(beta) Surface draft and dive time mod + more release update! | Forums

[swdw973]

Here it is,

This is the mod that changes the way the boats ride on the surface, They now sit lower, roll and pitch is more natural (from the feedback I've received) and dive times are closer to realistic. This mod is JSGME ready.

As with most work like this, credit is due to multiple people. These files are dreived from previous works, changes were made by more than one individual and individuals helped test. So credit should be given to:
Previous work utilized: Ducimus_rapax, LeoVampire
Current changes: LukeFF, swdw
Testing: AVGWarhawk, Wilcke, Ducimus_rapax

It should work with any mod. If you use TM, RFB or ROW, make sure this is installed after all of these.

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READ THIS SECTION BEFORE TESTING!!!!!

Because of all the possible ways to do the tests that will give varying times, I used a standard based on what I could gather from reading some historical info. If you don't use the same method, you will get different numbers.

Here's how this was tested

Dive times are not to PD, but to where nothing is above the water any more. This was how the boats clocked their time. They knew the keel depth required to be totally submerged (40-50 ft depending on the boat)

If you tell the boat to go to PD and try to time to PD, the leveling off drastically slows the time down. The boat starts to change the angle of attack before the sub is entirely below the surface.

Normal dive was timed by using the normal dive command, or telling the boat to go to 100 ft by clicking on the depth gauge.

Dive rate tests for normal dive are at a standard bell and will be slower at lower bells. Once the ballast tanks are flooded, everything else depends on the planes and trim tanks.

Crash dive tests were performed with the boat starting at standard bell ( cruising speed)

Start clock after klaxon on dive or alarm on emergency dive (with ROW sound mod). If you start it at different time you can introduce a 5-10 second variation.

Underwater tests conducted at 2/3 bell

Ascent/descent
Start at 60 feet and dive to 250. Time as boat passes through 100-200ft so leveling off does not affect test

Start at 250 feet and set depth to 60. Time as boat passes through 200-100ft so leveling off does not affect test

At higher bells, the underwater time decreases.

Based on generic info for fleet boats, turning on fleet boats was set to 1 deg sec submerged at 8 knots.

Acceleration- close to historical
Deceleration- game engine problem, coasts like it's greased- 6x historical values. Will take a LOT of work to try and fix, if it's fixable, as game engine does not take into account prop drag so will save for later work.

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Additional changes-
Engine bell speeds changed to reflect maritime "definition" of how a standard bell is derived. A standard bell is defined as the best cruising speed that gives good fuel economy while getting you there at a reasonable speed. 1/3 and 2/3 are fractions of a standard bell, not a flank bell.

Ranges, Luke made some changes to the ranges. I threw in a couple of extras. Fleet boat no longer all have the same battery life. Endurance was improved as you progressed from the Porpoise to the Gato class.

Please note that the boats are "roughed in" in this release.

The S-boat is the fastest diver and turner.
There are slight variations in the dive time of each class because the difference between the surfaced and submerged displacement varies with each class of boat, as does the ballast tank flood speeds. This will need to be fine tuned in the future. Surface draft will probably be tweaked by a few inches with more testing (less than 6 inches in most cases. General rule of thumb I've found when playing with most changes related to physics modeling is the old 80/20 rule applies. It takes about 20% of the total time to get to about 80% of your goal and then 80% of the time is spent tweaking for that last 20%

If you want to give this mod a try, go here:
http://files.filefront.com/diverateR.../fileinfo.html

Hope you find this enjoyable

[capt_frank]

I'll give it a whirl this afternoon, thanks!!

[VikingGrandad]

Interesting project! I've added a link to the 'Tips, Mods, Tools, etc.' sticky.

If you update the mod, please update this thread rather than start a new one, so that the link in the stick always points to the latest version - thanks!

[ElAurens]

Can you be a bit more specific as to how range is affected?

My assumption is that range is decreased from what it is in TM. True?

Also turn times. Fleet boats (as most subs) are poor turners. In the game they are horribly slow in the turn. Have you lowered this performance even more?

