Torpedo speed setting question

[Rhodes]

Originally Posted by Pisces

See my latest reply. I might have mixed up the detonator pistol procedures with this topic.

Already saw.

[sharkbit]

I disagree with the statement that the torpedo speed cannot be set without pulling the torpedo out of the tube. Judging by the excerpt below, it appears that the speed could be changed.

Here is an excerpt from the British report on U-570 following its capture:

The Calculating Instrument


74. The calculating instrument is in the conning tower close to the attack periscope. It is considerably more elaborate than the British Submarine Torpedo Director and has a large number of dials but it does not give a clear picture of the relative position of own and enemy ships as does the British instrument.


75. The calculator performs the following functions:





A. Calculation of Director Angle


Settings


(i) Torpedo speed. Three positions 44, 40 or 30 knots set by hand.


(ii) Enemy speed. 0 to 40 knots set by hand.


(iii) Inclination. Set by hand in the first instance and then corrected automatically for change of bearing. This gear must be switched off when resetting inclination by hand.

76. The resultant director angle is shown on a dial on the face of the instrument.

I've always understood that there are rods inserted into the torpedo while in the tube that adjust the various settings and are retracted prior to firing. I believe this report makes mention of them if you read through it.

There are all kinds of technical tid bits in the report.

Here is the link for the whole report:
http://uboatarchive.net/U-570/U-570BritishReport.htm

[schlechter pfennig]

Originally Posted by sharkbit

I disagree with the statement that the torpedo speed cannot be set without pulling the torpedo out of the tube. Judging by the excerpt below, it appears that the speed could be changed.

Here is an excerpt from the British report on U-570 following its capture:


I've always understood that there are rods inserted into the torpedo while in the tube that adjust the various settings and are retracted prior to firing. I believe this report makes mention of them if you read through it.

There are all kinds of technical tid bits in the report.

Here is the link for the whole report:
http://uboatarchive.net/U-570/U-570BritishReport.htm

Great find! Thanks!

[Rhodes]

Originally Posted by sharkbit

I disagree with the statement that the torpedo speed cannot be set without pulling the torpedo out of the tube. Judging by the excerpt below, it appears that the speed could be changed.

Here is an excerpt from the British report on U-570 following its capture:


I've always understood that there are rods inserted into the torpedo while in the tube that adjust the various settings and are retracted prior to firing. I believe this report makes mention of them if you read through it.

There are all kinds of technical tid bits in the report.

Here is the link for the whole report:

Yes, as Pisces acknowledged, he confused the changing of the detonator (impact/magnetic) with the speed. The first had to be done outside the torpedo tube and directly at it, the speed could be changed via TDC, has I had posted and now you, with the report of the captured U-570.

[Pisces]

Originally Posted by sharkbit

I disagree with the statement that the torpedo speed cannot be set without pulling the torpedo out of the tube. Judging by the excerpt below, it appears that the speed could be changed.

Here is an excerpt from the British report on U-570 following its capture:


I've always understood that there are rods inserted into the torpedo while in the tube that adjust the various settings and are retracted prior to firing. I believe this report makes mention of them if you read through it.

There are all kinds of technical tid bits in the report.

Here is the link for the whole report:
http://uboatarchive.net/U-570/U-570BritishReport.htm

That describes the function of the TDC, the solution calculator located in the control room. It does not say anything about the mechanical parts of the torpedo tube. I'm sorry, it does not settle this argument. [EDIT: well not this particular part. Haven't read the entire document yet.]

If someone can find evidence that there indeed was some kind of hardware in the tubes that could change the torpedo speed from the outside then I'll concede my statement completely. There should be some kind of mechanical parts to transfer the gyroangle from the TDC. But a external way of setting torpedo speed is the confirmation that we need in this argument. (or torpedo documentation mentioning a input on the torpedo side that influences it's speed)

[Pisces]

Originally Posted by Rhodes

Yes, as Pisces acknowledged, he confused the changing of the detonator (impact/magnetic) with the speed. The first had to be done outside the torpedo tube and directly at it, the speed could be changed via TDC, has I had posted and now you, with the report of the captured U-570.

I said I may have confused them. I'm not totally convinced I was.

[Pisces]

Ok, that settles it, there was a fitting to transfer torpedo speed setting in the tube: Chapter III, bottom of page 16:

Tube Fittings
Rear Doors, Caps and Shutters
11. Rear doors, caps and bow shutters are generally similar to British design.
12. The stern cap opens upward, and carries a fixed shutter which conforms to the hull shape when the cap is closed.
13. All caps are worked by hand, two operating handles being provided for each bow cap - one in rear of the tube and one in the midship gangway.
14. Flooding and Draining. Normal arrangements are fitted for blowing up and draining down between tubes and torpedo tanks (W.R.T. tanks).
15. No T.O.T. or A.I.V. tanks are fitted.

External Adjustment Fittings
16. The following external adjustment gears are provided:
Gyro angling in 1° steps.
Speed - High, medium and low.
Depth - 0-12 metres in 0.5 m. steps.
17. The gyro angling gear can be set by hand either at the gear box in rear of the tubes, or at angling gear on each tube, or by electric power from the director angle calculator.
18. The gyro angling gear is normally engaged by hand after loading, and remains locked in this position until automatically removed by the operation of the firing lever.

[stork100]

See also this excellent article which further confirms all of the above:

http://www.ubootwaffe.pl/en/u-boats/...german-u-boats