British BL 18in/40 gun

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Kyler
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British BL 18in/40 gun

Post by Kyler » Wed Sep 30, 2009 9:16 pm

This is the largest naval gun ever made and used in combat by the Royal Navy.

Only 3 guns were ever produced. 2 were originally built for HMS Furious (light battlecruiser). During completion only the after turret was installed with the forward section being used to launch aircraft. After trials it was determined the ship could not cope with the recoil of the gun. Furious was later completed into a regular aircraft carrier. One gun was later used for testing while the other two were installed on WW1 monitors HMS General Woolfe & HMS Lord Clive. The monitors were later used in 1918 to bombard German positions in Belgium. 2 guns were later scrapped in 1933 and the final in 1947.

Entered service - 1917
Bore - 18 inches (457 mm)
Length - 40 calibres (18.28 m)
Rate of fire - 1 round per minute maximum [1]
Shell weight - 3,320 lb (1,506 kg)
Propellant weight - 630 lb (285.8 kg)
Range - up to 40,500 yards at 45 degrees. General Wolfe fired in action at a range of 33km, the greatest range at which a Royal Navy vessel has engaged an enemy with gunfire.
Muzzle Velocity - Standard Charge: 2,270 ft/s (683 m/s), Super Charge: 2,420 ft/s (738 m/s)
Mountings
Single turret 15" B (840 Metric tonnes, 30 degree elevation)- used on HMS Furious
Single non rotating mounting (390 metric tonnes, 45 degree elevation) - used on monitors

Source: Wikipedia.

If anyone else has additional information please post it. There is not a lot information about this gun on the web.

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"It was a perfect attack, Right Height, Right Range, Right cloud cover, Right speed,
Wrong f@%king ship!" Commander Stewart-Moore (HMS Ark Royal)

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Re: British BL 18in/40 gun

Post by marcelo_malara » Wed Sep 30, 2009 11:54 pm

Did you see navweaps.com?

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Re: British BL 18in/40 gun

Post by Kyler » Fri Oct 02, 2009 4:14 am

Unfortunately our IT director at work doesn't like the fact that I read articles about guns at work when things are slow.

So the site was blocked when I wrote the article at work.
"It was a perfect attack, Right Height, Right Range, Right cloud cover, Right speed,
Wrong f@%king ship!" Commander Stewart-Moore (HMS Ark Royal)

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Re: British BL 18in/40 gun

Post by RF » Fri Oct 02, 2009 7:54 am

I don't know about other people but I find it rather bizarre looking at a turret with only one gun.......
''Give me a Ping and one Ping only'' - Sean Connery.

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Re: British BL 18in/40 gun

Post by Karl Heidenreich » Fri Oct 02, 2009 4:45 pm

No interference problems...
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Re: British BL 18in/40 gun

Post by marcelo_malara » Fri Oct 02, 2009 5:07 pm

No trouble deciding to fire one or two guns salvo....

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Re: British BL 18in/40 gun

Post by Karl Heidenreich » Fri Oct 02, 2009 5:33 pm

Which is a problem, you know. The ideal salvo in order to generate a "ladder" to close up requires two guns per turret and, also ideal, four turrets. That´s why Hood or Bismarck turret arragement were optimum over the triple turrets.
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Re: British BL 18in/40 gun

Post by lwd » Fri Oct 02, 2009 7:03 pm

Karl Heidenreich wrote:.... The ideal salvo in order to generate a "ladder" to close up requires two guns per turret and, also ideal, four turrets. ....
How was this determined? Note that it also is dependent on firing "ladders".

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Re: British BL 18in/40 gun

Post by Bgile » Fri Oct 02, 2009 9:57 pm

Karl Heidenreich wrote:Which is a problem, you know. The ideal salvo in order to generate a "ladder" to close up requires two guns per turret and, also ideal, four turrets. That´s why Hood or Bismarck turret arragement were optimum over the triple turrets.
Yes, it's much better to have 8 guns rather than 9 or 12. :?

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Re: British BL 18in/40 gun

Post by Karl Heidenreich » Fri Oct 02, 2009 11:27 pm

Bgile:
Yes, it's much better to have 8 guns rather than 9 or 12.
When you guys want to play dumb it´s really sad. The turret arragement ideal came from twin gun turrets. Royal Navy experts and designers knew that since WWI. The issue is to have the twin turret arragement and, ergo, having a maximun of 4 turrets then the arragement is 8 guns. There are other arragements that could give a more heavy broadside or ar required in order to reduce the displacement of the ship by having less turrets, three instead of four.

That´s what I was meaning without any atempt to draw flak here.
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Re: British BL 18in/40 gun

Post by Bgile » Fri Oct 02, 2009 11:55 pm

Karl Heidenreich wrote: When you guys want to play dumb it´s really sad. The turret arragement ideal came from twin gun turrets. Royal Navy experts and designers knew that since WWI. The issue is to have the twin turret arragement and, ergo, having a maximun of 4 turrets then the arragement is 8 guns. There are other arragements that could give a more heavy broadside or ar required in order to reduce the displacement of the ship by having less turrets, three instead of four.

That´s what I was meaning without any atempt to draw flak here.
Yes, of course I knew that and I apologize. You rankled me with the "generic" statement that four twin turrets are "better" than any other arrangement.

I also disagree with your salvo assumption, though.

Please explain to me why a ladder containing two (or three) salvoes of four guns each is better than a ladder of three salvoes of three guns each. Or a ladder containing four salvoes of three guns each. The difference is between three and four spashes per salvo, and three is usually sufficient to detect one shell which is a "flier" for whatever reason, usually error in drill. Of course with both elevation and traverse automatic server control such errors are much less likely.

