![]() |
SUBSIM: The Web's #1 resource for all submarine & naval simulations since 1997 |
![]() |
#1 |
Weps
![]() Join Date: Nov 2006
Location: London, England (Usually in a pub...)
Posts: 358
Downloads: 49
Uploads: 0
|
Calculating Speed - Correctly??
Hi all,
After getting rid of the stuttering gremlins and finally having a smooth-ish installation of SH4 I decided to begin from the beginning using all realism settings except for external camera (for the eye candy). I quite understand the TDC and can accurately track a course and locate distance etc. but the main problem I have is accurately finding speed of the target. For example, with a cargo merchant in calm seas, using the bow wave and travel across the periscope you can roughly guess a good speed - say 6 knots - in bad weather it's a lot harder! But, when faced with naval ships - especially destroyers, cruisers and battleships etc. that can go up tp 30 knots it is much more difficult! Countless times I have a good target track and waiting to shoot 90 degrees off their port or starboard, but the speed gets me most of the time. ![]() The 'manual' says to click on the chronometer for as long as possible and by magic it works out a good estimate of the speed - this has never worked - I guess one of the restrictions with high realism settings. So, without a nomograph (like SH3) I find it extremely difficult to to get the speed - a crucial part of the puzzle, without getting so close that every escort is on top of me. Can anyone please advise? What has (and hasn't) worked for others here? Cheers! Px3000 |
![]() |
![]() |
![]() |
#2 |
Sea Lord
![]() Join Date: Jul 2002
Location: Pacific NW
Posts: 1,894
Downloads: 6
Uploads: 0
|
![]()
If you've got the time, plot the bearing and range of the target over several points and use time X speed = distance. If you're short on time (which is most of the time engaging TFs) get as good as a solution as you can by just guessing, and a minute later check the targets actual bearing against the position keeper computed bearing. Assuming you have a decent range/AOB estimation and the ship hasn't changed course speed will be your only variable. If the computed bearing is close to observed bearing, you know you have a good solution, if the observed bearing is in front of the computed bearing you know your speed estimate is too slow and so on. The position keeper is your friend.
PD |
![]() |
![]() |
![]() |
#3 |
Mate
![]() Join Date: Mar 2007
Location: Arizona
Posts: 57
Downloads: 0
Uploads: 0
|
![]()
Yup the speed is what killed me in the beginning.....
However what I do now is kinda 2 part. Basically I follow Neal's advice by reviewing the recognition manual and dividing it in half based on the total knots that the vessel can actually go. Next I place the periscope or TBT crosshairs in front of the vessel by the water line until the vessel passes into the T of the crosshairs. Then I click on the stopwatch or chronometer. When the vessel clears the T then I click on the stop. Based on the seconds I have an estimate if I believe it is going fast, medium, or slow. I follow this logic and most of the time the bad guy is at the bottom swimming with Davey Jones. ![]() |
![]() |
![]() |
![]() |
#4 |
Loader
![]() Join Date: Mar 2005
Posts: 90
Downloads: 0
Uploads: 0
|
![]()
It sounds like they shipped it without the chronometer working. Hopefully it will be patched soon. I'm supprized it wasn't done in the first patch.
__________________
![]() |
![]() |
![]() |
![]() |
#5 | |
Fleet Admiral
![]() |
![]() Quote:
This sounds like a good technique to use and I would truly like to understand it. |
|
![]() |
![]() |
![]() |
#6 |
Sea Lord
![]() Join Date: Jul 2002
Location: Pacific NW
Posts: 1,894
Downloads: 6
Uploads: 0
|
![]() |
![]() |
![]() |
![]() |
#7 |
Mate
![]() Join Date: Mar 2007
Location: Arizona
Posts: 57
Downloads: 0
Uploads: 0
|
![]()
Sorry. The seconds that I stated is the estimate based on how fast the enemy ship is traveling. If the stopwatch states 15 seconds from end to end, (and also review the wake in the periscope) then I will estimate that the enemy ship is moving slow.
If the stopwatch stated 40 seconds then I would estimate that the ship is traveling fast. Hope this helps! |
![]() |
![]() |
![]() |
#8 |
Silent Hunter
![]() Join Date: Jul 2002
Location: At periscope depth in Lake Geneva
Posts: 3,512
Downloads: 25
Uploads: 0
|
![]()
I think you mean the opposite but yea.
|
![]() |
![]() |
![]() |
#9 |
Grey Wolf
![]() Join Date: Oct 2005
Location: Deep Waters
Posts: 871
Downloads: 31
Uploads: 0
|
![]()
As stated above, if you have time, plot the ships position on the map, wait either 3 or 6 or 30 or 60 mintues and then plot the position again. the speed is roughly:
3 minutes: 20Xdistance=speed 6 minutes: 10Xdistance 30 minutes: 2Xdistance 60 mintues: 1Xdistance. Any of these will give you a halfway decent estimate of speed. Obviuosly, the longer the time, the more accurate the estimate.
__________________
Guess I should change my sig since SH5 has an offline mode now ![]() |
![]() |
![]() |
![]() |
#10 | |
Engineer
![]() Join Date: Nov 2003
Location: Portland, OR
Posts: 210
Downloads: 10
Uploads: 0
|
![]() Quote:
I've found 5 minutes to be accurate enough and have had 70% hit accuracy so far. 5 minutes: 12xdistance=speed However I wish the ruler on the nav map was more exact. I have to guess because the distance marked between the two points is very rarely at that tenth of an nm mark. Example: ruler says .5nm but it's really closer to .58nm |
|
![]() |
![]() |
![]() |
#11 |
Officer
![]() Join Date: Mar 2005
Location: South Wales, UK
Posts: 237
Downloads: 2
Uploads: 0
|
![]()
Agree the ruler could do with another decimal place on its measuring.
Metric is "more accurate" due to this at the moment. |
![]() |
![]() |
![]() |
#12 |
Electrician's Mate
![]() Join Date: Apr 2005
Posts: 140
Downloads: 1
Uploads: 0
|
![]()
THIS needs to be fixed in next patch without question.
__________________
DJSatane - https://twitter.com/DJSatane |
![]() |
![]() |
![]() |
#13 |
Sailor man
![]() Join Date: Mar 2007
Location: Singapore
Posts: 46
Downloads: 0
Uploads: 0
|
![]()
I guess, the best thing is firing some torps in a spread or salvo, so you can get a better chance.
During the Falklands War, the ARA Admiral Belgrano was sunk with a spread - 2 out of 3 torps. Oddly enough, they prefered the tried and test straight running torps like the Mk 14 we have on the US Subs.
__________________
![]() |
![]() |
![]() |
![]() |
|
|