Estimating target speed

[ninja turtle]

Hi guys

I've been using the 3'15 method with success but I've also seen tutorials on youtube and read that you can use 3'30. Does anyone know which method might be the most accurate? I'm just curious why there are two measurements.

Thanks and good hunting :salute:

[reaper7]

One is for Metric, the other is for Imperial.

[ninja turtle]

One is for Metric, the other is for Imperial.

Aha!! Thanks Reaper for the quick reply. That makes perfect sense :yep:

[ninja turtle]

One more question, though. Which one is used with which? :hmm2:

I sound quite dense :/\\!!

:)

[Shado]

Hi there, I believe that the Germans used the 3' 15", and the Americans used the 3' 30". The Germans I am sure used the metric numbers and Americans the imperial.

[Sailor Steve]

Americans used 3:00 precisely. 3:15 is adjusted for metric. I don't know where 3:30 comes from, as this is the first time I've ever seen it mentioned anywhere.

[MantiBrutalis]

As 100 yards is something like 91,5 meters, 3:00 would quite precisely correspond to 100 yards, while 3:15 is for 100 meters...

3:30 is something around 110 meters per 1 knot. I don't which metric would that be...

Edit - Anyway 3:15 works for me, managing those extra-precise shots at desired ship compartment.

[Pisces]

Don't know how they'd come up with 3m30sec either.

[Gustav Schiebert]

Hi there, I believe that the Germans used the 3' 15", and the Americans used the 3' 30". The Germans I am sure used the metric numbers and Americans the imperial.

So were these methods used operationally? How did they do that without 'map updates' in real life - I've never used that method because I play without updates on, I always thought 3' 15" was a game method only.

If they plotted it, surely that's not as accurate as the U-jagd or the periscope scratchmark method on OLC GUI?

[ninja turtle]

Hi guys

Thanks for all the help with my query. Here's a link to the tutorial I watched the other day:

http://www.youtube.com/watch?v=E_mIUx0e374&list=PLiqs4P9OOUFBlJOE0Wbo2YKxwvqz3DEBy&index=9

I'm sure I've read or seen others with this 3'30

:salute:

[ninja turtle]

So were these methods used operationally? How did they do that without 'map updates' in real life - I've never used that method because I play without updates on, I always thought 3' 15" was a game method only.

If they plotted it, surely that's not as accurate as the U-jagd or the periscope scratchmark method on OLC GUI?

Hi Gustav

To be fair at the moment I am using 'updates' as an option in my career, but will try and use the 'plotting method' mod when I'm confident enough. I'm sure this timing method can still be used but maybe takes longer to find the target direction and range estimates for that final speed. There's also the method of placing periscope on the bow, and starting the chronometer and stopping it once the stern has passed. I'm still learning how to play this fantastic subsim.

:yeah:

:subsim:

[Gustav Schiebert]

Hi Gustav

To be fair at the moment I am using 'updates' as an option in my career, but will try and use the 'plotting method' mod when I'm confident enough. I'm sure this timing method can still be used but maybe takes longer to find the target direction and range estimates for that final speed. There's also the method of placing periscope on the bow, and starting the chronometer and stopping it once the stern has passed. I'm still learning how to play this fantastic subsim.

:yeah:

:subsim:

Hey ninja - yeah after a while using map updates I went over to the stopwatch method. I use a real stopwatch and a printout of the U-jagd, so I don't have to fiddle with drag-and-drop stopwatches on the screen or anything like that, I can just take one measurement independent of the computer then input it directly into the TDC.

I sometimes even, when in a desperate fast-paced convoy attack, just whack in 5kts for merchant ships and fire. At short ranges you still hit even if they're actually going much faster.

I suppose you use the plotting method on the approach, when you have the time, and that gives you a standard speed for the convoy which you can use throughout the attack?

I read once about an allied tactic whereby on every leg of a zigzag they would also change speed. This would also confuse an onlooker, since they would probably assume a constant speed.

