Historical crash dive time for fleet boats? - Page 2

Floyd · 04-03-07, 12:28 PM

Quote:

Originally Posted by Loaf

Does anybody know if crew experience affects dive times in SHIV?

Put the crew to battle station and the boat should dive way faster. Time might be affected
by fatigue status of crew, but i have no real numbers. I forgot my crew on battle station
once and all were approx. 90-99 fatigue. Had the impression that every command
too very long to be followed. Oh, and the engines stopped.

NEON DEON · 04-03-07, 01:06 PM

An excerpt from the USS Pampanito web site.

"A World War II submarine spent most of its time on the surface where it could travel quickly and more easily find its targets. She dove to make stealthy attacks or escapes from the enemy. To make it possible for the crew to walk outside the boat while on the surface, and to protect equipment that is not in the pressure hull, the main deck is built up over the pressure hull. The space between the pressure hull and the deck is the free-flooding superstructure. The many holes that are visible allow air to escape and water to flood this space. Any trapped air would slow down the dive. Pampanito can go from the surface to 60 foot depth in under 30 seconds."

http://www.maritime.org/tour/tadeck.htm

Anyways that's my story and I am sticking to it.

Sgian Dubh · 04-03-07, 01:12 PM

I don't have much to add in terms of factual data, but I can tell you that if you travel with 'desk awash' in SH4, the dive time is greatly reduced, mainly because the dive-planes are already run out and (I guess) the boat is already cloaser to neutral boyancy.

I only travel this way on the surface during the day. Even with the short range of the "Plane!" calls, I am under long before the plane can get to me.

AVGWarhawk · 04-03-07, 01:14 PM

Quote:

Originally Posted by Sgian Dubh

I don't have much to add in terms of factual data, but I can tell you that if you travel with 'desk awash' in SH4, the dive time is greatly reduced, mainly because the dive-planes are already run out and (I guess) the boat is already cloaser to neutral boyancy.

I only travel this way on the surface during the day. Even with the short range of the "Plane!" calls, I am under long before the plane can get to me.

Nice to know but I love shooting the twin .50's at the planes

Sgian Dubh · 04-03-07, 01:23 PM

you can run 'desk awash' and shoot the gun yourself.

The watch crew is still on the bridge as well.

AVGWarhawk · 04-03-07, 01:25 PM

Quote:

Originally Posted by Sgian Dubh

you can run 'desk awash' and shoot the gun yourself.

The watch crew is still on the bridge as well.

Yes, I know but I like staying surfaced and shooting away

sgt.weasle · 04-03-07, 02:31 PM

Quote:

Originally Posted by Sgian Dubh

you can run 'desk awash' and shoot the gun yourself.

The watch crew is still on the bridge as well.

when i run 'desk awash' my computer crashes every time..

(lol jk)

Bilge_Rat · 04-03-07, 03:04 PM

just to add more fuel to the fire, I was skimming through the online version of "The Fleet Type Submarine" http://www.maritime.org/fleetsub/index.htm

In chapter 18A dealing with diving, it states:

Quote:

18A2. Types of dives

Quote:

Three types of dives are possible: 1) the quick dive, 2) the running dive, and 3) the stationary dive, the choice being dictated by existing conditions. In all dives the ship is placed in the condition of neutral or negative buoyancy; the use of negative buoyancy shortens the diving time. A quick dive is made when the ship is underway on one or more main engines. The bow planers are placed on FULL DIVE and the forward speed results in a maximum downward thrust on the bow planes. As the submarine submerges, the upper surfaces of the hull and superstructure act as planing surfaces and increase the downward thrust. The quick dive is the fastest of the three types and is used in acceptance trials of new submarines, when it must be executed within 60 seconds from standard diving trim.

This seems to imply that the US Navy standard was for the dive to be completed in 60 seconds. Certainly, a crew testing to achieve the quickest time could possibly dive in 30 seconds, but if a boat is surprised and does an emergency dive, 30 seconds from the dive order to periscope depth seems a little tight.

NEON DEON · 04-03-07, 03:48 PM

Quote:

Originally Posted by Bilge_Rat

just to add more fuel to the fire, I was skimming through the online version of "The Fleet Type Submarine" http://www.maritime.org/fleetsub/index.htm

In chapter 18A dealing with diving, it states:

Quote:

18A2. Types of dives

Quote:

Three types of dives are possible: 1) the quick dive, 2) the running dive, and 3) the stationary dive, the choice being dictated by existing conditions. In all dives the ship is placed in the condition of neutral or negative buoyancy; the use of negative buoyancy shortens the diving time. A quick dive is made when the ship is underway on one or more main engines. The bow planers are placed on FULL DIVE and the forward speed results in a maximum downward thrust on the bow planes. As the submarine submerges, the upper surfaces of the hull and superstructure act as planing surfaces and increase the downward thrust. The quick dive is the fastest of the three types and is used in acceptance trials of new submarines, when it must be executed within 60 seconds from standard diving trim.

This seems to imply that the US Navy standard was for the dive to be completed in 60 seconds. Certainly, a crew testing to achieve the quickest time could possibly dive in 30 seconds, but if a boat is surprised and does an emergency dive, 30 seconds from the dive order to periscope depth seems a little tight.

The boat is moving they flood negative and set the planes. Is that an acceptance trial for the boat done by a civilian crew? Sounds like it is a trial for the boat itself.

