Check my Math please!

[CybrSlydr]

I'm taking trig this semester in College and I couldn't pass up this opportunity to try and plot my first intercept of a convoy.

Here are the details:

Convoy is reported to me at 1450hrs. It's heading East at Medium speed.

I draw a line from the convoy East, past my position. I then draw a line North from my position (I'm south east of the convoy) and have the two lines intersect. I'm 125km south of the intersect point. I draw a line from my position to the convoy and measure the angle (54 degrees).

I then use tangent since I have the opposite and adjacent sides to my triangle and one angle. So my formula is thus:

125 * tan54[degrees] = 172

This means the distance from where the convoy currently is until it reaches the intercept location is 172km.

I then divide the 172km by 8kts (medium speed for convoys is about 8kts, correct?) and get 21.5 hours until they reach the intercept point from their current position. Since the report time was 1450 hrs, I round up to 1500 and get the time for my intercept at approximately 1130hrs the next morning.

https://c2.staticflickr.com/6/5832/22410719002_cb4d5b1d9a_o.jpg

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Did I do this correctly?

[CybrSlydr]

I'll answer for myself - yes!

The intercept point was a bit late (intercept was around 11:18 instead) but location was almost spot on.

Turns out it was a LARGE convoy with... a Queen Elizabeth BB right-smack dab in the middle!

Well, seeing as how it was in the middle, I used it as my aiming point and shot a 4 torpedo salvo at it figuring that even if it missed the BB, it'd hit the plethora of other ships around it.

Good and bad news - it was bad weather, so I could get closer to the convoy than usual without being spotted. Bad news, I loaded the entire sub with TII torps, so I had to inch my way within 5km of them to have a chance.

I fired all 4 and immediately dove to 120m. Good news is I scored two hits with my torps - one on a cargo ship carrying Sherman tanks (which sunk eventually for 1824 tons) and one hit the BB - which, we all know practically shrugged it off.

But, it worked!

[HW3]

Good work!:up:

[Sailor Steve]

I'm glad you figured it out. :rock:

[GT182]

Do another intercept that BB and try again. Try to not let it get away. After a few hours those escorts should calm down and you'll be able to sneak back in for the kill. Good luck.

[Aktungbby]

Well, seeing as how it was in the middle, I used it as my aiming point and shot a 4 torpedo salvo at it figuring that even if it missed the BB, it'd hit the plethora of other ships around it.

What depth setting did u set the eels (TII-eto's with magnetic pistols ) on to hit shallower draft cargo ships in the salvo while taking into account the armor-belt of a BB's draft. possibly 7-8 meters depending on the game?

[CybrSlydr]

What depth setting did u set the eels (TII-eto's with magnetic pistols ) on to hit shallower draft cargo ships in the salvo while taking into account the armor-belt of a BB's draft. possibly 7-8 meters depending on the game?

Actually, I didn't think to alter the depth of the torpedoes. I left it at default which is, what, 3-5m? It was stormy and rough seas (not the worst, but the middle - overcast, windy and thunder/lightning but no rain) so visibility was right around 5km.

I did switch to impact detonators instead of magnetic.

I did attempt to surface at night and sprint past them to re-engage the following day, but my navigation skills let me down as I never saw them again.

Unfortunately, when I went back to Kiel to dock, the game crashed (game crashes a lot...).

But I did save it when I plotted my intercept course, so I suppose I'll have another go at it. :)

It's August 1940 and I'm in a VIIC.

[CybrSlydr]

Nevermind - appears the save-game is corrupted and it crashes on loading. lol

Oh well.

[KingOfNothing22]

Oh how I wish I could do things like this. Fair play to you :salute:

[CybrSlydr]

My math was also incorrect.

I needed to convert knots to km/h (1kt = 1.852km/hr) and multiply that by 8 (speed of convoy) which gave me 14.816km/hr. Divide the 172 km by the speed in km/hr and we get 11.6hrs until intercept.

That explains why I ran into them around midnight. lol