Faster Dive achieved

captiandon · 10-28-07, 01:49 PM

I remember someone talking about how US Skippers would run with there ballast tanks flooded. I found you can simulate this ingame by running at a slightly deeper debth on the surface. Right around 24 to 25 feet. However at 24 feet the bow dive planes start to raise and lower. At 25 feet there extended and at eather debth your speed is reduced to 12 kts at flank. I was wondering at what debth does the sub switch to electric? I was wondering if it was possable to change that debth so that one could run at a higher speed with the ballast tanks flooded. Or is this more accurate since the boats weight has changed?
I was also wondering if there was a way to add a command to flood the ballast tanks

swdw · 10-28-07, 03:55 PM

You may be thinking about a tactic called 'riding the vents"

From the US Pampanito site:
Riding the vents. Riding the vents is a surface condition in which the main ballast tanks are prevented from completely flooding by the closed main vents which prevent the escape of air.

The ballast tanks were not flooded, rather some water would slosh into the tanks while moving. This added drag to the boat and used more fuel, so was usually used in areas with a lot of possible Japanese ASW encounters (planes or ships). Basically, you airlock the ballast tanks. You don't have to wait for the ballast tank's flood valve to open and this allows a quicker in rush of water. I think it only shaved off 10 seconds max on your dive time.

What you are doing in your post is similar to the "decks awash" tactic. It will cost you speed, but should help with stealth. Boat is heavier with a lot more drag due to surface area

Not sure where the changeover from mains to battery occurs and can't check until my replacement MB gets here. However, 12 kn is is a little high for flank on the battery.

captiandon · 10-28-07, 04:37 PM

I found that at 25 ft which keeps the deck above the water your still on diesel power. However the Ballast are at netural boyancy and the boat dives instantly I can hold 10 kts at standard at that debth and seems to be a better way to combat air attacks. Just hit the d key and the boat starts to dive to what ever debth you choose. With the Gato I normaly go to about 350 to 400 feet then level off makes it easy to get away from the aircraft. However it seems that the aircraft ingame dosent see you at that level it seems that the game treats you as if your submerged and aircraft seemingly dont see you even thought your on the surface. I am wondering if I just stumbled on another bug.

Ducimus · 10-28-07, 04:45 PM

There is another way to decrease dive time, and if anyone finds a better way , im all ears.

Theres several variables to play with, but the main one being ManBT_Flood_speed, in the submarine sim file, if your using the S3D editor. By default, i think their around 20,000. If you increase it to 35,000 you can make a 1min and 10 second dive time, to around a 45ish second dive time.

There is one other variable dealing with ballasts that im unsure what it does. This is a new variable in SH4, and does not exist in Sh3 submarine sim files. This variable being "DiveBT_Flood_speed". Default is 9,000.

I have tried improving dive times by fiddeling with hydroplane drag, and havent had any good results.

Another thoguht ive had is to reduce the surface and submerged displacement in the sim file. Yes a lighter displacment is inaccurate, but in the SIM file, who will really notice? Overall, in trying to improve dive time, ive been comparing Sh4 gato sim files to a type 9 sim file from Sh3, and trying to match the variables as a type 9 has aruond a 42-45 second dive time with an MBT_FloodRate of 7,000. Yet, in SH4, we have 20,000 flood rates, for a much slower dive time. I do not understand that, so i figure the answer is probably in other variables, or the game just handles it's computations completly different, which is most likely the case.

Digital_Trucker · 10-28-07, 05:09 PM

Thanks for that info, Ducimus.

Hopefully will solve some

trying to dive while watching the land/sea scape.

swdw · 10-28-07, 07:04 PM

Quote:

Originally Posted by Ducimus

Another thoguht ive had is to reduce the surface and submerged displacement in the sim file. Yes a lighter displacment is inaccurate, but in the SIM file, who will really notice? Overall, in trying to improve dive time, ive been comparing Sh4 gato sim files to a type 9 sim file from Sh3, and trying to match the variables as a type 9 has aruond a 42-45 second dive time with an MBT_FloodRate of 7,000. Yet, in SH4, we have 20,000 flood rates, for a much slower dive time. I do not understand that, so i figure the answer is probably in other variables, or the game just handles it's computations completly different, which is most likely the case.

