Aroooo Posted February 15, 2003 Report Share Posted February 15, 2003 [This is more a design question than a rules question...] When adapting, or even just creating, a vehicle, when determining the size (cost), should you use the vehicle's dimensions or mass as the primary governing factor? More specific (to help understand the question) example: I'm writing up B5 starships. I have length (and width in a few cases) and mass of the ships. When 'fitting' those numbers into the size chart, sometimes there is a great disparity between dimension and mass, in terms of where the ship fits in the size chart. An Explorer class ship is about 3000 inches long, but only 37 megatons. The size chart would make it either a cost of 175 points - based on length, giving the ship a mass of 3.2 gigatons; or it would be a cost of 145 points - based on mass, giving a length of only 800 inches. Which should I use? Aroooo Quote Link to comment Share on other sites More sharing options...
Chaosliege Posted February 15, 2003 Report Share Posted February 15, 2003 Re: Vehicle Construction - Size vs Mass Originally posted by Aroooo [This is more a design question than a rules question...] When adapting, or even just creating, a vehicle, when determining the size (cost), should you use the vehicle's dimensions or mass as the primary governing factor? More specific (to help understand the question) example: I'm writing up B5 starships. I have length (and width in a few cases) and mass of the ships. When 'fitting' those numbers into the size chart, sometimes there is a great disparity between dimension and mass, in terms of where the ship fits in the size chart. An Explorer class ship is about 3000 inches long, but only 37 megatons. The size chart would make it either a cost of 175 points - based on length, giving the ship a mass of 3.2 gigatons; or it would be a cost of 145 points - based on mass, giving a length of only 800 inches. Which should I use? Aroooo I think you can adjust the length up or the mass down, so it would simply be peronal prefernce. Quote Link to comment Share on other sites More sharing options...
Agent Escafarc Posted February 16, 2003 Report Share Posted February 16, 2003 Hey Aroooo, The term tons(I've also seen it spelled tonnes) when used with ship size is not a unit of weight but a unit of volume (the amount of water displaced by the hull) so a 1000 tons wooden ship is the same size as a 1000 tons metal ship though the dead weight of each is different. It's one of those confusing old English measuring systems. I'm suddenly blank on the exact size in cubic meters but only number in my head this early in the morning is 4 cubic meters but that seems too small Quote Link to comment Share on other sites More sharing options...
Monolith Posted February 16, 2003 Report Share Posted February 16, 2003 Sometimes it is impossible to match up stats with items, but keep in mind that the item you are trying to create was designed by a scriptwriter, not a scientist. If a vehicle engineer were designing the Explorer class it might be far lighter or heavier. But to make things match all you have to do is buy some extra STR and Knockback Resistance for the vehicle; SFX being that it is heavier (works just like Density Increase, only we do not buy DI always on any more). Quote Link to comment Share on other sites More sharing options...
Syberdwarf2 Posted February 16, 2003 Report Share Posted February 16, 2003 My biggest hang-up (the only one actually), with the Vehicl rules was not a question of Mass. It was a question of Height. SIZE provides for length and width (Area). It doesn't touch on height (l*w*h). For example; I started working on a writeup for the Andromeda Ascendant. I've figured the L x W, in game terms. But how tall would it be? How many deck levels? etc. Quote Link to comment Share on other sites More sharing options...
Agent Escafarc Posted February 16, 2003 Report Share Posted February 16, 2003 Originally posted by Syberdwarf2 My biggest hang-up (the only one actually), with the Vehicl rules was not a question of Mass. It was a question of Height. SIZE provides for length and width (Area). It doesn't touch on height (l*w*h). For example; I started working on a writeup for the Andromeda Ascendant. I've figured the L x W, in game terms. But how tall would it be? How many deck levels? etc. Just like Bases each deck's L x W are added together to figure the total area. Quote Link to comment Share on other sites More sharing options...
Talon Posted February 16, 2003 Report Share Posted February 16, 2003 TUV answers this question, but I can't remember what the answer is. I think the default is to base the Size stat on the vehicles length (or longest dimension). Quote Link to comment Share on other sites More sharing options...
