British submarines' torpedo hits compared to German u-boats'

[marcelo_malara]

That doesn't make sense. What does make sense is that target angle = 80deg actually states that the target is moving rapidly away from the Uboat.

Forget the U202 KTB and the Rio Tercero sinking. Generically speaking, could you draw the geometry of an 80° angle on the bow and explain how in this situation the target is moving rapidly away from a firing sub,

[dunmunro]

That doesn't make sense. What does make sense is that target angle = 80deg actually states that the target is moving rapidly away from the Uboat.

Forget the U202 KTB and the Rio Tercero sinking. Generically speaking, could you draw the geometry of an 80° angle on the bow and explain how in this situation the target is moving rapidly away from a firing sub,

If target angle = 0 means the target is on a parallel course to the sub, than target angle = 80, means the target is moving almost directly away from the sub. If Target angle = 90 means that the target is on a parallel course with the sub, then target angle 80 means that the range is opening slowly as the target is moving slightly away from the target.

Target_geometry.jpg (19.96 KiB) Viewed 2723 times

[marcelo_malara]

If target angle = 0 means the target is on a parallel course to the sub, than target angle = 80, means the target is moving almost directly away from the sub. If Target angle = 90 means that the target is on a parallel course with the sub, then target angle 80 means that the range is opening slowly as the target is moving slightly away from the target.

Ok, now I understand. You are mistaken with the concept of target angle.

Angle on the bow (AOB for short)/inclination/target aspect angle = the angle of the course or mid line of the target with the line of sight, (not with the sub course).

That means that an AOB of 90° means that the target is viewed from its beam, 0° is viewed from its bow. An AOB of between 90 and 180° means that the target is viewed from its quarter. All this independently of the course taken by own ship.

In fact it is the combination of AOB and target bearing which determines the variation of distance. A target with an 80° AOB viewed from a relative bearing of 40° red will be coming closer, while the same AOB viewed from a relative bearing of 180° means that it will be getting away.

[dunmunro]

The USN's Arma Mk3 TDC was an excellent WW2 torpedo fire control system. Many argue that a valid argument can be made that it was the finest such device of the war.

The Mark XIV torpedo, not so much. Multiple design flaws plagued it until 1943 - bad depth sensor design, badly designed contact fuze, bad magnetic influence detonator, terrible bureaucratic infighting.

Byron

If you can get the book:

https://www.amazon.com/Fleet-Submarine- ... 0974304530

Without doubt it was a complex and fine piece of equipment, having even the capability of blind firing basing the target info on sonar alone (don´t know how many times this was actually used).

You can read it here for free:

https://www.hnsa.org/manuals-documents/ ... e-control/

[Byron Angel]

UNITED STATES SUBMARINE OPERATIONS IN WORLD WAR II, Theodore Roscoe, page 54
"Throughout the war the percentage of hits was more or less constant for track angles between 60deg and 120deg and ranges between 1,000 and 3,000 yards. Within the region the scored hits averaged 36%. The percentage of hits was independent of the gyro angle for values of the gyro angle between zero and 40deg."

The USN's Arma Mk3 TDC was an excellent WW2 torpedo fire control system. Many argue that a valid argument can be made that it was the finest such device of the war.

The Mark XIV torpedo, not so much. Multiple design flaws plagued it until 1943 - bad depth sensor design, badly designed contact fuze, bad magnetic influence detonator, terrible bureaucratic infighting.

Byron

I'm certain that the RN thought the TDC was excellent as well, but the fact remains that if USN subs had been equipped with RN torpedoes and the RN STD, that their torpedo hit rate would have been much higher than it was, for at least the first two years of the USN's entry into the Pacific war.

>>>>> Dunno about torpedo HIT rates. AIUI, the aggregate hit rate for torpedoes fired by British submarines in WW2 (certain + probable hits versus total submarine torpedoes fired over the course of the war) was 22.2 pct. FWIW.

B