Usn 15" Rodman Can't Penetrate?

[ickysdad]

Follow this link ,look at page 30...Am I wrong or does it just says it was "estimated that the 15" rodman wouldn't penetrate said plate????

 

http://books.google.co.uk/books?id=15MNAAAAQAAJ&pg=PA3#v=onepage&q&f=false

Edited June 11, 2012 by ickysdad

[Sardaukar]

I can already see how many ways this discussion is going..

[ickysdad]

I can already see how many ways this discussion is going..

 

Well it is the usual culprit in another forum,he also has an accomplish now,however my main point is that we've been spoon fed all through th years that the British carried out tests with Rodman 11" & 15" as in shooting them at various targets however from reading this tests it seems to me that Captain Noble in the Shoreborness Tests only calculated that they wouldn't penetrate a certain target,no actual firing at an actual target. Furthermore they only used 50 lbs of powder for the 15" & 20 lb for the 11" when both were quite capable of 100 lb & 30lb respectively. we also have the meme that 50lbs of British powder equals 60 lbs of US powder from said test however try as I might I couldn't find any reference to this in that document. I've sen it said in Parkes but don't remember him footnoting it and D.K Brown states it in "Warrior to Dreadnought" but footnotes it back to Jone's book "Our Ironclads" so ihaven't seen any primary documents stating British powder is any better then US powder just a couple of secondary sources referencing other secondary sources.

 

Just asking for opinions guys!!!! LOL!!!!

Edited June 11, 2012 by ickysdad

[DKTanker]

Well it is the usual culprit in another forum,he also has an accomplish now,however my main point is that we've been spoon fed all through th years that the British carried out tests with Rodman 11" & 15" as in shooting them at various targets however from reading this tests it seems to me that Captain Noble in the Shoreborness Tests only calculated that they wouldn't penetrate a certain target,no actual firing at an actual target. Furthermore they only used 50 lbs of powder for the 15" & 20 lb for the 11" when both were quite capable of 100 lb & 30lb respectively. we also have the meme that 50lbs of British powder equals 60 lbs of US powder from said test however try as I might I couldn't find any reference to this in that document. I've sen it said in Parkes but don't remember him footnoting it and D.K Brown states it in "Warrior to Dreadnought" but footnotes it back to Jone's book "Our Ironclads" so ihaven't seen any primary documents stating British powder is any better then US powder just a couple of secondary sources referencing other secondary sources.

 

Just asking for opinions guys!!!! LOL!!!!

I'm probably way off base, but the HE component shouldn't have much to do with penetration, the HE being for blast effect after the armor is penetrated.

[ickysdad]

One correction I referred to Joen's book "Our Ironclads" the auther was a gentleman named Reed.

[Rich]

Well it is the usual culprit in another forum,he also has an accomplish now,however my main point is that we've been spoon fed all through th years that the British carried out tests with Rodman 11" & 15"

 

Gee, let me guess who the Usual Suspects are...but I exposed them in that "little" lie a long time ago on this Grate Sight. Of course, it is the standard MO of these creatures to run off elsewhere to pedal their nonsense when exposed.

 

Cheers!

[ickysdad]

Well it is the usual culprit in another forum,he also has an accomplish now,however my main point is that we've been spoon fed all through th years that the British carried out tests with Rodman 11" & 15"

 

Gee, let me guess who the Usual Suspects are...but I exposed them in that "little" lie a long time ago on this Grate Sight. Of course, it is the standard MO of these creatures to run off elsewhere to pedal their nonsense when exposed.

 

Cheers!

 

Rich,

I remember a statement that Rodman's ended up using up to 125 lbs of powder ,do you know what that was referenced from? Anyways it's the same old,same old you know who. I think's it's interesting that everybody references those Shoreburness Tests but in said test no actual firing of a Rodman was done at an actual target,Capt Noble just merely estimated it wouldn't penetrate a certain target therefore no more testing was done. Those tests were supposedly used to prove British powder was superior to US powder but for the life of me I can't any reference of that issue in the test. Parke's book on RN BB's states it but doesn't footnote it,and Brown in "Warrior to Dreadnought" states it on page 25 but footnotes it back to Reed's "Our Ironclads". Pretty circular argument isn't it?

Edited June 11, 2012 by ickysdad

[Max H]

I'm probably way off base, but the HE component shouldn't have much to do with penetration, the HE being for blast effect after the armor is penetrated.

 

By powder I think they mean the propellant charge. Also, a bursting charge does reduce the penetration of a round - I believe it's something to do with making it more fragile compared to a solid steel shot.

[baboon6]

I thought Rodman could penetrate anything! (boom tish)

[ickysdad]

This is a discussion going on over at warships1.com. I noticed that once Tigger & drachnifiel were hit with the fact that those Capt Noble tests don't even mention the old "50 lbs British powder equals 60lbs US powder meme" or that no US guns were even fired at targets they stopped bringing it up.

