Doctor X | 13 May 2016 9:58 p.m. PST |
I'm looking for sources that will give me data on ROF and maybe even percentage of hits at any given range while in combat. "Jane's WW1 Ships" doesn't really have anything on this that I could find. I looked at Friedman's "Naval Weapons of WW1" and while it does have good info on a number of guns I couldn't find anything about ROF. I also saw this website where they have data on some of the guns but I'm wondering what their source was for the ROF as it seems a little high to me. navweaps.com Anybody out there that can point me in the right direction? |
rmaker | 13 May 2016 10:23 p.m. PST |
It was rare for any navy to fire its guns at full theoretical ROF in WW1. The only exception would be very light guns firing at attacking torpedo or air craft. For the big guns (at least modern ones), one would expect about 1 rpm, mediums would go 2-3 rpm. Light guns (under 6"/15cm) might go 4-5 rpm. Ammunition supply and the need to conserve it was a factor as was aiming time. Older weapons would be 2/3 to 1/2 as rapid in their fire. |
GildasFacit | 14 May 2016 5:23 a.m. PST |
Theoretical RoF and test ground accuracy figures are both pretty irrelevant to the effectiveness of guns above about 120mm at that time. Performance in combat isn't a simple 'percentage hit and probability of damage' – the range of factors that affect it is far too large for any system to model it with any reasonable degree of 'accuracy'. Later (even to some extent by the end of WW1) gunnery systems get a great deal more sophisticated and it becomes possible to model and so predict the likely effect of fire but too many human factors influence the result in the early part of the war. |
Virtualscratchbuilder | 14 May 2016 5:34 a.m. PST |
At Jutland, assuming Hipper's main targets were the eight British battlecruisers: Hipper's ships fired 1670 heavy rounds The British BC's cumulatively were hit by 53 heavy rounds (V. E. Tarrant) Hit rate = about 3% However, take what I wrote with a grain of salt because some of Scheer's force fired on Beatty, but I do not recall if they scored any hits. If they did, then Hipper's numbers are even lower. OTH, I do not recollect if Hipper's force fired on Evans-Thomas, so the numbers may be skewed in the other direction. In any event, the percentage was very low. The 3% jives with what I have read for WWII pre-radar cruiser engagements. Note that there are significant exceptions to the 3% generalization both pre and post radar – Matapan, Washington vs Kirishima, etc. |
Shagnasty | 14 May 2016 9:01 a.m. PST |
Tarrant's "The German Perspective" gives a rate of a 4 gun salvo each 20 seconds for intensive firing for Hipper's BCs. The German commentators remarked that the British were "slower.' |
yarkshire gamer | 14 May 2016 11:35 a.m. PST |
The best book by far is Jutland an analysis of the fighting by John Campbell. Lots and Lots of technical data about everything related to gunnery with an excellent summary at the rear. ROF covered giving some interesting stats on the Germans fired quicker than the Brits notion. Also good info on how poor the British 15" shells were. A must read for technical stuff, it will put you to sleep though, reads like an old Haynes Car Manual ! Regards Ken yarkshiregamer.blogspot.co.uk |
Doctor X | 14 May 2016 7:33 p.m. PST |
Thanks for the suggestion Ken. Just ordered this off Amazon for a look. |
Doctor X | 14 May 2016 10:49 p.m. PST |
rmaker – what source are you quoting those ROF numbers from? Shagnasty – you use the term "intensive firing". Do you mean that in the context that the firing was intense or that this was a specific mode used in firing the gun to get more rounds out? |
hindsTMP | 15 May 2016 10:24 a.m. PST |
I looked at Friedman's "Naval Weapons of WW1" and while it does have good info on a number of guns I couldn't find anything about ROF. It's usually in there, but you have to parse the text rather than the tables. MH |
Doctor X | 15 May 2016 5:29 p.m. PST |
Thanks. I have that on order as well and it should be here tomorrow. |
hindsTMP | 15 May 2016 6:56 p.m. PST |
BTW, I agree with some of the other posters that maximum ROF would not usually be used, mainly due to fire control procedures, but also for other reasons. Not only is shipboard ammo supply finite, but getting on target at anything but short ranges typically required deliberate firing according to an elaborate fixed procedure (spotting etc.). This includes WWI, despite the claim of one of the above posters. Now it is true that once on target ships might fire at maximum rates, but being "on target" was a very temporary condition, due to maneuvering, visibility, damage, etc. MH |
Pontius | 16 May 2016 3:31 a.m. PST |
