how to confirm the heading of the stop ship

[558800]

How to confirm the heading of the stop ship?

[joea]

Wut? More information please.

[558800]

when hitted the stationary ship , I can't confirm its heading by the speed button.So how can I confirm the heading of the stationary ship?

[donut]

You can guess AOB.,but speed is zero.Fire on bearing angle of TBT in scope,or UZO.,range dosent matter,except run range of torp. You could draw A line stem to stearn,on target,& use the protractor,put 0 to North.

[SteamWake]

Well if the ship is stopped its heading is more or less irrelevant so just use your best guess.

[Rockin Robbins]

A stopped ship isn't headed anywhere.

So the answer is the same as:

What is north of the north pole? or What is east of the north pole? or What is the temperature of a solid that is 5º below absolute zero. Are you asleep? (asked of a sleeping person)

[Von Manteuffel]

Do you mean "How do you work out the direction a stopped ship is facing?"

a) Have a look and note the bearing of the stopped ship
b) You know the heading of your boat.
c) On the chart, draw a line from your boat along the bearing of the stopped ship.
d) Have another look and you should be able to work out roughly the angle
("heading") of the stopped ship, relative to its bearing from your boat - the way it's
facing.
e) Estimate/calculate/"ping" for the range of the stopped boat
e) Draw a line on the chart indicating the stem to stern direction of the stopped boat
across the line of its bearing from your boat and at the calculated range.

That should give you enough to manouevre for a killing shot from an AOB of 90, or so.

[LukeFF]

How do you find the direction of the go ship?

[Snowman999]

A stopped ship isn't headed anywhere.

Not true in a legal, logbook sense. A vessel in water always has a heading. Speed doesn't enter into it.

Normally it wouldn't matter, except in some obscure admiralty law situation (Dragged anchor, what was anchored heading?) or in cases of high winds or seas where anchored aspect to the elements is a safety issue. But the heading is the direction the bow is facing, moving or not.

In cases where the vessel is going astern the log entry would be "Astern 1/3, making 4 knots, heading 000" even though the hull was moving toward 180 True. The course would be 180; the heading would be 000.

[donut]

Protracted law:rotfl:

[Rockin Robbins]

Originally Posted by Snowman999

Not true in a legal, logbook sense. A vessel in water always has a heading. Speed doesn't enter into it.

Normally it wouldn't matter, except in some obscure admiralty law situation (Dragged anchor, what was anchored heading?) or in cases of high winds or seas where anchored aspect to the elements is a safety issue. But the heading is the direction the bow is facing, moving or not.

In cases where the vessel is going astern the log entry would be "Astern 1/3, making 4 knots, heading 000" even though the hull was moving toward 180 True. The course would be 180; the heading would be 000.

But he is asking the question in relation to targeting with the TDC. It does not allow negative speed, so a backing ship would have legal heading minus 180º for TDC entry. Otherwise your torpedo isn't coming anywhere near that target.

And from a plotting point and TDC point of view, a stationary ship has no heading or angle on the bow, as heading and AOB in that frame of reference are always related to the motion of the target. Actually for a ship with zero speed, you an input any heading or angle on the bow you choose for a correct targeting solution. No measurements of any kind are necessary. Use your favorite number! I use 42, the answer to life, death, the universe and everything.

A target making 2 knots across a 2 knot current would have quite a different plotted heading than the compass course of the ship, which would be irrelevent to the submarine making the observation. If you are interested in striking the side of that ship with a torpedo, the heading is the combination of the two vectors for course/boat speed and current direction/speed.

A sub captain is interested in results, not the legal definition of "heading." In fact, the legal definition is worse than useless to him. We have no interest in the lawyer's heading because he is on shore and cannot help or hurt us. We have no interest in the target captain's heading because we are going to put him safely in Davey Jones' locker in a short while. We sink ships and worry about the legal bullschnitzel later. We confine ourselves to heading definitions that put the enemy on the ocean floor. Arrrrrrrr matey!

[Sailor Steve]

Originally Posted by Snowman999

Not true in a legal, logbook sense. A vessel in water always has a heading. Speed doesn't enter into it.

Normally it wouldn't matter, except in some obscure admiralty law situation (Dragged anchor, what was anchored heading?) or in cases of high winds or seas where anchored aspect to the elements is a safety issue. But the heading is the direction the bow is facing, moving or not.

In cases where the vessel is going astern the log entry would be "Astern 1/3, making 4 knots, heading 000" even though the hull was moving toward 180 True. The course would be 180; the heading would be 000.

Dang...someone who's more nit-picky/legalistic than me. My kind of guy!

[Snowman999]

But he is asking the question in relation to targeting with the TDC. It does not allow negative speed, so a backing ship would have legal heading minus 180º for TDC entry. Otherwise your torpedo isn't coming anywhere near that target.

I didn't refer back to the OP, but in the case he's talking about (TDC) he (and you) shouldn't be talking about heading at all. Course only. At an ahead bell course and heading are the same thing and conning officers sometimes use the terms interchangably. But as I correctly stated, they are not fundamentally linked and the two numbers can be quite different. (I left out the head-scratching question of what term is correct when a tug is made up midships and the hull is moving perpendicularly to the heading.)

And from a plotting point and TDC point of view, a stationary ship has no heading or angle on the bow, as heading and AOB in that frame of reference are always related to the motion of the target.

Completly wrong.

AOB has no input from speed or motion. It is an instantaneous measure of the angle between the line-of-sight and the target's hull in the direction toward the target's bow, with the addition of port or starboard to maintain the AOB at 180 degrees or less. It is only due to this forum's insistance on gaining AOB from time-series plot data that this misperception is held. AOB can be reliably gained if both own ship and target are motionless, both moving forward, moving in reverse, or one moving and the other not moving. I've done all four in RL.

The very term itself tells you what it is--the angle on the bow. Period.

Actually for a ship with zero speed, you an input any heading or angle on the bow you choose for a correct targeting solution. No measurements of any kind are necessary. Use your favorite number! I use 42, the answer to life, death, the universe and everything.

Your chances of a hit are significantly different with an AOB of 180 than 90, but your point is true so far as it goes. That doesn't mean heading and course are the same thing.

A target making 2 knots across a 2 knot current would have quite a different plotted heading than the compass course of the ship, which would be irrelevent to the submarine making the observation.

Still not heading. You have compared observed course-made-good and steered course. Observed course is the only concern of the Approach Officer. Again, "heading" is not a variable in torpedo fire control. Never has been.

I've served with two submarine COs and I can assure you that there were times they were concerned with "heading." Just not during FC party-time. That deck log has their name on it, however, and heading is a legal term important to accurate logs in certain circumstances.

[Snowman999]

Dang...someone who's more nit-picky/legalistic than me. My kind of guy!

I hang out with a lot of lawyers. It rubs off. <g>

[WernerSobe]

a lot of BS posted here.

A stopped ship doesnt require a firing solution. Submariners use a term of "finishing shot" which just means a shot without firing solution, mostly used agains crippled or docked ships.

so how do you fire a fish without a firing solution?

All you need is to set up the torpedo course or in other words to tell your torpedo the bearing of the target. In real sub the ordnance officer would disconnect the torpedo from tdc and programm the torpedo course manualy. It is not possible in sh4 so you must send the bearing to the torpedo by taking range. Remember when you take range, your torpedo remembers the bearing where your optics are looking at.

So this is how it works in sh4

1. aim with periscope optics for desired impact point.
2. make sure speed is set to 0, remember to send zero speed to tdc.
3. take range and send to TDC.
4. make sure torpedo course (small arrow in tdc) is pointing the same direction youre aiming with your optics and fire.


-It doesnt matter wether position keeper is running or not. Since speed is set 0 it wont do any calculations anyway.

-AoB doesnt matter. Target is not moving, there is no need of course deviation. The torpedo itself just follows the given course it doesnt care from which side it will hit the target.

- even range doesnt matter. The only reason to take range is to know the interception time so you know when the torpedo is going to impact. But since you cannot programm torpedo course manualy, the only way to do that is to send the range. Actualy it doesnt need to be exact range. Just send anything important is that your optics are aimend at the target when youre sending range.