Formula Question

[JPeck96272]

I recently watched a video on youtube titled "How to intercept an convoy received by radio from BDU in SH5" (http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CEwQtwIwAQ&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DiRu VGPKrj7A&ei=iz_JT9nmB8PUgAeNiIDlDg&usg=AFQjCNG6zBZEF5OCrTNUxDa8YcjzmuesiQ) and was introduced to a formula to plot the quickest interception point of a convoy.

The Formula looked like this:
(Distance of the Convoy from your position / 100 * 3.33) * Speed of the Convoy = Distance Traveled by the Convoy along current heading

then,

(Distance of the Convoy from your postion / 100 * 3.33) * Your Intercept Speed = Distance traveled by you towards Convoy's known Position

then you get the angle from your plotted position using the formula to the plotted position of the convoy using the formula, then take that angle from your current location and draw a line to the convoy's plotted course and where the line intersects is the quickest interception point to the convoy.

This works rather well for intercepting convoys, but I am wondering how accurate the formula is... Specifically, if it is accurate enough that if you know a ship's current speed and his heading if you could utilize this formula on a smaller scale to set up a manual torpedo solution?

[gutterrat13]

I don't know about a formula, but I have seen somewhere online how to do it using the ruler and other map tools. You make a ruler line the length of the approximate speed of the convoy in the direction they're traveling, and make a cirlce around the end of the line you just made with a radius of your speed. Draw another line from your sub to the contact report position. Now take the protractor and measure the angle between the contact, to the point where the line between you and the contact meet the circle, then to the end of the line suggesting the contacts path. Take that measured angle and go from the contact to your sub and cross the path that will be taken by the contact. You should get your heading.

Hopefully that makes sense! I'm currently out of town working, so i can't make a screen shot or pictures to explain. I dont remember where i found this online, but a google search may help you. it was in a tutorial for SH3

[CaliEs]

(Distance of the Convoy from your position / 100 * 3.33) * Speed of the Convoy = Distance Traveled by the Convoy along current heading



What did you mean?
http://img.xrmb2.net/images/798638.jpeg
Learn about the use of appropriate parentheses.

[JPeck96272]

This is the correct one,

[ ( ConvoyDistance / 100 ) * 3.33 ] * ConvoySpeed = Traveled Distance of Convoy

or as you put it

[ ( ConvoyDistance * 3.33 ) / 100 ] * ConvoySpeed = Traveled Distance of Convoy

I was typing it in from memory at the time, so I apologize if it looked confusing...

[CaliEs]

His grafical solution looks like an intercept course of ca. 184.54T.
The mathematical solution , however, would be 183.48T.
So with this grafical solution a torpedo would miss the targeted hitpoint by around 18.5m at a range of 1km. The uncertain of this graf. solution are the unpredictable errors of the SH5-map-tools which can be greater or smaller.