Deliberate, directed firing of main guns was a relatively slow process. Ships usually fired in salvos, one gun from each turret at a time. Allowing for time of flight and the director passing corrections to the guns after spotting the fall of shot I doubt a gun fired more than once per minute. Once the range was found and the target straddled the rate of fire might be stepped so a salvo would be fired before the previous one had landed. But as Hinds TMP says this was a temporary state. Even in WW2 rates of fire were considerably less than the theoretical maximum. I seem to recall that Bismarck fired four gun salvos at 20 to 30 second intervals during the Denmark Strait action and Prinz Eugen was roughly twice as fast. |
Blutarski | 16 May 2016 5:43 a.m. PST |
A brief observation regarding maximum rate of fire: The official maximum rate of fire of the German WW1 30.5cm L/50 naval gun was said to be up to three rounds per minute (say one round every 20-24 seconds). This may have been technically true under ideal proving ground conditions. However, the gunnery log entries reproduced in "Kiel and Jutland" clearly indicate that the actual maximum rate of fire of Derfflinger's main battery under action conditions at Jutland was about half that, and author von Hase further commented that the gun crews could not physically maintain such a level of output for more than a few minutes before onset of exhaustion. B |
Wolfhag | 16 May 2016 9:04 a.m. PST |
From what I've read including John Campbell's book on Jutland here is how I see it: Battleships opened fire at almost maximum range with ranging shots. At long range ROF depends on TOF, observation of splashes and results, plotting room activities, relay of new info to turrets and then firing again. That "loop" can take longer than the amount of time to reload and fire. The TOF for guns over 12" was about 20 seconds to 15,000 yards. So the "loop" would generate a maximum ROF of about 1- 1.5 rounds per minute under pretty much ideal conditions and depending on crew quality and internal ship communications. You can see firing single rounds it could take a few minutes to get a consecutive over and under and start firing salvos. Keep in mind, Gunnery Officers cannot control how many hits they get, they can only control if the salvo straddles or not and keep adjusting the salvo ranges and lengths. All guns were not aimed at the same range. To hit you need to straddle. Knowing the rounds angle of descent and target beam (easy to find) determines danger space behind the target. Shorter ranges and flatter trajectories increase the targets danger space resulting in chances for more hits. The reverse is true. Wider and taller targets have a greater danger space at all ranges. The reverse is true. The theoretical maximum ROF can take place under two conditions: at extremely short range or after getting a straddle on your target. Once you straddle your target you've found the range and can most likely straddle on consecutive salvos – if the enemy cooperates by maintaining the same speed and heading and you have good observation of the target and splashes. Most likely they'll change heading or take evasive action. You need to pour it on once you've found the range. At Jutland IIRC the Germans after getting a good straddle went into rapid fire every 20 seconds (not waiting to see the results of each salvo) and they tightened up the salvo length too if they could. This had the drawback of multiple splashes obscuring observation but it did not matter if consecutive salvos were straddling. This max ROF could only be maintained for a couple of minutes as the target would maneuver out from under the salvos and not be observed. Another drawback is that it is hard to make corrections after each salvo. You'd need to start over getting ranging info and firing again once the target came back into view. That 20 second ROF I think is misleading. I think they fired one round from each turret every 20 seconds as shagnasty stated but they were 4 round salvos, not 8 rounds. That gave the Germans an advantage of keeping their targets under fire longer and less splashes gave better observation. It also allowed tighter salvos. Smaller salvo lengths have a greater chance of hitting IF you straddle. No straddle = no hits (OK very small chance of the first or last round of a salvo hitting without a straddle). If a salvo is too long you can straddle and not hit because the rounds in the salvo are spaced too far apart. Too short of a salvo length and you may not straddle. Are there any naval warfare games that let players make those decisions? For an example, let's say you have a target with a total danger space (target footprint on the surface) 50 yards wide (30 yard beam and 20 yard danger space behind the target). You fire an 8 round salvo that is 400 yards long that straddles. Theoretically an 8 round salvo 400 yards long a round will land every 50 meters giving about a 90% chance of 1 hit, a smaller chance of 2 hits and almost no chance of 3+ hits. A 500 meter salvo will have a fair chance of 1 hit and almost no chance of 2+ hits. A 200 meter salvo will have an excellent chance of 2 hits, fair chance of 3 