[REL] Improved Ship Physics

[TorpX]

I am happy to announce the release of the first version of ISP!

It can be found in the SH4 gameplay mods section:
http://www.subsim.com/radioroom/down...o=file&id=4440



This should be considered at beta. When I finish the ships, and anything else that needs to be done, I will combine everything into one mod.

I have provided a summery of development, so if anyone wants to attempt further efforts, they won't have to start from square one.

If the post meanders, bear with me; I had to cut and paste from very incomplete notes taken along the way.



Improved Ship Physics version 1.0:

The goals of this mod are:
1. Tame the outragous acceleration of subs.
2. Make turning more realistic.
3. Improve diving characteristics.
4. Fix battery issues of subs.
5. Improve weather/wave effects.


Acceleration

Many here have commented about the fantastic acceleration of ships in this game. Awhile ago, I took a look at the sim files to see what could be done about this. If you open the file (using S3D), and look under propulsion, you find max_speed, max_force, eng_power, and eng_rpm. There are also seperate values of max_speed, eng_power, and eng_rpm in the E_propulsion element. The significance of the max_force did not immediately come to me, but after pulling out my old high school physics text book, and doing some simple calculations, I could see the lay of the land here.

If we had an object at rest, and applied a constant level of power to make it move, a graph of its speed vs. time would look like graph 1. Note that the acceleration (the slope, shown by the blue lines) is very steep at the start, but diminishes as speed increases. If we had an object at rest, and applied a constant force, the graph would look like graph 2. Note that the slope in this case is constant.

The ships in the game have acceleration characteristics that correspond most closely to graph 1. The steep slope of the graph is why ships seem to almost leap into motion. What we
would like to have is something like graph 3, where the acceleration is limited by both a maximum force, and maximum power.

I started to play around with the S-18 submarine, to see what might be done with this file. Rough calculations suggested a max force of maybe 5 or 10 tons might be suitable.
According the this file, the max force is in tons, and both the stock and RFB values are at 0. I started by using 10. There was no difference. I tried 5, 1, .5, all having the same
acceleration. By this time, I was disgusted, so I dropped the max force and tried reducing the eng power. By greatly reducing the eng power, the acceleration can be significantly
reduced. This seemed like it might be the way to go, until I happened to shut down the engines, and noticed the sub continued to glide along toward the horizon like a hockey puck
on very slippery ice - not good!

I should also note, I tried messing around with the engine rpm's. This seemed to be equally pointless. While the screws will twirl faster or slower, the propulsion is unaffected! This flew in the face of some of what I read about modding ship acceleration, but maybe SH3 was different. Going back to the max force, it still bugged me why I couldn't get any results. I mean why even have it, if it doesn't do anything?

I put in a negative number. The boat goes rocketing backwards, porposing into the water, takes heavy damage, and sinks. Ok, that's a difference alright. I try a negative number of smaller magnitude. It goes porposing backwards, but doesn't sink this time. Hmmm. I then try a very small positive number, .0001, or so. It accelerates very slowly, reaching a top speed of one half knot. Better; but we probably will want to go faster than that. By trial and error, I zeroed in on the figure of .0185. Anything much below this does not allow the boat to reach it's stated 'maximum speed'.

At this point, you might be wondering why such a low value is indicated. .0185 tons is a very low value - implausibly low. My first thought was that maybe this value is multiplied by the rpm's, but testing quickly disproved that hypothesis. Possibly, it is multiplied by the ship's mass. In any case, we can make good use of this, provided we input suitably low values.

This bit of success inspired me to look at the physics of the subs and ship generally, and see what can be done to improve the situation. I approached the acceleration by trying to find
the minimum value that would permit the vessel to reach it's stated maximum speed. Pretty simple, but with the subs, I needed to check both the surface and submerged speeds.
The later seemed to be the limiting factor here.



Diving

Then I started to deal with turning and diving. After a considerable amount of experimentation, I decided it would be best to do the diving first, as there are more factors
involved. In fact, diving performance proved to be by far the most difficult part of all this. First, I should state, that my view of diving performance is that it should be realistic overall, not just that a boat should have a super-quick dive to periscope depth, with all other aspects being secondary. That is, the boat should take on a sensible dive angle, but should not dive or climb like a P-47. I mainly focused on three standard tests: #1, dive to periscope depth starting at 10 kts. (8 kts. for S-class), #2, dive from p/s depth to 150 ft., #3, climb from 150 ft. to p/s depth. The 150 ft. tests allowed me to observe how well (or poorly) the dive planes worked. I also did supplementary tests, here and there; like making a dive to p/s depth starting at 10 kts., but going to full speed as the dive is ordered ( I called this a 'quick dive').