Aroooo Posted February 16, 2003 Author Report Share Posted February 16, 2003 Originally posted by Agent Escafarc Hey Aroooo, The term tons(I've also seen it spelled tonnes) when used with ship size is not a unit of weight but a unit of volume (the amount of water displaced by the hull) so a 1000 tons wooden ship is the same size as a 1000 tons metal ship though the dead weight of each is different. It's one of those confusing old English measuring systems. I'm suddenly blank on the exact size in cubic meters but only number in my head this early in the morning is 4 cubic meters but that seems too small I understand displacement tons. I got the impression that SH was dealing in mass, not displacement. But then you get into the old habit of trying to fit everything in the volume of a ship Like others have suggested, I've just gone with length in most cases, and disregarded the mass column where it is 'off' from the 'real world' stats I have. In those few cases where I have length and width, I've used area as the basis for the vehicle's size. I keep having to remind myself its about the effect, not the 'hard' reality Aroooo Quote Link to comment Share on other sites More sharing options...
Syberdwarf2 Posted February 16, 2003 Report Share Posted February 16, 2003 Originally posted by Agent Escafarc Just like Bases each deck's L x W are added together to figure the total area. So to use my ealier example; The Andromeda measures in at Length (657 hexes), Width (164 hexes, and Height (493 hexes). Assuming 1 hex= 6.5 feet, that's 4270.5, 1066, and 3204.5 feet respectively. With L x W to figure SIZE that's an area of107748 square hexes. Cost for that much area (closest figure in SH expanded vehicle chart is 125000 sq hexes) is 135 points. Now the juicy part,...... The height is 493 hexes. Assuming that the average deck is 10 feet tall (approx. 1.5 hexes to make it easy), that would give the Andromeda..... 328 decks!.... Okay, so let's whittle that down. Make the average deck height 2 hexes; 246 decks. Now (only if all decks are the same size), 135 points times 246 decks comes to 33,210 character points. ugh......... Quote Link to comment Share on other sites More sharing options...
Chaosliege Posted February 16, 2003 Report Share Posted February 16, 2003 Originally posted by Aroooo Like others have suggested, I've just gone with length in most cases, and disregarded the mass column where it is 'off' from the 'real world' stats I have. In those few cases where I have length and width, I've used area as the basis for the vehicle's size. I keep having to remind myself its about the effect, not the 'hard' reality Aroooo Another thing to remember when talking about starships. There are no 'real world' stats. It's still just a game. Quote Link to comment Share on other sites More sharing options...
Agent Escafarc Posted February 16, 2003 Report Share Posted February 16, 2003 Originally posted by Aroooo I understand displacement tons. I got the impression that SH was dealing in mass, not displacement. But then you get into the old habit of trying to fit everything in the volume of a ship Like others have suggested, I've just gone with length in most cases, and disregarded the mass column where it is 'off' from the 'real world' stats I have. In those few cases where I have length and width, I've used area as the basis for the vehicle's size. I keep having to remind myself its about the effect, not the 'hard' reality Aroooo L x W is fine for a vehicle with a single "deck" but for larger ships with multible decks you should add the area of each deck to come up with the vehicle size. HERO does use mass for it's size charts, but most outside sources use displacement for ship/starship descriptions. Quote Link to comment Share on other sites More sharing options...
Aroooo Posted February 16, 2003 Author Report Share Posted February 16, 2003 Originally posted by Agent Escafarc L x W is fine for a vehicle with a single "deck" but for larger ships with multible decks you should add the area of each deck to come up with the vehicle size. HERO does use mass for it's size charts, but most outside sources use displacement for ship/starship descriptions. Oh, I agree. When you're designing star ships from scratch, or adapting ships that have a lot of data available (like deck plans), its easy to get l*w*h and number of decks. But when you're working with only partial info, its hard. Aroooo Quote Link to comment Share on other sites More sharing options...
Chaosliege Posted February 16, 2003 Report Share Posted February 16, 2003 With the size you're obviously talking about, I'd buy it as a base. I've never tried anything like that, but there must be a way. Quote Link to comment Share on other sites More sharing options...