hits and almost no chance of 4+ hits. The advantage of the German 4 round salvo was a grouping of only about 100 yards and could result in 3 hits which according to some accounts actually happened at Jutland. Three consecutive 4 round salvos that straddle in a 60 second period getting 8-12 hits is going to cripple most capital ships. Can your favorite game simulate this? As you can see the fact that 3% of the total shots fired in the battle hit is meaningless when dealing with gunnery on a salvo by salvo basis. You may not straddle on 5 consecutive salvos with no hits and then straddle on the next two salvos and get 3-4 hits. If you cannot observe the shell splashes you cannot make adjustments to straddle. Once you start shooting salvos observation is more important than range finders. Taking evasive maneuvering degrades your firing solution too. If you like the gunnery aspect of naval warfare Seas of War is a good one to check out: panzer-war.com I think his gunnery charts are based on the real thing and you can fire a loose salvo (better chance to straddle but less hits) or closed salvo (less chance to straddle but chance for more hits). I've played a customized version of the WWI game. My solution is to use a 10" x 10" "plotting table" representing 400 yards by 400 yards with a scaled target image (you could also use a real model) placed in the center with the correct heading to the shooter. I use clear plastic salvo templates that can represent each round fired in the salvo. A single die roll determines where the center of the salvo lands based on ranging information and then you get a visual on the results of the entire salvo and exactly where each round lands in relationship to the target. Any rounds on the salvo template that land directly on the target image or in the danger space behind are hits. This can also determine near misses that cause underwater concussion damage. You can even determine which section of the target is hit without additional die rolling. One die roll and instant visual results. I think my calculations on this are correct. If not I'm sure someone will correct me. Wolfhag |
Doctor X | 16 May 2016 2:59 p.m. PST |
Thanks for all the great comments. Just to be clear to keep the conversation on point, I'm looking for actual not theoretical ROF. Once you factor in slower rate for the whole process of bracketing, then maybe a faster sustained fire once locked in, what would that average out to be? Yes, I realize there are a number of variables so dealing in generalities is fine. My thoughts are anywhere from maybe 25-50% of quoted theoretical ROF based on the discussion here. |
Blutarski | 16 May 2016 4:56 p.m. PST |
Dear Doctor X, Actual as opposed to theoretical rate of fire ….. ? The broad and general rule of thumb employed by the RN itself was one round per minute per gun when discussing the main battery of a battleship, but that average smoothed over a vast array of ranges and tactical conditions. To refine the figure, the following questions required answers" What is the nature of the gun of the firing battery? How old is the mount technology? What is the range? What are the visibility conditions? Is the firer employing simple bracketing fire or using ranging forks/ladders? Is the firing ship under helm or altering course? What type of FC computing system is in use (if any)? I have been studying this topic for 45+ years. Trust me when I say that, even in WW1, it was extremely complex and differentiated in many subtle ways. What exactly is your goal (fun game or a more serious simulation)? B |
Doctor X | 16 May 2016 10:58 p.m. PST |
B, Thanks for the response. As I mentioned I'm looking at this in generalities so all the variables you mention I can put some kind of value on. I think you are looking for specifics so assume that visibility, sea condition, smoke, etc. are not factors. Take away all those variables you mention. Maybe its easier to think of it as two battelines sailing parallel to one another trading shots with nothing other than being fired on by enemy ships is a factor. If I interpret your 45+ years of study on this matter, and generalizing as to guns mounts, ranges, etc. it sounds like a main battery one one round per minute is what you are stating is a generalized average. Is that one round per gun or one round per turret? As for my reason of asking this, I question the numbers I have seen quoted on ROF on guns. I think it is too high and the ROF under perfect conditions. In a game I am not looking to plot out each individual shot. On the high end of complexity I would think something like Fleet Action Imminent is on my high end and Ship Base III on the low end. And, if you have a reliable source you feel comfortable quoting that gives realistic, not "parade ground" ROF please let me know what that is. |
Wolfhag | 16 May 2016 11:26 p.m. PST |
