Tachy-tele wristwatch

joegrundman · 01-22-09, 07:45 PM

Hi Guys

i found this thing - in fact i think Hanhart still make them more or less identically, but i seems to be the KM wristwatch for Kaleuns and officers

http://www.historypreservation.com/h...ates/uboot.php

the resolution isn't quite good enough for me to read everything clearly, and it claims to differ from the Fliegerchrono by the same company, although i can't tell the difference from this better resolution image of thisFligerchrono :

anyway i'm thinking of implementing it as an alternative stoppuhr

I have a couple of questions:

does anyone know what the red blob does at the top? is this a rotatable bug?

how does one use the telemeter and tachymeter scale?

thanks in advance

joe

MauserKar98k · 01-22-09, 10:35 PM

I think Hanhart watches look awsome, especially the Luftwaffe version:
http://www.historypreservation.com/h...es/Hanhart.php
It's too bad that they are so expensive. I don't have a grand to drop on a watch.

joegrundman · 01-22-09, 11:39 PM

thanks for that, it looks like the large picture i posted is in fact the U-boat commander version, not the flieger version, despite the label.

in the link you provided the flieger version clearly does not include Telemeter and tachymeter markings in red

so..now..who can explain to me how to use the telemeter and tachymeter scales

i already answered my other question which is that the red mark at the top is a rotating bug, which presumably is used in conjunction with the telemeter

joegrundman · 01-22-09, 11:53 PM

I found that one way to use the telemeter scale is for ranging between the sight of something happening and the sound of it.

so for example you see a torpedo explode and start the timer, then hear it through the air and stop the timer. If it says 6 seconds it's 2km distant.

this is an explanation that i found on the internets, but i can't believe this is what the KM used it for, since (a) the scale is much larger and it was rare that torps ran for more than 3 kilometers, so the entire scale beyond 10 secs would have been unused, and (b) the speed of sound underwater is much faster than through the air.

The markings are in red incidentally to be more effective with battlestations "redlight"

Hitman · 01-23-09, 08:29 AM

Ah yes the famous Hanhart watch

I readed some time ago that the scale was meant for timing the torpedo impacts, hence it would act as the current fake red needle displayed in the chrono when a torpedo is shot, showing -according to the set speed- the estimated time of impact.

Here is an interesting link about the use of tachymeters:

http://en.wikipedia.org/wiki/Tacheometer

Given the divisions shown in the external scale (1-20), my bet is that it is probably to allow the commander calculating the speed of his own U-boat, an enemy ships or similar which travels between two marked positions.

The spiral shaped interior scale is clearly meant for longer timings, so probably for the aforementioned torpedo runs.

joegrundman · 01-23-09, 09:15 AM

Thanks Hitman

The human U-boat encyclopedia comes to the rescue again!

so by following that link, i've concluded that the telemeter scale and the tachymeter scale are two different things -i'll study the telemeter later

as for the tachymeter, let's suppose we want to use it like we use the U-jagd chrono.

Let's say we have a target of 150m - to get it's speed with the fixed wire method and the UJ chrono couldn't be easier.

With the tachymeter, let's say it takes 30 seconds. On the tachymeter scale it gives a value of 120 (the rings further in are for timings of more than 1 and 2 mins respectively, so is quite useful in that regard)

The value of 120 means the speed in hours is 120 units of the measured length

the measured length was 150 m, so the speed per hour was

120 x 150m = 18000m/hour
=18km/hour
which is about 10 knots

i had a calculator to help me, even for easy one's like this.

Conclusion: it is definitely not as convenient as the UJ chrono, even if it is more versatile

from what i can see: the telemeter really is used for assessing range based on the time elapsed between a visual cue and hearing it though the air - i cannot really imagine what U-boats used it for

One question: when is it so important to have accurately timed torpedo runs anyway?

