Contacts speed determining via turn count historically correct?

raduz · 04-15-07, 05:54 AM

Did the american sonarmen get the speed of contact using some kind of RPM reference chart, counting the RPM? Or it was only an utopia that had no real use?

FinnN · 04-15-07, 07:02 AM

I have a reprint of the US recognition manual for Japanese naval vessels (according to the intro the original was carried on a USN sub), and it does have a table of RPMs and speeds for most ships. The catch is that although the table is there, it only lists speeds for a handful of the ships, and then only for one or two values. I guess the data simply wasn't available and the sub commander might have been expected to fill in the blanks. Possibly for merchant ships more info was available.

Have fun
Finn

MikeJW · 04-15-07, 11:14 AM

It was used IRL in WW2.

04-15-07, 05:54 AM	#1
raduz Engineer Join Date: Sep 2006 Location: Slovakia Posts: 205 Downloads: 3 Uploads: 0	Contacts speed determining via turn count historically correct? Did the american sonarmen get the speed of contact using some kind of RPM reference chart, counting the RPM? Or it was only an utopia that had no real use?

04-15-07, 07:02 AM	#2
FinnN Swabbie Join Date: Jul 2006 Location: London Posts: 14 Downloads: 10 Uploads: 0	I have a reprint of the US recognition manual for Japanese naval vessels (according to the intro the original was carried on a USN sub), and it does have a table of RPMs and speeds for most ships. The catch is that although the table is there, it only lists speeds for a handful of the ships, and then only for one or two values. I guess the data simply wasn't available and the sub commander might have been expected to fill in the blanks. Possibly for merchant ships more info was available. Have fun Finn

04-15-07, 11:14 AM	#3
MikeJW Helmsman Join Date: Mar 2005 Posts: 106 Downloads: 0 Uploads: 0	It was used IRL in WW2.