Is this a good way to find course and speed?

[conura]

Hey all,

I've watched quite a few tutorials for how to do this on real navigation/manual tdc and the one that makes most sense to me is to take the range and bearing of a ship, start the timer, then take the range and bearing again in exactly 5 minutes. With this information I have the ships course, and using the distance / time / knots conversion chart the speed too.

With this, I'd then go flank speed, and set myself up ahead of the vessel, submerge, and wait til I have a 90 degree AOB.

I often find the speed is a little off, but this is probably my not being very precise with everything. Is this a good way to get this information? Is this the correct method?

[XenonSurf]

Fastest and also fairly precise way is to make 2 hydrophone positionings in 5 minutes intervalls and mark everything on the map. You are using your sonarman with this asking him to listen to the closest or to a specific ship. Then you use the calculation tables, those where you can read what's the speed of a ship if it makes x km in y time.
There are other methods ofc.

[Cyborg322]

If you want to get a last final speed calculation Using the U-Jagd is probably the best option. Plotting speed over time is good for longer range

You can do it on the fly you just need to time the ship passing from aft to stern thru the scope its useful if the target changes speed at the very last moment you just need an approximation of the ships length . It is surprisingly accurate. I use it most of the time combined with time over distance for long range . Also using the scale which is displayed on the right of the map Knots/Km/Minutes is useful that method just needs a line drawing across the scale from dist thru time the intersection in the middle gives the speed saves working it out in your head

There are few more ways it depends on the scenario and what suits you best some of the more complicated methods don't necessarily give a more accurate calculation. Same applies for AOB and course etc

This is a decent video on the U-Jagd you need TDW's UI or any mod with U-Jagd included. It switches over from the normal stopwatch by right clicking on it

[jimmbbo]

From Dick O'Kane's method IIRC, I mark the ship's position, start the stopwatch and mark it again 3 minutes later.

Extending the line through the Xs gives the course line, and the ship's speed will be the distance in yards divided by 100... e.g.; in three minutes, if the ship travels 1200 yards, its speed is 12 knots. If it travels 900 yards, it will be 9 kt, or accurately enough for a close in shot.

I then move far enough ahead while remaining at least 5 miles from the target's course to avoid detection, then turn the corner to set up a submerged 90 degree position at 1000 yards from the course line.

[Captain_AJ]

Originally Posted by jimmbbo

From Dick O'Kane's method IIRC, I mark the ship's position, start the stopwatch and mark it again 3 minutes later.

Extending the line through the Xs gives the course line, and the ship's speed will be the distance in yards divided by 100... e.g.; in three minutes, if the ship travels 1200 yards, its speed is 12 knots. If it travels 900 yards, it will be 9 kt, or close enough for a close in shot.

I then move far enough ahead while remaining at least 5 miles from the target's course to avoid detection, then turn the corner to set up a submerged 90 degree position at 1000 yards from the course line.

but .. also consider the sim sh5 IS IN METTERS, READ BERSTERS TEACHING ON WHO TO CALCULATE SPEED .. HUGE DIFFERENCE IN METERS AND YARDS

[Fifi]

3M 15s between two marks, then the distance in meters gives you the right speed for sure

[Shibbyland]

I used to do a lot of map plotting but I got lazy and get the officer to calculate the speed for me.

I've recently become even more lazy and often just estimate the speed based on eyeballing it, using the size of the waves off the bow and the wake, works well enough close in.

My biggest problem is all I seem to be able to find is Destroyers, the North Western approaches just seem to have enormous convoys of Destroyers who don't detect me even when I'm on the surface. I pick off one after the other.

If you're calculating speed using the Hydrophone, how do you get an accurate distance to plot with the bearing?

[XenonSurf]

Originally Posted by Shibbyland

If you're calculating speed using the Hydrophone, how do you get an accurate distance to plot with the bearing?

Good question. My method was based on a tutorial that is now outdated because: in the new TWoS 2.2.6 I just realize that the sonarman doesn't give you the distance anymore, he says only 'long range, short range, medium range'. This is not helpful unless you do the 4-bearing method which takes longer and is therefore only suited for long range targets.

As a consequence, the hydrophone becomes useless at short range for quick decisions or for plotting targets and reading the speed with the calc tables. You would need to know the range EXACTLY, else your speed calculation is far off to be precise.

BUT:

For quick decisions, your target is close enough usually, meaning you can use the periscope and Stadimeter to make a good range calc. So you can combine the hydrophone plotting and change it according to your range calc; you then can calculate the speed based on the distance that your target did in a certain time intervall (and what about the Nomograph? I never used this one...should be good for something...). And once you are at the periscope there is the U-Jagd like suggested above.


Personally I don't like dial instruments very much (RAOTB, U-Jagt...), I rely on geometry on the map if possible,...and eyeball...I then calculate a solution for a specific bearing to the target in order to make my torps hit at 90°. I want it simple, and if I miss, oh well...

[Captain_AJ]

Originally Posted by XenonSurf

Good question. My method was based on a tutorial that is now outdated because: in the new TWoS 2.2.6 I just realize that the sonarman doesn't give you the distance anymore, he says only 'long range, short range, medium range'. This is not helpful unless you do the 4-bearing method which takes longer and is AFAIK only suited for long range targets.

As a consequence, the hydrophone becomes useless at short range for quick decisions or for plotting targets and reading the speed with the calc tables. You would need to know the range EXACTLY, else your speed calculation is far off to be precise.

BUT:

For quick decisions, your target is close enough usually, meaning you can use the periscope and Stadimeter to make a good range calc. So you can combine the hydrophone plotting and change it according to your range calc; you then can calculate the speed based on the distance that your target makes in a certain time intervals (or using the Nomograph maybe? I never used this one...)

Learning a few things and based on experience The callouts medium. short long Range has numbers in the distance that can be estimated, There is a chart in the charts visibility tab that has ranged in numbers."hydro sounds chart All I have been doing is hunting by hydrophone and using a method to find a target that was shown by Kukilegs after taking 4 plots, and also if the target is closing as it is called out you can turn your boat and plot out a few bearings and you will get a snapshot of a course . the sonor guy when you are in the hydro station will give you an estimate in range if the target ship is closer than 30 km, even if it is called out as long medium and short

[XenonSurf]

Thanks CaptainAJ, I will take a look in the charts next time, there are tons of them indeed, so they must be good for something
I rather like to use lines and circles on the map for my guesswork instead of using dial instruments, the only one I like is the Stadimeter which is really helpful.