Then you can explain why I need a ladder at all when I can achieve a straddle on the very first nine gun salvo (and a chance for hits) using radar range and visual bearing directed FC.

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Re: British BL 18in/40 gun

Post by lwd » Fri Oct 02, 2009 11:58 pm

Karl Heidenreich wrote: .... The turret arragement ideal came from twin gun turrets. Royal Navy experts and designers knew that since WWI. The issue is to have the twin turret arragement and, ergo, having a maximun of 4 turrets then the arragement is 8 guns. ....
It's sounding to me like you are saying twin guns are best because twin guns are best. Obviously I'm missing something.

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Re: British BL 18in/40 gun

Post by Karl Heidenreich » Sat Oct 03, 2009 12:40 am

Please give a try and read R&R on British Battleships where that subject is clearly explained. I don´t have now the book with me but it found there. Also in the Bismarck and her Contemporaries thread that same issue is regarded.

It amazes me the way both of you, Lwd and Bgile, like to shoot anything that does not came from your side, really. Not a single comment can escape the scrutiny of your Inquisition mode. On the other hand, which is funny, both of you rejoice at the magnificence of the USN BB design (or that of the Sherman tank) with the ease of not having to justify or back up any one of your affirmations.

Having said this I will not address any "bait" or "joyfull treat" from you guys in this thread. I just made a comment with Marcelo Malara in which it was not expected your understandable McArthist questioning.

Good night, I´m off for the day.
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Re: British BL 18in/40 gun

Post by Bgile » Sat Oct 03, 2009 1:16 am

Karl Heidenreich wrote:Please give a try and read R&R on British Battleships where that subject is clearly explained. I don´t have now the book with me but it found there. Also in the Bismarck and her Contemporaries thread that same issue is regarded.

It amazes me the way both of you, Lwd and Bgile, like to shoot anything that does not came from your side, really. Not a single comment can escape the scrutiny of your Inquisition mode. On the other hand, which is funny, both of you rejoice at the magnificence of the USN BB design (or that of the Sherman tank) with the ease of not having to justify or back up any one of your affirmations.

Having said this I will not address any "bait" or "joyfull treat" from you guys in this thread. I just made a comment with Marcelo Malara in which it was not expected your understandable McArthist questioning.

Good night, I´m off for the day.
Have a good evening.

Karl, the nature of debate between people with different views is such that when someone says something I don't agree with, I feel I need to challenge it. You often do the same.

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Re: British BL 18in/40 gun

Post by tommy303 » Sat Oct 03, 2009 6:37 pm

If I might be permitted to interject a comment or two on ranging practices, of the various turret arrangements, there really was no ideal per se; mostly it came down to preferences on the part of the naval ordnance boards in question. There is little doubt that the Germans preferred twin turrets even though they produced a number of successful triples; aside from French and british excursions into quads, most everyone else adopted triples as standard. Even single gun turrets are viable, if one has a ship large enough to mount a useful number of them, as numerous destroyer classes showed. The Germans simply felt that four twin turrets offered better flexibility when engaging more than one target and allowed equal coverage fore and aft.

As to ranging practices, one gun ranging shots were not preferred as it gave too little data, might be hard to spot, and one would not know for certain if a single shot was over short or wide of the target due to a drill error of some sort, or due to poor range, course and speed data. Two shells were better, though there was always a chance the shells might fall in a line and be difficult to distinguish. Three was felt to be the minimum required for a good estimate of MPI. Thus, the Germans tended to fire turret salvos in the ships with triples and turret groups in ships with twins.

The use of ladders in ranging, obviously dated back to days when one had only optical means to determine range; and while radar shifted emphasis from optical to electronic means, ladder salvos were never completely dispensed with for various reasons. Early war sets like the USN Mark 3 was good for about 28,000 yards against battleships, so if one is firing in excess of that range, then one had perforce to fall back on ranging ladders. Even when you were getting radar range data, ladders were often necessary to correct for errors in initial enemy course and speed estimates so as to fine tune the targeting data being provided by the range keepers. Among the important, but often forgotten aspects of gunnery was barrel wear, and the actual ballistics of the guns might not be in agreement with the ballistic elements of the fire control system.

This was due to barrel wear which occurs every time a gun is fired. In the most up to date systems employed by most navies in WW2, barrel wear was accounted for by incorporating data provided by the gun makers into the ballistic computers. This could be done by applying a correction from computed range tables or by the actual cams and gears of the ballistic computer. In either case, the corrections were only approximate as barrel wear might be more or less than computed--ie the difference between computed gun range and actual gun range. It was normal, after a ship had fired her guns over a period of time, to periodically check barrel wear by using a star gauge to phyiscally measure the amount of wear in each barrel. This was normally a dockside task performed during periods of overhaul, as it was first necessary to chemically treat the barrel liners and lap them to remove copper deposits which cause bore choke and to remove high points in the liner resulting from uneven stretching of the liner during firing. The results could then be tabulated for each gun and averaged for the entire battery and new range tables computed (or new gearing and cams produced).

Another reason to utilize or at least practice ranging ladders was because Murphy's Law was and still is in effect. Early war radars were very susceptible to the shock of gunfire and naturally battle damage might be incurred as well, so that one never quite knew how long one's gunnery radar was going to be available.

That said, radar assisted gunnery should be able to produce very quick target acquisition. Following the usual deflection salvo, a well trained fire control team should be able to straddle or come very close with one of the salvos of the initial ranging ladder.

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