Do American Submarines ever submerge

[Platapus]

I guess I was spoiled by my VIIB being able to hit Periscope depth pretty fast. But in SH4???

Crikey! the war will be over by the time my Submarine gets to Periscope depth. It is so bad that I use TC just so I don't fall asleep.

I swear, I can give the command to dive to periscope depth at the same time the Japanese factory is just finishing up constructing an Airplane. By the time the Airplane gets to its base, undergoes testing, gets a new pilot assigned, the pilot gets certified, goes out on his first patrol he will STILL catch me on the surface!

Sheeesh, my last patrol, I gave the order to crash dive and before we went under I had two Petty Officers retire!

So in reality, were the German boats able to dive that much faster than American boats?

Well I am going to dive now, it is August 1942. With any luck I should be at periscope depth about the time they sign that little piece of paper on the USS Missouri.

[NEON DEON]

I guess I was spoiled by my VIIB being able to hit Periscope depth pretty fast. But in SH4???

Crikey! the war will be over by the time my Submarine gets to Periscope depth. It is so bad that I use TC just so I don't fall asleep.

I swear, I can give the command to dive to periscope depth at the same time the Japanese factory is just finishing up constructing an Airplane. By the time the Airplane gets to its base, undergoes testing, gets a new pilot assigned, the pilot gets certified, goes out on his first patrol he will STILL catch me on the surface!

Sheeesh, my last patrol, I gave the order to crash dive and before we went under I had two Petty Officers retire!

So in reality, were the German boats able to dive that much faster than American boats?

Well I am going to dive now, it is August 1942. With any luck I should be at periscope depth about the time they sign that little piece of paper on the USS Missouri.

The first crash dive takes a long time.

The second crash dive within 2 hours of the first will take about 25 to 35 seconds to get under water.

Never really bothered timing a regular dive since I am not in a big hurry when I do.:D

[Fearless]

U boats were much faster in dive time basically because they had bow and stern planes whilst the US subs only have bow planes. Thus the push and lift affect in U boats when diving reduced the dive time. I also assume that in SH4 the crew ability and skill level would also be a factor to take into consideration.

That's my theory I believe.

[FAdmiral]

This thread reminds me of something I used to do in SH3. I ran the boat
down slightly (like semi-decks awash) so I could get under faster. I have
not tried it yet in SH4 but I know that you can drop the US boat slightly
deeper (feet) in the water. Whether it will make a difference remains to be
tested....

JIM

[CaptainHaplo]

The dive time is longer for US boats - comparable to the type IX. A good boat could get the time down to 45 seconds or so - an elite crew could hit the 30-35 second mark. (Note - reference Silent Running by Calvert). That being said - I dont know of anyone who has gotten an elite crew in SH4 that has been able to test if that helps at all. However, since the flooding rate of the tanks is the main key the program uses - I suspect crew effect will be minimal.

I have edited my Tambor files to increase the MBT flooding rate - and gotten a more realistic dive time now. If your looking for something like that - you can do it yourself or post a request in the Mod forum for a mod to do it.

Good Hunting.
Captain Haplo

[Ducimus]

Stock diving times are abnormally long. Historically they didnt take that long to dive.

[Chock]

I watched Run Silent Run Deep the other day and looked carefully at the shots of the sub diving. I know that's probably not the most scientific way to come to a correct value, but it did seem that SH4 was fairly close to the mark, if perhaps a little slow.

Needless to say, getting a fast dive time is one of the central themes of that movie, so you could always try doing what one crewmember suggests - leave the hatches open :D

They do take a while to get under, but that's hardly surprising when you consider that they were massive in comparison to a Type VII U-Boat, roundabout double the tonnage in fact.

Look on the bright side; imagine how long an I-400 would take to dive, that thing was 400 feet long, with 177 crew on board.

[LZ_Baker]

U boats were much faster in dive time basically because they had bow and stern planes whilst the US subs only have bow planes. Thus the push and lift affect in U boats when diving reduced the dive time. I also assume that in SH4 the crew ability and skill level would also be a factor to take into consideration.

That's my theory I believe.

US boats had stern planes, right by the rudder, just like the Germans.

[WWSandMan]

There may be a little lag induced by the game as well.If you happen to bump any other command (rudder one way or the other, battle stations, speed increase/decrease) the "go to periscope depth" command seems forgotten. There have been several instances where I've had to re-apply that command, or manually set my depth to get the boat to begin diving.

Of course it could be because I didn't 'click' quite as thoroughly as I had intended. :oops:

Still, it's quite irritating to have the deck watch reporting an incoming plane well after those men should be closing the hatches.

