Who's good at math to calculate ..

robj250 · 06-08-06, 06:50 AM

.. a night time attack on a convoy. Here is the situation: it is presently 1952 hrs. I just received a message that there is a convoy doing 8 kts NNE. My course is 268°. Now if I stay on my course, it will probably end up as a daylight attack because their course will cross my course if I continue on 268°. Now in all my past encounters with reported convoys, the convoy has never changed course. I have no idea what course to take with my upgraded VIIB at ahead flank to intercept them during the night. If I wait for them to cross my course they would have to travel about 263 km and I would only have to travel 100.7 km. Oh, the weather is clear and the seas are calm so I should be able to do 18 kts. Is this enough information? Is it possible for me to change to a certian course to make a night-time attack? I have no idea whether it is possible or not.

don1reed · 06-08-06, 07:03 AM

More input, please. What grid are you in, and what grid is the convoy in?

robj250 · 06-08-06, 07:08 AM

Quote:

Originally Posted by don1reed

More input, please. What grid are you in, and what grid is the convoy in?

I am in grid BE69, they are on the edge at BE94 and BE95. It is Jan 4, 1943, so SR 0805 Universal time Jan 5

moselgott · 06-08-06, 07:20 AM

hi, can you prepare a little sketch?? i.e. with all distances (sub-convoy;shortes way from sub-imaginary cours of the convoy[->right ankle];convoy-point where sub will cross the cours at its shortest way), ankles, bearing of sub and convoy...would be helpful. i think it would be the best if you mark all these information in your F5-map and make a sreenshot.

robj250 · 06-08-06, 07:24 AM

Quote:

Originally Posted by moselgott

hi, can you prepare a little sketch?? i.e. with all distances (sub-convoy;shortes way from sub-imaginary cours of the convoy[->right ankle];convoy-point where sub will cross the cours at its shortest way), ankles, bearing of sub and convoy...would be helpful. i think it would be the best if you mark all these information in your F5-map and make a sreenshot.

Sure, I made a snap of the map. I have to reduce it and host it on imageshack first.

don1reed · 06-08-06, 07:25 AM

The way I see it, Rob, if you both continue on and reach the point of interdiction, i.e., 263km @ 8kn., it would take the convoy--

D = S x T, or transposing,
T = D/S = 142 nm / 8 kn. = 17hr and 45 min.

You, on the other hand, have 17:45 to travel 100.7 km (54.4 nm) to meet the convoy. Then,

S = D/T = 54.4 nm / 17:45 = 3 knots. <---Your speed.

You said the time was 19:52...plus the 17:45 = 13:37 the next day.

If you travelled at 5 kn. you'd get there a little earlier ... to set up your ambush, or, stay off enough to shadow them 'til dark, then move in to attack.

robj250 · 06-08-06, 08:00 AM

Quote:

Originally Posted by don1reed

The way I see it, Rob, if you both continue on and reach the point of interdiction, i.e., 263km @ 8kn., it would take the convoy--

D = S x T, or transposing,
T = D/S = 142 nm / 8 kn. = 17hr and 45 min.

You, on the other hand, have 17:45 to travel 100.7 km (54.4 nm) to meet the convoy. Then,

S = D/T = 54.4 nm / 17:45 = 3 knots. <---Your speed.

You said the time was 19:52...plus the 17:45 = 13:37 the next day.

If you travelled at 5 kn. you'd get there a little earlier ... to set up your ambush, or, stay off enough to shadow them 'til dark, then move in to attack.

Thank you. I don't wanna seen stupid, but how do I calculate nm from km? Reason being, I would like to design a spreadsheet to do the calculations for me. Did you use .54 to get nm?

Ula Jolly · 06-08-06, 08:20 AM

One nm = 1852 m = 1,852 km
To go from km to nm, take 100.7 km and divide it on 1,852 - equals just short of 54.4 nm
From nm to km, take 54,4 nm and multiply with 1,852 - equals just under 100,75 km, or 100 750 m

don1reed · 06-08-06, 08:25 AM

You're not stupid, Rob, the fault lies with the Devs for not including nautical miles with a nautical sim...

km x .54 = nm

btw: If you don't want to wait 17:45 to link up with the enemy...you can meet them half way in between their starting point to the interdiction site. Instead of them travelling 142 nm, how about 80 nm or 148 km?
You'd have to change course to about 234° and travel about 97 nm. Use the same Distance = Speed x Time formula to figure your speed to arrive at that point when they do.