Huzzahs for SH!

[MantiBrutalis]

It is very possible to use the 3:15 rule without map updates. You just need its bearing from you (rather easy) and a confident skill in measuring distance.

If you take those two values 3:15 apart from each other, you have two positions on the map, so you have both AOB and speed right under your hands. These things are far easier done if you're not moving, but still possible to count in your speed and heading.

Things get a little awkward if:
1) You don't have enough time. Doing the measurement at least twice means you will be watching your target for 6 and a half minute.
2) The target is far away. The range estimate miserably fails for me from 3km upward. (see the problem between 1) and 2) ?)
3) You are moving. It gets very hard to account for your own movements. But do you have the time to watch the target for 6 minutes when you should be getting at some estimated firing position?


Personally, I totally fail at measuring distances and estimating AOB. When I try to play without map updates, I frequently fail to get to proper firing position, making the shot even harder. Also I tend to force ships aground or even ram them when leaving the base...

[GoldenRivet]

Ninja Turtle...

here is a simple and straight forward formula i have been using all these years.

1. Come to a complete stop as close to zero speed as possible...

2. While watching the ship through the periscope or UZO, Place the vertical cross hair slightly ahead of the ship. Start the stopwatch when the ships bow touches the periscope's vertical cross hair.

3. Stop the stopwatch when the ships stern crosses the periscope's vertical cross hair. (make sure not to move the scope or UZO at all)

4. make a note of this "Traverse Time" it will usually be something like 30 or 45 seconds or could be more or less.

5. Check the length of ship as recorded in the recognition manual.

Length of ship, divided by "traverse time" multiplied times 1.94 = target speed in knots

take more than one measurement if you can but this is deadly accurate

Example: Ship is 180 meters long, traverse time was 32 seconds

180 / 32 x 1.94 = 10.9 knots

in this case set 11 knots in the TDC and sink her!

[ninja turtle]

Ninja Turtle...

here is a simple and straight forward formula i have been using all these years.

1. Come to a complete stop as close to zero speed as possible...

2. While watching the ship through the periscope or UZO, Place the vertical cross hair slightly ahead of the ship. Start the stopwatch when the ships bow touches the periscope's vertical cross hair.

3. Stop the stopwatch when the ships stern crosses the periscope's vertical cross hair. (make sure not to move the scope or UZO at all)

4. make a note of this "Traverse Time" it will usually be something like 30 or 45 seconds or could be more or less.

5. Check the length of ship as recorded in the recognition manual.

Length of ship, divided by "traverse time" multiplied times 1.94 = target speed in knots

take more than one measurement if you can but this is deadly accurate

Example: Ship is 180 meters long, traverse time was 32 seconds

180 / 32 x 1.94 = 10.9 knots

in this case set 11 knots in the TDC and sink her!

Thanks very much for the technique, GoldenRivet. I will try this method as soon as.

:yeah:

[ninja turtle]

It is very possible to use the 3:15 rule without map updates. You just need its bearing from you (rather easy) and a confident skill in measuring distance.

If you take those two values 3:15 apart from each other, you have two positions on the map, so you have both AOB and speed right under your hands. These things are far easier done if you're not moving, but still possible to count in your speed and heading.

Things get a little awkward if:
1) You don't have enough time. Doing the measurement at least twice means you will be watching your target for 6 and a half minute.
2) The target is far away. The range estimate miserably fails for me from 3km upward. (see the problem between 1) and 2) ?)
3) You are moving. It gets very hard to account for your own movements. But do you have the time to watch the target for 6 minutes when you should be getting at some estimated firing position?


Personally, I totally fail at measuring distances and estimating AOB. When I try to play without map updates, I frequently fail to get to proper firing position, making the shot even harder. Also I tend to force ships aground or even ram them when leaving the base...

