120 Degree Track?

[groomsie]

With a new job I've had more time for leisure reading. I'm currently reading "Wahoo" by Dick O'Kane (which by the way does not seem as well written as I recall "Clear The Bridge" being--he seems to skip some details which I'm sure he knows the backstory but the reader may not).

Anyway, one item that jumped out at me was several references by O'Kane to Morton preferring a track of 120 as it afforded the target the least chance of evading the torpedo. I've used the "Dick O'Kane" targeting method with great success; I've played around with the "Cromwell" method when I have time and inclination and can appreciate that it provides least time to avoid (ie: faster rate of closure between weapon and target).

Has anyone tried anything like what I'm referring to (weapon approach aft of the beam around 30 degrees)? It would obviously lessen the closure rate between weapon and target but I hadn't thought about (and have not worked through) the thought that the angle may make evasion more difficult. Morton obviously was a really aggressive and innovative skipper who enjoyed great success, so I have to feel he knew what he was talking about (although the differences in game play--like dragster-like targets--may negate what in real life may in fact have been valid).

Anyway, I don't recall ever seeing this approach ever mentioned and was curious if anyone has looked into this.

[Pisces]

Are you sure that 120 isn't supposed to mean the torpedo track makes a 60 degree angle with the bow, and 120 with the stern. Because that way the torpedo still comes somewhat head-on-ish and the closure rate is bigger than the other approach.

What might have been the reason for it's succes in real life is that the torpedo's bubbles might have been disguised by the target's wake/bow-waves.

[groomsie]

As I completed my reading I also see reference by O'Kane to the 90-degree track, so it seems both were used. Here is where I got the 120-degree reference (I saw it several times, but this was the first I found to lend context); from "Wahoo: The Patrols of America's Most Famous World War II Submarine" by RADM Richard H. O'Kane, East China and Yellow Seas Chapter 4 (page 202 in my edition):

At 0455 it was light enough to see through the scope, and finally two blasts took us down, pausing while a final radar range and periscope bearing fixed her position. Both Chan and Richie agreed on an enemy speed of 9 knots instead of 10. Captain Morton had readied two tubes forward and aft, and now ordered the forward doors opened; it would be a bow shot. Her port angle was opening as it should. I could hear Richie advise, "750 yards from the track," as I called 90 port.

The captain waited for an approximate 120 track, the aspect that would allow maximum enemy maneuvers and still insure that our torpedoes would hit, and then said, "Any time Dick. Fire just one torpedo."

So, I feel confident that this is a torpedo track of 120 degrees off the port side (or a 240 target angle). Clearly they waited after the 90-degree bearing to allow the target to move beyond that point to fire.

Now, I did see where Morton also used the 90-degree track and whatever else came up for opportunity, but the comment that this would allow maximum enemy maneuvers with best chance to get a hit caught my eye.

Discussion?

[groomsie]

Same book and chapter as cited before, this time page 210;

Our approach to the firing point moved swiftly, in part because the enemy ship was cruising at 11 knots, and because of our compensating speed. Again, the captain selected a 120 track. That meant Wahoo's torpedoes would strike from 30 degrees abaft her beam, and I made a mental note for the future to accept any broad track and hit before another zig...

So, that entry removes doubt of the torpedo track. My questions remain as:

1. Confirming in my mind that this would be the most difficult track to maneuver away from (could play into advance and transfer of a ship maneuvering in real life, which I'm not sure how well the game simulates), and
2. Would this track work as well in the simulation (I'm guessing not unless one of the acceleration corrections has been added via a mod).

Thoughts? If nothing else I'd think Rockin' Robbins would have some insight...

[Pisces]

Oh, ok then. If the master says he does it like that... But I'm not sure I agree with his reasons.

[Nisgeis]

Here is the fire control manual from the 1950s for fleet boats:

http://www.hnsa.org/doc/attack/index.htm

Thge optimum track angles are shown in plate XVII and plate XVIII. What calculations that graph is based on isn't shown. It appears from the graph though, that for a zero gyro angle shot, the maximum deflection angle you can get is the best.

That graph is a theorhetical example as it's for a zero gyro angle shot with a torpedo run length of 1,000 yards, so it's not something that you could manouver for. So, trying to read that graph as it is is quite hard.

If though you are shooting from behind, the speed of the torpedo will be reduced in relation to the target, which will mean that the target and torpedo have more chance to converge, as the torpedo will spend longer travelling across the target's course so the effective target length is larger. The opposite of the Cromwell method, where the target speed adds to the closing speed.

BUT! That graph is misleding, as you cannot directly compare a shot with a track of 45 degrees and a shot with 120 degrees, as you will need to be in completely different positions to get the same theorhetical 1000 yard run and zero gyro angle. Obviously you will need to be much closer if shooting from behind than if you are shooting from ahead to achieve a 1000 yard run length for both shots and the range difference in the two firing positions will increase the faster the target is.