Manual TDC speed figuring

[pythos]

I haqve been having a very annoying thing occur with my speed figuring when setting up a solution.

When I get a visual contact, I stay out of visual detection range, but keep track of the target's position. On the map, I place a mark at the reported position (map updates on), and start the watch. Wait 5minutes, and place another mark. Measure that distance, and work out the speed using the nomengraph.

Every time I have done this it has been wrong, usually to fast, which causes the torps to zoom ahead of the target.

Using the crew to figure the speed is worthless (500 plus knots most of the time).

anyone have better methods for figuring speed for manual TDC? Or is there a possibility that this is an simulated bug of the MK14 torp.

[DrBeast]

I use the simple 3min 10sec rule: jot down the position of the ship on the map, start the watch, and put down the next mark after exactly 3 minutes and 10 seconds. I then measure the distance traveled in Km, multiply by 10 and hey! presto, I have the target's speed in knots. Being a European, I don't bother with feet, hands, brows, or any of that jargon: it's metric system for me. :p

*DrBeast sits back and waits for Rockin Robbins to come charging in

I always pause and zoom in completely when I'm jotting down the marks and measuring, that could help a bit.

[Joe S]

I suspect your problem may be the use of the nomograph, if you dont draw the line exactly where it should be you could be off a little bit, and a small error in speed will ofter result in a miss. I divide the distance travelled by the time in minutes to get yds per minute and convert to knots based on a chart I made up. It works most of the time but I still get more misses than I should. I did find out that if you get detected the ships will change speed, and that had messed me up a few times. Taking multiple speed estimates over a period of time is the best way. The crew estimates are only good at close range and when visibility is good so you know you are getting an accurate placement of the split image, which is difficult to do in bad weather or heavy seas. I would keep experimenting and modifying your method until you get results, I think your basic method is sound. Joe S

[Rockin Robbins]

Originally Posted by DrBeast

I use the simple 3min 10sec rule: jot down the position of the ship on the map, start the watch, and put down the next mark after exactly 3 minutes and 10 seconds. I then measure the distance traveled in Km, multiply by 10 and hey! presto, I have the target's speed in knots. Being a European, I don't bother with feet, hands, brows, or any of that jargon: it's metric system for me. :p

*DrBeast sits back and waits for Rockin Robbins to come charging in

I always pause and zoom in completely when I'm jotting down the marks and measuring, that could help a bit.

Charrrrrrrrrrge! In human measurement terms, use the 3 minute rule. Distance traveled in nautical miles (the knot is nautical miles per hour. That's a CLUE!!!:rotfl times 20 is speed in knots.

If they have the sense to use knots, you'd think they would have the sense to use sensible units all the time instead of mixing them all up. And hey, these are American boats. We'll have none of that kilohertz stuff here, it's kilocycles!!!! Ya see, that term actually MEANS something. All those Europeans HATE words that actually mean something... Maybe that's why they speak all those foreign languages? OUCH! Onkel Neal, he hit me!

[DrBeast]

Originally Posted by Rockin Robbins

Charrrrrrrrrrge! In human measurement terms, use the 3 minute rule. Distance traveled in nautical miles (the knot is nautical miles per hour. That's a CLUE!!!:rotfl times 20 is speed in knots.

If they have the sense to use knots, you'd think they would have the sense to use sensible units all the time instead of mixing them all up. And hey, these are American boats. We'll have none of that kilohertz stuff here, it's kilocycles!!!! Ya see, that term actually MEANS something. All those Europeans HATE words that actually mean something... Maybe that's why they speak all those foreign languages? OUCH! Onkel Neal, he hit me!

*DrBeast hides the fly-swatter behind his back
No I didn't! :rotfl:
When it comes to terminology, I must admit I have a fair advantage over you anglo-saxons. Many words derive from greek, and being greek sure helps me understand words that'd make you guys dig up a dictionary in sheer frustration

I hope I remember the nm rule this time...I keep seeing it time and again and I always forget it...maybe I should engrave it on the monitor..."3 minutes, nm x 20 = knots"...there, that should do the trick!

[looney]

How do the yards work then?? I'm also a metric person but when playing US sub I try to work in knots.

[Raptor1]

Holy thread bump of eternal bumpiness!

Anyway, 1 knot = 2,025.372 yards/h, Mesa think

[Puster Bill]

Originally Posted by pythos

I haqve been having a very annoying thing occur with my speed figuring when setting up a solution.

When I get a visual contact, I stay out of visual detection range, but keep track of the target's position. On the map, I place a mark at the reported position (map updates on), and start the watch. Wait 5minutes, and place another mark. Measure that distance, and work out the speed using the nomengraph.

Every time I have done this it has been wrong, usually to fast, which causes the torps to zoom ahead of the target.

Using the crew to figure the speed is worthless (500 plus knots most of the time).

anyone have better methods for figuring speed for manual TDC? Or is there a possibility that this is an simulated bug of the MK14 torp.

Have you tried using a Submarine Attack Course Finder/IS-WAS?

Here is the manual so that you can get an idea of how to use it:
http://www.hnsa.org/doc/attackfinder/index.htm

The files you need to build one yourself are at the top of the page. It's not hard, I built one:



I built it before Hitman made the Kriegsmarine version. I used it in SHIII, and applied the proper corrections (ie., for ranges I would take the meters that SHIII produced, convert to yards, then use the IS-WAS).

There are a couple different ways to use it. All of them produce pretty good speed estimates.

They are also handy for figuring things like course from AOB, or AOB from course, etc.

My personal favorite method involves creeping at 1 knot at PD, and taking two range/bearing observations separated by a reasonable length of time. You then perform a simple procedure with the wheel, and it gives you both the AOB *AND* speed.

Here is the Subsim thread (and pictures of some examples much nicer than mine):
http://www.subsim.com/radioroom/show...ghlight=IS-WAS