(WIP)Submarine Draft Fix

[ancient46]

I have been working on a fix for the problem of incorrect position of the submarines in the water. I have been comparing Screen Shots of the subs, making adjustments to match the pictures of the WW2 subs I have collected from the net. Here are three composite pictures of the work so far.

I started with the stock game but I will have a version for RFB 1.52. I don't use TMO but I could easily make one if someone wants it. Once I get a draft number to match the photo, it can be used in any MOD.

The Balao Class- notice the two torpedo tubes out of the water in the Stock Shot
http://home.comcast.net/%7Eancient25/Pictures/ModBalao.jpg

The Gato Class- one Torpedo tube out of the water
http://home.comcast.net/%7Eancient25/Pictures/ModGato.jpg

The Gar and Tambor Classes- One torpedo tube out of the water
http://home.comcast.net/%7Eancient25/Pictures/ModGar.jpg

[keltos01]

Good job ! :up:

keltos

[looney]

Aren't those pictures taken with a full load of fish?? Compared to of being completely empty? The subs where terrible in depth keeping when moving slowly.

[Soundman]

I'm very interested in a TMO version. Looks good. :up:

[ridgewayranger]

Hi There,
With or without fish makes no difference when the boat is in diving trim. Water is used to replace the weight of fish, otherwise she would never get down! When a torpedo is fired an automatic compensating system allows water equivalent to the weight lost to enter a tank. Likewise when a bow cap is opened she doesn't suddenly get heavy 'cos water is blown into the tube from said tank.
RR

[ancient46]

I ignored all the just after launch pictures and concentrated on the ones of the ships at sea and on sea trials. Those pictures are all similar with small variations due to wave conditions and ship speed. As a check I looked at post commission in port pictures to confirm the look of the subs in the water. The pictures I used are representative of that work and the clearest views to use. Many of the other photos needed manipulation to enhance the details to confirm my determination of the proper look. The seas had to be quite rough in order to show the top torpedo tube.

As a side note, the stock screenshots shown are similar to the post launch pictures taken after the buntings were removed.

For the screen shots I started a career when each sub class was available, calmed the sea and saved. I restarted the saves and took the stock screen shots. I loaded the mod and used the same saves to take the screen shots under the same conditions. I used FooBor's sub skins but compared the results with a completely stock skin set and saw no difference. PE4 was used because I could not get calm seas with the stock game setup for consistent results.

[gimpy117]

there have been a couple of these but so far it looks like it's the most historically accurate so far.

[Lt commander lare]

can wait to see it looks great keep up the good work


lt commander lare

[Webster]

looks good but one note of caution, as you change the draft heights you will also change your range and distance do to increased fuel consumption and speed can also be effected as well as it relates to the drag settings. sitting a little lower in the water can have a big effect on the drag applied to your boat so it is very likely you will have to tweak the drag settings so the sub acts correctly. there is a certain height level that if you go below it will change the drag coefficient like you are decks awash and your fuel consumption goes way up. changing the drag coeficient is not a hard thing to do but it is easy to overlook this if you dont know about it.

do some testing to see if your fuel consumption or range is different than stock

[NEON DEON]

Oh kewl. I was going to lower all the boats in my gun mod but for a different reason. The lower in the water you sit, the harder it is for you to man the gun station in bad weather. I only applied it to the Sargo so far and I am running around testing it now.

[Webster]

Oh kewl. I was going to lower all the boats in my gun mod but for a different reason. The lower in the water you sit, the harder it is for you to man the gun station in bad weather. I only applied it to the Sargo so far and I am running around testing it now.

if you want guns harder to man in rough weather just change the storm conditions setting in the subs cfg file to a lower number and they wont be able to man the guns if conditions are above that number

[NEON DEON]

Oh kewl. I was going to lower all the boats in my gun mod but for a different reason. The lower in the water you sit, the harder it is for you to man the gun station in bad weather. I only applied it to the Sargo so far and I am running around testing it now.

if you want guns harder to man in rough weather just change the storm conditions setting in the subs cfg file to a lower number and they wont be able to man the guns if conditions are above that number

Thanks Webster.

Will that stop the player from manning the gun?

[ancient46]

Webster thanks for the warning. I had planned to test it thoroughly before releasing but I had not really considered the fuel aspect. Mainly because each of draft numbers I came up with put the subs slightly higher in the water than RFB, but I will look at it now to make sure. Multiple fuel expended over a certain time in the same conditions run will show any differences. Although if I get slightly better fuel economy in RFB I will be tempted to leave it be.:D

[NEON DEON]

It would appear that lowering the boat a meter in the water has no effect on fuel consumption.

I lowered the the Sargo almost a meter and she went 5,000 KM at manual setting for 10 knots. Fuel left was 82/100.

I then ran stock with the same settings and got the exact same results.

