I've seen many people throw around the term "caliber" without really knowing what it means... I've also seen a lot of people talking about the diameter of primaries (scharnhorst?) and equating it with weapon effectiveness. I pose to you, Is this correct? Is there nothing else? (I know my answer, but I want to see what kind of discussion is created.) Is a gun of smaller diamter really less effective than a larger diameter gun? --->>> Please forget about gunner accuracy; obviously if a 18.1" misses every time a pea shooter is more effective. Things to consider: Diameter Caliber (not the same as Diameter!) Muzzle Velocity (Is this related to Caliber?) Weight Reload rate
A larger diameter barrel will lob a heavier shell, carrying more KE or explosive or just plain payload. Caliber has nothing to do with the shells fired, it relates the diameter of the bore to the length of the barrel, so a "high-caliber" gun will develop more shell velocity than an otherwise identical gun with a shorter barrel. Assuming an equal (or nearly so) technological base between two countries (i.e. metallurgy, chemistry, manufacturing and design), a smaller shell will never exceed the performance of a larger diamter shell of the same type. If there is a significant difference in the t4ech base, the advanced country can make some improvement in the performance of any given size shell. For example, the advent of base-bleed technology (it bleeds a thin stream of gases from the base of an artillery shell in flight, reducing drag) extended gun range by upwards of 50% from the same barrels. Advanced explosives can make a difference in the explosive strength of a round, or in the velocity attained at firing. Short form: All other things being equal, yes, the smaller gun is less effective than a larger gun.
Hmmmm... That doesn't seem to be what you were arguing for on the Scharnhorst discussion!? I actually dissagree with you, but want to see what other ideas people have before I post myself...
I argued that the Scharnhorst class had armor built to defeat their own gun, making them a battleship (which is what the Germans called it). I also argued that the Scharnhorst could take several older battleships in a stand-up fight. This is not based solely on gun power, but also on damage control capabilities (which the Brits really had problems with).
The question is what do you mean by performance, damage caused or penetration (not always the same thing) as far as theoretical armor/gunnery go here http://www.combinedfleet.com/gunarmor.htm First, lets look at BB on BB. All things being equal, the heavier, larger shell, will be able to fly further and more accurately while retaining its impact energy better than the smaller shell, for one very simple reason: Air drag on a geometrically similar object is a function of speed and surface area. While surface area increases as the square of the shell diameter, mass (based off volume) increases off of the cube of the dimension. Mass here is the key, as while the air drag for a shell that is 2X the size of its identical smaller sibling is ~4x larger, the kinetic energy of the shell (iff they are fired at the same / similar velocity) is ~8x larger. That 4x larger drag has to dissipate 8x more energy than our reference shell. You see this in rifles as well, the larger the bullet given a similar shape, the better it does at longer distances as far as accuracy and the more energy it retains at longer distances. They are also less affected (accuracy wise) by wind, etc than the lighter smaller shells. Now armor penetration in real life is often a matter of impact energy and the resistance to deformation of the impacting projectile. But there is such a thing as too much. BB shells (the Armor Piercing variety) have been known to over penetrate on soft (DD/CL/CV/CVE) targets and explode underneath or not at all, generally dramatically reducing the damage that they do. In that case one would switch to a non-armor piercing shell or a shell from the smaller secondary armament, depending on the situation. Now as to the would you rather have 8x 18 inch shells or 16x 12 inch shells, that is far more dependent on the quality of the shell, the fire control system, and who sees who first. The 18 inchers will be able to hit at a longer range but you do not necessarily have to sink a ship to destroy it. Complete destruction of the soft topside of any ship will generally render it useless in a fight. In this case, it is more of a wash, and will greatly depend on individual ship qualities and who gets a good line on who first.