Cheers buddy

I'm curious. Have you been playing this game for a while and only just joined subsim or have you been playing since last month? If it's the latter then you are a fast learner :yep: It took me months to even get a torpedo travelling in the correct direction :D

[MantiBrutalis]

Cheers buddy

I'm curious. Have you been playing this game for a while and only just joined subsim or have you been playing since last month? If it's the latter then you are a fast learner :yep: It took me months to even get a torpedo travelling in the correct direction :D


I was playing the game back in 2004-ish (whenever the thing came out), but at that time I was twelve, so it was mostly me watching stuff blow up at 50% Realism. Just played it for a few months, I think...

Somewhere between then and now I was playing the superb (and old) Jane's 688i Hunter/Killer. I did want to play the game about 3 years ago, but it was the dreadful time of Vistas ruining every old game there was. In January this year I felt a sudden urge to try again on Win7 to no avail. But I did remember SH3, so I did return to it. And it actually works on my weak laptop...



Just a side note - my dad used to play SH3, SH4 and possibly SH5. A felt like SH4 was kinda out of place (I like German U-boats just more) and SH5 just felt really awkward.

Another side note - I switch games quite often, but I always do come back to the favorites. Out of WW2 "simulators" I enjoyed World of Tanks (doesn't work on my laptop after some patching), IL2 Sturmovik (boy, that was pretty hardcore on Real setting, does not work with Win7), right now digging War Thunder (looks so nice on high-end PCs, but is still playable on old machines (or my laptop).



Back to the question:
On 10th March 2013 I found my SH3 in the cellar, searched for patches, found Subsim and GWX, went straight for it. First 2 weeks I was playing it daily, but since I started writing a story about one of the careers I play like 3 hours a week. Writing the story took up all the time I had for playing games...

I don't know if I am a fast learner, I just think I'm good at geometry...

[ninja turtle]

I was playing the game back in 2004-ish (whenever the thing came out), but at that time I was twelve, so it was mostly me watching stuff blow up at 50% Realism. Just played it for a few months, I think...

Yes I was playing it when it first came out (although I was a little older than you were :D) I used to love fast forwarding the sunrise and sunset. Mind you I still enjoy these time compressed moments.

Just a side note - my dad used to play SH3, SH4 and possibly SH5. A felt like SH4 was kinda out of place (I like German U-boats just more) and SH5 just felt really awkward.

I much prefer SH3 for the German part of it but I also like the extra missions of reconnaissance or dropping off spies in SH4. Shame there aren't any additional mission add ons for SH3. Or are there?

IL2 Sturmovik (boy, that was pretty hardcore on Real setting, does not work with Win7)

I used to play this flight sim. An excellent flight sim. One of the best imo. Was terribly rubbish at it. I could take off and land, but hitting targets once I'd found them was very unlikely. I have a terrible sense of direction so once I'd turned to make a strafe I'd lose where I'm supposed to be aiming :haha: Got rid of the games and joystick now (had a Saitek stick and throttle combo too).

Back to the question:
On 10th March 2013 I found my SH3 in the cellar, searched for patches, found Subsim and GWX, went straight for it. First 2 weeks I was playing it daily, but since I started writing a story about one of the careers I play like 3 hours a week. Writing the story took up all the time I had for playing games...

I'm glad I returned to this old favourite. As I say it's been a learnig curve, not only with the torpedo aiming methods etc but also with the mods and to a certain extent programming the game to how I like it :hmmm:

I don't know if I am a fast learner, I just think I'm good at geometry...

I'm not that good at geometry (not a very logical mind) and quite a slow learner but once I've set my mind to find out something I never give up :yep:

[CaptBones]

So were these methods used operationally? How did they do that without 'map updates' in real life - I've never used that method because I play without updates on, I always thought 3' 15" was a game method only.

If they plotted it, surely that's not as accurate as the U-jagd or the periscope scratchmark method on OLC GUI?

I didn't see anyone answer the first and second questions. So, the answer, from the USN POV, is yes we did and still do.

