10th Patrol of U-53 - Radio Contact Intercept

[XLjedi]

I actually used MoBo pretty sparingly on this one... I thought some folks might like to see how easy it is to calibrate the TDC without a lot of complex measurements or AoB guesstimates. I spent zero time on visual observations. I was setting up the TDC before I ever saw the target.

Originally Posted by Canovaro

I have one comment though. A lone ship is always reported with speeds like slow or medium, unless BdU gives another contact report (like in your case).
This is the weak point of any calculation. You took 6 but the range could have been 4-7 or even greater.

For a "slow" report I'm pretty successful with 6. Setting it for 7 does usually give you some cushion. I wouldn't set it higher than 7 for slow.

Originally Posted by Canovaro

The contact report seems to be from 14:50. It is now 14:53. That's hardly any difference, but nexttime it may differ half an hour. It's just a matter of how quick you can get out of time compression.

How fast you click TCx1 actually doesn't matter at all. In this case, I was pretty nimble, but sometimes I can be off by 30 mins. In which case I would just advance the target position for distance travelled in 30 mins by means of dead reckoning. Your intercept calculations are then based off the proper time adjusted position.

Originally Posted by Canovaro

You also don't want to cross the target's path literally, because it can spot you an start zig-zagging. you want to lay and wait submerged. The range of view depends of the time of day, the wind speed and fog. I would say it's max 7000 meter

Rather than submerge and wait, I like to submerge and stay on the advance...

Notice I did submerge well beyond visual range. The first time the target had any chance to spot me was when I peeked the scope out of the water at 1500m and had the ship in my sights at a bearing of about 25°. At which point, I was opening tube 1.

Generally speaking, I try to station myself such that I can make the final approach submerged at 4kts regardless of which direction I'm coming from. So I try to intercept a station for a 4kt approach... not necessarily the direct method. As I mentioned, the initial stationing of this intercept is my favorite starting point because it decreases my workload by not having to plot an appropriate end-around.

Originally Posted by Canovaro

I have made the convoy intercept 'theory' below which is based on some other basics.

Appears reasonable... The intercept was based on how I like to do it; but that was only half the story here. The other message I wanted to get across in this report is how easy it is to get started in manual targetting by choosing your attack position. In which case, all of your TDC dial settings are known.

That circle diagram you posted is pretty clever... I like it.