SUBSIM Radio Room Forums - View Single Post - Tachy-tele wristwatch

Hitman · 01-23-09, 03:45 PM

Regarding the telemeter:

I think you made the calculation too complicated. The way to make it easier is to use the same units for both input and output, hence you should convert a ship's length to nautical miles (1802 metres).

A 180 metres ship is 0,10 NM

A 90 metres ship is 0,5 NM

A 45 metres ship is 0,25 NM

Following your example they would respectively be travelling at:

120x0,10=12 knots

120x0,5=6 knots

120x0,25=3 knots

But anyway yes, the U-Jagd chrono is still superior

Regarding the tachymeter:

Here is a US Civil War artillery chrono. The inner scale is adjusted to the speed of sound, and it was used to determine distance to enemy artillery by timing the difference between seen the flash and hearing the sound.

See if the scales match :hmm:

You ask for its use, and the answer is simple: Artillery

The U-Boats carried a deck gun, remember? Also they could be fired upon by enemies while unable to dive, or they could want to see the distance to a distant battle taking place over the horizon at twilight, etc. But also its use was for metereology, to measure the time between lightning and thunder and determine if a storm is closing or heading away.

Regarding the timed torpedo runs:

The importance of them was:

-To check wether estimations made by the Kaleun or IWO had been correct, overestimated or undersestimated

-To have an idea of when there would be a huge sound in the water that could eventually render enemy hydrophones useless for some minutes

-Similarly, to have an idea of when the enemy escorts would be alerted about the prescence on a submarine

-To listen carefully to the proper bearing for a possible dud or premature detonation (Something BdU emphasized a lot)

I think there will be some more, but right know I can't remember them :hmm:

01-23-09, 03:45 PM	#7
Hitman Pacific Aces Dev Team Join Date: Sep 2002 Location: Spain Posts: 6,109 Downloads: 109 Uploads: 2	Regarding the telemeter: I think you made the calculation too complicated. The way to make it easier is to use the same units for both input and output, hence you should convert a ship's length to nautical miles (1802 metres). A 180 metres ship is 0,10 NM A 90 metres ship is 0,5 NM A 45 metres ship is 0,25 NM Following your example they would respectively be travelling at: 120x0,10=12 knots 120x0,5=6 knots 120x0,25=3 knots But anyway yes, the U-Jagd chrono is still superior Regarding the tachymeter: Here is a US Civil War artillery chrono. The inner scale is adjusted to the speed of sound, and it was used to determine distance to enemy artillery by timing the difference between seen the flash and hearing the sound. See if the scales match :hmm: You ask for its use, and the answer is simple: Artillery The U-Boats carried a deck gun, remember? Also they could be fired upon by enemies while unable to dive, or they could want to see the distance to a distant battle taking place over the horizon at twilight, etc. But also its use was for metereology, to measure the time between lightning and thunder and determine if a storm is closing or heading away. Regarding the timed torpedo runs: The importance of them was: -To check wether estimations made by the Kaleun or IWO had been correct, overestimated or undersestimated -To have an idea of when there would be a huge sound in the water that could eventually render enemy hydrophones useless for some minutes -Similarly, to have an idea of when the enemy escorts would be alerted about the prescence on a submarine -To listen carefully to the proper bearing for a possible dud or premature detonation (Something BdU emphasized a lot) I think there will be some more, but right know I can't remember them :hmm: __________________ One day I will return to sea ...