The Dreadnought Project Forum Index The Dreadnought Project
Naval History in the years 1890-1920
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   Reg1sterReg1ster 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Naval Fire control equipment
Goto page Previous  1, 2
 
Post new topic   Reply to topic    The Dreadnought Project Forum Index -> Simulation
View previous topic :: View next topic  
Author Message
maxyang



Joined: 31 Oct 2004
Posts: 100
Location: Shanghai, China

PostPosted: Sat Sep 23, 2006 4:20 am    Post subject: Reply with quote

Man! I did not notice this thread until now, what a shame. Excellent work!

8) I was wondering if I can have those models being fixed onto my Dreadnought or Queen Mary, such as on onto the platform between two funnels in the picture. http://141.212.133.101/Dreadnought/Picture/Partial%20Upper%20Deck.jpg
Back to top
View user's profile Send private message Visit poster's website MSN Messenger
RobB



Joined: 22 Aug 2005
Posts: 11
Location: Woking, United Kingdom

PostPosted: Sat Sep 23, 2006 5:06 pm    Post subject: Reply with quote

Just checking this series of posts, and I find that the images of the Argo Clock have disappeared!! Is this a plot by the Dreyer camp? (probably not, they must have just decayed in the image hosting service).

The Argo clock was, to my mind, the first of the modern fire control computers. I can clearly recognise many of the mechanisms that this computer uses that I used 70 years later in torpedo fire control equipment. In 1912, it was ahead of its day, but clearly not robust enough for naval military service. Nevertheless, it was a marvelous piece of engineering, and worthwhile remembering in any survey of naval Fire Control equipment.







One of the major problems for long range gunnery is that in order to predict the target's future position, you must be able to calculate the target's course, speed and range. Rangefinders will give range, and with sufficient cuts, a good estimate can be obtained by averaging the cuts. However, with a ship continually yawing, bearings taken relative to the ship's head will be inaccurate. Enter the vital component for long range gunnery - the Gyro Compass. The Argo range finder, being gyro stabilised, could transmit a series of stabilised bearings, but the initial designs were very limited in capability (they initially used a pair of torpedo gyros that were only stable for about 4 minutes, swapping between the two).

By 1910, however, the German company Anschutz, had developed a gyro compass that could be, and was adopted to stabilise fire control bearings. A number of the Argo rangefinders were fitted with an Anchutz gyro.



These two images show a cross section of the Anschutz gyro compass, and the components laid out for inspection. Essentially, the Anschutz gyro compass had a small gyro wheel, rotating at about 20,000 rpm, the gyro wheel and casing suspended from a float revolving freely in a dish of mercury. This provides a very low friction support to the gyro wheel.







The Anschutz gyro modeled above had a number of shortcomings, which were addressed in a revised design using three gyros attached to a frame, again with the weight of the gyro assembly supported in a pool of mercury. Unfortunately, I don't have enough detailed photographs or drawings to attempt to model this very successful design (it was still about in 1922 I believe). If anyone out there can let me have drawings or photos, I should be very grateful.

With the outbreak of war in 1914, the supply of Anschutz gyro compasses to the Royal Navy dried up. Fortunately, Elmer Sperry, in the US had developed a very effective gyro compass, that was purchased in large numbers, outfitting all battleships and large submarines (think about it, magnetic compasses are very ineffective inside a steel tube!).

This image shows a Sperry Mark I or Mark II, from about 1915.



Gyros may be very boring (they just sit there, ignoring everything going on around them), but are vital for the fire control system. This is just a taster, as I am working on a proper essay for Tone's Dreadnought web site, with maybe even with a little animation. Keep watching this space.

Rob
Back to top
View user's profile Send private message
Harley



Joined: 23 Oct 2005
Posts: 131
Location: Great Britain

PostPosted: Tue Sep 26, 2006 5:13 am    Post subject: Reply with quote

Thanks for re-posting the images along with your excellent description Rob. It's alot easier than trying to re-read In Defense of Naval Supremacy. I look forward to your essay.

Simon
Back to top
View user's profile Send private message AIM Address MSN Messenger
tone
Site Admin


Joined: 29 Oct 2004
Posts: 479
Location: Boston

PostPosted: Tue Sep 26, 2006 9:48 am    Post subject: Reply with quote

maxyang wrote:
Man! I did not notice this thread until now, what a shame. Excellent work!

8) I was wondering if I can have those models being fixed onto my Dreadnought or Queen Mary, such as on onto the platform between two funnels in the picture. http://141.212.133.101/Dreadnought/Picture/Partial%20Upper%20Deck.jpg


Max... the RF to use on that particular platform, IIRC, is an Barr and Stroud FQ 2. Did I not send you some images of that doo-dad?

tone
Back to top
View user's profile Send private message Send e-mail Visit poster's website AIM Address
tone
Site Admin


Joined: 29 Oct 2004
Posts: 479
Location: Boston

PostPosted: Wed Sep 27, 2006 9:49 am    Post subject: Reply with quote

I'm going to have to disagree with Rob that "many books" have been written on this subject. Too few have, and many others have been written with a total reliance on these few.

Until we hear from an author or two, I'll offer a very few corrections to Rob's description. Before doing that, however, it's worth pointing out that my video on the dumaresq's design and function (right-click and save before playing) is key to understanding how the Royal Navy liked to approach the fire control solution, geometrically.

Rob indicated that the director received range and bearing rates from the Dreyer table in the TS, but this is not really the case (although technically, by war's end, they were starting to send calculated bearings to the director, but that is beyond any reasonable scope here). The director (and guns) really received just a continuous series of ranges and deflections from the TS, and technically one could say firing signals were routed through and sometimes firing cues originated from the TS. But the big outputs were range and deflection.

That said, I'd like to refer you to a quicky placeholder article I set up around Rob's splendid Dreyer table model. It is part of the new Technology section I added, which melds the videos with the essays. It's a veritable fire control-apalooza over there.

tone
Back to top
View user's profile Send private message Send e-mail Visit poster's website AIM Address
Display posts from previous:   
Post new topic   Reply to topic    The Dreadnought Project Forum Index -> Simulation All times are GMT - 5 Hours
Goto page Previous  1, 2
Page 2 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group