fuel usage in FOTRSU

[Wrongway Malcolm]

I've had FOTRSU installed for about 2 patrols now. With FOTRS (noU) 1.3, I could cruise for from Pearl to Japan with a Gato, have a little fuel for tactical maneuvers and chasing at full or flank, and have just enough fuel to get home.

Since I installed FOTRSU, I've been able to cruise at 2/3 from Pearl with a Gato to Truk or beyond, maneuver an chase at full or flank, go to another patrol site, do the same, and get back to Pearl on 1/2 a tank of fuel. Seems like overly miserly fuel use. That's not normal FOTRSU behavior, is it?

I presume not, so what might be happening?


By the way, I've used time compression around x3000 for long distances in both FOTRS and FOTRSU. That wouldn't cause any issues, would it?

[propbeanie]

Had you cleared the Save folder contents after activating FotRSU, or used MultiSH4 to a new Save folder?

Generally speaking though, the FotRSU mod is more conservative in its fuel usage. The Gato might be capable of 12,000 nm travel without too much effort, and if you find the most efficient speed, might be able to get more from it. The game is very unforgiving if you run out of fuel, and while there are some inconvenient ways to get around running out, it was decided to go a little long, rather than a little short on fuel range for the mod. :salute:

[Nicolas]

ALso the world in SH have 'messed up distances' if i'm understanding right, because the world is flat and not a sphere, so distances away from the equator are the same as the equator? in sh3 for example, the distance between lorient and new york is like 10,000 km, while in reality is like 5400 km if i remember correctly...

[Wrongway Malcolm]

Thanks both of you for your replies. I did clear the saves directory before install. The issue of map distances not being comparable is interesting. I’ll have to compare distances more carefully, and make a run to Japan rather than southeast asia to see if that’s part of the issue.

While I’m at it I gotta say I love what FOTRSU has done to SH4!

[LUKNER]

All Gato-class boats are counted at a normal fuel reserve of 11,000 miles. But if you increase the fuel to the maximum, the range should definitely be higher. I have not yet documented maximum range data with maximum fuel reserve. Especially the system of diesel generators without rigid connection to the propeller shaft gives significant fuel savings.


According to my data, the normal fuel reserve is 175 tons maximum 300 tons. I believe that the documents everywhere have a range data of 11,000 miles at 175 tons of fuel, but nowhere is there a maximum range at 300 tons.


For example, at 350 tons of KD6B Class fuel, Japanese Submarines 10,000 nautical miles (19,000 km) at 16 knots surfaced is significantly superior to Gato???



http://pwencycl.kgbudge.com/K/d/KD6B_class.htm

[Wrongway Malcolm]

Thanks all for the answers. Here's what I've discovered re: map distances: A patrol to the Bismark Sea is between 3000 and 4000 nm. A patrol to Japan is more than 10x that distance. On the visual map, it looks like a patrol to the Bismark Sea is about as long distancewise as a patrol to Japan. But if you check the distances with the map ruler, you see immediately the distances that look equal are way way different. I'm sure 90% of my issue is this map issue. I have no doubt the FOTRSU conservative fuel use magnifies the issue a small amount. But I'm sure at this point, most of it is map projection issues. Map projection can make it seem like fuel usage is off, when it's not.

[Wrongway Malcolm]

I need to correct myself. I misread a decimal point using the ruler. The distance to Japan isn't 10x longer. It's more like 1/3 longer. But it is longer.

[Navelintel]

Hi All,

I just downloaded FOTRS Ulitmate Edition v1.0.1 and had another question regarding fuel consumption as I explore its many options. I noticed in the operational order at the beginning of one's career, there's mention of conserving fuel by running on the surface at night with 'one' engine. Is this possible or was it used to emphasize slower speeds for greater fuel efficiency?

https://i.postimg.cc/Zq5mZMsP/Screenshot-136.png (https://postimages.org/)

I've been playing SH4 and many of its variants since 2007 but I don't recall seeing this instruction before or being able to execute it. Any thoughts, mates?

BTW, a very impressive Mega mod so, well done to all involved. :Kaleun_Applaud:

[propbeanie]

A US Fleetboat in the game is basically built on an SH3 U-boat, so it has two "engines" and two "shafts" that are joined at the hip. It would be nice if they simulated four engines and donkey, along with two separate shafts. If they had, then you could reverse one shaft and forward the other for quicker turns. With separate engines, you could designate one for charging and two for propulsion, or whatever combination you wanted. However, none of that is implemented in the game. Instructions such as those, like most everything put on "paper" in the game can be ignored and the player do as they please, with no penalty involved. Hence, that is just an "immersion" thing, similar to orders they received in December 1941. We will eventually include "instructions" from the 7th Fleet to use the magnetic and only the magnetic pistol, while Pearl will allow a skipper to defeat it, and only use the impact pistol. However, the game does not allow that either... oh well. We can at least make it seem like it can. :salute:

[Navelintel]

A US Fleetboat in the game is basically built on an SH3 U-boat, so it has two "engines" and two "shafts" that are joined at the hip. It would be nice if they simulated four engines and donkey, along with two separate shafts. If they had, then you could reverse one shaft and forward the other for quicker turns. With separate engines, you could designate one for charging and two for propulsion, or whatever combination you wanted. However, none of that is implemented in the game. Instructions such as those, like most everything put on "paper" in the game can be ignored and the player do as they please, with no penalty involved. Hence, that is just an "immersion" thing, similar to orders they received in December 1941. We will eventually include "instructions" from the 7th Fleet to use the magnetic and only the magnetic pistol, while Pearl will allow a skipper to defeat it, and only use the impact pistol. However, the game does not allow that either... oh well. We can at least make it seem like it can. :salute:

Hi Propbeanie,

Thanks for the clarification. Nevertheless, I'm totally enjoying the immersion experience too! :up:

[LUKNER]

A US Fleetboat in the game is basically built on an SH3 U-boat, so it has two "engines" and two "shafts" that are joined at the hip. It would be nice if they simulated four engines and donkey, along with two separate shafts. If they had, then you could reverse one shaft and forward the other for quicker turns. With separate engines, you could designate one for charging and two for propulsion, or whatever combination you wanted. However, none of that is implemented in the game. Instructions such as those, like most everything put on "paper" in the game can be ignored and the player do as they please, with no penalty involved. Hence, that is just an "immersion" thing, similar to orders they received in December 1941. We will eventually include "instructions" from the 7th Fleet to use the magnetic and only the magnetic pistol, while Pearl will allow a skipper to defeat it, and only use the impact pistol. However, the game does not allow that either... oh well. We can at least make it seem like it can. :salute:
It not the main thing. Interestingly, the navigation range documents indicate that the maximum range for Gato boats is 11,000 miles. But this data is obtained with a normal fuel reserve of approximately 170 tons. The boat could take more fuel, up to 300 tons. How much could a boat with the maximum fuel reserve have passed? Where can you read the combat log of any of the commanders to highlight this question? Please forgive me in advance for my English translation.

[propbeanie]

There are several sites that have the War Patrol Reports. My favorite is The HNSA Section (http://www.hnsa.org/manuals-documents/submarine-war-patrol-reports/) on them. They use a different reader than does the Maritime dot Org Section (https://maritime.org/doc/subreports.htm). I have been through quite a few of those reports, and I do not remember "fuel" being a subject in them very often. There are some supplement sheets amongst some of the reports, and you might be able to get a picture of how much they used a day from those. You could then extrapolate that out across their patrol time, and come up with how much they used... :salute:

[LUKNER]

There are several sites that have the War Patrol Reports. My favorite is The HNSA Section (http://www.hnsa.org/manuals-documents/submarine-war-patrol-reports/) on them. They use a different reader than does the Maritime dot Org Section (https://maritime.org/doc/subreports.htm). I have been through quite a few of those reports, and I do not remember "fuel" being a subject in them very often. There are some supplement sheets amongst some of the reports, and you might be able to get a picture of how much they used a day from those. You could then extrapolate that out across their patrol time, and come up with how much they used... :salute:


Thank you so much for your help! This information will improve fashion work.




https://www.subsim.com/radioroom/showthread.php?t=243564

[Bilge_Rat]

Fuel usage in SH4 is not realistic for a bunch of reasons.

1. since the map is flat and the Pacific is huge, some distances can be as much as 25% higher than in RL;

2. fuel usage at speed is faster or slower than in RL. As I understand it, this is because the game was originally designed for 2 engine Uboats, so it does not exactly match the fuel usage of 4 engine Fleet boats;

upshot is that if the fuel capacity in data is set to historical (i.e. 11-12,000 NM), you are at only 66-75% of the "real" fuel capacity for the game. Ducimus in TMO got around the problem, by bumping up the fuel capacity by 25% as I recall.