Ducimus · 04-03-07, 04:02 PM

So far im guessing that from crusiing on the surface at 8 kts, and hitting crash dive, the boat should be completely covered with water with only the little pole on the stern protruding on the surface - in about 45 seconds?

NEON DEON · 04-03-07, 04:21 PM

Maybe a test should be run to see how much crew training is factored in.

Hack it a bit with the most elite crew you can come up with and time it till the point that the boat is no longer visible.

Then run the same test with a bunch of Newbies.

Just to see what the extremes are so you have a gauge you can use to adjust it.

Sailor Steve · 04-03-07, 04:24 PM

Quote:

Originally Posted by simsurfer

The USS Nerka dove and sank a Akikaze DD in 32 seconds.

:rotfl:

That's great!

It's true! I saw it too!

Ducimus · 04-03-07, 04:38 PM

Quote:

Maybe a test should be run to see how much crew training is factored in.

Yeah im wondering about that.

jerryt · 04-03-07, 04:53 PM

Has anyone done a crash dive in really rough seas? It took forever to get below the surface!

I didn't time it, but it was way over the usual time.

I'm thinking maybe the dive planes couldn't get a good bite because of the wave action? They were in and out of the water. Anybody know if this would be a realistic behavior?

On another note. Surfacing in really rough weather seems to take a long time to get well above the surface. I notice even in calm seas, it takes a while for the boat to get completely to zero depth, but when its rough I sure can't send my lookouts above deck for a few minutes. I have to use the periscope for safety. :p

NoLine · 04-03-07, 05:05 PM

Anybody notice the s-boat crash diving in 15 seconds, which seems a bit short

NoLine

04-03-07, 01:06 PM	#17
NEON DEON Ace of the Deep Join Date: Apr 2005 Location: Los Angeles, CA Posts: 1,207 Downloads: 39 Uploads: 5	An excerpt from the USS Pampanito web site. "A World War II submarine spent most of its time on the surface where it could travel quickly and more easily find its targets. She dove to make stealthy attacks or escapes from the enemy. To make it possible for the crew to walk outside the boat while on the surface, and to protect equipment that is not in the pressure hull, the main deck is built up over the pressure hull. The space between the pressure hull and the deck is the free-flooding superstructure. The many holes that are visible allow air to escape and water to flood this space. Any trapped air would slow down the dive. Pampanito can go from the surface to 60 foot depth in under 30 seconds." http://www.maritime.org/tour/tadeck.htm Anyways that's my story and I am sticking to it. __________________ Diesel Boats Forever!

04-03-07, 01:12 PM	#18
Sgian Dubh Officer Join Date: Sep 2002 Posts: 245 Downloads: 0 Uploads: 0	I don't have much to add in terms of factual data, but I can tell you that if you travel with 'desk awash' in SH4, the dive time is greatly reduced, mainly because the dive-planes are already run out and (I guess) the boat is already cloaser to neutral boyancy. I only travel this way on the surface during the day. Even with the short range of the "Plane!" calls, I am under long before the plane can get to me. __________________ \"One ping to find them all, One ping to link them; One ping to promote them all, and in the darkness sink them.\" with apologies to J.R.R. Tolkien

04-03-07, 01:23 PM	#20
Sgian Dubh Officer Join Date: Sep 2002 Posts: 245 Downloads: 0 Uploads: 0	you can run 'desk awash' and shoot the gun yourself. The watch crew is still on the bridge as well. __________________ \"One ping to find them all, One ping to link them; One ping to promote them all, and in the darkness sink them.\" with apologies to J.R.R. Tolkien

04-03-07, 04:21 PM	#26
NEON DEON Ace of the Deep Join Date: Apr 2005 Location: Los Angeles, CA Posts: 1,207 Downloads: 39 Uploads: 5	Maybe a test should be run to see how much crew training is factored in. Hack it a bit with the most elite crew you can come up with and time it till the point that the boat is no longer visible. Then run the same test with a bunch of Newbies. Just to see what the extremes are so you have a gauge you can use to adjust it. __________________ Diesel Boats Forever!

04-03-07, 04:53 PM	#29
jerryt Loader Join Date: Mar 2007 Location: Queen Creek, AZ. USA Posts: 88 Downloads: 23 Uploads: 0	Has anyone done a crash dive in really rough seas? It took forever to get below the surface! I didn't time it, but it was way over the usual time. I'm thinking maybe the dive planes couldn't get a good bite because of the wave action? They were in and out of the water. Anybody know if this would be a realistic behavior? On another note. Surfacing in really rough weather seems to take a long time to get well above the surface. I notice even in calm seas, it takes a while for the boat to get completely to zero depth, but when its rough I sure can't send my lookouts above deck for a few minutes. I have to use the periscope for safety. :p __________________ JerryT

04-03-07, 04:02 PM	#25
Ducimus Rear Admiral Join Date: May 2005 Posts: 12,987 Downloads: 67 Uploads: 2	So far im guessing that from crusiing on the surface at 8 kts, and hitting crash dive, the boat should be completely covered with water with only the little pole on the stern protruding on the surface - in about 45 seconds?

04-03-07, 05:05 PM	#30
NoLine Medic Join Date: Jun 2005 Location: AN85 Posts: 167 Downloads: 55 Uploads: 0	Anybody notice the s-boat crash diving in 15 seconds, which seems a bit short NoLine