This is normal Ducimus. I'll see if I can find the link later, but I seem to remember the US boat's normal dive speeds (not riding the vents or some other trick) were typically 15-20 seconds+ longer than the U-boats. Fastest diving boats in WWII where actually British boats. (must be the rum

)

So, no reason to worry about trying to get a US boat to match the normal dive speed of a U-boat.

Ducimus · 10-28-07, 07:25 PM

You misinterpret me. My intention isnt to get a fleet boat to dive as fast as a uboat, albiet it could dive as fast as a type9 (maybe even faster). Wartime dive for a US fleet boat was around 35 seconds, with a 45 second dive being the bare acceptable minium for a crew in training.

In SH3, a type 7 had a floodrate of around 9,000 to 10,000. A type 21, or type 2, (even faster divers), had a flood rate of around 12,000. By comparsion a type 9 had a flood rate of 7,000.

A type 9D2 in SH3 had a such a floodrate (7,000), and took 45 seconds to dive. A reasonble figure. So why is it, that a Fleet boat in sh4, has a floodrate of 20,000 by default, and is ALOT slower?

Somethings not right there. My attempts have been to figure out the answer to that question. Somethings not right with the physics themselves, as increased speed tends to make you dive a little slower when it should be faster. In short, i feel that the floodrate is the tip of the iceberg of a larger problem. Another reason why ive been looking at it, off and on, as patience allows.

swdw · 10-28-07, 08:31 PM

Quote:

Originally Posted by Ducimus

Somethings not right there. My attempts have been to figure out the answer to that question. Somethings not right with the physics themselves, as increased speed tends to make you dive a little slower when it should be faster. In short, i feel that the floodrate is the tip of the iceberg of a larger problem.

Hmmm, weird. the whole reason for diving on the mains until the last second was to keep speed up to dive faster.

This is strange, and I can see why you're looking into it

Quote:

Another reason why ive been looking at it, off and on, as patience allows.

Patience is something you seem to have much more of than many of us do.

leovampire · 10-28-07, 08:59 PM

The size of the Ballest tanks and the sub are very differn't from the US to German Boat's.

The German boat displacment was much less than the US sub's so it took less water in the tank's to start going down. Also because the German sub's had less room the Airtank's were smaller so if there was too much water to pump out of the tank's Air got used up very fast and took time to replenish.

Wasn't the dive plane's on the German sub's also lower to or under the water line to give better dive control?

Ducimus · 10-28-07, 09:31 PM

Well, the technical specifications are what they are in Real life. But i look at the inner works of the sim file, and its outward performance seperatly. In other words, if using a submerged displacement of 1000 in the sim file, makes the submarine in game behave more realisticlly, or at least, more towards the desired result, then so be it!

Just because what the real life specifications say one thing, doesnt neccessarly mean they have to be the same in the sim file itself. Its the outward results that are projected that are of interest - at least to me. My view is the player doesnt see the internal workings of a sim file as they play, only its results during play.

leovampire · 10-28-07, 09:43 PM

Quote:

Originally Posted by Ducimus

Well, the technical specifications are what they are in Real life. But i look at the inner works of the sim file, and its outward performance seperatly. In other words, if using a submerged displacement of 1000 in the sim file, makes the submarine in game behave more realisticlly, or at least, more towards the desired result, then so be it!

Just because what the real life specifications say one thing, doesnt neccessarly mean they have to be the same in the sim file itself. Its the outward results that are projected that are of interest - at least to me. My view is the player doesnt see the internal workings of a sim file as they play, only its results during play.

You might start to get a little better result's on dive time. It takes longer to dive at a higher displacment as far as I understand it. Lower the under water displacment let's say 100 at a time and then use the watch to time the dive.