Since a nautical mile is approximately 2000 yards, the 3-minute rule is used all the time to mentally compute a "target" speed, as well as your own distance covered for any specific station-keeping maneuver or when maneuvering in restricted waters (leaving/entering port, narrow channels, etc.). The 3-minute rule, for use with Imperial units (yards and nautical miles-per-hour [knots]) is...the distance, in yards, travelled in 3 minutes is equal to the speed, in knots, times 100. So, the converse is...the distance in yards, travelled in three minutes, divided by 100 equals the speed in knots. For "target" speed, you use the 3-minute rule to generate the target's relative speed from visual and/or radar bearings & ranges and plot that (along with the direction of relative movement) using a Maneuvering Board to solve for the target's true course and speed. Even though it is an approximation (the nautical mile is actually a tad more than 6076ft or 2025yds - and don't ask me how much a "tad" is, it doesn't matter)...it was close enough for good targeting solutions. Of course today that's all done by computer as well.

With a bit of practice and a grease pencil (one that you can see on the screen...I was once handed a black pencil in the middle of the night by a QM striker who thought he was being funny...turned out it was perfectly good under the "green glow" of the night-time black-out scope hood), you can do the plot very quickly on a radar repeater PPI screen, using the Maneuvering Board for a more refined solution. "Back in the day", that was always the source of spirited competition between the bridge watch and CIC on surface ships...who could get the quickest and most accurate solution for any surface contact. The closest point of approach (CPA) was critical information that triggered numerous decisions/actions.

Submerged submarines had/have both a more difficult task and "better" tools to use. First, you don't want to expose the scope for very long periods or at repeated (and therefore predictable) intervals, and your periscope "height-of-eye" creates a severe limitation regarding the distance to the horizon and therefore requires you to be/get much closer to a target to make the required observations and measurements. But, the built-in stadimeter and relative bearing circle on the tube housing were typically faster and more accurate to use than the stadimeters and pelorus bearing circles used on surface ships (in my experience, anyway). Ultimately, the ability to rely on accurate passive sonar bearings and use Target Motion Analysis made it essentially unnecessary to raise a scope and risk visual detection. Although, in "peacetime" it was sometimes nice to positively ID the "target" you were tracking (and then again, sometimes not); if you were close enough, that is.

But, one of the big problems in real life and in the game, is that the visually observed distance travelled by a target is generally not too accurate, to begin with at least; unless the target is presenting a nearly beam-on or stern/bow-on aspect to the observer (you, Herr Kaleun). BTW, in real life anything within 30 degrees or so of that last aspect ratio generally creates a significant "pucker factor"; you REALLY need to figure out that solution in a hurry! The "solution" is a relative motion problem and most people are not too good at intuitively solving relative motion problems (SubSimmers who use manual targeting do get lots of practice at that though :up:). Also in real life, radar largely took care of that and in the game that's where the plot ("map update" in game terms) comes in and where an ability to accurately estimate angle on the bow is just about the most useful observation to start with. There have been some interesting techniques presented here to overcome that problem in the game and all of that has been discussed at great length in other threads anyway. So, that's enough of that I'd say...good hunting.:salute:

[MantiBrutalis]

I used to play this flight sim. An excellent flight sim. One of the best imo. Was terribly rubbish at it. I could take off and land, but hitting targets once I'd found them was very unlikely. I have a terrible sense of direction so once I'd turned to make a strafe I'd lose where I'm supposed to be aiming :haha: Got rid of the games and joystick now (had a Saitek stick and throttle combo too).



My main weakness has always been rudder control, as I didn't have pedals and the controls on my old joystick were pretty bad apart from the main stick.

You should try War Thunder. Free, good-looking, runs on nearly anything. Good fun even if still in beta. Has an Arcade mode, which is perfectly playable with mouse and keyboard while not being too arcady (like for example HAWX), and a Historical mode (joystick recommended), which is much more hardcore, nearly IL2-style, but not as hard. I enjoy the Arcade mode, since my joystick doesn't work anymore, it is just right between fast paced easy-to-play action and semi-real WW2 models and physics. Many of the maps do have land objectives, so it isn't just a 15v15 team deathmatch, there is some actual bombing and map objectives done.