However, it does appear that when setting your ship speed you get this:

Make revolutions for 10 knots.

As opposed to actually going 10 knots.

So when making revolutions for ten knots you get the same fuel consuption but maybe not the same actual speed thus the drag aspect.

Timing the two would require a mod of the environmental variables to see what effect lowering the boat would do to the time of arrival when making revolutions at 10 knots.

[Webster]

Oh kewl. I was going to lower all the boats in my gun mod but for a different reason. The lower in the water you sit, the harder it is for you to man the gun station in bad weather. I only applied it to the Sargo so far and I am running around testing it now.

if you want guns harder to man in rough weather just change the storm conditions setting in the subs cfg file to a lower number and they wont be able to man the guns if conditions are above that number

Thanks Webster.

Will that stop the player from manning the gun?

AFAIK there is nothing that stops the player from manning the gun but it will stop the crew from automatically manning the gun if ordered and during battle stations.

[Webster]

It would appear that lowering the boat a meter in the water has no effect on fuel consumption.

I lowered the the Sargo almost a meter and she went 5,000 KM at manual setting for 10 knots. Fuel left was 82/100.

I then ran stock with the same settings and got the exact same results.

However, it does appear that when setting your ship speed you get this:

Make revolutions for 10 knots.

As opposed to actually going 10 knots.

So when making revolutions for ten knots you get the same fuel consuption but maybe not the same actual speed thus the drag aspect.

Timing the two would require a mod of the environmental variables to see what effect lowering the boat would do to the time of arrival when making revolutions at 10 knots.

it wouldnt hurt to compare each speed setting when surfaced and submerged to see if anything changed there, you might find a half knot difference somewhere.

one thing i learned about this game is minor changes to some things have a way of causing issues you never expected so always test all the possabilities.

[dean_acheson]

I'd be interested in a TMO version

[Scharnhorst1943]

I have a quick question about this mod.

First of all, looks EXCELLENT and I am looking forward to it. Secondly, will this mod be able to fix the way the sub dives? In current stock, the bow is the last part of the deck to go under. It would be nice to have the bow be the first part to go under ... If this mod does not address this problem, is there another mod that does?

[gimpy117]

would be nice to see a nose down dive

[NEON DEON]

I have a quick question about this mod.

First of all, looks EXCELLENT and I am looking forward to it. Secondly, will this mod be able to fix the way the sub dives? In current stock, the bow is the last part of the deck to go under. It would be nice to have the bow be the first part to go under ... If this mod does not address this problem, is there another mod that does?

I dont know about the bow going under first in a fleet boat. If you take a close look at a fleet boat down its lenght you will notice that the ships bow rises up from the hull. So I am thinking it would be hard for the boat to get the prow under before the stern.

Take a look at the second to last picture on this page of the Gato.

http://www.navsource.org/archives/08/08212a.htm

The deck clearly rises slowly upward almost the entire length.

I am thinking thats because the boat was not designed to be a true submersible.

Nose it down too much and you might have the props comming partly out the water.

PS:

If you call battle stations all ahead flank in a Balao and give it time to build up speed then call crash dive the nose will go under first as the stern rises a bit. At least with the boat lowered it does.

[gimpy117]

hmm....we need diving photos to know for sure...

[skookum]

Any progress to report?

[Sledgehammer427]

about the nose-down diving thing.

the fleet boats weigh far too much and are too wide to do a nose-down dive that i imagine.
when a fleet boat, or any submarine for that matter crash dives, its very hard to get under until the deck is under. then, it hydroplanes itself deeper. thats with the planes doing all they can to push the nose down when a crash dive is ordered, then they taper off when the Conning tower is awash.

[edjcox]

Jerry Lewis once clinged to the Shears of a sub in a dive mode... Wonder if anyone knows where that sequenc could be found. Viewing it gives you a rel sense of how a Gato dives in a normal dive...


Diving is initiated by flooding a negative bouyancy tank and putting the forward and aft planes on a downward pitch. The rapidity of the dive can be increased with plane pitch, boat speed and additional negative bouyancy acquisiton by flooding..

The whole idea is to minimize the amount of compressed air needed to resurface. Subs were kept slightly positive boyancy the majority of the time fo safety reasons. In a combat dive safety is at depth so certain risks where accepted for a rapid immersion in to the safety of the deep. Blowing dray a flooded tank is costly in compressed air... Intitial surface psoition is then improved by useing the turbo blowers to fillout the bouyancy by blowing the tanks with shut valves... The whole idea of the Christmas tree is to visually see that water is able to flood and air is able to be retained on command...

Using elemnets of the boat like flooding empty forward tubes could also increase onces dive angle to get that bow down look some of the Simers are looking for...


:shifty:

[Webster]

Jerry Lewis once clinged to the Shears of a sub in a dive mode...