[Kal_Maximus_U669]

Fuel usage in SH4 is not realistic for a bunch of reasons.

1. since the map is flat and the Pacific is huge, some distances can be as much as 25% higher than in RL;

2. fuel usage at speed is faster or slower than in RL. As I understand it, this is because the game was originally designed for 2 engine Uboats, so it does not exactly match the fuel usage of 4 engine Fleet boats;

upshot is that if the fuel capacity in data is set to historical (i.e. 11-12,000 NM), you are at only 66-75% of the "real" fuel capacity for the game. Ducimus in TMO got around the problem, by bumping up the fuel capacity by 25% as I recall.

Yes I find that fuel has a problem too now I am not a sailor but I agree with you that it can be solar powered:har:

[propbeanie]

The "difficult" part of the problem is that one change in the sub's sim file will affect other aspects of the sim file, which have no direct bearing on the changed setting, such as GC and others of that ilk, will influence more than just the way a boat "rides" in the water. The best a modder can do is to try and "balance" things a bit.

[Kpt. Lehmann]

:hmmm:

Now, the way I see it is thus:

If you guys were really being aggressive enough, you would drive your boats hard enough that you'd have just a little diesel left for patrol when you get there. You'd take what you needed from the Japanese to get home, or you wouldn't have the temerity to haul back into Pearl.

Now stop eating all that ice cream and be more aggressive.

Now, you see, back in my day... we patrolled backwards both ways.... upstream naked.... with no toilet paper in the North Atlantic... :D

Sorry for the off-topic. Couldn't resist.
Sink'em ALL, guys!!!
:arrgh!::salute:

[Kpt. Lehmann]

.... annnd CRICKETS....


Hey! It was funny because it was true.:yep:

[propbeanie]

I would have rolled on the floor if I would have stopped by in here... :har:

"Be more aggressive."... The ice cream maker on my boat is broken though. Someone tried to use the parts in conjunction with some torp juice recipe someone had sent them from home... :salute:

[Kal_Maximus_U669]

As I told you I am not a sailor I did not want to criticize the work done here quite the contrary ... I know very well that this game is very complicated to modify because I have read a lot of forums before I can try all these modes I do not understand this irony I all just wanted to joke .. it is true that if we push the beast it is different but I found it strange .... here then the bottom valves calles c is good ..! !!:up:

[propbeanie]

No disrespect is intended, no insults thrown. We were just trying to have a little fun at the modders' expense Kal_Maximus_U669 - which would mostly be me in this regard, because I was the one that tried to edit a few of the subs ~lower~ in fuel range, and all I managed to do was to move the curve of the subs' "most efficient" speed... I also was not aware that the game was that inept at giving an "estimated range at this speed" set of figures. That was used as our "test" paradigm, or methodology. "Bingo fuel" is rather important for a skipper to know, so if the game says you are good for 12,500nm, you would figure "bingo" would be 6,250nm, and be very mindful of that figure prior to your furthest point of travel. If the game is several thousands of miles off on that figure, it should be attempted to change it, which we did. Unfortunately, all I succeeded in doing was move the "most efficient" from 5, 6 or 7 knots up to 9 or 10 knots, or basically Standard speed... Another attempt will be made for the next release, but "testing" it will include driving a submarine at TC1x overnight while I sleep (not at war-time), to see the "real" fuel useage, rather than relying on the game to give me a "maximum range at xx speed" function. One caveat to this, is that the game may then give a skipper a really bad estimate, and you might then be 1200nm from home, and be out of fuel, with no recourse other than to abandon your career. We don't want that either... we do thank you for your comments on the subject though, and want to let you know that we are attempting to work on it. Also be aware that I used to get in trouble at school all of the time as a youngster. I was never the class clown - I was just the one that "fed" the class clown and encouraged their behavior... so probably two-thirds of what I post is tinged with self-deprecating sarcasm, liberally sprinkled with facetiousness... in other words, do not take me seriously in most postings... In all seriousness though, I do apologize for unintended insensitivity toward the reports. Keep them coming (both the reports and the jokes)! :salute:

[SilentPrey]

Greetings Propbeanie,


I think the fuel usage issues in FOTRSU are related to the battery recharge fix special ability. I'm running 1.004.a and was patrolling in a Gato out of Midway. With one officer with that ability, I would typically return to base with no torpedoes and more than half my fuel after patrolling all the way to 11-B at ahead full for most of the trip.


