Why don't targets zigzag? - Page 2

runyan99 · 07-14-08, 01:59 AM

Interesting zig plans.

Also, some ships and groups used constant helming, by which the ships were always slightly turning to the left or right, around a base course. Even harder to target than a zig pattern with straight lines. Not possible to simulate in game, however.

I took a look at the mission editor today, and adding some form of zig plan is possible for all traffic by simply redrawing the routes for convoy and merchant traffic.

Possible, but time consuming, which is I suppose why it hasn't been done.

DeepIron · 07-14-08, 10:51 AM

Quote:

Possible, but time consuming, which is I suppose why it hasn't been done.

If I remember correctly, tater worked around with this a bit and the conclusion was that plotting *realistic* "zig-zag" patterns in the editor created a huge overhead for the game engine to cope with. There may have been other issues as well...

Mush Martin · 07-14-08, 11:09 AM

I think theres still an issue of language

evasive routing
versus
tactical maneuvering

LukeFF · 07-14-08, 10:34 PM

Quote:

Originally Posted by tater

"Organic" ZZ behavior would be a major game improvement. There might be a library of ZZ patterns like those above, and the waypoint would have a pull down to pick which pattern to use between waypoints (defaulting to "NONE.").

That indeed would be great. Devs, please take note of this!

Peto · 07-14-08, 11:50 PM

I've tried to create some zig-zag patterns in SH4 but, frankly, it involves so many way points that it over-loads my system. Not to mention taking about 200 hours to plot (by hand) a convoy from Palau to Tokyo.

It would be great to have to "figure out" a zig-zag plan and then dive on a projected point of intercept (in RL this could take hours to do). "How" to do it in game is beyond me though...

Great Charts tater! As usual

!

runyan99 · 07-15-08, 12:11 AM

I can understand if totally realistic zig plans create too many waypoints, but is there a happy medium? If real convoys changed course every 15 minutes, would it be possible to create 'lite' patterns where the convoy changes course each hour? Each two hours? Even this would be an improvement over the straight routes in stock.

Peto · 07-15-08, 12:26 AM

Quote:

Originally Posted by runyan99

I can understand if totally realistic zig plans create too many waypoints, but is there a happy medium? If real convoys changed course every 15 minutes, would it be possible to create 'lite' patterns where the convoy changes course each hour? Each two hours? Even this would be an improvement over the straight routes in stock.

You are absolutely correct. But even that is Hundreds of waypoints... Especially for slow convoys. Zig-Zagging is definitely on my wish list.

tater · 07-15-08, 11:43 PM

The patterns in the above images are all for 1 hour, I believe. The angle shown, then the time in minutes.

I have a thread (search the forum for zig zags) that shows how to do it with the automated campaign editor. It makes a godawful pile of ZZs. You need to split the layers or it crashes the mission editor.

Also, the AI doesn't deal with it well. I did try "light" versions, but tthe ZZs literally need to be on the time scale of getting a firing solution, plus the travel time of the fish. Much longer and it's only good to make an end around slightly more difficult—cept the ZZ pattern slows them down. You NEED shorter time frame ZZ behavior for it to be effective. The japanese patterns shown above were the short time frame they were for a reason

tater

joegrundman · 07-15-08, 11:53 PM

That is so interesting

Evolution in practice!

Do you know what allied zigzag policy was like?

seaniam81 · 07-16-08, 12:07 AM

If i remember correctly from what my grandfather told me a officer on a British DD. The Allied Navies used different plans that could be changed hourly or daily or just when ever.

The convoy would have one ship who knew the plan and executed it. The rest of the convoy would have to do what the lead ship did. That lead ship would preform the ZZ at specific times on the clock. And this would negate the use of flags/lights/radio.

tater · 07-16-08, 12:09 AM

Allied procedure was similar. They had a plan book of different ZZs and would execute them.