Doctor X, Here is an excerpt from Campbells book on Jutland: link The Lutzow's first salvo was well to the left as the inclination of the Lion towards the 1st SG was under-estimated, but she seems to have fired her first five salvos in 3 minutes and hit with her fifth salvo. The Derfflinger also fired five salvos in 3 minutes, but then had a period of firing short, and does not appear to have scored a hit until 10 minutes after opening fire, while the Moltke made two hits in the first 3 minutes, and continued hitting in one of the most accurate spells of firing in the whole battle. According to the officer of `Q Turret in the Tiger, the Moltke's first salvo appeared to fall about 300yds short, and she straddled the Tiger very soon afterwards. The spread for range was estimated as 100-150yds, and for deflection as `nil'. There are many factors but overall salvos appear to be 1-1.5 per minute. Then you need to find out how they are firing the salvos which can get complicated (sorry about that). Salvos could be fired as full salvos, where all guns were discharged more or less simultaneously, as partial salvos, where half the main battery (usually either the forward after group) fired together, or as split salvos, where one gun of each turret fired together. Each system had its own advantages and disadvantages. Full salvos looked spectacular, but resulted in relatively large patterns which were difficult to spot and which arrived at relatively long intervals, thus making corrections difficult. Partial salvos reduced the pattern size, made spotting easier, and meant that corrections could be made (on the average) twice as often. Split salvos, due to the extreme separation of the guns, lead to the greatest accuracy and, theoretically, to the highest rate of fire as the director could fire as soon as any arbitrarily selected number of guns was ready to shoot. I like Seas of War because the gunnery rules allow firing split salvos with a correction after each one. In the game it is more effective than full salvos because with more corrections you find the range and straddle more quickly. The down side is you are only firing half of the guns each salvo. Are you confused yet? Wolfhag |
Blutarski | 17 May 2016 5:01 a.m. PST |
Doc X, The one round per gun per minute figure is indeed per gun. Both British and German designers favored two-gun turrets and salvo fire rather than broadside fire. Each salvo discharge was intended to involve the fire of half the guns of the ship's battery (say 4-6 guns if firing within the A arc), accomplished either by discharge of one gun per each turret or both guns of one half of the number of turrets. Why was this? Because, in order to ascertain the correct deflection, range and most importantly range rate, it was the most economical means of maximizing "the sampling rate" (my term of convenience), i.e. the number of salvoes that could be fired and effectively spotted for correction within a given unit of time. A salvo of 4-5 shots was considered optimal for spotting, as it was the fewest number of shots whereby the observer could reliably and accurately sense the center of impact of the salvo relative to the target and call for a correction; single shots could not provide an accurate sense of salvo impact. Note – All the shots of a salvo were customarily aimed at a single point on the surface of the sea, with necessary corrections for parallax and even turret height differences applied to the deflection and elevation orders sent to each turret. The dispersion of the shots in a salvo was the product of small manufacturing differences in ammunition and propellant, gun tube condition and gun mount calibration. It was possible to artificially spread the shot in a salvo by tampering with elevation orders to the guns and the Beatty Papers contain a post-Dogger Bank memo from Beatty to Chatfield discussing the idea of finding an "ideal" salvo size that would maximize the possibility of straddling while still promising a good chance to obtain a hit on the target, but I have never seen any evidence that this was institutionally pursued by either of the opposing services. How many salvoes could be fired per unit of time? The above discussion suggests two salvoes per minute, but making such a leap is a bit dangerous. For example, here is an extract from the post-Jutland 1916 Spotting Rules on the topic of rate of fire - quote - The following table gives the spread and average firing interval for the various natures of guns, and forms the basis on which the method and rules have been drawn out - Gun – - – - Average Spread – - – - Average Firing Interval 15-inch -------- 200 yards ----- 60 seconds 14-inch -------- 200 yards ----- 50 seconds 13.5-inch ------ 300 yards ----- 50 seconds 12-inch -------- 400 yards ----- 50 seconds </= 9.2-inch --- 400 yards ----- 40 seconds For example, if half the guns are fired in each salvo a ship with 13.5-inch guns could fire a salvo every 25 seconds. - unquote N.B. (a) Take the spreads to represent 4-5 shot salvoes at battle range (~15,000 yds for 12-inch and larger calibers and 12,000 yds for 9.2-inch); (b) the salvo rate of fire should be considered a maximum rate, as it does not necessarily allow time for spotting between discharges – these post-Jutland 1916 rules heavily featured use of "double salvo" fire for ranging> The best and most easily accessible single volume data source to answer this question in more detail remains NJM Campbell's book "Jutland – An Analysis of the Fighting". If you do not already possess this volume, I urge you to put aside whatever you are doing, avail yourself of a copy and study it. FWIW. B |