[ninja turtle]

I didn't see anyone answer the first and second questions. So, the answer, from the USN POV, is yes we did and still do.

Since a nautical mile is approximately 2000 yards, the 3-minute rule is used all the time to mentally compute a "target" speed, as well as your own distance covered for any specific station-keeping maneuver or when maneuvering in restricted waters (leaving/entering port, narrow channels, etc.). The 3-minute rule, for use with Imperial units (yards and nautical miles-per-hour [knots]) is...the distance, in yards, travelled in 3 minutes is equal to the speed, in knots, times 100. So, the converse is...the distance in yards, travelled in three minutes, divided by 100 equals the speed in knots. For "target" speed, you use the 3-minute rule to generate the target's relative speed from visual and/or radar bearings & ranges and plot that (along with the direction of relative movement) using a Maneuvering Board to solve for the target's true course and speed. Even though it is an approximation (the nautical mile is actually a tad more than 6076ft or 2025yds - and don't ask me how much a "tad" is, it doesn't matter)...it was close enough for good targeting solutions. Of course today that's all done by computer as well.

With a bit of practice and a grease pencil (one that you can see on the screen...I was once handed a black pencil in the middle of the night by a QM striker who thought he was being funny...turned out it was perfectly good under the "green glow" of the night-time black-out scope hood), you can do the plot very quickly on a radar repeater PPI screen, using the Maneuvering Board for a more refined solution. "Back in the day", that was always the source of spirited competition between the bridge watch and CIC on surface ships...who could get the quickest and most accurate solution for any surface contact. The closest point of approach (CPA) was critical information that triggered numerous decisions/actions.

Submerged submarines had/have both a more difficult task and "better" tools to use. First, you don't want to expose the scope for very long periods or at repeated (and therefore predictable) intervals, and your periscope "height-of-eye" creates a severe limitation regarding the distance to the horizon and therefore requires you to be/get much closer to a target to make the required observations and measurements. But, the built-in stadimeter and relative bearing circle on the tube housing were typically faster and more accurate to use than the stadimeters and pelorus bearing circles used on surface ships (in my experience, anyway). Ultimately, the ability to rely on accurate passive sonar bearings and use Target Motion Analysis made it essentially unnecessary to raise a scope and risk visual detection. Although, in "peacetime" it was sometimes nice to positively ID the "target" you were tracking (and then again, sometimes not); if you were close enough, that is.

But, one of the big problems in real life and in the game, is that the visually observed distance travelled by a target is generally not too accurate, to begin with at least; unless the target is presenting a nearly beam-on or stern/bow-on aspect to the observer (you, Herr Kaleun). BTW, in real life anything within 30 degrees or so of that last aspect ratio generally creates a significant "pucker factor"; you REALLY need to figure out that solution in a hurry! The "solution" is a relative motion problem and most people are not too good at intuitively solving relative motion problems (SubSimmers who use manual targeting do get lots of practice at that though :up:). Also in real life, radar largely took care of that and in the game that's where the plot ("map update" in game terms) comes in and where an ability to accurately estimate angle on the bow is just about the most useful observation to start with. There have been some interesting techniques presented here to overcome that problem in the game and all of that has been discussed at great length in other threads anyway. So, that's enough of that I'd say...good hunting.:salute:

Interesting stuff. Thanks for the post :up:

[Captain Wreckless]

IL2 Sturmovik (boy, that was pretty hardcore on Real setting, does not work with Win7)

I've never had any problems getting Il2 Sturmovik to run in Win 7. I have the 64 bit version, runs just fine and didn't do anything special to get it to work.

Mike

[Father Goose]

Appreciate the insight CaptBones. No substitute for real life experience. :up:

Thanks GoldenRivet for the speed calculating technique. Will try it this weekend. :lurk: