Is it not possible to accurately portray the German Type XXI?

[TorpX]

More about Snorkeling:

This pertains to earlier types, and may or may not apply to type XXI.

Blair emphasized boats did not snorkel all the time. It was hard on the crews, and really wasn't necessary. On the other hand, batteries were not fully discharged either. That would not only risk leaving you with a flat battery at a bad time, but would be wear out the batteries faster.

Since snorkeling made the boat 'deaf', I am guessing they usually snorkeled in the daytime, so they could at least use the periscope, and run deeper at night on the battery, unless they considered it safe enough to surface. However, bad weather could make snorkel use impossible, so maybe they had to use it at night, sometimes.
The danger there is that a plane could home in on the snorkel echo, and attack them without warning.

[RoflCopter4]

Sorry to necro this thread after a month, but I don't know why I didn't reply. I am still curious about this.

The type XXI modelled in Operation Monsun is clearly not some kind of barely cloaked XXIII, it's definitely it's own boat with a lovely model and all. The thing does run for a fair time underwater, and while I haven't tested how far, the big problem with it is the fact that it takes almost two days to charge the batteries under most conditions. I started this thread to ask about that. Is there any data on how long it would normally take? Should it simply be a matter of multiplying engine performance by time to see how long it would take to generate x number of joules for the batteries?

Incidentally you mentioned that snorkeling leaves a boat deaf, blind, and a very blatant target for late war radar. Two questions to that: firstly at what point in the war did allied radar have the ability to see a snorkel from the air? And secondly, didn't the snorkel have a radar detector on it? Wouldn't that give away any aircraft that spotted it?

[TorpX]

Originally Posted by RoflCopter4

Incidentally you mentioned that snorkeling leaves a boat deaf, blind, and a very blatant target for late war radar. Two questions to that: firstly at what point in the war did allied radar have the ability to see a snorkel from the air? And secondly, didn't the snorkel have a radar detector on it? Wouldn't that give away any aircraft that spotted it?

I didn't say snorkeling would make the boat blind, only deaf. If they were using it at night, they would be blind, as well. Not entirely blind, but not able to see aircraft in time.

Don't know exactly when aircraft got centimetric radar; probably later, but not every unit will get the equipment at the same time.

About the radar detectors; my understanding of these is that they were not able to detect the later Allied radar.



About the batteries; I'm not surprised battery performance is lousy. SH4 has a major bug regarding batteries. You should be able to set performance to proper (historical, or whatever desired) levels in the *.sim files, but it just doesn't work. Undoubtedly a mistake in the code somewhere.

TMO and ISP mods (for allied subs) had to use an awkward workaround to achieve sensible battery performance.

[ColonelSandersLite]

Originally Posted by TorpX

I didn't say snorkeling would make the boat blind, only deaf. If they were using it at night, they would be blind, as well. Not entirely blind, but not able to see aircraft in time.

Robins did, not you.


Since this thread died, I had done some more research on it and somehwere I found some german general orders on the use of snorkels. The order was to recharge at the start and end of every night. I'll see if I can't find the link again soon.

[ColonelSandersLite]

Originally Posted by RoflCopter4

Is there any data on how long it would normally take? Should it simply be a matter of multiplying engine performance by time to see how long it would take to generate x number of joules for the batteries?

The answer to that question is found in Subnuts link above:
"As it is necessary to furnish approximately 1200 HP for 4 hours to the generators for charging each of the two batteries at the normal charging rate"

It is noteworthy that the captured submarine could only make 850 hp snorkeling, so charge time would be substantially more. It's not a simple 41% longer either, as a higher proportion of the generated power would be going towards propulsion at whatever speed they where recharging at. At a guess, recharge while snorkeling probably took in the vicinity of 7-8 hours or so. I'm sure it could have been fixed if Germany had more time, but they didn't.

But yes, if it's taking two days, that would be a bug as described by torpex. Someone might have worked around it, I dunno. I would do some searching on operation monsun oriented mods (which I'm almost totally unfamiliar with).

Originally Posted by RoflCopter4

firstly at what point in the war did allied radar have the ability to see a snorkel from the air? And secondly, didn't the snorkel have a radar detector on it? Wouldn't that give away any aircraft that spotted it?

We had centimetric radar on aircraft before the germans even started snorkeling.
DMS-1000 (10cm radar, forward looking only) was operational on liberators in march of 1942.
AN/APS-2 (10cm radar) was operational on american aircraft from feb 1943
AN/APS-15 (3cm radar) was operational on american aircraft from nov 1943

I don't have exact timeframes for the british, but I'm sure it's similar.

From Uboat.net:
The first boat to be fitted with the Schnorchel was U-58 which experimented with the equipment in the Baltic during the summer of 1943 but operational boats didn't start to use it until early 1944 and even as late as June 1944 only about half of the boats stationed in the French bases had Schnorchels fitted.


The only german radar detector that I can remember seeing references to being snorkel mounted naxos. Range wasn't good, less than the range of the radar it was detecting. It was *very* rare as well. I don't think I have ever actually seen a picture of it in operational use. Further, it probably would have been useless vs AN/APS-15, though still could have helped with detecting the older AN/APS-2 when encountered.

A good portion of the problem is that the germans didn't trust their radar warning receivers at all. This stems from a british POW that convinced them that we where homing in on metox signals in august 43. This offered a believable lie to the germans, since we where detecting them with AN/APS-2 that the germans couldn't detect. From their point of view, attacks where just coming out of nowhere and this finally explained why. From that point on, the germans where completely paranoid about their receivers. Later designs reduced emissions, which reduced detection ranges and the captains still didn't trust them so they where often just not used, even when equipped.

A good solid read on the detection/countermeasure war between germany and the western allies can be found here:
http://www.ibiblio.org/hyperwar/USN/...51/ASW-14.html

[nionios]

Originally Posted by ColonelSandersLite

We had centimetric radar on aircraft before the germans even started snorkeling.
DMS-1000 (10cm radar, forward looking only) was operational on liberators in march of 1942.
AN/APS-2 (10cm radar) was operational on american aircraft from feb 1943
AN/APS-15 (3cm radar) was operational on american aircraft from nov 1943

I don't have exact timeframes for the british, but I'm sure it's similar.

From Uboat.net:
The first boat to be fitted with the Schnorchel was U-58 which experimented with the equipment in the Baltic during the summer of 1943 but operational boats didn't start to use it until early 1944 and even as late as June 1944 only about half of the boats stationed in the French bases had Schnorchels fitted.


The only german radar detector that I can remember seeing references to being snorkel mounted naxos. Range wasn't good, less than the range of the radar it was detecting. It was *very* rare as well. I don't think I have ever actually seen a picture of it in operational use. Further, it probably would have been useless vs AN/APS-15, though still could have helped with detecting the older AN/APS-2 when encountered.

A good portion of the problem is that the germans didn't trust their radar warning receivers at all. This stems from a british POW that convinced them that we where homing in on metox signals in august 43. This offered a believable lie to the germans, since we where detecting them with AN/APS-2 that the germans couldn't detect. From their point of view, attacks where just coming out of nowhere and this finally explained why. From that point on, the germans where completely paranoid about their receivers. Later designs reduced emissions, which reduced detection ranges and the captains still didn't trust them so they where often just not used, even when equipped.

A good solid read on the detection/countermeasure war between germany and the western allies can be found here:
http://www.ibiblio.org/hyperwar/USN/...51/ASW-14.html

In RFB-German campaign the description for Metox RWR says that it can be detected although it's a passive device.So should we use Metox or not?And how we can get rid of it:
by switching radar off or by uninstalling it from the conning tower?