 

I feel one has to be careful trusty secondary sources unconditionally ,as one can tell from D. K. Brown's book "Nelson to Vanguard" citing Garzke & Dulin's "Allied BB's of WW2" book as a source for the old "British CA armor is 25% superior to USN Class A armor meme". Now Brown in Warrior to Dreadnought states that US powder of 60 lbs equals 50 lbs of British powder citing Reed's "Our Ironclads" which is availiable online but doesn't seem to cite where they got that info. It certainly didn't come from the oft cited Noble/Shoreborness tests,at least not per the document I've been spoon fed.

 

http://warships1discussionboards.yuku.com/topic/20453/25-better-British-armor-revisited

[ickysdad]

Here's a link to some document showing the 50 lbs = 60 lbs meme but it seems it's a part of an article rather then the original Shorebourness Tests. Don't know what to make of it. However it doesn't state which type of powder was used in the tests.

 

http://books.google....epage&q&f=false

Edited June 13, 2012 by ickysdad

[EchoFiveMike]

The X American powder equals Y British powder is irrelevant, as the Rodman operationally used a progressive burning prismatic powder (125lbs) which is not comparable to conventionally granulated BP. Peak pressures dictate max charges, but the progressive burning character meant that prismatic powder had a greater area under the pressure curve, resulting in increased velocity. Magnum catridges typically operate at the same pressures as conventional, they simply use slower burning powders, which give greater area under the pressure curve, hence greater velocity. You trade efficiency for effectiveness.

 

Even if actually tested, pointing out that a Rodman couldn't penetrate with a charge never used is the most rediculously irrelevant deception. S/F....Ken M

Edited June 13, 2012 by EchoFiveMike

[ickysdad]

echofivemike,

 

I've sure you have a point but my point is that certain people are using a document pertaining to a test in which the Rodman was never tested it's performance was just estimated. I know they say never argue with idiots but sometimes it's neccessary to counter the crap they're spreading.

[EchoFiveMike]

I understand that, but even assuming it were true and done, it wouldn't matter.

 

Arguing with idiots is fine, as potentially you may educate them. Arguing with liars however, is pointless; no honesty means no reality is going to matter. They must be dealt with in other fashions. S/F....Ken M

[ickysdad]

The X American powder equals Y British powder is irrelevant, as the Rodman operationally used a progressive burning prismatic powder (125lbs) which is not comparable to conventionally granulated BP. Peak pressures dictate max charges, but the progressive burning character meant that prismatic powder had a greater area under the pressure curve, resulting in increased velocity. Magnum catridges typically operate at the same pressures as conventional, they simply use slower burning powders, which give greater area under the pressure curve, hence greater velocity. You trade efficiency for effectiveness.

 

Even if actually tested, pointing out that a Rodman couldn't penetrate with a charge never used is the most rediculously irrelevant deception. S/F....Ken M

 

Yes but it's being stated that a Rodman never used anything larger then a 100 lb charge even "Munitions of War" states a 110 lb charge. It's being stated that the 130 lb charge originated just from our tank-net companion Rich and nowhere else.

[RETAC21]

If Rich said it, it must be true, probably Richard told him

 

Trusting anything by a certain Tiger over Rich is like calling the Earth flat, you can, but it cannot be proved by any means.

[EchoFiveMike]

Yes but it's being stated that a Rodman never used anything larger then a 100 lb charge even "Munitions of War" states a 110 lb charge. It's being stated that the 130 lb charge originated just from our tank-net companion Rich and nowhere else.

 

From Ordnance, July-August 1962. Written by Donald B. Webster, Jr.

With charges of his hexagonal powder, Rodman's 15-inch gun, with its abnormally low bore, length-diameter ratio, fired its 330-pound shell at a muzzle velocity of 1,735 feet a second, much faster than the velocity achieved with any other gun, including many with bore length-diameter ratios as high as 20 to 1. With a 50-pound charge of hexagonal powder (two-fifths of the later standard 125-pound charge) the 15-inch gun at 25 degrees elevation had a maximum range of 4,680 yards.

 

Here's text from a Secretary of War report, describing initial testing in 1860, whereupon they settled on 100lbs of Mammoth powder, which is specifically differentiated from prismatic powder, with prismatic being the slower burning, and thus capable of greater MV. 100lbs of mammoth is stated as giving 1500 fps with 440lb shot.

 

http://books.google.com/books?id=PlBHAQAAIAAJ&pg=PA445&lpg=PA445&dq=15%22+rodman+powder+charge&source=bl&ots=tQxvhGpFiT&sig=29S8cOT9r57pdJvO3a_9NsgstFw&hl=en&sa=X&ei=vdPZT77jMZSu8QTRuIHsBQ&ved=0CF8Q6AEwATgK#v=onepage&q=15%22%20rodman%20powder%20charge&f=false

 

S/F....Ken M

[DougRichards]

What I find interesting in this discussion is the 'elephant in the room': not what the Rodman could or could not penetrate, but the fact that it was apparently still using a spherical shot, noted in a previous post as weighting 440lb at 1500sec, when its British contemporary - the RML 12in 25 ton gun were firing, from a rifled barrel a 600lb Palliser shell at 1300ft/sec. The Rodman weighed a bit less, at around 20 tons but the British 25 ton guns also actually went to sea.