I should point out here, that the stock/RFB values of drag coefficients of the planes are zero, hinting there are improvements to be had here. A dive from the surface is best
thought of as having three phases. In the first, the MBT and 'down express' tanks are flooded. These are probably full about the time the deck goes below the surface. In the second phase, the bow planes are rigged out and start to bite into the water, so the boat takes on a significant angle, and is driven down. In the last phase, the planesmen level out the boat and the boat makes the last 5 or 10 feet of the descent. For depth changes (up or
down) the flooding of the MBT's don't come into it, though there are some negative/bow buoyancy tank factors modeled.

The rate of descent in the first phase can be altered easily by changing the ManBT_flood_speed, but I suspect is also influenced by the values of surface draft and submerged draft. I played around a little with the DiveBT_flood_speed, but it just didn't seem to do much. While the DiveBT speed can be altered, there is no provision for changing the negative buoyancy, so I didn't see too much point in playing with this. In the second phase, the rate of descent is mostly a function of the dive plane coefficients, the UD drag values, and the speed of the boat. A good dive angle combined with a high speed makes for a rapid descent. In the last phase, the AI crew calls the shots. The submerged UD drag factor, and planes factors apply, but the planesmen seem to level out the boat too fast, and
there doesn't seem to be much to be done about it. This turned out to be a sore point.

The ManBT_flood_speed, and DiveBT_flood_speed are in liter/sec. This means little to me. As a guide to having sensible values, I subtracted the surfaced displacement from the
submerged disp. to find the number of tons of seawater taken on. Then used the density of seawater to calculate how long it would take to flood the tanks:

t = B/(f * .00114)

t: time in seconds
B: ballast capacity, tons
f: flood rate, l/s

I started with flood times of 10 sec. and adjusted from there. I am aware of the quoted standards that fleetboats could dive in 35 to 45 sec., S-boats in 75 sec., and V-boats in 90
sec. I used these as a guideline, but I had to consider the dive angles and deep diving aspects as well. The quoted times are somewhat ambiguous, and may represent something closer to a crash dive, in game terms.

One thing I found out early on, that simply increasing the flood rate isn't very useful. It is possible to crank that up and have a quick descent at the start, but the boat tends to go down at a shallower angle, and after you get down to 40 ft. or so, most of the early downward momentum is gone, so you end up with a longer time to reach the ordered depth. If you doubt how important the dive planes and dive angle are, just zero out all the planes' drag factors, along with the prop factors, and see how long it takes to dive.

I went back and forth with the planes. The planes' drag coefs. along with the UD drag coef. are the main factors that determine the dive angle the boat takes on. The planes' drag coefs. (along with the prop factors), put force on the ends of the boat. The surface and submerged UD drag coefs. resist these forces. If the planes' coefs. are too high, the boat dives and
climbs like a fighter plane, too low and it goes up and down like an elevator. I would have liked to hold the dive angles to 15 deg. or less, but that wasn't possible without greatly nerfing the planes. The AI planesmen seem to want a 30 degree angle, if they have enough space and speed to obtain it. The inclinometers only go up to 15 degrees; this suggests that
this angle was seldom exceeded. Unfortunately, the AI crew would not cooperate in this. They want to dive or climb at very steep angles, they level out the boat too soon, and generally creep the last few feet to the ordered depth, an inch at a time. This last phase of a dive, often takes an inordinately amount of time. This last item is, more than anything else, the reason for slow depth changes.

When I reviewed some of the sub manuals around, I noticed that the stern planes were said to mainly influence the angle, and the bow planes mainly the depth. With this in mind,
I thought I could reduce this creeping tendency, and speed up the last part of the dive. This was only partly successful. In practice, both the bow and stern planes seem to cause the
boat to take on a steeper angle. The problem is, that while we can change the planes' drag coefs., we can't change the way
the crew uses them. The last feet of the dive or climb are made with very small angles on the planes, especially the bow plane. The same goes for the negative buoyancy tank, and the bow buoyancy tank. There isn't any way to exercise manual control over these things, nor can they be addressed within the sim file.
I didn't put a lot of effort separately adjusting the prop_fact of the stern planes. Suffice it to say, by zeroing out the other planes factors, I got an idea of how much they influence the
angle. The rear diveplane prop_fact will have an effect even if the drag coef. is zero and vice versa. The bow planes clearly shouldn't have any propeller influence. Also, keep in mind, the
drag coefs. will slow down the boat.

