Confusing passage in U-boat commander's handbook

[Platapus]

I would like someone smart to translate the following in to nice small words I can understand.

From the U-Boat Commander's Handbook section 105 e

In every submarine attack, whether by day or by night, the attempt must be made to obtain reliable data for aiming (controlling) the torpedo, by exhausting all possibilities with care and deliberation (measuring the deflection with the aid of the line (of the horizon), increase the size of the masts at a given height in the 1/16 scale, overhauling as to course and speed, by day and night, on the surface.

That is one hell of a sentence. I realize that this is an English translation from German, and hence there will be some awkwardness. But I am confused at some of the statements.

My questions are

1. What is meant by “ measuring the deflection with the aid of the line (of the horizon)”. Especially the line of the horizon portion.

2. What is ment by “increase the size of the masts at a given height in the 1/16 scale.”

[Hitman]

Ha ha good job , you found one of the translation errors I have noticed so far in the english version of the UKH

The fixed line this refers to, is NOT the horizon, but the fixed line or wire in the periscope, which you can use to measure speed exactly as the U-Jagd tools reflects. In the original german version there is no "(of the horizon)", as this is something that the translator added himself, probably to try to explain what he understood, but which is utterly WRONG. I was also puzzled with that until I could get the german version, and knew about the fixed wire speed measuing method

The scond paragraph is also wronly translated. First, it is NOT "masts at a given height", but masts OF KNOWN heigth.

Second, it is NOT a "1/16 scale", but a 1/10 scale, and it refers to the vertical scale in the periscope. Here's how it works:

The procedure is to be used mainly as close to 0º AOB as possible, i.e. when you have submerged forward of the target's course and it is coming at you (Not coincidentally, the main procedure the UKH suggests to approach an escorted convoy).

1.- Estimate the enemy mast heigth. Let's say it is 25 metres. Measure the mark of the scale it currently reaches. Let's say it is the "5" mark. Start the chronometer.

2.- Make frequent short observations until the mast covers double as many marks in the scope as in the first observation. In this case, when the mast reaches the "10" mark you are ready. Stop the chronometer and read the time it took for the mast to double its observed size. In our example it took let's say 1 minute.

Use the following formula:

((Mast in metres x 10) / Time in minutes ) x 0,03 = Enemy speed in knots.

Now, using that formula in our example:

((25 metres x 10) / 1 minute ) x 0,03 = 7,5 knots.

You must now apply as a correction your own U-Boat speed. If you were going towards the enemy at 2 knots, then substract that from the 7,5 knots. So, 5,5 is the true enemy speed.

[Platapus]

Oh you rock!

So this speed method works best when the ship is moving toward you where the other method (verticle line) works best when the ship is moving more perpendicular to you.

That is way cool. Never knew that formula and based on the poor translation I would never have figured it out.

Thanks

[mookiemookie]

Originally Posted by Hitman

Ha ha good job , you found one of the translation errors I have noticed so far in the english version of the UKH

The fixed line this refers to, is NOT the horizon, but the fixed line or wire in the periscope, which you can use to measure speed exactly as the U-Jagd tools reflects. In the original german version there is no "(of the horizon)", as this is something that the translator added himself, probably to try to explain what he understood, but which is utterly WRONG. I was also puzzled with that until I could get the german version, and knew about the fixed wire speed measuing method

The scond paragraph is also wronly translated. First, it is NOT "masts at a given height", but masts OF KNOWN heigth.

Second, it is NOT a "1/16 scale", but a 1/10 scale, and it refers to the vertical scale in the periscope. Here's how it works:

The procedure is to be used mainly as close to 0º AOB as possible, i.e. when you have submerged forward of the target's course and it is coming at you (Not coincidentally, the main procedure the UKH suggests to approach an escorted convoy).

1.- Estimate the enemy mast heigth. Let's say it is 25 metres. Measure the mark of the scale it currently reaches. Let's say it is the "5" mark. Start the chronometer.

2.- Make frequent short observations until the mast covers double as many marks in the scope as in the first observation. In this case, when the mast reaches the "10" mark you are ready. Stop the chronometer and read the time it took for the mast to double its observed size. In our example it took let's say 1 minute.

Use the following formula:

((Mast in metres x 10) / Time in minutes ) x 0,03 = Enemy speed in knots.

Now, using that formula in our example:

((25 metres x 10) / 1 minute ) x 0,03 = 7,5 knots.

You must now apply as a correction your own U-Boat speed. If you were going towards the enemy at 2 knots, then substract that from the 7,5 knots. So, 5,5 is the true enemy speed.

One hell of an answer. I defer to your greatness, Hitman.

This is why I love Subsim!

[Hitman]

Cheers guys, my pleasure! Being able to share everything I have learned so far, plus learn from what others know and I don't, is one of the things why you gotta love subsim

[Pisces]

Originally Posted by Hitman

Ha ha good job , you found one of the translation errors I have noticed so far in the english version of the UKH

The fixed line this refers to, is NOT the horizon, but the fixed line or wire in the periscope, which you can use to measure speed exactly as the U-Jagd tools reflects. In the original german version there is no "(of the horizon)", as this is something that the translator added himself, probably to try to explain what he understood, but which is utterly WRONG. I was also puzzled with that until I could get the german version, and knew about the fixed wire speed measuing method

Do you know if the german language version is also available in digital form somewhere? Or only as an original paper edition (most likely a collector's item).

[Hitman]

The guys in flottenbasis did the translation in their online magazine "Marine Kurier", but you need to browse older numbers to find all chapters.

I myself got it from a friend in PDF, scanned from a photocopy of an original one. It's even in old german lettering (Fraktur), so a bit difficult to read

[klh]

You can get a paper reprint for a reasonable price from

http://www.bunkermilitaria.com/Merch...&Category_Code=

[Pisces]

Originally Posted by Hitman

The guys in flottenbasis did the translation in their online magazine "Marine Kurier", but you need to browse older numbers to find all chapters.

I myself got it from a friend in PDF, scanned from a photocopy of an original one. It's even in old german lettering (Fraktur), so a bit difficult to read

The link you gave to the online magazine is the oldest edition I can find. I tried altering the month/year part of the link without succes. It could be those editions are in a different part of the website. Which month/year are you talking about?

Fraktur is certainly not an easy read. But maybe we are spoiled in these modern times. Does anyone know if that was a commonly used font in that time, or just to enhance the 'aryan' feel and work on people's germanic feelings? (i know the Kaleun's and officers were the targeted audience, not the German people in general)

[Hitman]

LOL well in fact fraktur was the classic german script, and IIRC it was the nazis who started changing that