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PostPosted: Fri Apr 04, 2008 9:18 am 
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PostPosted: Fri Apr 04, 2008 9:20 am 
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This is an actual image from the Tabby Equipment -


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PostPosted: Fri Apr 04, 2008 9:21 am 
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PostPosted: Fri Apr 04, 2008 9:23 am 
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PostPosted: Sun Apr 13, 2008 8:01 am 
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British Comments on the USN "F" function Armour Piercing formula (1 of 4)

Here are extracts from Ordnance Board minutes from August (posts 1 to 3) and November (post 4) 1941.

As part of the UK/US technical exchanges (naval performed under the aupicies of the Bailey Committee) the UK/RN and US/USN compared many aspects, including ordnance. As part of this Professor R H Fowler visited, on behalf of the Ordnance Board, various experimental ordnace facilities (both service and universities) in 1941. This is an extract covering the revelation to the British of the USN's variation of the De Marre formula by using an "F" function to project performances.

The first post is second in the printed version, but is better first. It is part of the Professor's report covering the formula.

The second post is "first" in the printed version and is the Board's comment on this report.

The third post is from later in the same minutes and are the DNO's specific comments.

The fourth post is from the November minutes when it gives the USN's comments (from Chief of the Bureau of Ordnance) on the Board's previous minutes and the Board's comments on those.

You will see from the posts that the British were very skeptical about the USN formula believing that it could not be applied to other types of shell/armour without large amounts of testing, but also that the formula would not take properly into account the change of impact from head to shoulder of the AP cap and also that the shattering effect of armour was not fully modelled.

Obviously this has an effect on people's take on modern useage of the USN's formula to estimate shell/armour performance.

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Last edited by phil gollin on Sun Apr 13, 2008 8:08 am, edited 1 time in total.

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PostPosted: Sun Apr 13, 2008 8:02 am 
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British Comments on the USN "F" function Armour Piercing formula (2 of 4)


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PostPosted: Sun Apr 13, 2008 8:03 am 
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British Comments on the USN "F" function Armour Piercing formula (3 of 4)


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PostPosted: Sun Apr 13, 2008 8:04 am 
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British Comments on the USN "F" function Armour Piercing formula (4 of 4)


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 Post subject: Re: Odds and Sods
PostPosted: Sun Jun 01, 2008 6:27 am 
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A bit of an experiment, but this should show up as 2 pages giving the details of a ("the" ???) part of the discussions in 1933 about the desirable design of side armour/side protection system for a modern (for 1937) capital ship (at this stage for a 12-inch one, but this design process led to the KGVs) :-

Attachment:
Ships cover 528 folio 13 - 1 of 2.JPG


and

Attachment:
Ships cover 528 folio 13 - 2 of 2.JPG



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 Post subject: Re: Odds and Sods
PostPosted: Mon Jun 02, 2008 10:04 am 
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O.K. - let's try again (just got a previous reincarnation of this post "swallowed")

Well, now some extracts re. Nelson's and Warspite's proposed, but abortive, refits in the USA, late war.

Nelson was to have got Mark 37 directors and US close range and AA Armament.

Warspite was to get 4 Mark VI directors, an additional 4 twin 4-inch guns (making a total of 8 twins) an extra couple of quad pom-poms (one each on B and X turrets) and a pair of US quad bofors for the hangar roof.

So (first 3 of 7) :-

Attachment:
Nelson and warspite abortive refits 1 of 7.jpg


Attachment:
Nelson and warspite abortive refits 2 of 7.jpg


Attachment:
Nelson and warspite abortive refits 3 of 7.jpg


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 Post subject: Re: Odds and Sods
PostPosted: Mon Jun 02, 2008 10:07 am 
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extracts 4 to 6 of the abortive Warspite and Nelson refits :-

Attachment:
Nelson and warspite abortive refits 4 of 7.jpg


Attachment:
Nelson and warspite abortive refits 5 of 7.jpg


Attachment:
Nelson and warspite abortive refits 6 of 7.jpg


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 Post subject: Re: Odds and Sods
PostPosted: Mon Jun 02, 2008 10:08 am 
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Last extract re. Nelson's and Warspite's abortive US refits :-

Attachment:
Nelson and warspite abortive refits 7 of 7.jpg


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 Post subject: Re: Odds and Sods
PostPosted: Thu Feb 19, 2009 2:45 pm 
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An additional input re. the proposed Nelson and Warspite refits in the US ;

This information was posted by Rick E Davis on the Steel Navy Board ;

Without getting too involved, while I was going through the Weekly Updates to the Armament Summaries in 1944 I came across something that was interesting. Some time in 1943 or 1944 BuOrd changed the format of how changes to "installed" and "Ultimate/Temporary Authorized Armaments" were listed in the weeklies. Also, they started to include foreign Warships that were being refitted on in the USA. Included were French Cruisers, Destroyers, etc and South American Destroyers and various British warships. I came across a "PROPOSED" armament change for the Nelson coming to the USA for a refit. I didn't make a copy of the listed details, there were no drawings or sketches, but listed was the adding of eight twin 5-in/38-cal guns ... apparently replacing the 6-in and 4.7-in guns. One of the reasons I didn't write the particulars down (I was digging into destroyer details) was that I thought there would be a discussion in one of the British Battleship reference books with details, but I have not found any in the books I have. Obviously this never took place at her reft at Philadelphia Navy Yard September 1944 - January 1945.