Note that in the IJN examples, the ships are back on base course every X minutes (certainly every hour). All the skippers would know that at the top of the hour (or whatever) they'd be back on base course.

joegrundman · 07-16-08, 12:10 AM

I don't know if this interests you, but these excerpts show the USN end of war attack doctrine for dealing with these sorts of short time zig-zags

http://www.hnsa.org/doc/attack/index.htm

Some terminology:

critical range = distance target would travel in 7.5 mins - which is easy right? you all know the 3 min rule, so just double it and add a bit. 7 knots=c. 1500 yards. 10 knots= 2200 yards. This is the range at which you really must be moving from approaching the target to readying the shot.

target track: a line extended forward from the target along it's present course (ie the track the target will follow assuming no change of course)

distance to target track= distance from your submarine to this line

Situation 1a Target has zigged in last 2 mins, target is on sub's beam. Distance to track less than 1000 yards

Situation 1b as above but target on sub's bow

Situation 2

Target has not zigged in last 2 mins (and therefore will soon), distance to track less than 1000 yards

Situation 3

Target zigged in last 2 mins, distance to track more than 1000 yards

Situation 4 Target has not zigged in last 2 mins, distance to track more than 1000 yards

joegrundman · 07-16-08, 12:14 AM

You see i'd been following the previous threads, and i knew they had this short leg zig zag, but i never realised why they made it so tight!

So the allied convoys also used say 5-10 minute zig zag legs?

Man, this HAS to be in the next gen subim, but perhaps as an optional realism thing

Sailor Steve · 07-16-08, 09:00 AM

I didn't know it was constantly so short either.

Cool stuff!

Peto · 07-16-08, 10:02 AM

I remember a story from Monsarrat's (sp?) book Three Corvettes about convoying/station keeping in North Altlantic convoys. He said they were in fog and couldn't change station from the merchant they were using as a guide. So all night they held a constant distance and bearing on the that one ship--the only one they could see. In the morning, the fog lifted and they were the only two ships visible

. It took them the rest of the day to locate and rejoin the convoy.

Kind of off topic but a quaint antidote

.

07-14-08, 11:09 AM	#18
Mush Martin Eternal Patrol Join Date: Dec 2006 Posts: 4,398 Downloads: 4 Uploads: 0	I think theres still an issue of language evasive routing versus tactical maneuvering __________________ RIP Mush Tutorial

07-14-08, 11:50 PM	#20
Peto Ace of the Deep Join Date: Jul 2007 Location: The details of my life are quite inconsequential Posts: 1,049 Downloads: 4 Uploads: 0	I've tried to create some zig-zag patterns in SH4 but, frankly, it involves so many way points that it over-loads my system. Not to mention taking about 200 hours to plot (by hand) a convoy from Palau to Tokyo. It would be great to have to "figure out" a zig-zag plan and then dive on a projected point of intercept (in RL this could take hours to do). "How" to do it in game is beyond me though... Great Charts tater! As usual ! __________________ If your target has a 30 degree AOB, the range from his base course line equals the current range divided by 2.

07-15-08, 11:53 PM	#24
joegrundman Ocean Warrior Join Date: May 2007 Posts: 2,689 Downloads: 34 Uploads: 0	That is so interesting Evolution in practice! Do you know what allied zigzag policy was like? __________________ "Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill

07-16-08, 12:07 AM	#25
seaniam81 Commodore Join Date: Dec 2003 Location: Ontario, Canada Posts: 624 Downloads: 87 Uploads: 0	If i remember correctly from what my grandfather told me a officer on a British DD. The Allied Navies used different plans that could be changed hourly or daily or just when ever. The convoy would have one ship who knew the plan and executed it. The rest of the convoy would have to do what the lead ship did. That lead ship would preform the ZZ at specific times on the clock. And this would negate the use of flags/lights/radio. __________________ Ultima ratio regum. (The final argument of kings) - Inscription on french cannons, on order of Louis XIV

07-16-08, 12:10 AM	#27
joegrundman Ocean Warrior Join Date: May 2007 Posts: 2,689 Downloads: 34 Uploads: 0	I don't know if this interests you, but these excerpts show the USN end of war attack doctrine for dealing with these sorts of short time zig-zags http://www.hnsa.org/doc/attack/index.htm Some terminology: critical range = distance target would travel in 7.5 mins - which is easy right? you all know the 3 min rule, so just double it and add a bit. 7 knots=c. 1500 yards. 10 knots= 2200 yards. This is the range at which you really must be moving from approaching the target to readying the shot. target track: a line extended forward from the target along it's present course (ie the track the target will follow assuming no change of course) distance to target track= distance from your submarine to this line Situation 1a Target has zigged in last 2 mins, target is on sub's beam. Distance to track less than 1000 yards Situation 1b as above but target on sub's bow Situation 2 Target has not zigged in last 2 mins (and therefore will soon), distance to track less than 1000 yards Situation 3 Target zigged in last 2 mins, distance to track more than 1000 yards Situation 4 Target has not zigged in last 2 mins, distance to track more than 1000 yards __________________ "Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill

07-14-08, 01:59 AM	#16
runyan99 Mate Join Date: Sep 2005 Posts: 51 Downloads: 0 Uploads: 0	Interesting zig plans. Also, some ships and groups used constant helming, by which the ships were always slightly turning to the left or right, around a base course. Even harder to target than a zig pattern with straight lines. Not possible to simulate in game, however. I took a look at the mission editor today, and adding some form of zig plan is possible for all traffic by simply redrawing the routes for convoy and merchant traffic. Possible, but time consuming, which is I suppose why it hasn't been done.

07-15-08, 12:11 AM	#21
runyan99 Mate Join Date: Sep 2005 Posts: 51 Downloads: 0 Uploads: 0	I can understand if totally realistic zig plans create too many waypoints, but is there a happy medium? If real convoys changed course every 15 minutes, would it be possible to create 'lite' patterns where the convoy changes course each hour? Each two hours? Even this would be an improvement over the straight routes in stock.

07-15-08, 11:43 PM	#23
tater Navy Seal Join Date: Mar 2007 Location: New Mexico, USA Posts: 9,023 Downloads: 8 Uploads: 2	The patterns in the above images are all for 1 hour, I believe. The angle shown, then the time in minutes. I have a thread (search the forum for zig zags) that shows how to do it with the automated campaign editor. It makes a godawful pile of ZZs. You need to split the layers or it crashes the mission editor. Also, the AI doesn't deal with it well. I did try "light" versions, but tthe ZZs literally need to be on the time scale of getting a firing solution, plus the travel time of the fish. Much longer and it's only good to make an end around slightly more difficult—cept the ZZ pattern slows them down. You NEED shorter time frame ZZ behavior for it to be effective. The japanese patterns shown above were the short time frame they were for a reason tater

07-16-08, 12:09 AM	#26
tater Navy Seal Join Date: Mar 2007 Location: New Mexico, USA Posts: 9,023 Downloads: 8 Uploads: 2	Allied procedure was similar. They had a plan book of different ZZs and would execute them. Note that in the IJN examples, the ships are back on base course every X minutes (certainly every hour). All the skippers would know that at the top of the hour (or whatever) they'd be back on base course.

07-16-08, 12:14 AM	#28
joegrundman Ocean Warrior Join Date: May 2007 Posts: 2,689 Downloads: 34 Uploads: 0	You see i'd been following the previous threads, and i knew they had this short leg zig zag, but i never realised why they made it so tight! So the allied convoys also used say 5-10 minute zig zag legs? Man, this HAS to be in the next gen subim, but perhaps as an optional realism thing __________________ "Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill

07-16-08, 09:00 AM	#29
Sailor Steve Eternal Patrol Join Date: Nov 2002 Location: High in the mountains of Utah Posts: 50,369 Downloads: 745 Uploads: 249	I didn't know it was constantly so short either. Cool stuff! __________________ “Never do anything you can't take back.” —Rocky Russo

07-16-08, 10:02 AM	#30
Peto Ace of the Deep Join Date: Jul 2007 Location: The details of my life are quite inconsequential Posts: 1,049 Downloads: 4 Uploads: 0	I remember a story from Monsarrat's (sp?) book Three Corvettes about convoying/station keeping in North Altlantic convoys. He said they were in fog and couldn't change station from the merchant they were using as a guide. So all night they held a constant distance and bearing on the that one ship--the only one they could see. In the morning, the fog lifted and they were the only two ships visible . It took them the rest of the day to locate and rejoin the convoy. Kind of off topic but a quaint antidote . __________________ If your target has a 30 degree AOB, the range from his base course line equals the current range divided by 2.