All the best,

06-08-06, 06:50 AM	#1
robj250 Sea Lord Join Date: Mar 2006 Location: Port Hardy, BC, Canada 75 yo with M.S. & C.O.P.D. & heart problems Posts: 1,930 Downloads: 1 Uploads: 0	Who's good at math to calculate .. .. a night time attack on a convoy. Here is the situation: it is presently 1952 hrs. I just received a message that there is a convoy doing 8 kts NNE. My course is 268°. Now if I stay on my course, it will probably end up as a daylight attack because their course will cross my course if I continue on 268°. Now in all my past encounters with reported convoys, the convoy has never changed course. I have no idea what course to take with my upgraded VIIB at ahead flank to intercept them during the night. If I wait for them to cross my course they would have to travel about 263 km and I would only have to travel 100.7 km. Oh, the weather is clear and the seas are calm so I should be able to do 18 kts. Is this enough information? Is it possible for me to change to a certian course to make a night-time attack? I have no idea whether it is possible or not.

06-08-06, 07:03 AM	#2
don1reed Ace of the Deep Join Date: Dec 2004 Location: Valhalla: Silent Generation Posts: 1,149 Downloads: 910 Uploads: 0	More input, please. What grid are you in, and what grid is the convoy in? __________________ [SIGPIC][/SIGPIC] During times of universal deceit, telling the truth becomes a revolutionary act. ~ George Orwell

06-08-06, 07:20 AM	#4
moselgott Watch Join Date: Apr 2006 Posts: 23 Downloads: 0 Uploads: 0	hi, can you prepare a little sketch?? i.e. with all distances (sub-convoy;shortes way from sub-imaginary cours of the convoy[->right ankle];convoy-point where sub will cross the cours at its shortest way), ankles, bearing of sub and convoy...would be helpful. i think it would be the best if you mark all these information in your F5-map and make a sreenshot. __________________ "War does not determine who´s right, only who´s left" - Bertrand Russel

06-08-06, 07:25 AM	#6
don1reed Ace of the Deep Join Date: Dec 2004 Location: Valhalla: Silent Generation Posts: 1,149 Downloads: 910 Uploads: 0	The way I see it, Rob, if you both continue on and reach the point of interdiction, i.e., 263km @ 8kn., it would take the convoy-- D = S x T, or transposing, T = D/S = 142 nm / 8 kn. = 17hr and 45 min. You, on the other hand, have 17:45 to travel 100.7 km (54.4 nm) to meet the convoy. Then, S = D/T = 54.4 nm / 17:45 = 3 knots. <---Your speed. You said the time was 19:52...plus the 17:45 = 13:37 the next day. If you travelled at 5 kn. you'd get there a little earlier ... to set up your ambush, or, stay off enough to shadow them 'til dark, then move in to attack. __________________ [SIGPIC][/SIGPIC] During times of universal deceit, telling the truth becomes a revolutionary act. ~ George Orwell Last edited by don1reed; 06-08-06 at 07:45 AM.

06-08-06, 08:20 AM	#8
Ula Jolly Samurai Navy Join Date: Jun 2005 Location: Norway Posts: 567 Downloads: 0 Uploads: 0	One nm = 1852 m = 1,852 km To go from km to nm, take 100.7 km and divide it on 1,852 - equals just short of 54.4 nm From nm to km, take 54,4 nm and multiply with 1,852 - equals just under 100,75 km, or 100 750 m __________________ I shall punish yee, landlubber! C'mere for spankings and popsicles! Last edited by Ula Jolly; 06-08-06 at 08:33 AM.

06-08-06, 08:25 AM	#9
don1reed Ace of the Deep Join Date: Dec 2004 Location: Valhalla: Silent Generation Posts: 1,149 Downloads: 910 Uploads: 0	You're not stupid, Rob, the fault lies with the Devs for not including nautical miles with a nautical sim... km x .54 = nm btw: If you don't want to wait 17:45 to link up with the enemy...you can meet them half way in between their starting point to the interdiction site. Instead of them travelling 142 nm, how about 80 nm or 148 km? You'd have to change course to about 234° and travel about 97 nm. Use the same Distance = Speed x Time formula to figure your speed to arrive at that point when they do. All the best, __________________ [SIGPIC][/SIGPIC] During times of universal deceit, telling the truth becomes a revolutionary act. ~ George Orwell