I had what I thought was a pretty good diving scheme and had moved on to adjusting other things associated with 'sea-keeping'. When I went back to check and make sure the
dive times were good, I found out I couldn't replicate what I recorded before. This was very discouraging, as the UD drag, planes drag, and prop factors were all the same as before. It
turned out, that my adjustment of the gc_height was the culprit. I lowered it, as I realized the boat was rolling even in calm waters. The reason the dive times were longer, was that
the boat now leveled out faster in the last phase of a dive. I had to accept this, as saving some seconds in a dive wasn't worth the constant rolling. I didn't want people to reject the
mod on account of sea-sickness. :-)

Something else I tried; putting zero values for both the submerged and surfaced draft. It seemed to make for better dives, but I found out I could not put the sub in a 'decks awash'
condition. I'm not really big on the decks awash thing, but you should be able to use it if you want to. I went back to previous values. BTW, having the max force limited, also reduces the speed you can reach at decks awash quite a bit. This wasn't a deliberate act on my part, it just worked out that way. It is probably realistic, though.

One other thing I tried. I tried some mass values slightly higher than the surface displacement. I wanted to eliminate the hovering business, and maybe help the last phase of diving. This didn't work; all it did was make for lousy depth control. Increase it a lot and the boat plunges out of control the minute you dive. Decrease it a lot, and you can't get under the surface. I returned the mass to '0'.



Battery Capacity

I did a lot of tedious experiments to try to figure out what was going on with the batteries. At first, it seemed there was a sharp limit to the maximum submerged range (i.e. battery capacity). However, this turned out not to be strictly true.

I found that the observed range increases quickly it low values, but much less at higher values. This makes it appear that there is a fixed limit, as one reaches a point where increasing the range input improves the actual range too little to be noticed. One might get proper range by using a very large input range, but the problem with this is that the recharge time increases in direct proportion with the input. So, this is a non-starter.
Nobody wants to spend a week recharging batteries.

I reluctantly decided to use Ducimus fix, where a 'special ability' crewman has a -45 battery consume ability. This allowed the batteries to have book capacities (or at least close to it), and reasonable recharge times. I couldn't find precisely what the recharge times should be. The capacities (in amp-hours) were listed, but actual recharge times seemed to be variable according to circumstances. It was clear that the navy wanted their subs to be
able to complete a charge in 8 hours or less, though.

The reason I could not precisely match submerged range to historical specs is that I had to choose one ability value that would work for every sub. The Salmon, and later subs come out a little ahead, the older ones a little behind. I had to put 2 special ability crewmen in the S-class to get reasonable performance.

One other thing about the batteries; the 'special ability' value reduces the drain on the batteries (as expected), but also reduces the recharge rate. Yes, you read that right. So, if one wants optimum performance, he should put the battery expert in Hogan's alley when he starts charging. I assumed this procedure when I decided on the numbers, so it should not be considered a cheat.




Turning

I found the turning circles were not out of line with my sources, but the speed drop off was terrible. The LR drag coefs. control the resistance to turning, and the rudder drag and prop factor, the force on the tail of the boat. The rudder drag slows the boat, but the turning itself increases drag on the boat, as well. To put it another way, the boat will slow down even with very small rudder drag values.

I worked over the factors by trial and error, until they were at least close to what I wanted. My sources gave a fleetboat turning circle of about 450 yd. and a speed drop off of about 25% (submerged). The surface turning circle was given as 500 yd., but I don't know what the speed drop off was.





Weather

One of my major points of dissatisfaction with SH4 is the lack of any meaningful storms or heavy seas. Oh we have clouds, rain, and even lightning, but these have but small effect on the movement or operation of the boats. I wanted to have waves that would severely cut your speed, knock your boat around, and drain your fuel. You shouldn't be able to plot a 5,000 nm route, and know how much fuel you will need to the nearest gallon. The changes
to the waves should make the weather more of a factor in your operations.