Agent Escafarc Posted February 16, 2003 Report Share Posted February 16, 2003 Originally posted by Syberdwarf2 So to use my ealier example; The Andromeda measures in at Length (657 hexes), Width (164 hexes, and Height (493 hexes). Assuming 1 hex= 6.5 feet, that's 4270.5, 1066, and 3204.5 feet respectively. With L x W to figure SIZE that's an area of107748 square hexes. Cost for that much area (closest figure in SH expanded vehicle chart is 125000 sq hexes) is 135 points. Now the juicy part,...... The height is 493 hexes. Assuming that the average deck is 10 feet tall (approx. 1.5 hexes to make it easy), that would give the Andromeda..... 328 decks!.... Okay, so let's whittle that down. Make the average deck height 2 hexes; 246 decks. Now (only if all decks are the same size), 135 points times 246 decks comes to 33,210 character points. ugh......... From your example your total number of hexes would be 26,506,008 sq hexes which would 195 pts you don't have to by each deck separtly:) Quote Link to comment Share on other sites More sharing options...
Syberdwarf2 Posted February 16, 2003 Report Share Posted February 16, 2003 Originally posted by Agent Escafarc From your example your total number of hexes would be 26,506,008 sq hexes which would 195 pts you don't have to by each deck separtly:) Let's see......657 times 164 times....... yup. What you said. Thank you, thank you, thank you. Quote Link to comment Share on other sites More sharing options...
Fuzzy Gnome Posted February 16, 2003 Report Share Posted February 16, 2003 Doesn't the law of buoyancy require mass and displacement to be identical? Is there some subtlety of naval architecture I'm missing or am I just wacked? Quote Link to comment Share on other sites More sharing options...
Dr. Anomaly Posted February 17, 2003 Report Share Posted February 17, 2003 Originally posted by Fuzzy Gnome Doesn't the law of buoyancy require mass and displacement to be identical? Is there some subtlety of naval architecture I'm missing or am I just wacked? Hardly. Take a mass of 10 kg as 1) a lump of lead 2) a lump of Styrofoam. Submerge them both in water (it will take quite a bit of force to make the Styrofoam submerge). The Styrofoam, when submerged, will displace FAR more water than the same-mass lump of lead...and thus they displace a different 'tonnage' of water, since the greater volume of water displaced by the Styrofoam will mass a great deal more than the mass of water displaced by the lead. Quote Link to comment Share on other sites More sharing options...
Dr. Anomaly Posted February 17, 2003 Report Share Posted February 17, 2003 Originally posted by Chaosliege With the size you're obviously talking about, I'd buy it as a base. I've never tried anything like that, but there must be a way. Sorry, no can do. The rules explictly state: "Bases cannot buy movement. If you want a moving base, buy a really large vehicle." Quote Link to comment Share on other sites More sharing options...
Agent Escafarc Posted February 17, 2003 Report Share Posted February 17, 2003 Originally posted by Fuzzy Gnome Doesn't the law of buoyancy require mass and displacement to be identical? Is there some subtlety of naval architecture I'm missing or am I just wacked? In this case it doesn't have anything to do with buoyancy it's strickly a measure of volume. Here's example: If you had two solid cubes one foot on the side, one made of steel and one made of copper, they would have a different mass but would both displace one cubic foot of water. Like I said earlier it's and old English mearsurment Quote Link to comment Share on other sites More sharing options...