I did read that a major modernization of Rodney was proposed in 1943 and plans drawn up in 1944. In the end the modernization didn't occur. Was there a relationship here for her sister? I'm curious if there was a serious effort with plans to rebuild this class and what they looked like.


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PostPosted: Thu Feb 19, 2009 2:48 pm 
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Post WW2 RN comments on machinery efficiencies

I have, at last, managed to obtain a copy of “Papers on Engineering Matters”, Number 22, dated December 1946 (from Evil-Bay).

These are relatively rare and are the forerunners of “Journal of Naval Engineering”.

The first article is “Marine Engineering from the Naval Aspect” and is an article based on a lecture given by Engineer-in-Chief of the Fleet at an inter-departmental discussion at the Admiralty on 18th June 1946. The journal was distributed at the “Restricted” level and there is a note to the effect “that several points of special interest have had to be omitted from this reproduction”.

He notes that the lecture is full of generalised information and that individual installations varied.

He covers, briefly, the history of machinery evolution and gives opinions on possible future directions.


Steam Power Plants

He goes on to be equally damning of British inter-war efforts at developing high pressure steam plants and praising of US successes. He notes that fuel consumption gains could be simplistically stated as “about 5% per 100 degrees F at 700-degrees F, falling to about 3% at 900-degrees F.” Steam pressure fuel efficiencies were harder to generalise as there are ideal pressures for different applications, but roughly “the gain is just over 1% per 100 lb. pressure rise in the zone 400 – 600 ib/sq. in.” He stated that “The direct saving in fuel due to the use of the higher steam conditions in American ships as compared with ours is therefore about 8 per cent.”

He criticised the German installation in the Narvik class destroyers with extreme congestion, increased complication with excessive engine-room personnel couple with doubtful reliability and worse fuel consumption than British destroyers.

He included a graph showing the Machinery weight curves for various classes of ship over time. The measures were “Machinery Weights in LBS/S.H.P.” versus years from 1900 to 1945. Roughly the figures are (taken at some arbitrary dates) ;

Battleships

1905 - 190
1920 - 110
1930 - 70
1940 - 55
1945 - 52


Cruisers

1905 - 115
1920 - 55
1930 - 43
1940 - 39
1945 - 38


Destroyers

1905 - 83
1920 - 33
1930 - 30
1940 - 29
1945 - 29


Boilers

He compared British natural circulation boilers favourably against German forced circulation ones. He did, however, like the USN system of controlled superheat which were being introduced in the Weapons Class. He noted various innovations in the French and US navies and said they were being watched with interest. He thought British automatic control of Feed Water was highly advanced and future automation likely.


Propulsion Turbines

Again, he reviewed the progress since WW1.

He provided another graph, this time for Steam Rate Curves for various classes plotting Steam Rate (LBS/S.H.P./HR) versus percentage full power (against a nominal 30 knot maximum speed).

For example in comparing the War Emergency class destroyers with US Destroyers fitted with cruising turbines ;

War Emergency

20% - 9.3
50% - 8.9
80% - 8.6
100% - 8.5

USN

20% - 7
50% - 6.5
80% - 6.5
100% - 6.6

(Both Vanguard and KGVs were slightly more efficient that the War Emergencies)


Staff Requirements

This included a small piece about comparing the KGVs with Washington. He noted that the KGVs were designed for maximum efficiency at full speed, but that Washington was designed for a maximum at 20 knots. He noted that not only was the Washington much more efficient at 20 knots, but it was still more efficient at maximum speed. He split the efficiency as follows “not more than a quarter of this gain was due to higher steam conditions, a third was due to the use of the economisers and controlled superheat and the remainder was sue to the turbines being designed for this [cruising] speed”


Auxiliary Machinery

Again, a brief history. He stated his belief that British Auxiliaries were generally ahead of German and USN ones and he hoped to stay ahead.


Reduction Gearing

A brief history. Not much comment other than to summarise the many lines of research being undertaken.

And a final graph. This time a “Full Power Efficiency Diagram”, plotting Efficiency % (Fuel to Shaft) against programme year. This is the most interesting graph as it gives a good overall summary so all relevant figures will be given ;

Years - Efficiency % - Steam conditions - Comment

1900-1905 - 13.2% - 220/260 psig, 400F - Coal reciprocating
1905-1908 - 11.0% - 220/260 psig, 400F - Direct Drive Turbines
1908-1910 - 10.0% - 220/260 psig, 400F - Oil Fired
1910-1924 - 12.8% - 220/260 psig, 400F - Geared Turbines
1924-1926 - 14.7% - 290 psig, 620F - Superheat
1926-1937 - 18.3% - 300 psig, 650F - Change of Steam conditions
1937-1943 - 17.8% - 300 psig, 650F - Two boilers, High Forcing Rate, Space Reduction
1943-1944 - 21.2% - 400 psig, 700F - Controlled Superheat Economisers
1944-1950 - 25.0% - 650 psig, 825F - Alloy Steel Rotors, Double Reduction Gearing


(It’s a shame there aren’t equivalent figures worked out on the same basis for US ships).


