Entfernungsunterschied/ Seitenvorhalt Anzieger

Jesus · Post by **Jesus** » Wed Mar 28, 2007 11:08 am

This is a device I don´t know how it works.
Could anybody explain ?

Thank You

mike1880 · Post by **mike1880** » Wed Mar 28, 2007 12:46 pm

Try looking at the information on the Dumaresq on the Dreadnought Project website:

http://www.dreadnoughtproject.org/

The two instruments basically do the same thing - calculation of the rate of change of range and bearing.

Mike

Ulrich Rudofsky · Post by **Ulrich Rudofsky** » Wed Mar 28, 2007 1:06 pm

I don't know how this instrument works, but it is like the circular artillery sliderule: An indicator (Anzeiger) of target distance change (Entfernungsunterschied) and lead (azimuth) angle (Seitenvorhalt)
http://www.navweaps.com/Weapons/Gun_Data_p3.htm

Terje Langoy · Post by **Terje Langoy** » Wed Mar 28, 2007 3:04 pm

Is it simply a manual device to read distance? Green and red perhaps mark lantern light (ship sides) with your own ship's bearing in center, the arrow and big ruler shows the bearing between yourself and contact (Hypothenuse) whereas the small ruler provide the third, unknown side = distance? A navigation device based on phytagoras theorem?

Ulrich Rudofsky · Post by **Ulrich Rudofsky** » Wed Mar 28, 2007 3:56 pm

It is a trig vector problem. Here is all you ever wanted to know about lead angle. http://www.eugeneleeslover.com/USNAVY/CHAPTER-17-C.html

Jesus · Post by **Jesus** » Wed Mar 28, 2007 4:01 pm

Thank you to everybody for your help.
I think it´s a great help for me.
If you find more information about the instrument or about the maker, please tell me.

Ulrich Rudofsky · Post by **Ulrich Rudofsky** » Wed Mar 28, 2007 5:01 pm

Jesus: here are some photos you may recognize

http://www.u-historia.com/uhistoria/for ... 0262138c67

Fahrt sm/Std. = speed knots/hour
Wind m/Sek. = Wind speed meters/second

Terje Langoy · Post by **Terje Langoy** » Wed Mar 28, 2007 5:04 pm

Thanks for the link, Ulrich...

I've been looking at the work of Gene Slovers before but it's very technical and a lot to digest for me. I'm still just a rookie.

Sometime I will hopefully understand these things as well.

Very best regards

Karl Heidenreich · Post by **Karl Heidenreich** » Wed Mar 28, 2007 11:19 pm

Hey:

Did the Dreyer Table look like that or was it a more complex instrument?

Kind regards.

Ulrich Rudofsky · Post by **Ulrich Rudofsky** » Wed Mar 28, 2007 11:25 pm

See HMS HOOD site: http://www.hmshood.com/ship/fire_control.htm

Karl Heidenreich · Post by **Karl Heidenreich** » Wed Mar 28, 2007 11:30 pm

Hi Ulrich!

Thanks for the link.

The photos there are for the Dumaresq. Interesting that the Mark V Dreyer was only used by the Hood.
I have always wonder if these was one of the cuases for Hood´s bad aiming during DS.

Kind regards.

Ulrich Rudofsky · Post by **Ulrich Rudofsky** » Wed Mar 28, 2007 11:37 pm

Karl: Can you enlarge the pictures by clicking on them? My computer refuses to do it or is it not working.

Karl Heidenreich · Post by **Karl Heidenreich** » Wed Mar 28, 2007 11:58 pm

Ulrich:

I can´t enlarge them neither. But I believe that´s not an option with them because the instrument for that is not shown.

Best regards.

RF · Post by RF » Thu Mar 29, 2007 10:46 am

Karl Heidenreich wrote:I have always wonder if these was one of the cuases for Hood´s bad aiming during DS.

Kind regards.

I thought the problem with Hood was that it was targetting the wrong ship, not that its gunnery was poor (prior to the DCT being knocked out).

Karl Heidenreich · Post by **Karl Heidenreich** » Thu Mar 29, 2007 3:59 pm

RF:

I thought the problem with Hood was that it was targetting the wrong ship, not that its gunnery was poor (prior to the DCT being knocked out).

Then, why Hood didn´t hit Prinz Eugen? And don´t tell me that it was because she was a smaller target.