BasilDrag Posted February 17, 2003 Report Share Posted February 17, 2003 Originally posted by Syberdwarf2 So to use my ealier example; The Andromeda measures in at Length (657 hexes), Width (164 hexes, and Height (493 hexes). Assuming 1 hex= 6.5 feet, that's 4270.5, 1066, and 3204.5 feet respectively. With L x W to figure SIZE that's an area of107748 square hexes. Except that a "hex" of area is the area of a hex 2m from side to side, or 2*sqrt(3) square meters. So it's (657*2) * (164*2) / (2*sqrt(3)) = 124,417 hexes in area, or almost exactly 135 points Cost for that much area (closest figure in SH expanded vehicle chart is 125000 sq hexes) is 135 points. Now the juicy part,...... The height is 493 hexes. Assuming that the average deck is 10 feet tall (approx. 1.5 hexes to make it easy), that would give the Andromeda..... 328 decks!.... Okay, so let's whittle that down. Make the average deck height 2 hexes; 246 decks. Now (only if all decks are the same size), 135 points times 246 decks comes to 33,210 character points. ugh......... No, no, no, no. You add all the areas, then look that up on the chart. 124,417 * 246 = 30,606,582, which is closest to 195 points. Or, you could say each doubling of area adds ~7.5 points, and 246 decks is ~8 doublings, for +6 points. Quote Link to comment Share on other sites More sharing options...
BasilDrag Posted February 17, 2003 Report Share Posted February 17, 2003 Originally posted by Agent Escafarc Hey Aroooo, The term tons(I've also seen it spelled tonnes) when used with ship size is not a unit of weight but a unit of volume (the amount of water displaced by the hull) so a 1000 tons wooden ship is the same size as a 1000 tons metal ship though the dead weight of each is different. It's one of those confusing old English measuring systems. I'm suddenly blank on the exact size in cubic meters but only number in my head this early in the morning is 4 cubic meters but that seems too small A) There is no reason to believe Steve Long et al. were using "tons" as anything but a unit of mass. a "ton" in the sense you refer to is one cubic meter (because one cubic meter of water masses on "metric ton"---properly, a megagram) C) Further, the "tons" you refer to do not measure the overall volume of the hull, but rather the volume (of water) displaced when the ship is carrying its maximum safe load. D) there are a number of "tons" used to refer to the size of a ship, only one of which has to do with it's displaced volume E) As a counter example, consider Traveller, where a ship's "ton" in 14 cubic meters (because liquid hydrogen masses about 1 megagram per 14 cubic meters) Quote Link to comment Share on other sites More sharing options...
Syberdwarf2 Posted February 17, 2003 Report Share Posted February 17, 2003 umm, okay... Originally posted by BasilDrag Except that a "hex" of area is the area of a hex 2m from side to side, or 2*sqrt(3) square meters. So it's (657*2) * (164*2) / (2*sqrt(3)) = 124,417 hexes in area, or almost exactly 135 points No, no, no, no. You add all the areas, then look that up on the chart. 124,417 * 246 = 30,606,582, which is closest to 195 points. Or, you could say each doubling of area adds ~7.5 points, and 246 decks is ~8 doublings, for +6 points. If you read my next post after that, I'd already fixed the problem with my math (thanx to the help of a fellow herophile). The problem was not so much with the numbers I was using as it was with my Order of Operations. --Syber "Please Excuse My Dear Aunt Sally" dwarf2 Quote Link to comment Share on other sites More sharing options...
Hawksmoor Posted November 14, 2004 Report Share Posted November 14, 2004 Re: Vehicle Construction - Size vs Mass Sorry' date=' no can do. The rules explictly state: "Bases cannot buy movement. If you want a moving base, buy a really large vehicle."[/quote'] But what about the manuvering rockets on the Space BAse in Champions? I am not arguing, I built Miranda the GGU/Dawnstars SuperJet, as a REALLY big vehicle, but it seems you can add some movement to a Base if the Base has the right SFX. Hawksmoor Quote Link to comment Share on other sites More sharing options...
Chris Goodwin Posted November 14, 2004 Report Share Posted November 14, 2004 Re: Vehicle Construction - Size vs Mass Wow, holy crap. Extreme thread necromancy. I do it by mass. It seems to me that many of the designs I've read have done it by size. Quote Link to comment Share on other sites More sharing options...
Hawksmoor Posted November 14, 2004 Report Share Posted November 14, 2004 Re: Vehicle Construction - Size vs Mass Liked that did ya? Hawksmoor -Who needs Fantasy Hero? Quote Link to comment Share on other sites More sharing options...
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