Ducimus · 10-28-07, 09:46 PM

Just as an side, The reason i keep refering to Sh3 uboat sim files, is because the type 9's, i feel are a baseline of variables known to work correctly. I honestly haven't tried lowering displacement yet. I ran out of patience earlier, and went back to work on the AI visuals. (in between sweating my butt off moving furniture and packing boxes

)

leovampire · 10-28-07, 09:58 PM

Quote:

Originally Posted by swdw

Quote:

Originally Posted by Ducimus

Somethings not right there. My attempts have been to figure out the answer to that question. Somethings not right with the physics themselves, as increased speed tends to make you dive a little slower when it should be faster. In short, i feel that the floodrate is the tip of the iceberg of a larger problem.

Hmmm, weird. the whole reason for diving on the mains until the last second was to keep speed up to dive faster.

This is strange, and I can see why you're looking into it

Quote:

Another reason why ive been looking at it, off and on, as patience allows.

Patience is something you seem to have much more of than many of us do.

That is normal. I always reduce speed till the dive start's once I hear that first big splash I floor it to get under and dive down deep fast. Just like in a car accleration always bring's the nose up. Have you ever noticed that if your going reverse emergency in the sub the prop's eventualy start to pull the sub under. That is why Front wheel drive car's give you better forward control through the snow vs rear wheel drive it help's to keep the nose and weight in front for better control just a matter of physic's. But I am willing to bet if you lower the sub's Under water displacment little by little you will see better dive time's. Also don't forget the crew matters in the game. The better the command crew the better the sub does thing's.

captiandon · 10-28-07, 11:33 PM

Well I am not trying to get a faster standard Dive time with dry tanks. I just want to be able to as you put it Ride the Vents. Its to bad one cant run with the tanks half full or so to make the dive times faster in Emergancy situations. I only do that when I am near a known Airbase like when headed from Midway, Wake Island always is sending aircraft out and I like to be able to wait till the last moment. The aircraft dont normaly spot me unless they are in visual range. I dont like to dive unless I really have to. Real Boats ran on the surface and only submerged when in danger. I am just trying to keep my Patrols that much realistic anyway. The only Other time I do that is when I am shadowing a Convoy and want to dive quickly. I also use the Decks awash Tactic when I am trying to reaquire a Convoy after being drivin off by a Destroyer.

Melonfish · 10-29-07, 04:27 AM

am i the only one that likes the longer dive times?
well i mean don't get me wrong i love the fact that my baby U-53 goes down like a lead balloon but in my newly commissioned Gato i am finding i'm there going "down, down ya slow bugger get down!" as the planes are edging closer and closer.....

adds to the immersion. i mean in sh3 it'd be like "plane spotted" crash dive, gone.
now its Radar contact, which gets you in spotting range, crash dive!
....

....

plane is visible, lining up

....

....

and we're down. the plane makes its run and misses by 40 feet. thats just fun!

10-28-07, 01:49 PM	#1
captiandon Soundman Join Date: Sep 2007 Posts: 148 Downloads: 0 Uploads: 0	Faster Dive achieved I remember someone talking about how US Skippers would run with there ballast tanks flooded. I found you can simulate this ingame by running at a slightly deeper debth on the surface. Right around 24 to 25 feet. However at 24 feet the bow dive planes start to raise and lower. At 25 feet there extended and at eather debth your speed is reduced to 12 kts at flank. I was wondering at what debth does the sub switch to electric? I was wondering if it was possable to change that debth so that one could run at a higher speed with the ballast tanks flooded. Or is this more accurate since the boats weight has changed? I was also wondering if there was a way to add a command to flood the ballast tanks

