Silent Hunter 5 TWOS How to Intercept a Convoy using Distance Speed Time Formula at 340kms

This video shows you how to intercept a convoy at a distance of 340kms using Distance Speed Time Formula. This is the method I use to intercept convoys with a high rate of success. Advantages of this method: 1. Based on the simple formula distance = speed x time. 2. No angles or trigonometry or geometric formulae are needed. 3. You decide where to intersect the convoy. This depends on the distance between sub and intersection point and the distance between convoy and intersection point and the time for both to get there. And all this in turn depends the on the speed of your sub (which you decide) and the speed of the convoy (given in the radio report). Best case scenario is arriving early and ahead at intersection point to give you time to plan both your interception and attack strategy. 00:00 Radio report received regarding a small enemy convoy. The only info I need is: Long 31 25W Lat 49 11N Course ENE Speed 7kts Range 448kms. Also note the time report is received, 4.58am What we know: 1. Speed of convoy from radio report, 7kts = 7 x 1.85 = 12.95km/h or rounded up to 13km/h 2. The speed of your sub is something you decide. You usually use Ahead standard or 13 knots x 1.85 = 24.05 km/h or Ahead full or 15 knots x 1.85 = 27.75 km/h or Flank Speed Ahead or 17 knots x 1.85 = 31.45 km/h What we need to calculate: Distance from sub to interception point. Lets call it a. From a above, we get the approximate number of hours sub has to travel to interception point. Lets call it b Distance travelled by convoy to interception point. Lets call it c. Let us see how this works in practice... 00:00 Plot location of convoy using User charts scrollable - Maps and Map Tools - Nautical lat/long Chart 01:02 Plot course of convoy, ENE, using ruler 01:31 Get navigator to find exact location of sub on map. 01:51 Draw a line from sub using ruler to the convoy location 02:17 Line drawn shows a distance of 450kms. use this line drawn as a check that you plotted convoy position correctly. If there is a big discrepancy, repeat all steps above. Since distance found is very close to the range of 448 kms given in the radio report, I can continue 02:19 Checking distance from sub to convoy interception point and other maths being done 03:01 This is the most important part !! Calculating for a: Use the compass to get an idea of the distance from sub to interception point, approx 340km. Calculating for b: I will use ahead full so time taken to travel 340km will be 340 / 27.75 = 12 hrs approx. Calculating for c: Convoy speed is given as 13km/h, so convoy travels 240km in 18.5hrs to interception point. 04:20 Using protractor I get 168 degrees, this is angle I need to turn the sub. 04:54 I turn sub and I set speed at ahead full and start using time compression to speed up things 08:05 Very clsoe to intercept point, 11hrs passed since radio report received 08:45 Dive to 100m for hydrophone reading 11:27 Changed course to 230 degrees so as to go down convoy course hoping to meet head on. I could do this because convoy is expected to arrive in 6hrs time. I dont want to wait 6hrs and also there is also a chance convoy might change speed and direction given long distance convoy has to travel (240kms) to arrive at intersect point 13:28 At a depth of 80m, convoy found using external camera. Seeing the ships is not easy given the very bad weather. Summary: Plot location and course of convoy using radio report info. Take note of time when radio report received. Tell navigator to give sub exact location Draw line from sub to convoy position to confirm your calcualtions above are correct Using compass, measure distance from sub to convoy course. Decide which speed you will use and calculate time to travel the distance you just measured. Using the time you just calculated and speed of convoy from radio report, calculate distance convoy will travel. Refine distance from sub to interception point allowing some distance to be able to do hydrophone checks Using protractor, see at what bearing you need to turn your sub to. Fire up engines and stay on course. Got visual sighting! Attack convoy and escape! The Distance Speed Time formula is better explained in video:    • Silent Hunter 5 - How to plot an Intercept...   Note: It will be nearly impossible to intercept convoy if convoy changes speed and/or direction. The longer the distance to interception, the higher the probability of this happening. Also if convoy heading is close to land and direction of convoy is towards land, convoy might change direction and / or speed.