:rotfl: :rotfl: :rotfl: :rotfl: :rotfl:

thanks for reminding me about that :up:

[ridgewayranger]

Hi Everyone,
I can only speak for British boats in which there was no such thing as 'Crash Dive' nor 'Dive,Dive,Dive'. The order was 'Klaxon,Klaxon,Klaxon', the button was in the tower, and the first man down pressed it.
All dives off the Klaxon were made as rapidly as possible. A tank known as Q (probably for quick) was kept flooded in order to achieve negative buoyancy as soon as MBTs were full. Once on the way down, Q would be blown to restore neutral buoyancy. To surface, MBTs would be blown until heading up, then full buoyancy gained by running a low pressure blower. Because diving and surfacing are the most hazardous times for a submarine in neutral buoyancy (being rolled over) the idea was to get through that barrier as quickly as possible.
When not in an urgent situation we would dive on the watch, just quietly slip under with hardly anyone knowing we had done so.
I realise that today they virtually fly underwater, but with their lack of speed, wartime boats could not turn bank and dive as they do today.
RR

[ancient46]

If you want to know how a sub submerges, the effects of the various controls, and the problems involved follow this link. http://www.maritime.org/fleetsub/chap18.htm#18A
If you are going down to periscope depth for firing balancing the trim and speed of the dive is important. a steep dive will get you underwater fast but the time it takes to balance the ship for fighting trim will be a lot longer.

So far I have finished setting all the numbers for each boat's draft and I am testing everything I can think of for adverse effects. I have already established the baselines for the stock game and RFB. I will soon be done with the Salmon class tests when I finish several runs at 10 knots until the boat runs out of fuel to make sure I haven't affected the range. The dive times are close enough when taking into account the height difference. I cover the same distance over time at several different speeds, so I don't see any problem there.

I have looked at the Salmon from several angles at flank speed in a 14 meters per second wind and every once in a while the rear half of the rear deck is under a wave. It looks right when compared to the pictures I have.

[ancient46]

Well I came across these pictures of fleet boats diving on exercises http://www.navsource.org/archives/08/0818615.jpg Looks to me like fleet boats normally dive stern down first almost like modeled in the game. Maybe a sub dives faster with a lesser loss of momentum if the bow is up to provide less drag as it dives. Maybe some hydraulic experts on the forum can answer that question for us.

Progress report: I am done testing the sub draft and am working on a new addition. During testing I noticed another little problem that I needed to fix, Periscope depth. I am now setting the periscope depth to put the bottom of the final tapered section just below the water line. The light colored portion of the periscope will no longer show above water. I will be done with this in a day or two depending on the extent of the admiral's "To Do" list. This is more in line with pictures of submerged subs I have seen. Now if it would be possible for the environmental geniuses to add a wake to the periscope it would greatly improve the games look.

[Sledgehammer427]

.....:hmmm: that pic just doooont look right in my eye...

theyr'e SURFACING! look at the water coming off the bridge!
also, theres not enough wake behind the bridge to show it was traveling on the surface
http://www.navsource.org/archives/08/0818615.jpg

[Scharnhorst1943]

I have seen several black and white sub movies of American subs. Run Silent Run Deep is an obvious one. In that movie they filmed an ACTUAL Gato/Balao sub diving. The bow went down first ... very much so. Don't believe me, go rent the movie.

[Scharnhorst1943]

Go to this link: http://www.youtube.com/watch?v=G6gFQH54k0M&feature=related and look at 0:30s.

Go to this link: http://www.youtube.com/watch?v=uSjKT8JPQAc&feature=related and look at 6:27s

Go to this link: http://www.youtube.com/watch?v=f2TA-mWjiRE&feature=related and look at 1:00s

Go to this link: http://www.youtube.com/watch?v=4HRStJF5Uh8 and look at 0:07s

Go to this link: http://www.youtube.com/watch?v=RJtdbX23ziY&feature=related and look at 1:05s

In several of these the exact bow is not shown, but by looking at the angle of attack of the conning tower, it HIGHLY suggests the bow going under first.

[Scharnhorst1943]

Go to this link: http://www.youtube.com/watch?v=G6gFQH54k0M&feature=related and look at 0:30s.

Go to this link: http://www.youtube.com/watch?v=uSjKT8JPQAc&feature=related and look at 6:27s

Go to this link: http://www.youtube.com/watch?v=f2TA-mWjiRE&feature=related and look at 1:00s

Go to this link: http://www.youtube.com/watch?v=4HRStJF5Uh8 and look at 0:07s

Go to this link: http://www.youtube.com/watch?v=RJtdbX23ziY&feature=related and look at 1:05s

In several of these the exact bow is not shown, but by looking at the angle of attack of the conning tower, it HIGHLY suggests the bow going under first.