10-28-07, 03:55 PM	#2
swdw Grey Wolf Join Date: Sep 2007 Posts: 921 Downloads: 75 Uploads: 0	You may be thinking about a tactic called 'riding the vents" From the US Pampanito site: Riding the vents. Riding the vents is a surface condition in which the main ballast tanks are prevented from completely flooding by the closed main vents which prevent the escape of air. The ballast tanks were not flooded, rather some water would slosh into the tanks while moving. This added drag to the boat and used more fuel, so was usually used in areas with a lot of possible Japanese ASW encounters (planes or ships). Basically, you airlock the ballast tanks. You don't have to wait for the ballast tank's flood valve to open and this allows a quicker in rush of water. I think it only shaved off 10 seconds max on your dive time. What you are doing in your post is similar to the "decks awash" tactic. It will cost you speed, but should help with stealth. Boat is heavier with a lot more drag due to surface area Not sure where the changeover from mains to battery occurs and can't check until my replacement MB gets here. However, 12 kn is is a little high for flank on the battery. __________________ "There are only two types of ships- submarines...... and targets" Unknown "you wouldn't catch me on a ship that deliberately sinks itself"- comment to me from a surface sailor. System: AMD 6300 3.5 GHz \| 32GB DDR3 \| SATA 300 320GB HD, SATA III 1TB HD, SATA III 1.TB HD \| ASUS Sonar DS sound card NVIDIA 1660 Super OC \| Windows 10 Last edited by swdw; 10-28-07 at 08:25 PM.

10-28-07, 05:09 PM	#5
Digital_Trucker Silent Hunter Join Date: Jul 2007 Location: The Peach State Posts: 4,171 Downloads: 141 Uploads: 10	Thanks for that info, Ducimus. Hopefully will solve some trying to dive while watching the land/sea scape. __________________ RSM-GIEP-Killflags-LV Tribute-Playable Elco __Peace be with you, Dave.

10-28-07, 08:59 PM	#9
leovampire Eternal Patrol Join Date: Apr 2007 Location: Waterbury, CT. USA Posts: 2,336 Downloads: 0 Uploads: 0	did you look to see the difference between Tanks The size of the Ballest tanks and the sub are very differn't from the US to German Boat's. The German boat displacment was much less than the US sub's so it took less water in the tank's to start going down. Also because the German sub's had less room the Airtank's were smaller so if there was too much water to pump out of the tank's Air got used up very fast and took time to replenish. Wasn't the dive plane's on the German sub's also lower to or under the water line to give better dive control? __________________ AIR_BASE_NAV_MAP_MOD Reflections_on_the_Water

10-28-07, 04:37 PM	#3
captiandon Soundman Join Date: Sep 2007 Posts: 148 Downloads: 0 Uploads: 0	I found that at 25 ft which keeps the deck above the water your still on diesel power. However the Ballast are at netural boyancy and the boat dives instantly I can hold 10 kts at standard at that debth and seems to be a better way to combat air attacks. Just hit the d key and the boat starts to dive to what ever debth you choose. With the Gato I normaly go to about 350 to 400 feet then level off makes it easy to get away from the aircraft. However it seems that the aircraft ingame dosent see you at that level it seems that the game treats you as if your submerged and aircraft seemingly dont see you even thought your on the surface. I am wondering if I just stumbled on another bug.

10-28-07, 04:45 PM	#4
Ducimus Rear Admiral Join Date: May 2005 Posts: 12,987 Downloads: 67 Uploads: 2	There is another way to decrease dive time, and if anyone finds a better way , im all ears. Theres several variables to play with, but the main one being ManBT_Flood_speed, in the submarine sim file, if your using the S3D editor. By default, i think their around 20,000. If you increase it to 35,000 you can make a 1min and 10 second dive time, to around a 45ish second dive time. There is one other variable dealing with ballasts that im unsure what it does. This is a new variable in SH4, and does not exist in Sh3 submarine sim files. This variable being "DiveBT_Flood_speed". Default is 9,000. I have tried improving dive times by fiddeling with hydroplane drag, and havent had any good results. Another thoguht ive had is to reduce the surface and submerged displacement in the sim file. Yes a lighter displacment is inaccurate, but in the SIM file, who will really notice? Overall, in trying to improve dive time, ive been comparing Sh4 gato sim files to a type 9 sim file from Sh3, and trying to match the variables as a type 9 has aruond a 42-45 second dive time with an MBT_FloodRate of 7,000. Yet, in SH4, we have 20,000 flood rates, for a much slower dive time. I do not understand that, so i figure the answer is probably in other variables, or the game just handles it's computations completly different, which is most likely the case.

