Is there useful info in smoke trails?

[MKalafatas]

Five hours into what may be an all-day parallel pursuit of a 10-knot convoy in the S-boat (yes, these can be long days in the S-boat), I was watching the smoke trails in the distance, wondering if there is any intelligence information I might glean from them? I thought it safer in the S-boat to maintain my distance... tracking the smoke trails rather than the ships.

The S-boat has no surface radar, at least in Jan '42, nor even surface sonar --- so any bits of information are valuable.

Obviously, the "number" of smoke trails gives useful information, but is there more? We know the wind speed and direction; ergo, we know in which direction the smoke trails point. But, they are not uniform when compared to each other. The slope of their angles against the horizon are not precisely the same. Why? Sometimes they are crooked --- which indicates to me that a ship has changed course.

If the stadimeter had a bridge mast reading capacity of a few thousand feet, we might measure their distance from the boat.

I could not figure out anything useful from these smoke trails, but perhaps some grognards can. And more to the point --- surely some sub captains in real life, without the benefit of "time compression", had time to ponder these questions as well.....

[Armistead]

I've often pondered it myself, but could never really decide, up close smoke appears to travel behind the ship slightly, but it doesn't seem wind direction plays any role. From a distance I can never really get much info from smoke. There is one mod that gives merchants heavier black smoke and warships a more thin blue smoke since most merchants were coal run, warships fuel run, that can be helpful.

[WernherVonTrapp]

http://www.cartoonstock.com/newscartoons/cartoonists/awh/lowres/awhn327l.jpg
:haha:

[TorpX]

Obviously, the "number" of smoke trails gives useful information, but is there more? We know the wind speed and direction; ergo, we know in which direction the smoke trails point. But, they are not uniform when compared to each other. The slope of their angles against the horizon are not precisely the same. Why? Sometimes they are crooked --- which indicates to me that a ship has changed course.

Other than the number of ships, and what Armistead mentioned, I think there isn't much to be gained from observing the smoke. I don't think the wind has much effect on the smoke. Like the ship flags that are always pulled out, even when it's calm. If the game was very carefully crafted with regard to physics, then maybe we could get something here.

[Diopos]

They are target's bearing indications. And as such you can use them for a "bearings only" estimation. Doing it properly you even can get estimations on target speed course and range (I stress the "estimation" part). You can use them in a more traditional "constant bearing" approach to the target. In the pre-radar era, "smoke on the horizon", a dip for a hydrophone sweep and a knowledge of the general direction shipping moves in the area is what a captain had to "work" with, plus whatever contact reports (which were usually less uhmmm ... trust worthy then those in-game).

If you play with contacts "off" they are useful :yep:.


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[Platapus]

Of course the cogent question is not what submarine captains could infer from smoke trails, but what a player of SH4 can infer.

There should be no automatic assumption that smoke is rendered to be anything but eye candy in a computer game.

Do we have any information from the developers whether smoke was rendered accurately or was it just background graphics?

[Armistead]

They are target's bearing indications. And as such you can use them for a "bearings only" estimation. Doing it properly you even can get estimations on target speed course and range (I stress the "estimation" part). You can use them in a more traditional "constant bearing" approach to the target. In the pre-radar era, "smoke on the horizon", a dip for a hydrophone sweep and a knowledge of the general direction shipping moves in the area is what a captain had to "work" with, plus whatever contact reports (which were usually less uhmmm ... trust worthy then those in-game).

If you play with contacts "off" they are useful :yep:.


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Yea, you can get bearings with smoke with contacts off, but it's still very hard.to get an accurate course. When I use contacts off, I find it best to come to a stop to do this, easier if you're not moving to see how the enemy is, but dang near impossible to tell by smoke what the exact course is, easier to get close enough to see the funnels and mast.

[Rockin Robbins]

I agree that the smoke tends to trail behind the ship, regardless of wind direction. Therefore you can determine a rough heading for the target. If you see the angle of the smoke change, that would indicate a course change.

If their is a progression in smoke height, tallest to shortest, that means the tallest smoke is above the nearest target. That can give you an indication whether the column is headed generally toward or away.

On occasion, the game can generate smoke where there is no ship under it. This is kinda rare. One thing modders chased (was associated with WernerSobe's damage mod) was a smoke column that followed the submarine, whether on the surface or submerged. Attention! Sub here!

Fortunately, smoke IS eye candy having no significance in gameplay at all. There was never any evidence that enemy vessels saw that smoke and realized it was your submerged sub under there.....:D

That brings us to our quote of the day:
Of course the cogent question is not what submarine captains could infer from smoke trails, but what a player of SH4 can infer.

There should be no automatic assumption that smoke is rendered to be anything but eye candy in a computer game.

Do we have any information from the developers whether smoke was rendered accurately or was it just background graphics?

What, sir, was your FIRST clue?????? Could it have been:


Submarines with rather large holes blown in their sides which can still submerge normally?:haha:
Target vessels with no visible holes in them which obligingly sink anyway?:up:
Zero fighters used as ASW planes actually dropping depth charges on your submarine?:har:
An ocean which contains only a couple dozen merchant types, every single one of which is in your recognition manual with exact measurements? And each ship of each type is perfectly identical!
I know! I know! It was the men who remain rooted to the deck at their posts, magnetic boots I think, standing upright (okay, they're upright with respect to the deck, but jutting out sideways in relation to gravity!) and not sliding down the deck at all as the target slips vertically into Davey Jones' locker.:rotfl2:

Yup we're all seduced by the eye candy, sometimes giving it great significance when it is nothing but a show, having no affect on game AI at all. Remember all the posts about the size of holes from deck gun shelling? Yikes, what a donnybrook. All over meaningless eye candy.

