The Ship Model Forum

by **phil gollin** » Tue Dec 18, 2007 7:35 am

Anonymous wrote:
The rigorous meaning of the phrase "I invented that" usually becomes shrouded in the fog of expediency when one spots an opportunity to utter it for the posterity.

???????????

.

by **Guest** » Tue Dec 18, 2007 3:21 am

phil gollin wrote:
Anonymous wrote:
........ Thomas Alva Edison, .......................

Oh dear, not perhaps the best example to raise on this thread.

Edison whilst a brilliant man is maybe the prime example of the problem of "forgetfulness" with regards to his false claim of the invention of the electric (incansecent filament) light bulb.

The rigorous meaning of the phrase "I invented that" usually becomes shrouded in the fog of expediency when one spots an opportunity to utter it for the posterity.

by **phil gollin** » Tue Dec 18, 2007 1:06 am

Anonymous wrote:
........ Thomas Alva Edison, .......................

Oh dear, not perhaps the best example to raise on this thread.

Edison whilst a brilliant man is maybe the prime example of the problem of "forgetfulness" with regards to his false claim of the invention of the electric (incansecent filament) light bulb.

by **phil gollin** » Mon Dec 17, 2007 5:36 pm

bengtsson wrote:Phil,
Thanks for all the information on the PRO. I will visit the website and get acquainted with their system. I know for years I have told myself to pay the PRO a visit. But being American, I knew little about it all. In any case, it gives me another excuse to visit London and stay a long time . Keep me jumping between the IWM photo section, the PRO and National maritime museum, I may have to stay a month!

I do see that to get a reader's ticket and the ability to search the catalog online, one must visit Kew in person to obtain the ticket. So a visit is a must. The Royal Navy Operational records are what I am after, so the PRO looks like the place I want to be at.

Depending on what you want to do at the NMM, you may have to book up ahead of times.

The Ships covers are held at Woolwhich Arsenal (also where the Royal Artillery Museum is). They only take one researcher per day so you need to book your day. They do NOT allow digital cameras and the ships covers are bound in such a way that photocopying is almost always impossible - so it is paper and pencil only. For their plans and photo service it is equally necessary to book.

by **bengtsson** » Mon Dec 17, 2007 2:22 pm

Phil,
Thanks for all the information on the PRO.

I will visit the website and get acquainted with their system. I know for years I have told myself to pay the PRO a visit. But being American, I knew little about it all. In any case, it gives me another excuse to visit London and stay a long time

. Keep me jumping between the IWM photo section, the PRO and National maritime museum, I may have to stay a month!

I do see that to get a reader's ticket and the ability to search the catalog online, one must visit Kew in person to obtain the ticket. So a visit is a must. The Royal Navy Operational records are what I am after, so the PRO looks like the place I want to be at.

by **Guest** » Mon Dec 17, 2007 8:25 am

The only book (of relative interest) that ABE produces is :
The Story of Thomas Alva Edison, Inventor The Wizard of Menlo Park, by either Margaret Davidson,or Mickey Compere.
Unfortunately there are several ISBN's listed as well as prices (ranging from 1us$ upwards)

Hope that is what was meant - at least the name Edison would be in the right direction, and Menlo Park is the Research Centre.

Terry

by **phil gollin** » Mon Dec 17, 2007 1:52 am

bengtsson wrote:
ar wrote: There are files waiting to be looked at in the PRO that tell the entire story.
The problem with the British, is that almost nobody will get off their fat lazy bums. Unlike the US archives, the UK stuff is laid out with indexes and available on demand..
Sounds like the PRO should be on my list of places to visit when I arrange another London trip. A few questions though: Where is it? How does one arrange a visit? Do they need to know before hand the subjects you are after or can one browse the index and then request materials at the time one is there?

I 'will' search out that book. The radar devlopments made possible by the Cavity magnetron are what we might call of the "War Winning" nature.
One of the biggest stories of the allied war effort

Bob B.

A book on the Tizard mission is :-

"Top Secret Exchange" by Zimmerman

This really only tells the partial story of the Tizard mission (including Cavity Magnetron and proximity fuze) not the fuller story of the exchange of information.

At least as far as naval information goes there are files I've looked at on the "Bailey Committee" which covered the long-term copying of military and war-related civilian information from the British to the US.

This included the appointment of US technicians, experts and serving officers to areas of research and serving units. Well known examples of this are the observers within the British radar (RDF) research establishments (including samples of all RDF sets being sent to the US together with a circuit diagrams and sample valves), copies of all information on de-gaussing, etc......

As well as techncal information, tactical and operational information was sent - and this included (just to keep AR happy) the names and addresses of the firms which produced the various deck coverings used by the Royal Navy (including Semtex and Corticene !)

I do not know if there was a "Land" and/or an "Air" equivalent to the Bailey committee, I presume there was (anyone any info ?)

--------------------

Now, as far as the PRO (or more correctly if uselessly TNA:PRO) their website is at :-

http://www.nationalarchives.gov.uk/default.htm

There are sections on how to visit etc. but basically allow most of a moring to get signed on, go on the introductory tour and then you can settle down to order documents.