Two points from previous posts: 1.) All things are not equal. 2.) Having enough armor to "defeat" your own gun is called a "balanced ship", not a battleship. It is undeniable that weight (and therefore size) makes a difference in the overall effectiveness of a shell; but I suggest it is not the end all be all. The range of of a gun is based on it's kinetic energy, and since: Kinetic Energy = (mass * velocity * velocity) / 2 velocity cannot be ignored. Basically, if you try to throw a bullet (very low speed) your shell will travel a lot shorter distance and do far less damager than if it was fired from a gun. Further, if you look at the equation, you will see velocity actually makes more of a difference than mass! Caliber is defined (for big guns) as the ratio of the length of the barrel to the diameter of the shell... Shells that spend a longer time in the barrel (should) pick up more speed and will have a higher kinetic energy, therefore larger caliber is good... but dependant on diameter. It is absolutely possible to have a larger caliber on a smaller gun. Example: Scharnhorst: 11 inch / 55 Cal = 50 ft @ 728 lb --> 2,919 f/s Iowa: 16 inch / 50 Cal = 67 ft @ 2,700 lb --> 2,690 f/s I say a shell's effectiveness is measured in its kinetic energy. & being that I don't want to calc wind resistance (nasty diff.eq.) I will measure KE(joules) @ muzzle exit. Scharnhorst: 2,919 f/s @ 728 lb = 3.1 gigajoules Arizona: 2,600 f/s @ 1,500 lb = 5.0 gigajoules KGV: 1,590 f/s @ 2,475 lb = 6.2 gigajoules Queen Eliz.: 2,575 f/s @ 1,920 lb = 6.36 gigajoules Bismark: 2,690 f/s @ 1,764 lb = 6.38 gigajoules Hood: 2,790 f/s @ 1,920 lb = 7.4 gigajoules SoDak: 2,520 f/s @ 2,700 lb = 8.5 gigajoules Iowa: 2,690 f/s @ 2,700 lb = 9.7 gigajoules Yamato: 2,560 f/s @ 3,220 lb = 10.5 gigajoules WAIT A MINUTE: This was about cannon effectiveness! Not shell effectiveness. So that's just part of the equation. Throwing 1 shell @ 10lbs should be considered less (or equally) effective as 2 shells @ 5lbs, right? So we have to consider how many cannons were on each ship. Being that time is an issue during battle, how long it takes to reload each cannon should also be taken into consideration. What we have here is cannon effectiveness over time. Scharnhorst: 3.1 gigajoules * 9 cannons @ 2.5 shells/min = 69.7 gigajoules / min Queen Eliz.: 6.36 gigajoules * 8 cannons @ 2 shells/min = 101.8 gigajoules / min Arizona: 5.0 gigajoules * 12 cannons @ 1.75 shells/min = 106.4 gigajoules / min KGV: 6.2 gigajoules * 10 cannons @ 2 shells/min = 125.1 gigajoules / min Hood: 7.4 gigajoules * 8 cannons @ 2 shells/min = 119.5 gigajoules / min Bismark: 6.38 gigajoules * 8 cannons @ 3 shells/min = 153.1 gigajoules / min SoDak: 8.5 gigajoules * 9 cannons @ 2 shells/min = 154.3 gigajoules / min Yamato: 10.5 gigajoules * 9 cannons @ 1.75 shells/min = 166.1 gigajoules / min Iowa: 9.7 gigajoules * 9 cannons @ 2 shells/min = 175.8 gigajoules / min So we now see why people say "Iowa's 16" guns were as effective as Yamato's 18.1". We also see why I say Scharnhorst is not a battleship. She simply doesn't have the gun power.
Hey Justin, could you separate out your figures with commas, like 12,000,000 instead of 12000000? It makes things easier to compare at a glance. thanks! When you're talking about cannon effectiveness, a lot depends on what you define as "effectiveness". I always consider "effectiveness" to be the ability of a tool, weapon, etc. to accomplish its design task. For cannons, this varies depending on the intended recipient of the cannon. Scharnhorst was designed to hunt transports, with the option of switching to larger-diameter guns to hunt bigger ships. Yamato, on the other hand, was designed to take down other battleships. You can clearly see the difference in their guns. As for battleship vs not battleship, I don't believe its historical use matters at all. What matters is how you use your model on the pond. When I operated a Big Gun scharnhorst, I used it like a battleship, standing in the line of battle and slugging it out with the big boys. Another club member operated a Dutch Battlecruiser (nearly identical to Scharnhorst) and he avoided other capital ships in favor of cruisers, destroyers, and merchants. His ship was well-suited to battleship combat, but his choice of opponents makes me consider his ship to be a battlecruiser.
1) You said, what makes a gun better, man... If you are letting other factors like fire control and reloading time enter into it, that's not really comparing the gun itself. Sure, If my 11" main battery on Scharnhorst is compared to 23rd century 10" photon torpedoes, it's going to be an inferior gun. If you don't provide any constants, it's a meaningless comparison. 2) The de facto standard in WW2 for a battleship was a vessel that had armor built to stop her own shells. Anything less than that made it something less than a BB, like a battlecruiser, cruiser, or destroyer. Every country in the fight in that era measured things from that perspective. Note that the Iowas were not armored to stop 18" shells, but 16". Extra aside, don't discount German damage control. The British had a less-than-stellar reputation for shite damage control and lost more than a few ships because of that. Whereas several German ships were able to sail home severely damaged (much more so than the British ones that sank). Best example is SMS Seydlitz.