When I talk about the weather here, I mean the wind and waves. I didn't try to change the
lighting and aesthetics. I think this is just as well, since the scene.dat file is a mess. The file
entries are not straightforward or intuitive at all, and one could probably spend a year fiddling with all this, and still not finish.

The relevant parts of the scene.dat file are index entries 9, EnvData, and 14, EnvSim. In the EnvData part, of particular importance is the MaxWaveHeight. Stock is 256; I increased it to 1000. No units are stated. It certainly isn't meters. The waves aren't nearly that high; centimeters perhaps. There are also 3 SupressWaves values which control wave harmonics, and SeaSpeed, and a ChoppyWave factor.

Moving down to the EnvSim portion, under the Wind part, we have four segments where the characteristics are indexed according to wind speed. The wind speed indexes are 0, 5, 10, and 15 m/s. The values under these are a mixture of visual and graphical elements. Why they chose to use this form is beyond me. Of interest to us, are the x,y,z scale values, LargeWavesArmonics, LargeWavesCoef, and SeaSpeed. The scale values control the size and geometry of the waves, the LargeWavesArmonics and LargeWavesCoef are related to the supression of wave harmonics, and the SeaSpeed governs the movement of the water. It is important to understand SeaSpeed does not mean wave speed in the sense of waves moving across the surface of the water. Rather, it is how fast the water surface moves up and down. Putting in a high value here gives you an unpleasant vibrating jelly effect.

Note that both the EnvData, and the EnvSim parts have LargeWavesArmonics,
LargeWavesCoef, and SeaSpeed entries. I don't know the reason for this. After many tedious experiments, I decided to rely mainly on the MaxWaveHeight, and x,y,z scale values to achieve the wave characteristics I wanted. One can use the scale values to make the waves very long (like we generally think of 'waves'), but this looked kind of
artificial to me, and they do not orient themselves to the direction of the wind. I did make them somewhat more rectangular, though.

I changed the wind index values to 0, 5, 13, 15. The idea here is to have the wave properties
at the lower range, 0 to 5, like before, the middle range, 5 to 13, only slightly higher, and
the higher range, 13, to 15, be much more formidable.

The waves properties in the Scene.dat file are only the first part of the matter. The waves, of themselves do not necessarily have much effect on a boat or ship. The second part is in the Sim.cfg file. Under the [Mech] portion there is the Waves amplitude value. Stock is 0.2 and I increased this to 0.4. Traveller used 0.4, and I think this is about the highest one should consider using. If this is set to zero, you have the sub on rails effect; it stays level
and is hardly affected. If it is set too high, the boat looks like a child's toy tossed around on a choppy lake. I experimented with the Waves Attenuation value, but I couldn't see any effect. The third part of this is in the boats' sim files themselves. The surface UD drag coef. controls the pitching of the vessel. I tried to use this to give the fleetboats better sea-keeping than the S-boats, but the way the mechanics of the game are, it didn't seem to make that much difference.

BTW, I tried changing the rebound coef. in the zon file, to make the wave push against the
boat more, but this did not have any effect.
Most of the speed loss seems to be a result of the screws coming out of the water. Waves
breaking over the bow, or the bow rooting into the waves, doesn't seem to have much, if
any, effect. The [average?] depth may come into play, but it's hard to tell. Whatever the
details, most of the speed reduction is nerfed when one goes above 32x TC. This is
unfortunate, but I don't see any fix for it. I hope if we ever get a new SH, the weather and
wave effects get more attention.
When one is logging the wind speed according to the face value of the wind speeds, x m/s
= 2x knots. With this mod I would suggest considering x m/s = 4x knots, up to 13 m/s, and
values of 14 or 15 m/s to be 'stormy' (> 50 knots).


Fuel Capacity and Range

I decided to use the 'special ability' idea to represent the extra fuel carried in fuel ballast
tanks. The idea is not perfect. The game doesn't model the extra weight of the fuel, maintenance issues, oil slicks, or such, but at least we can get the extra fuel, without having to manually edit game files.

The reason I didn't just increase the standard range is, apart from the above issues, not every sub had the capability at the start of the war. The S-class probably did, but I know that in at least one case in 1944, a fleetboat lacked this. I also consider that the reduction in reserve buoyancy (important in 'sea-keeping') would be a significant handicap, so the extra range shouldn't really come free.
I adjusted the book values given for endurance as follows: +30% as a reserve for battery charging, and an extra 5% to compensate for map distortion. I'm not sure the 30% should apply to every class, but by WWII, I think this was factored in to the numbers. The map distortion factor is intended to compensate (in part) for the distances at higher/lower latitudes being 'stretched out'. Depending on the length of your route, transiting to a patrol area might add a distance of a few percent, up to 10 or 12 percent. I split the difference and
settled on a 5% bonus. So, the Gato with a listed endurance of 11,000 nm. becomes 14,850 nm.