[Toastmann]

Hi SWDW973 ,
Thank you !! Finally someone figured how to make
the subs ride correctly IN the water, IN is definately better than the previous ON !!!
So far I've only tested the Porpoise class ,and
so far so good .
This sim just gets better and better !
Keep up the good work.

[AVGWarhawk]

Do not use the P key to dive to PD. It will take 4 minutes as the boat thinks it is using the forward and aft planes only. If you do, it will take 4 minutes to dive. Use the D key for normal dive (as they did and Swdw pointed out to me)and the planes/tanks will work in unison to submerge your boat properly

From one virtual submariner to another

[swdw973]

Update to file uploaded. This replaces the earlier version. Fixes problems I missed with periscope and surface depth in the config files.

Small change to a couple of sub drafts too (like 4 inches)

New file
http://files.filefront.com/diverateR.../fileinfo.html

Link in first post is updated.

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The reason for AVGwarhawk's warning has to do with how the game engine handles to PD command when on the surface. The boat starts to level off almost as soon as the deck is below the surface. This changes the angle of attack to a very shallow angle and makes the boat take forever to get to PD.

In real life the OOD would tell the planesmen how many degrees down bubble to use in getting to PD, or they'd just get down quick and then come to PD.

Since plane angle is beyond our control, I can't do anything about that.

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ElAurens, the turn speed were actually pretty close in stock. A couple were slowed down a little, and a couple were sped up a little.

The real issue is not the subs turning speed, but the speedboat characteristics of the surface ships- which will be tackled later. This mod is actually a part of the upcoming Real Fleet Boat update, so it's geared towards realism. This is also why we'll be working on the surface ship acceleration and turning issues- make them more realistic.

Because so many people are sick of the boat's riding on the water, we released it separately for everyone. If you want faster turn times, someone should be able to do it. Get S3D editor, load the sub .sim file you want to change and raise the "prop_fact" and "drag" setting for the rudder.

[Ducimus_Rapax]

First, great job.

I do have one point of observation, and one concern.

The standard bell, i think its acutally a little ineffecient on fuel when testing on a gato. Its CLOSE. Looking at the knotmeter, its acutally doing almost 11 kts, Using the "max range at current speed", im getting almost 10,000 NM . Lowering the speed to almost 10 kts , that max range was almost at 12,000 NM. It is my suggestion to experiment with a standard bell of 0.45 or there abouts tell maximum fuel effieciency is obtained.

My concern, is in submerged endurance or how far one can travel at 1/3rd to 2/3rds speed. With the increased submerged drag, is range being reduced?

[swdw973]

Originally posted by Ducimus_Rapax:
First, great job.

I do have one point of observation, and one concern.

The standard bell, I think its actually a little ineffecient on fuel when testing on a gato. Its CLOSE. Looking at the knotmeter, its actually doing almost 11 kts, Using the "max range at current speed", im getting almost 10,000 NM . Lowering the speed to almost 10 kts , that max range was almost at 12,000 NM. It is my suggestion to experiment with a standard bell of 0.45 or there abouts tell maximum fuel effieciency is obtained.

My concern, is in submerged endurance or how far one can travel at 1/3rd to 2/3rds speed. With the increased submerged drag, is range being reduced?

Drag had no noticeable effect on range. I set the L/R U/D submerged drag values to 1, rudder to 1, planes to 1. No observable effect. Tried the same with the surfaced values- no observable effect. Changed all of them to 0.1 both surfaced and submerged, no observable effect on range. Fuel / battery usage seems to be a simpler formula than we thought. (Thankfully in this case)

As for standard bell, It's not defined as the most fuel efficient bell, but is a compromise between efficiency and speed. Sometimes close to 50% , but can vary some in either direction. There is no hard and set rule that it is exactly a certain percentage or how much the compromise between fuel economy and speed should be.

So at this point it's personal preference. However, Donner has offered to do research for RFB as he now has copies of all the war patrol reports from WW2. So it may change.

Thanks for the feedback. Hope this helps with the drag concerns.

Hey- per your contacting modders post- you forgot to tell me it sucks

You also didn' follow the other 6 rules.

[Ducimus_Rapax]

LOL thanks man!