[NEON DEON]

U boats were much faster in dive time basically because they had bow and stern planes whilst the US subs only have bow planes. Thus the push and lift affect in U boats when diving reduced the dive time. I also assume that in SH4 the crew ability and skill level would also be a factor to take into consideration.

That's my theory I believe.

US boats had stern planes, right by the rudder, just like the Germans.

The U S Fleet boat also had a bow bouancy tank and the electric motors powered the props on and below the surface . No stopping the props to switch over from diesel to electric motor drive like the direct drive U boats had to do when diving.

[Tobus]

American boats are like IX's, the big flat deck and heavy sub steer like cows in both horizontal and vertical planes.

Oh, and I see my engines stop when diving, switching from diesel to electric. This should not be the case, since American boats were all electric, with no direct link between diesels and axels.

[vindex]

I timed one crash, as though I were drilling my crew, and I got something like 40 seconds from siren to complete submersion. This was a first-time dive, not a repeat. I thought that 40 sec was pretty reasonable for a big fleet boat.

[Grothesj2]

Comparing a dinky type VII to a US fleet boat is not a good comparison at all. Type VIII was like half the size of a WW2 fleet boat.

[GOZO]

The Gato fleet boat matches a german IXD2 quite well in length/weight etc I think and that one takes a lot of time to get below surface.:)

(Trust Kptlt H Sohler, U-195 WaW2:rock: )

Oh yes, the all electric drive is an advantage for the US subs compared to the gerries.

Cheers

[Overkill]

US subs were not shot up with holes from Sutherlands and Wildcats to help them in a dive. :p

[AVGWarhawk]

This thread reminds me of something I used to do in SH3. I ran the boat
down slightly (like semi-decks awash) so I could get under faster. I have
not tried it yet in SH4 but I know that you can drop the US boat slightly
deeper (feet) in the water. Whether it will make a difference remains to be
tested....

JIM

You can run the sub down to 39 feet before you have to leave the bridge. The crew will leave the bridge at 25 feet. Running this way at night during an attack is fun. Anyway, the crew leaves the bridge at 25 feet so you can run awash up to this point with crew, after that it just you standing there. Obviously your sub will submerge faster if you are running awash as you all know. I also notice once the dive planes are at 31 feet the sub really starts its fast decent.

[Morts]

US subs were not shot up with holes from Sutherlands and Wildcats to help them in a dive. :p:rotfl: :rotfl:

[SteamWake]

Just an off the cuff observation.

It seems as though the subs dive pretty quickly once the ballast has been taken on board.

It takes a while to fill the ballast tanks. Once their filled and the bow dips beneath the surface and the bow planes "bite" they go down pretty fast.

Any "definative" numbers out there on diving times ? Although Id bet there is a ton of variables. How much water were in the ballast tanks ? What kind of weather ? How efficent is the crew ? Speed ordered when diving ? What about overall weight (Torpedoes, provisions, crew members, etc.) ?


As to the diving time being "painfully long requiring time accelleration" perhaps a sub sim is not quite your style.

[NEON DEON]

Just an off the cuff observation.

It seems as though the subs dive pretty quickly once the ballast has been taken on board.

It takes a while to fill the ballast tanks. Once their filled and the bow dips beneath the surface and the bow planes "bite" they go down pretty fast.

Any "definative" numbers out there on diving times ? Although Id bet there is a ton of variables. How much water were in the ballast tanks ? What kind of weather ? How efficent is the crew ? Speed ordered when diving ? What about overall weight (Torpedoes, provisions, crew members, etc.) ?


As to the diving time being "painfully long requiring time accelleration" perhaps a sub sim is not quite your style.

The skipper of the Nautilus (Narwhal class. 371' length) noted that in order to achieve sufficient dive speeds in combat areas it was necessary to use ahead standard or better while on the surface in the daytime.

Fluckey in his book "Thunder Below" would flood negative while running on the suface in order to speed his dive times when trouble came his way.

The Pampinito web site lists the dive time of a Balao at 30 seconds.

Qualifications for the boat to pass over to the Navy is 60 seconds.

In game, a Gato will submerge the first time between 40 and 60 seconds on a crash dive. If the second crash dive is within 2 hours of the first then, the boat will go under in 25 to 35 seconds.

[cmdrk]

In game, a Gato will submerge the first time between 40 and 60 seconds on a crash dive. If the second crash dive is within 2 hours of the first then, the boat will go under in 25 to 35 seconds.

2 hours - Is it the same watch diving both times?

[NEON DEON]

In game, a Gato will submerge the first time between 40 and 60 seconds on a crash dive. If the second crash dive is within 2 hours of the first then, the boat will go under in 25 to 35 seconds.

2 hours - Is it the same watch diving both times?

Good point.

I will go back and check tonight.