10-28-07, 07:25 PM	#7
Ducimus Rear Admiral Join Date: May 2005 Posts: 12,987 Downloads: 67 Uploads: 2	You misinterpret me. My intention isnt to get a fleet boat to dive as fast as a uboat, albiet it could dive as fast as a type9 (maybe even faster). Wartime dive for a US fleet boat was around 35 seconds, with a 45 second dive being the bare acceptable minium for a crew in training. In SH3, a type 7 had a floodrate of around 9,000 to 10,000. A type 21, or type 2, (even faster divers), had a flood rate of around 12,000. By comparsion a type 9 had a flood rate of 7,000. A type 9D2 in SH3 had a such a floodrate (7,000), and took 45 seconds to dive. A reasonble figure. So why is it, that a Fleet boat in sh4, has a floodrate of 20,000 by default, and is ALOT slower? Somethings not right there. My attempts have been to figure out the answer to that question. Somethings not right with the physics themselves, as increased speed tends to make you dive a little slower when it should be faster. In short, i feel that the floodrate is the tip of the iceberg of a larger problem. Another reason why ive been looking at it, off and on, as patience allows.

10-28-07, 09:31 PM	#10
Ducimus Rear Admiral Join Date: May 2005 Posts: 12,987 Downloads: 67 Uploads: 2	Well, the technical specifications are what they are in Real life. But i look at the inner works of the sim file, and its outward performance seperatly. In other words, if using a submerged displacement of 1000 in the sim file, makes the submarine in game behave more realisticlly, or at least, more towards the desired result, then so be it! Just because what the real life specifications say one thing, doesnt neccessarly mean they have to be the same in the sim file itself. Its the outward results that are projected that are of interest - at least to me. My view is the player doesnt see the internal workings of a sim file as they play, only its results during play.

10-28-07, 09:46 PM	#12
Ducimus Rear Admiral Join Date: May 2005 Posts: 12,987 Downloads: 67 Uploads: 2	Just as an side, The reason i keep refering to Sh3 uboat sim files, is because the type 9's, i feel are a baseline of variables known to work correctly. I honestly haven't tried lowering displacement yet. I ran out of patience earlier, and went back to work on the AI visuals. (in between sweating my butt off moving furniture and packing boxes )

10-28-07, 11:33 PM	#14
captiandon Soundman Join Date: Sep 2007 Posts: 148 Downloads: 0 Uploads: 0	Well I am not trying to get a faster standard Dive time with dry tanks. I just want to be able to as you put it Ride the Vents. Its to bad one cant run with the tanks half full or so to make the dive times faster in Emergancy situations. I only do that when I am near a known Airbase like when headed from Midway, Wake Island always is sending aircraft out and I like to be able to wait till the last moment. The aircraft dont normaly spot me unless they are in visual range. I dont like to dive unless I really have to. Real Boats ran on the surface and only submerged when in danger. I am just trying to keep my Patrols that much realistic anyway. The only Other time I do that is when I am shadowing a Convoy and want to dive quickly. I also use the Decks awash Tactic when I am trying to reaquire a Convoy after being drivin off by a Destroyer.

10-29-07, 04:27 AM	#15
Melonfish XO Join Date: Nov 2006 Location: Warrington, UK Posts: 417 Downloads: 106 Uploads: 0	am i the only one that likes the longer dive times? well i mean don't get me wrong i love the fact that my baby U-53 goes down like a lead balloon but in my newly commissioned Gato i am finding i'm there going "down, down ya slow bugger get down!" as the planes are edging closer and closer..... adds to the immersion. i mean in sh3 it'd be like "plane spotted" crash dive, gone. now its Radar contact, which gets you in spotting range, crash dive! .... .... plane is visible, lining up .... .... and we're down. the plane makes its run and misses by 40 feet. thats just fun!