In SH4, diesel-electric drive engines idle at all stop. The ordinary diesels don't. This didn't seem too important at first, but after investigating this, I was dismayed to learn how much fuel was burned at 'all stop'. A Gato boat will consume the fuel equivalent of 8.55 nm @ 10 kt. per hour. In other words, standing still uses up 85% as much fuel as cruising at 10 knots!

Or, to look at it another way, if you planned a long patrol where you would spend 30 days on the surface standing still, waiting for contacts, this would come to 6,150 nm. That's a lot. In principle, I can see some fuel being lost to idling, but must all four engines be gulping fuel like this, just to stay warm? Remember, battery charging is extra.
With these numbers, it is more economical to submerge and run at 2 kt. for 12 hrs., surface, recharge, and idle for the rest of the day, than to sit idling for 24 hrs. This, of course, makes no sense, so I tried to eliminate or reduce this wasteful expenditure. Setting 'all stop' to a low speed value did no good; the fuel consumption isn't reduced. I even tried taking out all the crew out of the engine room, but that didn't work either. The only time
they stop is when you submerge. Just when I was about to give up, I thought of reaching into the 'Special Ability' bag of tricks for this.

The way it works is that he is normally stationed in the control room (where his ability is inactive). If/when you decide to stop for a time to conserve fuel, you move him into the engine room, where his ability becomes active, and cuts your fuel use to one quarter of the ordinary level. You can think of this as having him shut down 3 of your engines for
maintenance. To keep this from being a '44,000 nm. range cheat', he also severely cuts your surface speed, battery charging, and submerged speed. You have to move him out of the engine room for normal operations (e.g. movement, diving, charging).


I changed the engine telegraph settings to correspond to 20, 40, 60, 80, 100% POWER
levels. This means the lowest setting would be 1-engine speed and give you ~ 10 kt. in a
Gato. If you don't like it this way, feel free to change it. 10 knots will burn the same amount
of fuel whether you call it slow, 2/3, standard, or Uncle Carl. The game doesn't care.
The most economical speed is ~10 kt. for the fleetboats, and ~6 kt. for the S-class.

Here is a run down of the 'Special Abilities', that I altered:

1. MASTER ENGINEER
Improves dive speed, pump speed, and repair speed. The effect of the dive speed
bonus is not dramatic; mainly speeds up the first phase of a dive.
RECOMMEDED AVAILABILITY: ANYTIME AFTER 1st PATROL.

2. TIN CAN CROSSOVER
Sharpshooter ability, same as in TMO, but I tweeked the numbers.
RECOMMEDED AVAILABILITY: ANYTIME AFTER 1st PATROL.

3. MASTER TORPEDOMAN
Improves loading and reliability of torpedoes.
RECOMMEDED AVAILABILITY: ANYTIME AFTER 1st PATROL.

4. TORPEDO EXPERT
This provides you with TORPEX torpedo warheads.
RECOMMEDED AVAILABILITY: EARLY TO MID 1943.

5. DIESEL ENGINE EXPERT
This reduces idle fuel consumption. [FIXES IDLE ISSUES]
IMPORTANT! He should be put in the Engine Room when you want to idle and
save fuel, but be moved out for active operations.
RECOMMEDED AVAILABILITY: AT START.

6. BATTERY EXPERT
This reduces battery consumption. [FIXES BATTERY ISSUES]
IMPORTANT! He should be in Engine Room when submerged, but moved out
when charging.
RECOMMEDED AVAILABILITY: AT START.

7. FUEL BALLAST EXPERT
This reduces fuel consumption to simulate reserve fuel. Provides ~80% more
range.
RECOMMEDED AVAILABILITY: 1943 to 1944., 1942 for S-CLASS.

8. AHEAD EMERGENCY
This allows a short term boost of surface speed in an emergency.
RECOMMEDED AVAILABILITY: ANYTIME AFTER 1st PATROL.