01-22-09, 07:45 PM	#1
joegrundman Ocean Warrior Join Date: May 2007 Posts: 2,689 Downloads: 34 Uploads: 0	Tachy-tele wristwatch Hi Guys i found this thing - in fact i think Hanhart still make them more or less identically, but i seems to be the KM wristwatch for Kaleuns and officers http://www.historypreservation.com/h...ates/uboot.php the resolution isn't quite good enough for me to read everything clearly, and it claims to differ from the Fliegerchrono by the same company, although i can't tell the difference from this better resolution image of thisFligerchrono : anyway i'm thinking of implementing it as an alternative stoppuhr I have a couple of questions: does anyone know what the red blob does at the top? is this a rotatable bug? how does one use the telemeter and tachymeter scale? thanks in advance joe __________________ "Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill

01-22-09, 10:35 PM	#2
MauserKar98k Watch Join Date: Jan 2009 Location: Between Milwaukee and Chicago Posts: 19 Downloads: 1 Uploads: 0	I think Hanhart watches look awsome, especially the Luftwaffe version: http://www.historypreservation.com/h...es/Hanhart.php It's too bad that they are so expensive. I don't have a grand to drop on a watch. __________________ GWX 3.0 U-1 May 1940 9 Patrols (80 days) 9 ships (8/1) for 32,725 tons Currently at Sea

01-22-09, 11:39 PM	#3
joegrundman Ocean Warrior Join Date: May 2007 Posts: 2,689 Downloads: 34 Uploads: 0	thanks for that, it looks like the large picture i posted is in fact the U-boat commander version, not the flieger version, despite the label. in the link you provided the flieger version clearly does not include Telemeter and tachymeter markings in red so..now..who can explain to me how to use the telemeter and tachymeter scales i already answered my other question which is that the red mark at the top is a rotating bug, which presumably is used in conjunction with the telemeter __________________ "Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill

01-22-09, 11:53 PM	#4
joegrundman Ocean Warrior Join Date: May 2007 Posts: 2,689 Downloads: 34 Uploads: 0	I found that one way to use the telemeter scale is for ranging between the sight of something happening and the sound of it. so for example you see a torpedo explode and start the timer, then hear it through the air and stop the timer. If it says 6 seconds it's 2km distant. this is an explanation that i found on the internets, but i can't believe this is what the KM used it for, since (a) the scale is much larger and it was rare that torps ran for more than 3 kilometers, so the entire scale beyond 10 secs would have been unused, and (b) the speed of sound underwater is much faster than through the air. The markings are in red incidentally to be more effective with battlestations "redlight" __________________ "Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill

01-23-09, 08:29 AM	#5
Hitman Pacific Aces Dev Team Join Date: Sep 2002 Location: Spain Posts: 6,109 Downloads: 109 Uploads: 2	Ah yes the famous Hanhart watch I readed some time ago that the scale was meant for timing the torpedo impacts, hence it would act as the current fake red needle displayed in the chrono when a torpedo is shot, showing -according to the set speed- the estimated time of impact. Here is an interesting link about the use of tachymeters: http://en.wikipedia.org/wiki/Tacheometer Given the divisions shown in the external scale (1-20), my bet is that it is probably to allow the commander calculating the speed of his own U-boat, an enemy ships or similar which travels between two marked positions. The spiral shaped interior scale is clearly meant for longer timings, so probably for the aforementioned torpedo runs. __________________ One day I will return to sea ...

01-23-09, 09:15 AM	#6
joegrundman Ocean Warrior Join Date: May 2007 Posts: 2,689 Downloads: 34 Uploads: 0	Thanks Hitman The human U-boat encyclopedia comes to the rescue again! so by following that link, i've concluded that the telemeter scale and the tachymeter scale are two different things -i'll study the telemeter later as for the tachymeter, let's suppose we want to use it like we use the U-jagd chrono. Let's say we have a target of 150m - to get it's speed with the fixed wire method and the UJ chrono couldn't be easier. With the tachymeter, let's say it takes 30 seconds. On the tachymeter scale it gives a value of 120 (the rings further in are for timings of more than 1 and 2 mins respectively, so is quite useful in that regard) The value of 120 means the speed in hours is 120 units of the measured length the measured length was 150 m, so the speed per hour was 120 x 150m = 18000m/hour =18km/hour which is about 10 knots i had a calculator to help me, even for easy one's like this. Conclusion: it is definitely not as convenient as the UJ chrono, even if it is more versatile from what i can see: the telemeter really is used for assessing range based on the time elapsed between a visual cue and hearing it though the air - i cannot really imagine what U-boats used it for One question: when is it so important to have accurately timed torpedo runs anyway? __________________ "Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill Last edited by joegrundman; 01-23-09 at 09:25 AM.