Silent Hunter 5 TWOS How to Intercept a Convoy using Distance Speed Time Formula at 125kms

This video shows you how to intercept a convoy at a distance of 125kms 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 on speed of your sub (which you decide) and the speed of convoy (given in 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 large enemy convoy. The only info I need is: Long 23 01W Lat 53 53N Course ENE Speed 9kts Range 236kms. Also note the time report is received, 6.32am What we know: 1. Speed of convoy from radio report, 9kts = 9 x 1.85 = 16.65 km/h or rounded up to 17km/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 01:28 Plot course of convoy, ENE, using ruler 02:11 Get navigator to find exact location of sub on map. 02:29 Draw a line from sub using ruler to the convoy location 02:50 Line drawn shows a distance of 236.9kms. 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 236 kms given in the radio report, I can continue During this time did some maths and decided to change distances 06:07 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 125km. Calculating for b: I will use ahead standard speed so time taken to travel 125km will be 125 / 24 = 5.21 hrs or 5 hrs approx. Calculating for c: Convoy speed is given as 17km/h, so convoy travels 112km in 6.58hrs or 6hrs and 35mins to interception point. Using the compass draw out a circle with radius of 112km. 08:46 Using protractor I get 220 degrees, this is angle I need to turn the sub. 09:16 I turn sub to 218 degrees and I set speed at ahead full and start using time compression to speed up things 10:33 Check how far I am from interception point and am within 30km radius. Keep getting closer. 12:18 Diving deep to get hydrophone reading 12:33 Sonarman tells me we found warship at long range. External camera shows convoy found at 11.52am which is 5 hrs 20 mins since radio report 21:35 Visual contact made through periscope 21:55 Paused to speed up things. I am now very close to convoy and time is 1.10pm. Time that passed from radio report at 6.32am to 1.10pm is approx 6 hrs and 40 mins. I had predicetd above that sub should meet convoy at 6hrs and 35mins! 22:32 I am in the middle of convoy path, the best place to be, as convoy will pass right next to me and so I can fire all my fore torpedoes and also my aft torpedo. Eventually 5 hits! 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.