The article finishes with comments on the Internal Combustion Field – almost exclusively diesel (it praises RN submarine diesels, but admires large German engines and the large range of smaller US engines). It continues with Gas Turbine, HTP and a piece on Aircraft Carrier auxiliaries.

The conclusion again reiterates the lack of research and development between the war and lists on-going research.

=====================================


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 Post subject: Re: Odds and Sods
PostPosted: Thu Sep 24, 2009 9:26 am 
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As an end of year treat, I am attaching a photo (I hope) of the world’s first “stealth” naval vessel.

This is an LCA which was used for trials starting on 24th February 1943 to see whether the radar reflection of the vessel could be reduced. Strictly speaking it is not the first stealth vessel as a launch (“Springtime”) was used first, starting 29th December 1942.

The simple frame and mesh actually worked, reducing the launch’s radar return to approximately a quarter and the LCA’s to between a quarter and a tenth (both using a Type 273 set). However the actual range reduction of detection of the LCA was only 22% and this was deemed not worthwhile considering the seamanship problems of such a screen.

Further trials took place, including an LCA with overall mesh screens and also ones working in the L-Band.

In February 1944, HMS Wallflower, in trials, used a wire mesh screen around her funnel to reduce spurious returns from her Type 271Q. Two further ships were trialled with such mesh funnel screens, but the idea was abandoned for practical reasons. (Later one of the first major use of RAM was in the covering of the faces of masts facing the main radar antenna in ships such as the Leander class frigates – hence the “black” faces to some sides of the mast.)


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 Post subject: Re: Odds and Sods
PostPosted: Thu Dec 31, 2009 7:37 pm 
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[bump]

I carefully over-wrote an old post so that the new picture didn't come to the top, so here it is.

NOW, I can say, this is a New Year present (!)

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 Post subject: Re: Odds and Sods
PostPosted: Thu Dec 31, 2009 8:00 pm 
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looks like stealth was a lot cheaper back then. :cool_2:

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 Post subject: Re: Odds and Sods
PostPosted: Fri May 27, 2011 4:25 pm 
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.

“Decisive Range”

There have been various theories put forward for the RN's wanting to fight at their "decisive range" (which is simplistic).

The following paragraph which SEEMS to help in the understanding of what the Royal Navy thought about when looking at "decisive range" and the design for the 1937 Capital Ships comes from ADM 116/4041, and in particular from a Tactical Division memo (T.D. Memo No. 139) dated October 1935 entitled “Capital Ships – Tactical Considerations in Design.”

Part 1 - General Considerations, para. 8 reads ;

Decisive Range

8. On T.D. 151/35 it was suggested that in spite of the advance of air spotting and fire control, capital ships must still be designed as far as possible to fight at between 12,000 to 16,000 yards, as it may well be necessary to close to a range where direct spotting is possible in the smoke and confusion of battle, with, perhaps, air spotting and many of the refinements of fire control out of action. In these remarks, therefore, the term “decisive range” is used to indicate ranges from 12,000 to 16,000 yards, which are those given in the “Battle Instructions”.
"

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 Post subject: Re: Odds and Sods
PostPosted: Thu Jun 23, 2011 10:07 am 
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MORE THAN ANYONE CAN REASONABLY WANT ABOUT WW2 ROYAL NAVY CODES (sort of)


Actually this is a summary of a summary report which I think will contain lots of details about RN codes/cyphers and GERMAN attacks there on (It does not claim to cover Italian or Japanese efforts).

It was prepared in Late 1945 based upon German document and interrogations, so it may contain inaccuracies.

I found it fascinating, many will give up after a couple of pages.

.......................................

22 pages

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''

Page 1 :-

Attachment:
pp1.png


Page 2 :-

Attachment:
pp2.png


Page 3 :-

Attachment:
pp3.png


Page 4 :-

Attachment:
pp4.png


Page 5 :-

Attachment:
pp5.png


Page 6 :-

Attachment:
pp6.png


===========


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Last edited by phil gollin on Thu Jun 23, 2011 11:01 am, edited 1 time in total.

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 Post subject: Re: Odds and Sods
PostPosted: Thu Jun 23, 2011 11:00 am 
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Hopefully pages 7 to 12 ;

Page 7 :-

Attachment:
pp7.png


Page 8:-

Attachment:
pp8.png


Page 9 :-

Attachment:
pp9.png


Page 10 :-

Attachment:
pp10.png


Page 11 :-

Attachment:
pp11.png


Page 12 :-

Attachment:
pp12.png



==============================================================================

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