The recommendations are guidelines for REALISTIC play. Every boat should have #6, the
battery expert, at start. Every fleetboat should have #5 at start. If you never lay to, or don't consider idle fuel economy to be important, you can kick him off your boat, with no loss in other functions.

The #4, torpedo expert, and #7, fuel ballast expert are powerful abilities, so I made these expensive. The fuel ballast issue is not cut and dried. N. Friedman gives various figures for endurance and weights of fuel oil, but the matter is not clear. The same goes for dates when the tanks were modified.

***

I tried using this mod with TMO, but it didn't work. This is probably due to matters related to the crew members upc, and subs upc files.

I intend to start work on the next part, (ships), soon, but I didn't want to delay this release.
I don't know how long it will take, so releasing this takes off some pressure.

***

Thanks to all who have provided modding know-how, information, and encouragement for
this project:

aanker -provided needed help in sorting out the special abilities area.

Aktungbby
privateer
CapnScurvy
Hitman
Sailor Steve
cdp44
John Channing
HertogJan
mobucks
Sniper297
merc4ulfate
Admiral Halsey


- TorpX

[TorpX]

Version 2.0 is ready in the downloads section. - < HERE >

It features reworked sub diving, physics improvements for the ships, and the Narwhal sub fixes.

[ReallyDedPoet]

Nice

[fitzcarraldo]

Awesome, I´m trying it now.

This is the attention SH4 deserves, it is a great platform and it needs more work.

Many thanks for the mod and the excellent explanation. Happy Easter!!!

Fitzcarraldo

[captgeo]

[TorpX]

I have to apologize.

The mod doesn't work in the campaign mode for some reason.

I meant to check this before, but it skipped my mind. I'm don't know why it would crash in campaign mode, and work ok in missions. I didn't touch the campaign traffic elements.

The 'school' mission seemed ok.

[fitzcarraldo]

Originally Posted by TorpX

I have to apologize.

The mod doesn't work in the campaign mode for some reason.

I meant to check this before, but it skipped my mind. I'm don't know why it would crash in campaign mode, and work ok in missions. I didn't touch the campaign traffic elements.

The 'school' mission seemed ok.

OK, it´s true. I´m trying the mod and it don´t work in campaign mode (causing a violent CTD). I deleted the UPC files and works fine in my RFB, with these mods:

Generic Mod Enabler - v2.6.0.157
[F:\SH4\MODS]

RFB_2.0
RFB_2.0_Patch_23April2010
RSRDC_RFB_V575
RSRDC_V5xx_Patch1
Eye Patch for RFB
Fixed_CD_sonar_RSRDC
Fixed Zero Bomb Load RSRDC
Nav Map Make-Over v2.1
NMMO Airbase Add-on
NMMO v2.1 Patch 1 with AB
Improved Stock Environment_v3_TMO&RFB
#1 ISE New clouds+Waves
#2 ISE Realistic Colors
#4 PE4 Ship_debris_SH4_with bodies
PE4_low quality bow wave and stern wakes (more FPS)
SMALLER SEABED ROCKS
SMALLER SEA PLANTS SMALL
Webster's Eliminate Floating Plankton
d3d_antilag101
SH4 Authentic Flags Mod
Radio RAK-7 (CND-46155)
700 S-Boat Dazzle Color Camo
Gato Class My way
Improved Ship Physics_1.0


The sea works fine but I don´t like the colors the mod modify in ISE.

A question: work you on SH4 vanilla files? scene.dat (and UPC files, etc), are different according the supermod (TMO, or RFB, or FOTRS, or GFO).

Best regards!

Fitzcarraldo

[TorpX]

Ok, I figured out the problem. It was related to some of the special abilities I had in the file. They were ones (either 'watchman' or 'medic') I didn't have in the starting crew, but were still causing a problem. I deleted the offending parts and put it back together. It will work ok with RFB 2.0 with or without RSRDC.

*** Version 1.1 is Ready ***

[I updated the link at the first post.]

The sea works fine but I don´t like the colors the mod modify in ISE.

A question: work you on SH4 vanilla files? scene.dat (and UPC files, etc), are different according the supermod (TMO, or RFB, or FOTRS, or GFO).

I used RFB files. I actually tried changing the colors in the scene.dat, but quickly realized I wasn't helping matters, so I just went back to the RFB version with only the changes necessary for the bigger waves. There are just too many subtleties to figure out in all that.

I did include a alternate scene.dat that was built on top of a TMO version, so people can experiment, and see what they prefer.

