The Hunt: An illustrated example of how to sink a ship

[Dantenoc]

<Edit: PDF version here - Gizzmoe>

First of all, let me start by saying that I didn't reinvent the wheel or claim that I did. All of what you will find here can be found on other posts (and only one of them was done by me)

To learn more, go here:

http://www.paulwasserman.net/SHIII/
http://www.communitymanuals.com/shii...itle=Main_Page

This is just an attempt to show you how to apply all that wonderfull knowledge in a step by step illustrated fashion, playing a SHIII game modded with RUB and on 100% realism (only unchecked realism box is the one that relates to the nav-map updating contacts automatically, but that still gives you 100% realism on the newer RUB)

Having said that... Lets roll !!

Step 1:
Most of the times you'll get help from other german units by virtue of contact reports that you'll receive from the BdU... and you're in luck, 'cause you just got one now

You take notice of the ship's speed and heading: Slow, going towards West by Northwest.

You keep your cool and don't head straight for the contact. As a graduate from officer school in the Kriegsmarine, you know that any bilge rat that heads straight for the target will find it long gone by the time he gets there. You know that instead, you need to calculate an intercept course. You know that the answer can be very easily calculated with the law of the sines, but you don't carry the necesary trigonometric tables on board a U-boat to do that (So that would be cheating).

Notice on image 1 that you have allready ventured a guess as to what the intercept course will be, and have allready started heading towards it. It won't be very accurate of course, but at least you won't head in a completely wrong direction while you work out a graphical solution to the intercept problem

Step 2:
You take out the protractor and click on your U-boat and the on the contact to make the first leg. For the secon leg, make it so that it goes from the contact off into it's reported direction. In our case it was reported as West by North West, which is 292.5 degrees from north (click on the ? icon in the nav-map window to have these type of aids show)


Step 3:
Now you take out the ruler and measure from the contact's location of into the direction of it's course. You measure a distance that is representative of his speed. In this case, he was reported as slow, which you know means about 6 knots (medium is 9). In this case the image shows a distance of 60 kms on the ruler which works well. Other options would have been 6 kms, or 0.6 kms or whatever number that readily reminds you of 6 knots.


Step 4:
Now it's decision time: at what speed should you travel to intercept the contact ? It can be anything you want (within reason), and most captains like to go fast, but experienced kaleuns like yourself know that around 12 knots is plenty for most times... but in this case you realize that the contact is:
a) moving away from you
b) and very far away from you to start with
c) your in English controled waters
all of which means that you'll have to move decisevely... so 16 knots it is.

So you draw a circle, centered at the end of the ruler measurement you did in step 3, with a radius of 160 mks... why 160 mks? because in step three you chose to represent each knot by 10 mks, remember? (If in step three you'de had measured 6 kms for the 6 knots you would now be drawing a circle radius of 16 kms for 16 knots, and so on). Let's look at your circle

Achtung herr Kaleun!!: Take special notice of were the circle cuts the line formed from your u-boat to the contact.

Step 5:
Now the magical part. You take another protractor (second one) and click on the center of the circle you just made on step four, then you click on the spot the special spot noted at the end of step four (where the circle cuts the line that goes from your u-boat to the contact) to make the first leg of the protractor. For the second leg of the protractor, make it sow that it heads directly towards the contact. Your Nav-Map now looks like this

Take special notice of the angle that has been formed (in this example, 19 degrees) Congratulations, you now know how to succesfully intercept the contact: you should lead it by 19 degrees in order to intercept it.

Step 6:
This is just an auxiliary step that aids you in measuring those 19 degrees by which you need to "lead" the target. You take another protractor tool (third one) and click on the contact (you might have to fiddle around with all of the overlaping protractors), then click on the U-boat. You now have the first leg. For the secon leg, just make it so that it reads 19 degrees while cutting the contact's reported course. Your nav map now looks like this:


Step 7:
This last leg of the protractor tool you drew on step six is the exact course you need to take, so you move your navigation way point to match it. To make it even better, you take care to place the nav point precisely at the point where your new course and the contact's course both intesect. Your nav map now looks like this:

Notice that the way point says that interception will occur in 8 hours at a point that is 247kms from your current position !!! You can't help but feel silly for all those times before you knew how to do this and all those ships that used to vanish without a trace :hmm:

Step 8:
Before going of to sleep (you are playing this in 1xTC real time aren't you ?!?!) you realize that both you and the contact will arrive at the interception point at the same time. You don't like this because you'll be playing catch up with him from then on (rember that he's heading away from you?). To solve this you speed up the boat to 17 knots instead of 16, so that you'll arrive EARLY to the interception point. After this you ask the navigator to do some simple calculations and he comes up with this:

Good, we'll now arrive with plenty of time to spare

(continued on separate post)