One can use a PC and/or digital camera (but not a mobile scanner last I knew). There are photocopying facilities which one pays for.

IF you want to come try the "search the archives" pull down menu and then choose "the Catalogue"and then press "search the catalogue"

The search function is fast, but, as usual very literal.

The main naval files are in Department code "ADM"

It is best to just "play" a bit to see how sensitive things are.

Now, that's the good news. The "bad" news is that the files are many and varied and to get the full story needs lots of calling up of files.

The PRO has a decentish restaurant and is reasonably near to Kew Gardens (also the name of the nearest Tube station). So wives and/or girlfriends may be let to roam in one of the nicest botanical gardens in the world (come in mid-Spring when the daffodils are out) or high Summer. Some evenings are "late opening" and if you're trying to squash in research these may be better days to visit.

by **bengtsson** » Sun Dec 16, 2007 6:06 pm

ar wrote: There are files waiting to be looked at in the PRO that tell the entire story.
The problem with the British, is that almost nobody will get off their fat lazy bums. Unlike the US archives, the UK stuff is laid out with indexes and available on demand..

Sounds like the PRO should be on my list of places to visit when I arrange another London trip. A few questions though: Where is it? How does one arrange a visit? Do they need to know before hand the subjects you are after or can one browse the index and then request materials at the time one is there?

I 'will' search out that book. The radar devlopments made possible by the Cavity magnetron are what we might call of the "War Winning" nature.
One of the biggest stories of the allied war effort

Bob B.

by ar » Sun Dec 16, 2007 5:21 pm

Foeth wrote:Do you have an author with that book? Searching for Menlo Park at amazon gives 17350 hits

Regret I cannot remember. The book is really a biography, have forgotten who. Written by an American woman. Published about two years ago.
According to the book, that night the British laid out in detail the operational use of radar in the Battle of Britain, along with other things. A treasure trove of secrets, nothing was held back. There are little tit bits like how the journey was made from London to the US, how the train compartment was kept clear of other passengers, telephone calls etc. A description of the first time that one of the very first microwave sets using the British Cavity magnetron made by the Americans was placed on a aircraft, (a B18 I think) and tested aginst ships up and down Long Island Sound. Details that make the story come to life.
Try your local library, they will know. The book MAY, have been on the NY Times best seller list.

by **Foeth** » Sun Dec 16, 2007 4:31 pm

Do you have an author with that book? Searching for Menlo Park at amazon gives 17350 hits

by ar » Sun Dec 16, 2007 3:45 pm

bengtsson wrote:Back to the Didos and RN main armament AA fire. When did the Royal Navy get the VT fuse and how did it work out in practice? Did the VT go into all the major RN AA shells? 4in etc. etc. ??

Didn't the British bring over to the USA about the single most important development in radar history, the one thing that made allied radar superior. the Cavity Magnetron? The US was no better off than the axis nations till this little baby was handed over. Or so I understand.

Bob B.

I believe that the fuse was deleivered to the Fleet sometime in late 1944 bit cannot be certain.
There are files waiting to be looked at in the PRO that tell the entire story.
The problem with the British, is that almost nobody will get off their fat lazy bums. Unlike the US archives, the UK stuff is laid out with indexes and available on demand.

Read the book, Menlo Park, this gives in amazing detail the story of the transfer of the cavity magnetron and subsequent US development.
It recounts (in detail) when the thing was unveiled to the Americans in a Manhatten apartment in the summer of 1940 and the reaction that it drew. It was a revelation to them. THat night, the group of Americans while still in the apartment, began to plan out the future of the wartiome US radar programme.
Buy, borrow, or steal the book.

by **bengtsson** » Sun Dec 16, 2007 10:22 am

Back to the Didos and RN main armament AA fire. When did the Royal Navy get the VT fuse and how did it work out in practice? Did the VT go into all the major RN AA shells? 4in etc. etc. ??

Didn't the British bring over to the USA about the single most important development in radar history, the one thing that made allied radar superior. the Cavity Magnetron? The US was no better off than the axis nations till this little baby was handed over. Or so I understand.

Bob B.

by **phil gollin** » Sun Dec 16, 2007 4:39 am

Werner wrote:
phil gollin wrote:The British had a working proximity fuze for rockets in 1940 - this design was one of the secrets given to the US in the Tizard mission. It was this design that was patented for radio frequency proximity fuzes and formed the basis for US research.

The US tried to develop its own firing circuit design but failed and ended up using the British design.
I'm sure we would all like a reference supporting this.

Oh dear - yet again.

"The Deadly" Fuze" (previously recommended) will give you the details of the transfer of info and especially the problems regarding circuitry.

The Patent "problems" are held in the PRO files - the US scientists claiming the patent "forgot" about the British information until provcen wrong in 1952 and the US government accepted the British patent.

Lots of stuff got "forgotten" in those days.

by **Guest** » Sun Dec 16, 2007 3:35 am

RNfanDan wrote:
I wonder how a VT fuze would adapt to large-caliber shells; the Japanese fired main-battery barrages at US planes, purportedly with some success. Radar-directed main guns using VT-equipped HE shells would have been an interesting concept--provided, of course, the enemy had planes close enough to fire at!