The mod will not work with TMO, however. Possibly, if all the upc files are taken out of the folders (and the tsr file), it might work, but I didn't try that.

[Fish40]

Thanks Torpx! Glad to finally see some good stuff for RFB! Now if only we could convince Tater to release what he has for the Japanese Merchants Mod, we'll be riding high!

[TorpX]

Thank-you!

* * *

I don't know if you can use this mod with an existing career or not. Maybe someone can report in about that.

It would be best to start a new career, so you would have the fixes for the battery and idle issues.

Here is a tabulation of what kind of performance you can expect. I decided to use the Gato class as an example.

Acceleration, at Ahead Flank

RFB 2.0 + patch

speed,kt.____0______4______8_______12______16_____ _20

time_______0:00___0:05____0:10____0:19_____0:34___ _1:12

ISP 1.1

speed,kt.____0______4______8_______12______16_____ _20

time_______0:00___0:18____0:35____0:55_____1:22___ _2:12

Diving, surface to PD (64 ft.), at 10 kt.

RFB 2.0 + Patch

depth,ft.____18_____20_____30_____40_____50_____60 ____63

time_______0:00___0:07____0:32___0:38___0:50___1:3 1___2:11

speed,kt.___10.0___9.0_____6.5____6.4_____6.2____5 .7___5.4

angle,deg.___0______0______3______3______3______1_ ___<1

ISP 1.1

depth,ft.____17_____20_____30_____40_____50_____60 ____63

time_______0:00___0:08____0:24___0:30___0:37___0:5 3___1:16

speed,kt.___10.0___9.0_____6.0____5.4_____5.2____4 .9___4.5

angle,deg.___0_____<1______8_____10_____11______6_ ____1

Diving from PD to 150 ft., at 4.4 kt.

RFB 2.0 + Patch

depth,ft.____64____70_____80____100_____120_____14 0___149

time_______0:00___0:09___0:22___0:55___1:42____2:5 8___4:58

speed,kt.___4.4____4.2____4.2____4.1_____4.0____4. 0_____4.2

angle,deg.___0______0_____1______2______3______3__ _____1

ISP 1.1

depth,ft.____64____70_____80____100_____120_____14 0___149

time_______0:00___0:10___0:21___0:43___1:06____1:3 4___2:58

speed,kt.___4.4____4.2____4.0____3.8_____3.6____3. 9____4.4

angle,deg.___0______2_____7_____14_____>15_____11_ ____1

Submerged endurance

RFB 2.0 + Patch

50% battery gives 37 nm @ 2 kt.

Recharge, at stop 3:45

ISP 1.0

50% battery gives 61 nm @ 2 kt.

Recharge, at stop 2:49

Sea-Keeping [15 m/s wind], distance covered in 1 hr. at 32x

RFB 2.0 + Patch

9.7 nm @ 10 kt. and 20.8 nm @ AFlank

ISP 1.0

6.3 nm @ 10 kt. and 11.0 @ AFlank

This information is also in the readme with the mod.

[I tried to format the above information so people could actually read it, but that seems to be impossible here. No matter how I edit it, everything is smashed together. :-( ]

[Hitman]

You have been busy! Love to see SH4 getting some attention in the realism area

Maybe since you did it for RFB it could start a line of "unofficial" RFB patches? Would be less confusing for people who are looking for mods that apply to other supermods or the stock game.

[Admiral Halsey]

Originally Posted by TorpX

[INDENT][INDENT]I don't know if you can use this mod with an existing career or not. Maybe someone can report in about that.

So long as you load it in port you can load any mod up.

[TorpX]

Originally Posted by Hitman

You have been busy! Love to see SH4 getting some attention in the realism area

Maybe since you did it for RFB it could start a line of "unofficial" RFB patches? Would be less confusing for people who are looking for mods that apply to other supermods or the stock game.

Yes, it took quite a bit of work to get everything the way I wanted it.

It would certainly be good if there were some unofficial/semi-official patches for RFB and other supermods.

* * *

I started to do a little work on the ships. This will probably take some time ...

[avers]

what was the dive time for s-boats in real life?

[TorpX]

Originally Posted by avers

what was the dive time for s-boats in real life?

According to N. Friedman's book, they were rated 1:15 to get to p/s depth.

He mentions that they could not 'ride the vents', as the ballast tanks leaked badly, and leaving the valves open would cause the boats to take on a list.