[merc4ulfate]

I use the smoke to get bearings so I can plot intercept courses. Sometimes if is hard to tell if they are moving away or closing from a distance but if I do not mind wasting the fuel at Flank speed I will try to plot a course by the smoke to get into firing range.

[MKalafatas]

Thanks for the great discussion, and the clever cartoon. :)

I think that smoke trails *do* track the wind direction, but do admit to some uncertainty.

Yesterday I tracked a merchant --- turned out to be Dutch. I surfaced as it passed within 1000 yards and noted that the smoke column did not trail it, but instead spewed forth slightly ahead, corresponding with the wind direction. I'm pretty sure that's what I saw but obviously don't have a video to confirm. As a former attorney, I can tell you that eyewitness testimony is notoriously unreliable; especially mine. ;)

Also, I somehow managed to overshoot this 10-knot convoy (actually, task force) in the turtle S-boat and am viewing it now from the north, ahead of it, instead of to starboard. When I was tracking from its starboard beam, the smoke trails blew out behind. Wind was from about 30 degrees to its port side.

The task force has changed course, from a course of 25 degrees to a course of 90 degrees. I'm now on its port side and slightly behind. The smoke is not trailing out behind, but instead rises into long vertical columns, as if corresponding to the wind from bearing 331.

I'll be watching this. I hesitate to disagree with those who've played the game for years and have tracked hundreds or thousands of ships --- but is it possible I'm right?

[donna52522]

Well if your tracking by using smoke then you must be doing something right, how your keeping up with a Task Force in an S-Boat baffles me though, giggle.

Allowing for imagination and thought while playing is what a good game/sim does. If you only look at the pc/tech side of it, there's no sense in even playing. Might as well give up, go out and try to accomplish something in the real world.

[MKalafatas]

Well if your tracking by using smoke then you must be doing something right, how your keeping up with a Task Force in an S-Boat baffles me though, giggle.


lol ... well I haven't caught it yet. If it keeps changing course I never will. Frequently these episodes end with me taking a few shells in the bridge, without firing a single torpedo.

[TorpX]

I doubt the smoke and wind are properly modeled in this game. Very little else is. In any case you cannot see smoke (or anything else) beyond 10 nm. This bothers me a lot more than the smoke.

[Daniel Prates]

Are you guys sure that the smoke direction is merely eyecandy? does it nof face foward when the wind is coming from astern?

[Hylander_1314]

It's rare that I see smoke before sonar picks up noise.

When I do see it, I just use it to get a bearing on the ship(s).

Not much else. Usually I go in for a closer look to discern what I am potentially dealing with. Single mechant, or convoy, or warships, either single or in numbers.

After radar is available, the I use the radar screen to figure out what their directin is. Before radar is available, I get as close as i dare to them to get a general direction of heading, and then slink off and race ahead to lay in ambush.

It's not 100% successful, if the intended prey changes course, but that's the fortunes of war.

[TorpX]

Are you guys sure that the smoke direction is merely eyecandy? does it nof face foward when the wind is coming from astern?

I'm not really sure about anything with SH 4. :DL But my expectations would not be too high.

Once I made a night attack using both torps and guns on a convoy. At a certain point a small minesweeper escort came around and I dived. There was a huge amount of smoke pouring out of it (not just from the funnel opening). I thought that one of my torps had hit it and it was perhaps badly damaged. I thought about trying to finish it off with a gun attack, but after awhile, I realized it was not damaged in the least; this was "normal" smoke from the engines. Good thing I didn't go through with my idea of the gun action.

[MKalafatas]

I'm pretty convinced after several more hours of game play that smoke trails are accurately modeled. The smoke trail should combine two vectors: (1) the wind speed and direction in knots (about 1.67 x wind speed in meters per second); (2) the speed and direction of the ship. For instance, if a ship is traveling precisely with the wind at precisely the same speed in knots, the smoke trail should produce a straight vertical column.

This information is far more useful to S-boat captains, who lack radar and surface sonar, and when tracking a fast target, even the surface speed to compensate for quick dives to check sonar.

I tried to time the smoke trails. By my count, it took 45 seconds for smoke to rise from ship to invisibility in the atmosphere. I'm sure there is some geometric wizardry possible to determine the speed and course of the target from angular readings on smoke trails alone. I haven't tried it yet; it seems more like high school math homework than something fun to do.

One tip, though. If you're tracking a convoy and one smoke trail seems distinctly different in character and shape, beware. It may be a destroyer charging you. :-)

Edited: changed "into the wind" to "with the wind"

[Daniel Prates]

I tried to time the smoke trails. By my count, it took 45 seconds for smoke to rise from ship to invisibility in the atmosphere. I'm sure there is some geometric wizardry possible to determine the speed and course of the target from angular readings on smoke trails alone. I haven't tried it yet; it seems more like high school math homework than something fun to do.



Wow.

[TorpX]

I'm pretty convinced after several more hours of game play that smoke trails are accurately modeled. The smoke trail should combine two vectors: (1) the wind speed and direction in knots (about 1.67 x wind speed in meters per second); (2) the speed and direction of the ship. For instance, if a ship is traveling precisely with the wind at precisely the same speed in knots, the smoke trail should produce a straight vertical column.

This information is far more useful to S-boat captains, who lack radar and surface sonar, and when tracking a fast target, even the surface speed to compensate for quick dives to check sonar.


Interesting. I will keep this in mind when the opportunity arises.

[MKalafatas]

Correction: conversion from meters/second to knots is exactly 1.8. For example, if wind speed is 10 meters per second:

10 meters per second x 3600 seconds per hour = 36,000 meters per hour = 18 knots.

I think. ;) Please correct if wrong.

[TorpX]

My calculator tells me 1.9438 knots per m/s, but when I am recording wind speed in the log, I just double the number. :-?

Odd that the game doesn't have the value in knots.