Wolfhag | 17 May 2016 11:04 a.m. PST |
Blutarski, This is how I see it. Battleship with four 2 gun turrets. Half Salvo ROF every 25 seconds 20 second TOF to 15,000 yards Start the stopwatch: 0:00 – 1st half salvo of 4 rounds fired at 15,000 yards 0:20 – Salvo lands, splashes observed 0:40 – Info reported to plotting room and corrections given (this is an estimate) 0:45 – 2nd half salvo of 4 rounds fired 15,000 yards 1:05 – Salvo lands, splashes observed, target straddled 1:25 – Info reported , corrections given. All turrets go to rapid/intensive fire with half salvos 1:30 – 3rd half salvo of 4 rounds fired 1:55 – 4th half salvo of 4 rounds fired 2:20 – 5th half salvo of 4 rounds fired So in 2:20 there are 5 half salvos fired for a total of 20 rounds. Does that sound right to you? When waiting to observe the results of a salvo the TOF is what slows down the ROF. Normally about 20 seconds to 15,000 yards. Wolfhag |
Blutarski | 17 May 2016 2:01 p.m. PST |
Hi Wolfhag, Your arithmetic makes sense for your case as presented, assuming employment of straightforward bracketing fire. Your 20 second allowance for correcting fall of shot is not unreasonable; my own is about 12-15 seconds for a well-drilled ship. But to straddle on the second salvo would have been considered mighty fine shooting in WW1. My SWAG, based upon the assumption that on average a straddle would result in one hit, is that only about 10-12 pct of salvoes were straddles in the course of a typical WW1 battle. More later. B |
Blutarski | 18 May 2016 7:02 a.m. PST |
OK, I'm back. In order to understand the effect of range upon rate of fire, you need to know time of flight for various ranges. These data an be taken from detailed range tables for the gun in question, but such things are hard to come by. There is a simple (albeit less precise) alternative - 1 – To start, you will require the maximum range of your gun at a known elevation angle. 2 – Range will vary as the square root of the elevation angle, i.e., if "Gun X" can reach 20,000 yards at 16deg elevation it will reach 10,000 yards at 4deg elevation. 3 – Time of flight in seconds for any range will be approximately equal to: (range in yards divided by 1000) + (respective angle of elevation). "Gun X" will therefore have a time of flight at 10,000 yards of 10 + 4 = about 14 seconds and at 20,000 yards of 20 + 16 = about 36 seconds. 4 – For those interested, angle of fall can be approximated as 1.5x angle of elevation for any range. - – - Once again, this method does not deliver NASA precise results, but is IMO satisfactory for wargaming purposes and will correctly demonstrate the very rapid growth of time of flight as range increases. B |
Wolfhag | 18 May 2016 11:32 a.m. PST |
Blutarski, It looks as if you approach the game as a gunnery problem, so do I. I think when you start reducing a naval warfare game to a % to hit you are losing a lot of the flavor of the period and what makes it different from other types of warfare. For me the game starts with building a fire control solution as soon as the enemy is sighted. This takes time. The more time (game turns) spent the better your solution but there is a point of diminishing returns. Your range finder is the key to this step. Germans and Brits used different systems that can be differentiated in this concept. More time means better initial ranging but opening fire later. There are trade offs. Once you have a good enough solution (about 90-95% correct on the target range, speed and bearing) after 2-5 minutes (2-5 game turns) of consecutive ranging and plotting you start firing single ranging rounds adding 400-500 yards until you get a consecutive under and over or a ranging ladder like the Germans. Lets say the result of your initial ranging is a 1200 yard error. Your first ranging shot is 1200 yards short. Using 500 yard correction increments your second shot is 700 yards short. Third is 200 yards short and fourth is over the target. Lets say you spent 4 minutes ranging and the four ranging shots took an additional 4 minutes you start firing salvos after 8 minutes. If you had used 400 yard corrections you'd get the under and over in 5 turns with a +/- 400 yard range error. I think this is reflected in accounts in Campbell's book on Jutland. There is only one die roll to determine your initial ranging error modified by the rangefinder type, environmental factors, crew expertise and time spent ranging and plotting. The time to get an under and over to start firing salvos is easily calculated and can speed up a game immensely without compromising realism even with a large number of ships. Of course there is a minimum range error that can be obtained, probably 5% would be the best that could be obtained under pretty much ideal conditions. I'm open to suggestions. After the consecutive under and over you start firing salvos. Now your range finder is in a secondary role and direct observation, plotting and range keeping is most important (Brits and Germans differed here and each had advantages and disadvantages). Gunnery Officers do not try to "hit" a target with each round. They attempt to straddle the target. So how can you do that in a game without resorting to a lot of charts, math and getting on the floor on your hands and knees? In the example above the under and over spotting rounds were 500 yards apart. The Gunnery Officer now knows within +/- 500 yards the range to the target giving him a 1,000 yard zone to put a salvo into. If a 400 yard sheaf is fired it has a 40% chance to straddle. I don't think you need to get into a lot of modifiers for that roll. So then what is the chance to hit when straddling? Lets say the 400 yard sheaf has 10 rounds in it meaning an average of one round every 40 yards along the length of the salvo. If the target has a beam of 30 yards and 20 yards danger space behind it the total danger space (hitting space?) is 50 yards. Dividing 50 by 40 you get 1.2 which is one hit and a 20% chance for a second hit. Two die rolls, no modifiers, pretty simple. Of course that's the simple version. Crossing the "T" means a greater danger space and a greater chance to hit. A straddling 10 round 400 yard sheaf crossing the "T" on a ship 200 yards long means up to 5 hits or near misses. Again, no charts or modifiers unless you want a little more accuracy or randomness. Now the player is confronted with the same problem and decisions as a real Gunnery Officer, range keeping (tracking the targets speed and bearing). In the above example it was +/- 500 yards. However, since you straddled with a 400 yard sheath you now know it is +/- 400 yards. So what does the Gunnery Officer do next? In most games you get die roll modifiers. In reality he has a choice of another 400 yard sheaf with a 50% chance to straddle and 1.2 hits or shortening with a lesser chance to straddle but getting more hits if straddling. Let's say he shortens the salvo sheath to 300 yards (if the fire control system can do that at the target range). Now he has a 35% chance to straddle and if he does a 10 round salvo lands each round an average of 30 yards apart. With the same 50 yard danger space divide 50 by 30 for 1.7 or one hit and a 70% chance for a second hit. Hopefully I've explained it clear enough so you get the idea. Now the target starts taking evasive action increasing the range keeping error. Things that effect the range keeping error are poor observation, losing sight of the target, maneuvering and failing to straddle. You can have these increasing the "range keeping error" in 50 yard increments. Now the player is faced with the same decisions as real Gunnery Officers. Firing longer sheafs will keep the target straddled but not decrease your range keeping error or increase the number of hits per straddle. A straddling 10 round 500 yard sheaf can almost guarantee one hit on a 50 yard danger space target if it straddles but only 50% of your salvos will straddle. If you straddle and the target cooperates and does not change course you can keep shrinking you salvo sheath length and increase chance to straddle and hits. If he takes evasive action your range keeping error increases but he cannot fire back while evading. You use the same tactics as real Gunnery Officers used rather than selecting modifiers. Personally I think this is more interesting and a better representation of naval warfare than most games I've seen or played. There are some that go into great detail but the player is basically looking up modifiers and rolling the dice with very little influence or decision making on the outcome. The game is reduced to dice rolling mechanics and charts but to each his own. This is a simplistic and somewhat abstracted simulation of what really occurs. I have not run this concept past anyone else that would understand, critique or correct it so I'd be interested in any opinions and corrections. Thanks, Wolfhag |
Blutarski | 18 May 2016 7:41 p.m. PST |
Wolfhag – email me at - byronangel ( at ) verizon ( dot ) net Byron |
Doctor X | 19 May 2016 1:23 p.m. PST |
Wolfhag – That would make for an interesting game but what size game are you looking for? I think this approach may have a problem scaling up to bigger engagements of more than a few ships per side unless you could automate or abstract some of this. In any case I think that the player as the "30,000' Admiral" would tend to resolve all firing solutions the same way the majority of the time whereas in a real battle individual ships may vary more in the gunnery solutions. |
Wolfhag | 19 May 2016 5:41 p.m. PST |
Doctor X, Yes, for small to medium sized engagements for people that want detailed gunnery and differences, like me. If you are looking for the big picture probably something like the HPGPM formula like on the navweaps site would fit better. That can be scaled to any game turn length. At that level I doubt if ROF differences would matter much either. My example is a salvo by salvo portrayal so a game turn is about one minute. Larger games seem to use 3-5 minutes a turn . Wolfhag |
Doctor X | 19 May 2016 8:18 p.m. PST |
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Wolfhag | 20 May 2016 8:13 a.m. PST |
Doctor X, HPGPM = Hits per gun per minute link H = 100 / [1 + k(R-2000)] where: H = percentage of hits k = 0.00070 R = Range (yards) Use this as a spreadsheet formula to generate value for different range increments. By using HPGPM you can have incremental damage and turrets being knocked out. If you are doing a straight percentage chance you can't really factor in # guns and ROF unless you start getting into some wicked math calculations. Using HPGPM increasing ROF would be equivalent to adding guns. Example: If you are using ROF = 1 with 8 guns to compute the HPGPM and ROF is increased to 1.5 then it is the same as 12 guns. You'll still need to do a calculation like 0.165 x 8 = 1.32 or 1 hit and a 32% chance for 2 hits. To make it easier you could generate a chart that handles most of the situations. If you want something that is simple, accurate and one die roll I strongly urge you check out Seas of War. It's free and the WWI supplement uses a single D100 roll to determine if you straddle and # of hits. The game turns are 2.5 minutes but you can scale the hit charts to get the modifiers, feel and level of damage you want in the game to make it playable. The guy who designed the game based it on real life results, not some tricky abstracted dice mechanics. Good luck, Wolfhag |
Doctor X | 20 May 2016 11:10 p.m. PST |
Wolfhag, Interesting charts, but everything looks to be WW2 and I am only interested in WW1. Was there a WW1 module that I might have missed? |
Doctor X | 20 May 2016 11:13 p.m. PST |
Also, I received Friedman's "Naval Weapons of WW1" and have been poking around in it. As far as I can tell, even in the text, ROF info is not given the majority of the time. Maybe I'm unlucky picking out guns but that's what I am finding. I also wish he could have used an even smaller font. <SARCASM ALERT> |
hindsTMP | 21 May 2016 11:20 a.m. PST |
As far as I can tell, even in the text, ROF info is not given the majority of the time. Maybe I'm unlucky picking out guns but that's what I am finding. Could you give me a few examples? Now I am feeling guilty for recommending the book. Maybe I am just more tolerant of extrapolations from other data in those cases. MH |
Wolfhag | 21 May 2016 11:43 a.m. PST |
Any question about realistic ROF will always be answered by "It depends". Here is the AAR from Jutland showing the ROF and hits. What is still hard for me to find is the exact way the salvos were fired: full or split. It makes a huge difference. I think very few ships were able to use max ROF in full salvos for very long because they could not feed ammo and propellant fast enough. This is the reason the Brits stacked it in their turrets and could have resulted in conflagration and explosion. Personally I'd go with half/split salvos. Jutland Gunnery Effectiveness from Campbell's book The Battlecruiser Action -- The Run to the South (1548-1654) Germans open fire at 1548, r16,000 British open w/ 13.5" at 1548.30, 12" at 1551 Lion straddles Lutzow w/ 9th salvo at 1553, 5 salvos in 2.5 min Princess Royal 5 salvos in 3 min 40 sec Lutzow 5 salvos in 3 min, hit w/ 5th Derfflinger 5 salvos in 3 min All used 4 gun salvos (larger obstructed target w/ splashes) Germans except Lutzow use APC, Lutzow semi-capped AP British except NZ use APC, NZ using CPC then nose-fuzed HE 1559 Ger BCs turn together 11 deg by 1600 r back to 16,000, by 1610 to 21,000 1601/2 RN BCs turn 30 deg away Lutzow 31 salvos 1548-1607 Lion 23 salvos 1548-1607 Von Der Tann 51 11" in 14-15 min KM ceases fire 1610 1611 RN destroyers ordered to clear range 1608 Barham fires at vdT r 19,000 w/ CPC,switches to APC 1609 Beatty orders DDs to attack 5th BS fire causes last 2 KM BCs to zig-zag 1626 DD action 1637 BC fire dies away, vis bad for RN Derrflinger firing: 1548-1626 49 salvos (25-6 @ PR, 11 @ QM, 10 @ PR, 2-3 @ L) Lutzow firing: 1548-1626 60 salvos Lion firing: 1548.30-1634 48 salvos |
Doctor X | 21 May 2016 3:21 p.m. PST |
HindsTMP – not a problem. I'd still get the book for all the other good stuff in it. I was just hoping the ROF info would be in there…somewhere…haha |