np! [8D] The task of a cannon is to blow a hole in something, the task of the ship might be different, but we are not (trying to) compare ships here. You are absolutely right, TO US it doesn't matter at all. But I thought it would be an interesting "historical topic". [] The only parameter I specified was no human error, I think its implied that we are talking WWI&WWII. Everything else (related to the gun) is free game. I submit though you are right about fire control; that is really more a specification of the ship, not the gun. However, the weight of the shells is holding up reload time; I think they are something valid to consider. When we are talking 2,000lbs shell, I submit that human error isn't really an factor in reload time. Where did you find that? That is not the definition that I know & I think is the root of our scharnhorst discussions. [8D] Really? Not that I don't believe you, but I would like to see that. What was the penetration power of the 18.1" shells? Those yamato shells were the third slowest on my list & the kinetic energy was less that a gigajoule difference (+7%). Not discounting it; but isn't that the effectivness of the ship, not the gun?
Ahhh... I thought you were speaking historically, because you gave all the energy figures for the real ones. For model ships, hmm... I think that the 1/4" cannons will bleed energy less at range than lighter ball bearings, just like the 180gr bullet from my Remington in .300 WinMag is still cookin' along at 500 yards with less effect from wind or intervening personnel (i mean paper targets than the 150gr bullet that has an initially higher velocity for the same powder load.
"Where did you find that? That is not the definition that I know & I think is the root of our scharnhorst discussions." i read a LOT of books Dreadnought by Hough addresses it pretty well, but that's just the first one that springs to mind.
Now I'm doubly confused... you said "I think its implied that we are talking R/C Naval Combat boats."
whoa.... sorry... I didn't complete that thought or something! I was thinking of the timeframe, WWI&WWII... since our hobby is limited to WWIⅈ I somehow equated that to "talking rc boats".. oi... Let me just change that. Done. Sorry for the confusion!!!
I think smaller dia. shell's can be very good if you throw them hard enough especialy if you can hit your target consistantly!! smaller shells are lighter. If there german they may be more accurete? Velosity and rate of fire might be higher? And they shoot flatter wich is a big advantage with range estemation but dosn't help if your target is so hevily armored that you need to have alot of down angle to do sink damage (Kill)Can't say without noing what the target is!!!!!
Justin you said effectiveness is measured in kenetic energy? I propose a shell's ability to penatrate armor and the fact that they were ment to explode at the critical time just after impact would be very much a mesure of effectivness!! I suspect you will agree tugboat. Justin exellent question!
Caliber is not always king. Caliber leads one to have higher velocity shells, which in turn increases maximum range. But, the LOW velocity shells provide better plunging fire...read better deck penetrators. This is why the USN 16/45 aboard the NC/SoDak class battleships was known as a superior deck penetrator to the 16/50 aboard the Iowas. If deck penetration is what you're going for, the lower velocity shells are perfectly acceptable. As for the high muzzle velocity weapons, they are generally better BELT penetrators. While these ships generally have superior range, the simple fact is that most gun-equipped ships didn't have the firecontrol to take advantage of it. I think its quite telling that the record for long range capital ship gunnery is held jointly by a flat shooting, high muzzle velocity cannon and an out-dated rainbow shooting cannon (11" Scharnhorst and 15" Warspite). Scharnhorst, specifically is obviously designed for a close range brawl. Her high velocity 11" is theoretically an excellent belt penetrator, and her 12.59 inch belt is also excellent. Her deck armor leaves a bit to be desired, but she wasn't designed for a long range duel. As for BB or BC, once again, guns above 10 inches was always considered "capital ship" size weaponry. As Scharnhorst carried battleship sized weapons (even if small compared to her contemporaries) they were still battleship sized weapons. She carried the armor of a battleship. As there were still several 12" battleships in commission at the same time she was. It simply doesn't matter that they were not as powerful as Iowa or Yamato's guns. So, she was laid down as a battleship, carried BB guns, carried BB armor, and was called by the germans "sclachtshiff" as opposed to "slachtkreutzer" or grossekreutzer". They were battleships, even if only second class battleships. They assuredly were NOT battlecrusiers. Mike D
One other thing to keep in mind is that bigger shells generally provide a bigger BANG when they go off. I've done the "compare Iowa to Yamato" thing with some of my friends, and one of the big points that came up was that a penetrating hit by the Iowa on the Yamato was not comparable to a penetrating hit by the Yamato on the Iowa. The reason was that Yamato's 18.1" shells carried so much more explosives, that a single hit would blow up a whole lot more of the Iowa, than a 16" hit on the Yamato.
Too right, you hit the nail on the head! even small increases in the weight of explosives will have a dramatic effect (I know, I use the stuff on a daily basis).
One simple thing to remember gent's is that we are talking about LARGE caliber RIFLES...That fire HE or AP rounds..over extreme ranges. Not Artillery shells or howitzers or field guns.. Respectfully Raymond G. Bisson