 

Even the British RML 10" 18 ton gun fired a projectile with as much mass as the Rodman 15" at nearly the same velocity and at a longer range.

 

the US was apparently as advanced as Britain in the construction or artillery at the time. Why did it apparently stick with spherical projectiles from unrifled guns. A cylindrical projectile, with a pointed nose, should also have an advantage in terms of penetration, over spherical round of greater mass.

[EchoFiveMike]

Because rifled cannon had the nasty habit of blowing up, especially without using prismatic or other types of controlled burn powder. The accuracy advantage of rifles was not usable by USN ships of the day, round shot was good enough at the ranges of the day.

 

Also there was the cost, SB's were cheaper, although towards the end, Rodman was casting internally cooled rifles for experiement. Many 8 and 10" Rodmans were sleeved with rifled liners post ACW. S/F....Ken M

[Steven P Allen]

Exceptions crop up in odd places. Both the Filey and the Woodruff* guns used conical rounds (made of lead!) in both rifled and smooth-bore versions. They were light and low-production field pieces, but other examples might exist, especially out here in the West.

 

The guns Grierson pulled along on his raid were Woodruff guns.

[ickysdad]

Yes but it's being stated that a Rodman never used anything larger then a 100 lb charge even "Munitions of War" states a 110 lb charge. It's being stated that the 130 lb charge originated just from our tank-net companion Rich and nowhere else.

 

From Ordnance, July-August 1962. Written by Donald B. Webster, Jr.

With charges of his hexagonal powder, Rodman's 15-inch gun, with its abnormally low bore, length-diameter ratio, fired its 330-pound shell at a muzzle velocity of 1,735 feet a second, much faster than the velocity achieved with any other gun, including many with bore length-diameter ratios as high as 20 to 1. With a 50-pound charge of hexagonal powder (two-fifths of the later standard 125-pound charge) the 15-inch gun at 25 degrees elevation had a maximum range of 4,680 yards.

 

Here's text from a Secretary of War report, describing initial testing in 1860, whereupon they settled on 100lbs of Mammoth powder, which is specifically differentiated from prismatic powder, with prismatic being the slower burning, and thus capable of greater MV. 100lbs of mammoth is stated as giving 1500 fps with 440lb shot.

 

http://books.google....0charge&f=false

 

S/F....Ken M

 

Where can i get a hold of that article by Donald B Webster?

[EchoFiveMike]

I suspect you'll have to research at your local library. S/F.....Ken M

[ickysdad]

No i found a link to it on the web...

[ickysdad]

Ok what does 5 or 6- 1" plates sloped back at 35 degrees equal in vertical thickness / Anybody have any ideas?

[67th Tigers]

The X American powder equals Y British powder is irrelevant, as the Rodman operationally used a progressive burning prismatic powder (125lbs) which is not comparable to conventionally granulated BP. Peak pressures dictate max charges, but the progressive burning character meant that prismatic powder had a greater area under the pressure curve, resulting in increased velocity. Magnum catridges typically operate at the same pressures as conventional, they simply use slower burning powders, which give greater area under the pressure curve, hence greater velocity. You trade efficiency for effectiveness.

 

Even if actually tested, pointing out that a Rodman couldn't penetrate with a charge never used is the most rediculously irrelevant deception. S/F....Ken M

 

Slow burning, yes. Prismatic, no. The US did not adopt hexagonal cake. The only nation that ever did was Russia in the late 1860's. Everyone else (the US included, eventually) went with pellet and pebble type powders.

 

The Rodman's used "Mammoth" which was chemically the same basic powder DuPont supplied but the sieve sizes larger. Mammoth grain sizes were 0.6 - 0.9". The proof charge was 100 lbs Mammoth, and this was allowed to be fired in emergencies producing MV's of a little over 1,500 fps. US Navy no.7 powder and RN LG powder (both similar, smaller, grain sizes) produced about the same velocity (slightly over 1,500 fps) with 60 lbs of that powder.

 

Rodman's own report on the experiments that led to Mammoth are online: http://archive.org/s...ge/n37/mode/2up

 

In ~1883 the US adopted a brown sphero-hexagonal powder and the service charge adopted for this powder was 130 lbs. This gave an initial velocity of ~ 1,700 fps: http://archive.org/s...age/n9/mode/2up

 

There is a terrible tendency amongst some to ignore the fact that we're dealing with two different propellents and ascribe the characteristics of the latter powder to the former.

Edited June 16, 2012 by 67th Tigers