Battlestations uses the speed chart from the North Texas Battle Group. I am trying to extend the list a little bit. Can some one give me the formula used to calculate it? Thanks, James
I can help with that. The Big Gun Speed Chart is based on something called Dynamic Similitude Speed. DSS = speed * SQRT(scale) an example, 25 knots in 1/144 DSS: 25 kts * SQRT(1/144) = 25 kts * 1/12 = 2.0833 kts = 3.516 ft/s = 28.4 seconds per 100 feet The big gun speed chart is actually 63.1% of 1/144 scale DSS. The same speed would be 50.8% of 1/96 scale DSS. Big Gun speed = historical speed * 0.631 * SQRT(1/144) Battlestations speed = historical speed * 0.508 * SQRT(1/96) Note that Big Gun speed and Battlestations speed will be the same, because they use the same speed chart, so you can use either calculation to extend the chart. Another interesting point is that 1/10 KPH is ALMOST exactly 1 knot on the speed chart. That is, 2.2 KPH is very close to 22 knots and 3.5 KPH is very close to 35 knots, and so on. It turns out that the precision of the radar gun used for speed checks in the WWCC is less than the difference between the KPH and the speed chart, so it could be used with no noticeable difference in performance. I hope that answers the question.
Now it begs the question as to whether or not I should recalculate the Battlestations speed chart to make it based on a scale speed. We are currently using a 1/144 scale chart for 1/96 scale ships. As it would be a ton of work to change all the ship lists I think I shall leave things as they are.
DSS is used by ship and airplane designers when testing scale models. Because water and air don't scale down very well, DSS is the best approximation to "scale speed" possible. In other words, DSS is scale speed. The big gun chart is actually a fraction of scale speed. 25 knots on the big gun chart corresponds to 63.1% of 25 knots in 1/144 DSS, and also corresponds to 50.8% of 25 knots in 1/72 DSS. Full DSS in 1/96 will be much closer to fast gun speeds. A rough estimate indicates that 25 knots in 1/96 DSS would be around 23 seconds. Can you imagine the power that will take to get a battleship up to speed? Yes, 1 knots is 1.68710 ft/s.
The Fletcher is listed in Conways at 38 knots. That is equivalent to 3.8 kph and 2.36 mph hehe, I still find this amusing, Tugboat.
reguarding how much power it would take to get ships up to speed, if people in Battlestations want to use the formula to make its own speed charts it could eliminate the minimum speed and it doesn't really take too much to get even the biggest up to speed. found this out when my Yammer was hydroplaning 8) (I'll get some pics of this soon)
For anyone misreading KPH used here is km/h not knots/hr (which is kind of redundant). So, to reiterate 2.1 km/h (kilometers/hr) = 21 knots. Haven't done the math, but I am thinking that 0.1 mph per knot would be getting pretty close to appropriate for 1/96. So 2.3mph would be 23 knots. Easy to caldulate and measure. But, of course, if you want to stay with the speeds you are used to, 0.1 km/h per know makes it really easy to extend the chart both directions. Cheers,
Arise dead thread!! So, I had a bit of a debate while at the IRCWCC nats. Essentially my argument was this: All model warship comabt speeds are way faster than actual scale speeds. They insisted they were actually pretty close. I said that they might be close to the simulated speed (DSS: dynamic similtude speed) but no where close to the actual scaled down speed. I then presented that my Capitani Romani would cover a little less than 6" per second in actual scale speed. He said I was way off. I didn't have the math handy at the time to argue my point. My math: Capitani Romani= 41knots 1 knot (nautical mile)= 6076ft by international standard (hooyah, me being qualified quartermaster of the watch and navigation plotter) 41kts= 249116ft/hr 249116ft/hr= 1729.97ft/hr in 1/144 1729.97ft/hr= 28.83 ft/min 28.83ft/min= .481ft/sec .481sec/min= 5.77in/sec Time for 100ft course= 208sec or 3min28sec By my calculations... not even close in big gun. Much less the fast gun style speeds we were referencing. Mike "I did speed conversions to stay awake for the mid-watch while on deployment" Butts MN2 USN QMOW (quartermaster of the watch) BMOW (bos'n mate of the watch) JOOD (no real PQS, I still stood it though) Master Helmsman Navigation Plotter Radar Operator qualified VMS operator (Voyage Management System)... electronic navigation moboard master (maneuvering board) ........I know navigation/distance/speed Just the tip of my qualification iceberg;-)
I suspect that speed calculations may scale better proportionally between scales versus linear, i.e. such as mass calculations between scaled objects. For instance, object 1 is 1:1 scale. The same object in 1:2 scale (half sized) would only have 25% of the mass of the 1:1 object. If this was applied to scaled speeds: 249116ft/hr / 36 (25% of 144) = 6919 ft/hr 6919ft/hr / 60 (min per hr) = 115 ft/min 115 ft/min / 60 (secs per min) = 1.9ft/sec 100 ft (testing distance) / 1.9ft/sec = 52 seconds for a 100ft course. I bet that is closer to Big Gun speeds which use DSS calculations. I think I heard someplace that the fast gun speed charts were developed on a “that looks like a scale bow wave” type of thing. It is probably much more complicated than that though. Heh.
The basic problem when trying to calculate the scale of Fast Gun speeds is that they are not based on the historical ships's speed, but rather on class and hull length. Thus you can have two ships that historically went nearly identical speeds, but end up 2 seconds apart or more on the Fast Gun speed chart. There are both advantages and disadvantages to the system, but one disadvantage is that you simply cannot determine how "Fast Gun speeds" compare to scale or DSS speeds. You can only calculate how individual ships compare. I think, Mike, that your calculations prove beyond a shadow of a doubt why no club uses linear scale speed. If your Capitani Romani used linear scale speed, it would get blown backwards by even a moderate breeze.
A funny story about fast gun speeds ... A WW2 fast battleship looks good moving at 24 sec/100ft. The bow wave and water movement is fairly realistic. On the other hand, pre WW1 era ships in fast gun try to submerge at 28 seconds. The Verite PDN at 28 second speed is practically underwater. I can actually tell if the ship is on speed by how far the water travels back over the bow ... if the water starts sloshing against the front of A turret, then the ship is very close to 28 seconds. Heh.
Fast gun speeds use the Froude Number and are grouped into catagories (24 sec, 26 sec, 28 sec etc.) it basically comes out to speed by length since length drives the boat (pun intended) in the equation. Yes there are some exceptions where ships were moved around for various reasons. One big thing to remember is that while we scale down the boats we dont scale down the water, we still play on 1:1 water. It isnt a perfect solution but again the goal was to have something that was playable and fun, hard to argue that it isnt. Remember this is a game (played with scale looking ships, not much else really relates to actual warfare) and ment to be playable and fun, if you want to wait for 3.5 min for your boat to go 100ft go for it but that doesnt sound very fun or exciting. (but I imagine you would have significantly longer battles....) Other things we dont scale: Weapons/Ammo (what about big gun, haha sure, even different size guns are stupidly not scale, BBs would be about 25.5" shells scaled up, nobody complains about that ) HE (you mean exploding shells do more damage?) Armor (real ships didnt have uniformly thick armor, or internal armor that could stop every round) Range (5000' in real life (which is very short range for a naval engagment) is ~34.7' inscale, we fight at less than 5', often inches.) Death (I for one am very glad this hasn't been included in the hobby.) Weather Damage Control (Bulkheads, counter flooding, etc) Fire Control (wait? warships weren't controlled but really huge people standing thousands of yards away in real war?? damn history books...) Planes (in WW2 how many ships were sunk by planes vs surface fire) Submarines\Torpedos (not that these had any impact on naval warfare/tactics/etc...oh wait) ... you get the point I hope.
With all that said, I am glad to hear my math was on point. Also it definitely confirms (what I now know the terminology for) linear scale speed is useless to us. I have not seen treaty speeds yet however, I do think they are going to be the best as far as gameplay. I think the speed spread is too close in fast gun and the overall speeds are kinda slow in big gun. I think treaty allows fast ships to be truely fast i.e. a Capitani Romani will have an 11sec advantage over an Iowa. Certain subtleties are nice too. German dreadnaughts lose a bit of speed lowering their awesome maneuverability same with many fast battleships. No system is perfect but treaty is doing a good job of balancing things IMO. While massively fun, regular fast gun has an insane pace and the unlimited factor with pump design is crazy. I saw a couple of 60-80amp pumps that people had developed. Thats just crazy, were talking almost 1000w in a 12v setup! Mike Butts MN2 USN
Actually, the small ships in Treaty turn just as good, if not better, than the fast gun small ships. The slower Treaty speeds allows the ship to turn more instead of skidding. Watch one of the fast gun ships go into a turn. As speed bleeds off in the turn, watch the turning radius tighten up. Small ships still turn better than big ships, especially at Treaty speeds.