So did the Germans. The Tirpitz had 15" AA shells. There would be no technical problem whatsoever with adapting it to a large caliber shell. The condition in the large caliber shell would actually be much more mild than in a 5"/38 gun. Look how much distance an 18"/45 shell covers to reach its muzzle velocity, and how much distance it takes a 5" shell to do the same. Clearly a 18" shell is experiencing a lot less Gs than a 5" shell. The problem is the Japanese and Germans didn't have one to adapt.

Also, the idea of a proximity fuse probably defeats the concept of Japanese San Shiki shell. The shell was intended to really be an barrage weapon that has a leathality cone of about 1000 yards long and 300-400 yards wide. The idea was to explode 1000 yards ahead of the enemy formation and take out an significant number of planes all at once. The cone of smoke trails from the sub munition also presents a psychological deterrent to the enemy flyers.

If you trigger an San Shiki shell with a proximity fuse, it would trigger too late, and most of the enemy flight would be to the sides of the cone rather than be inside it.

Incidentally, I am not aware of any automatic fuse setting arrangement in Japanese main caliber turrets for the San Shiki shell. Does anyone have any information on how the fuse on San Shiki shells are set?

by **Guest** » Sun Dec 16, 2007 2:15 am

Werner wrote:
RNfanDan wrote: the Japanese fired main-battery barrages at US planes, purportedly with some success.
The Japanese san-shiki main-caliber AA shells were a spectacular failure. Essentially they were a bundle of rubberized explosive rods and steel pellets, shot out of the barrel and which ignited after a fixed delay.

Quite a misleading description. Far from being giant shot gun shells or roman candles, they were actually cluster weapons that leaves the barrel as an intact shell and release their incendiary sub munition upon reaching the predetermined barrage zone. When they release the sub munition ignites and creates a very distinctive fan shaped pattern of smoke trails that continue down range. This burst pattern is clearly seen on a number of photos taken from US aircraft during the late 1944 campaign.

by **Werner** » Sat Dec 15, 2007 10:50 pm

RNfanDan wrote: the Japanese fired main-battery barrages at US planes, purportedly with some success.

The Japanese san-shiki main-caliber AA shells were a spectacular failure. Essentially they were a bundle of rubberized explosive rods and steel pellets, shot out of the barrel and which ignited after a fixed delay.

In action they were said to resemble Roman Candles, and had no effect other than to generate an extraordinary amount of radio chatter.

They were used by Musashi during her failed transit of the Sibuyan Sea, October 24, 1944, and by Yamato on the final sortie.

by **RNfanDan** » Sat Dec 15, 2007 10:14 pm

phil gollin wrote: But the article's emphasise on the problems of ruggedisation is very true.

Oddly enough, the solution to the battery problem was nothing more than a refinement of the German Hertz horn mine trigger--used in WW1!

I wonder how a VT fuze would adapt to large-caliber shells; the Japanese fired main-battery barrages at US planes, purportedly with some success. Radar-directed main guns using VT-equipped HE shells would have been an interesting concept--provided, of course, the enemy had planes close enough to fire at!

by **Werner** » Sat Dec 15, 2007 6:46 pm

phil gollin wrote:The British had a working proximity fuze for rockets in 1940 - this design was one of the secrets given to the US in the Tizard mission. It was this design that was patented for radio frequency proximity fuzes and formed the basis for US research.

The US tried to develop its own firing circuit design but failed and ended up using the British design.

I'm sure we would all like a reference supporting this.

by **phil gollin** » Sat Dec 15, 2007 6:13 pm

Timmy C wrote:
Link to the USN's article on VT fuses: http://www.history.navy.mil/faqs/faq96-1.htm

Very good, just a couple of errors.

The British had a working proximity fuze for rockets in 1940 - this design was one of the secrets given to the US in the Tizard mission. It was this design that was patented for radio frequency proximity fuzes and formed the basis for US research.

The US tried to develop its own firing circuit design but failed and ended up using the British design.

But the article's emphasise on the problems of ruggedisation is very true.

by **bengtsson** » Sat Dec 15, 2007 3:20 pm

Foeth wrote:
I don't know much about sonar amplification, but I guess that's some distance from home audio. Perhaps not. But if you need more power tubes might do a bit better.

Passive sonar doesn't need alot of power, as you are only listening and boosting a weak signal. That signal needs little boosting for the human ear.
Active sonar is where the Massive Power Amplifier Tubes came into play. Six cabinets lined up down in the equipment spaces. All containing one huge tube for each branch of the transmitter. Big, like bigger than a large man's forearm. Of course active sonar needs massive power for the pulse. Shorting tubes when the pulse hit was a major problem. Everything looked good till the pulse hit then you lost that one channel and had to cut out that whole bank of tubes till you found the bad one. Good luck!

Passive sonar made alot of use of filters to try and get at a frequency the target seemed to produce alot of. Without the background noise you could key in on alot of different sounds a particular ship might happen to be making at the time.

Bob B.

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