Then I promoted an ensign who gained that ability. Once I had two officers with the battery recharge fix I could run flank speed submerged all day and still have half a charge that evening when I surfaced. And I could complete an entire patrol and pull back into Midway with 99% fuel remaining.


I accepted a Balao out of Fremantle and ran a patrol to Convoy College with the same results as above. Full speed to patrol zone, patrol five days at Standard, numerous runs at Flank to get in position, etc. and still returned with 99% and no torpedoes without stopping anywhere for fuel.


I'm a bit OCD with crew management: I promote and cycle off the boat the old hands so they can crew the new boats, etc. It's one of the ways I immerse myself. Anyhow, I released the original lieutenant with the battery recharge fix to his own captaincy and the former ensign became my only crew member with the ability.


Now my boat is using fuel again. This patrol had me down to 92% about the time I hit the Sulu Sea. So, to reiterate: I think the fuel usage issue is connected to the battery recharge fix special ability.


Good hunting!
SilentPrey

[Kpt. Lehmann]

No disrespect is intended, no insults thrown. We were just trying to have a little fun at the modders' expense Kal_Maximus_U669 - which would mostly be me in this regard, because I was the one that tried to edit a few of the subs ~lower~ in fuel range, and all I managed to do was to move the curve of the subs' "most efficient" speed... I also was not aware that the game was that inept at giving an "estimated range at this speed" set of figures. That was used as our "test" paradigm, or methodology. "Bingo fuel" is rather important for a skipper to know, so if the game says you are good for 12,500nm, you would figure "bingo" would be 6,250nm, and be very mindful of that figure prior to your furthest point of travel. If the game is several thousands of miles off on that figure, it should be attempted to change it, which we did. Unfortunately, all I succeeded in doing was move the "most efficient" from 5, 6 or 7 knots up to 9 or 10 knots, or basically Standard speed... Another attempt will be made for the next release, but "testing" it will include driving a submarine at TC1x overnight while I sleep (not at war-time), to see the "real" fuel useage, rather than relying on the game to give me a "maximum range at xx speed" function. One caveat to this, is that the game may then give a skipper a really bad estimate, and you might then be 1200nm from home, and be out of fuel, with no recourse other than to abandon your career. We don't want that either... we do thank you for your comments on the subject though, and want to let you know that we are attempting to work on it. Also be aware that I used to get in trouble at school all of the time as a youngster. I was never the class clown - I was just the one that "fed" the class clown and encouraged their behavior... so probably two-thirds of what I post is tinged with self-deprecating sarcasm, liberally sprinkled with facetiousness... in other words, do not take me seriously in most postings... In all seriousness though, I do apologize for unintended insensitivity toward the reports. Keep them coming (both the reports and the jokes)! :salute:


I agree with Propbeanie. Everyone is stressed out with everything going on, and sometimes we just need to laugh. I am not qualified to speak with authority on any Silent Hunter 4 mods. No offense was intended.

[Bilge_Rat]

old post, but good explanation of the hard coded issues with fuel usage in SH4:


https://www.subsim.com/radioroom/showpost.php?p=1806787&postcount=45


since SH4 is based on the SH3 code, it assumes all subs only have 2 engines like a U-boat, as opposed to the 4 engines in fleet boats, so ahead 2/3rds (8-9 knots) is the most efficient speed since the game seems to assume only one engine is running.

Problem is that it seems fleet boats usually travelled at 12-15 knots between their base and patrol areas. This was efficient since the boat was only running on 3 engines, but the game assumes the boat is running on both U-boat engines, therefore all 4 fleet boat engines.

There is no easy solution to this problem, only workarounds.

[KaleunMarco]

old post, but good explanation of the hard coded issues with fuel usage in SH4:


https://www.subsim.com/radioroom/showpost.php?p=1806787&postcount=45


since SH4 is based on the SH3 code, it assumes all subs only have 2 engines like a U-boat, as opposed to the 4 engines in fleet boats, so ahead 2/3rds (8-9 knots) is the most efficient speed since the game seems to assume only one engine is running.

Problem is that it seems fleet boats usually travelled at 12-15 knots between their base and patrol areas. This was efficient since the boat was only running on 3 engines, but the game assumes the boat is running on both U-boat engines, therefore all 4 fleet boat engines.

There is no easy solution to this problem, only workarounds.
i would have to agree with Ducimus' explanation of fuel usage in the link that Bilge Rat provided.
i would also agree with Bilge Rat in that there is very little that can be changed and that which we CAN change is a work-around.
just have some fun with it!
:Kaleun_Salute: