[TorpX]

Originally Posted by Rockin Robbins

You're confusing yourself by uncalculable random effects. If you are standing still they can miss you in any direction. If you are moving the same is true. You can't count the ones you miss. That's the defect in your method of calculation.

Not true.

It is much better to think of searching in the same way Eugene Fluckey of the Barb did. He spent a lot of time explaining the situation, so I'm going to condense it.

Fluckey did a lot of unorthodox things. As I recall part of his efforts involved probing/ raiding coastal anchorages where enemy ships were hiding out during the night. Is this what you are refering to? Looking for anchored ships or raiding coastal locations is not quite the same as searching for ships moving thru an area.

The fact is, we don't know the disposition of the enemy on the ocean. If you are static in the middle of the horde, you're going to be successful. If you're static in a vacuum, you're coming back with a goose egg.

How does this invalidate anything I said?

So you say, if you get a goose egg in 24 house, move! That's fine. Murphy's Law says you just moved from the next hot spot.

The only thing we can say for sure is that in any moment in time, the enemy is distributed in an unknown array over the surface of the ocean.

According to Fluckey, and I agree, the odds of finding a target approach unity when the distance between your sub and a target is within sensor range. So your job is to get within sensor range of as many targets as possible in a 24 hour period.



The corollary of that statement is that the number of targets you encounter is directly proportional to the number of square miles of ocean surface you search each day.

This is only true if you are searching for things that are not moving. While you are searching one end of your area, targets can move through the other and you'll never know it. Moving from one part of an area is not the same as being in both places at once.

Let's do the math! You're static with a visual search radius of about 5 miles and a sonar search range of 20 miles on a good day. So you're searching a circle 20 miles in radius. The area you've searched is 3.14*20^2 square miles or 1,256 square miles.


Let's move out! We'll assume a 20 mile range for our radar and we're moving on the surface for 24 hours at our best fuel economy speed of 9 knots. Now your searched area approximates a rectangle 40 miles wide and 216 miles long. That's 8,640 square miles.

Again, the square area is not what is important. If you were trying to find sea shells on a strip of beach, this would work ok. You could search an area, cross it off your list and move on to the next section. However, if the "sea shells" have the ability to move out from the water to the beach, and back into the water again, you will not be able to find nearly as many. They would be moving about in sections that you had "cleared". Your search efforts are only effective if there is a target nearby at the moment you are there. If the target moves thru either before or after you go by, you won't find it. Based on your analysis, it doesn't matter how fast enemy targets move, or if they move at all! An enemy cruiser moving at 30 kts could be found as easily as a drifting barge. You should see this is obviously not the case.

Since the enemy is moving and the effect of that movement is random we can safely ignore any effects on our results.

This is patently absurd if you think about it for two seconds.

Our movement will bring as many targets in range as it will leave beyond range. Therefore the comparison in the number of targets we develop can be expressed as the ratio between the two numbers of square miles searched.

If the first statement were true, it suggests there would be no difference.

So you are 8640/1256 times more likely to develop a target when moving. That is 6.88 times more likely. Another valid way to interpret the data is that a patrol during which you are actively searching at 9 knots, you will develop 6.88 times more targets in the same number of days as you would be searching statically.

OK, if this was really true, then you would get 2*6.88 times the number of targets in two days and 7*6.88 the number in a week. Do you really think just by moving at 9 kts this will get you 48 targets for every one I get in a single week? At this rate you could sink nearly 200 times as many targets in a month. Nice try, but your math does not hold up. Assuming that the number of contacts found will be proportional to the sq. area is a gross oversimplification.

But that is not the entire story. There are monstrous advantages to searching on the surface as opposed to searching submerged. Of most importance is the value of fully charged batteries. They can save your life, you know!

I never suggested submerged searching was better than surfaced searching. In fact the opposite is implied. Anything which increases your detection range (visual or otherwise), will improve your number of contacts by the same proportion. People seem to be reading things into this that I didn't write and don't intend. I never said it was better to drop anchor and remain motionless as if in a coma, or hide on the bottom of the ocean. Please, if you want to criticise what I've written, at least read it a little more carefully.

Ughh, too much typing. I'll try to find the relevent page in O'Kane's book.