Once I go to RUB , I 'll have the fix. Just a FYI for those who don't have the mod.

03-04-06, 12:25 AM	#5
mike_espo Sonar Guy Join Date: May 2005 Location: Chicago, USA Posts: 396 Downloads: 12 Uploads: 0	KPH?? thats kilometers per hour. Knots by defintion is nautical miles per hour. Which is it? :hmm: It makes a huge difference. 1knot =1.853 kilometers per hour

03-04-06, 08:34 AM	#6
MarshalLaw Navy Dude Join Date: Dec 2005 Location: Orlando Fla USA Posts: 174 Downloads: 0 Uploads: 0	Knots... Sorry KPH is from my old Mech warrior days. Old habits die hard.

03-05-06, 07:37 PM	#7
MarshalLaw Navy Dude Join Date: Dec 2005 Location: Orlando Fla USA Posts: 174 Downloads: 0 Uploads: 0	Had the chance to test the snorkel in heavier seas. You are picked up faster , than in calmer seas, due to the fact that the snorkel is more exposed in the (valleys) of the swells. So for aircraft you are a intermittant target that they can still home in on. Just takes them a bit longer is all. I used both periscopes for visual spotting. Helped to get a few extra extra seconds. Bottom line get the snorkel fix.

03-05-06, 08:39 PM	#8
Bucketlung Nub Join Date: Mar 2006 Posts: 4 Downloads: 0 Uploads: 0	Exactly where is the snorkel fix? Is it in Rub?

03-06-06, 03:05 AM	#9
VonHelsching Ace of the Deep Join Date: Aug 2005 Location: Athens, Greece Posts: 1,025 Downloads: 0 Uploads: 0	It's all up to the type of radar the Allies have that given time. As a rule of thumb, the further you progress in 1943 and 1944 the lower your snorkel must be in order not to be detected. In late 1944 (?) and 1945 the radar catches everything 3 cm above the surface. As for the patch, make a search for Jungman's snorkel fix.

03-07-06, 02:40 PM	#10
mike_espo Sonar Guy Join Date: May 2005 Location: Chicago, USA Posts: 396 Downloads: 12 Uploads: 0	Something unusual I noticed. I have NYGM crew management mod and its great, but a serious bug exists. It seems when you submerge and use the diesels and snorkel, that the crew in the diesel room does not fatigue. However, if you put them in the motor room, they do In NYGM, the unused engine rooms are rest areas where no further fatigue takes place. Everything works as it should when you submerge below the snorkel depth. Its too bad because NYGM is the best crew fatigue model I ran into.