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atgxtg
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 Posted: Fri Jun 11, 2010 11:27 pm Post subject: |
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[quote="Grimace"] | atgxtg wrote: |
That's what I was trying to get you to think about. |
Aw! Jedi Mind Trick!  No fair! 
Well, you succeeded. I thought of it. I even though of using the New Essential Guide to Vehicles as a possibility and matching up the SPACE ratings with the acceleration in the New Guide.
((Thrust/Mass)^0.9) /175 for example.
I even went and checked some data such as tonnage and power to weight ratio of some real jet engines to see how viable the idea is. It seems quite viable. Turns out commerical jet liners sometimes used the same engines as fighter jets, although the commerical jets needed more engines and moved slower.
| Grimace wrote: |
Basically, like you said, use some techno-babble like your "gravimetric resistance" or whatever and make the addition of more engines useful but not nearly as efficient as buying a single, better engine. That, coupled with the additional tonnage and more energy usage, will make most think twice about doing it to save some credits. Sure you'll have some that want the "acme rocket" variety of ship with multitudes of lower grade engines for a cheaper price, and they'll get some added benefit of greater speed, but not near what they would get if they invested more credits and bought a better single engine. |
That does seem like the best way to make "engine stacking" undesirable. At least with low output engines. Naturally, it should still be worthwhile to pair up higher output engines like they do on A-Wings and X-Wings. In those cases it will make sense because they can't find more powerful engines. They are probably at the cutting edge.
A square root progression seems to work okay, save for the Millennium Falcon. With the square root formula, either it has engines better than an A-Wing, or it has to have a bigger engine than 16 tons. On the other hand it might just explain why those SPACE 10 and 12 engines are so horribly expensive in Tramp Freighters.
I've got a table with some sample engine designs (A-Wing, X-Wing, TIE fighters, etc). that I'll try to put up here to see if it passes inspection.
One nice thing about a square root progression is that it should scale down nicely for vehicles. I know it works out well for cars, so it will probably be "close enough" for speeders and walkers. |
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atgxtg
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Joined: 22 Mar 2009
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| Posted: Sun Jun 13, 2010 2:07 pm Post subject: Benchmarking |
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Does anyone know good source for cutaways or other images that can give me a hint as to how big to make the engines on ships? Some ships are easy, with A-Wings and X-Wings the engines are pretty noticeable, but for some other ships (TIE fighters) it gets tougher.
I've got several formulas that could be made to work for ships, depending no how big and efficient we want the engines to be.
For example, assuming an A-Wing masses 96 mt, do we want it to have 20 tons of engines, 16 tons, 12? or something else?
And does 18 tons of engine sound like too much for a TIE Interceptor?
Here is a table with some possible test vaules using a spqare root progression for SPACE.
Ship mt Engines Thrust SPACE MGLT SPACE
A-Wing (120MGLT) 96 16 870 12 120 12
A-Wing (J77 match) 96 18 770 12 120 12
A-Wing 20t engine 96 20 690 12 120 12
A-Wing 4.9m 39 8 700 12 120 12
A-Wing (7700 thrust engines 96 16 960 12 126 13
A-Wing (150MGLT) 96 16 1350 12 150 15
B-Wing 169 12 500 6 60 6
B-Wing (75MGLT) 169 12 800 6 75 8
Cloakshape 150 12 500 6 63 6
Cloakshape (fit) 150 12 600 6 69 7
Vulturedroid 36 8 450 10 100 10
Delta 7 80 8 600 8 77 8
Delta 7 80 8 1000 12 100 10
X-Wing 125 16 500 8 80 8
X-Wing 125 16 500 8 80 8
X-Wing (100MGLT) 125 16 750 10 98 10
X-Wing (100MGLT) 125 16 750 10 98 10
Y-Wing 160 20 450 7 75 8
Y-Wing (100MGLT) 160 20 750 7 97 10
Z-95 118 14 410 7 70 7
TIE Bomber (MGLT 60) 78 6 470 6 60 6
TIE fighter 63 12 520 10 100 10
TIE Intercetpor 96 14 800 11 108 11
TIE Intercetpor 96 18 650 11 110 11
TIE Intercetpor (125MGLT) 96 16 920 11 124 12
Nabbo Starfighter 110 10 900 9 90 9
YT-1300 267 10 400 4 39 4
Mil. Falcon 270 24 700 8 79 8
Mil. Falcon (75MGLT) 270 24 640 8 75 8
Mil Falc (16 ton engine) 270 16 950 8 75 8
SLF 250 10 400 4 40 4
Tramp Freighters Test
SLF 4 250 10 400 4 40 4
SLF 6 250 12 740 6 60 6
SLF 8 250 16 950 8 78 8
SLF 10 250 18 1380 10 100 10
SLF 12 250 24 1500 12 120 12
Tramp Freighters Revised
SLF 4 250 10 400 4 40 4
SLF 6 250 16 560 6 60 6
SLF 8 250 24 590 8 75 8
SLF 10 250 28 850 10 98 10
SLF 12 250 40 850 12 117 12
Some feedback will help me work out some engine efficiencies. Right now I can go in several different directions. |
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ZzaphodD
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Joined: 28 Nov 2009
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| Posted: Sun Jun 13, 2010 2:52 pm Post subject: |
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| atgxtg wrote: | | ZzaphodD wrote: | | One of the main reason for having twin engines on fighters is for safety reasons. If one cuts out, you have the other one as a backup. Two engines are not more effective. |
In many situations they are. There are a host of design considerations that go into real world craft that won't be a factor for RPG purposes. For instance the merits of placing the engine in the front, middle or rear of a vehicle.
| ZzaphodD wrote: |
You have the answers in the example about the V10 (even if your starting reasoning is wrong as were talking two 'cheap' engines). Two engines = thrice the weight. Do the same thing for starships and you are home free. |
No, I'm not home free because starship engines are so efficient. Going back to the V10 example, the engine weights something along the lines of 325kg, or about a fifth the weight of, say, s Dodge Viper. Adding a second engine would increase the mass of the car by 20%
By comparison the engine on a "light Freighter" in Star Wars only weights 10 ton, or only 4% of the mass of the freighter. Adding a second engine would increase the mass of the freighter by only 4%. In fact, not even that, since the 10 tons will probably come off of the cargo capacity. The engines in Star Wars are a few thousand times more efficient that what we can come up with today.
That is one reason why in the real world they make more powerful engines-so they can get more bang for the buck. In Star Wars, they are getting such a high power output that the weight cost is negligible. So the added weight isn't as a discouraging a factor as in would be in life.
If the engines on a TY-1300 massed 50 tons or so then tossing in 2, 3 or 4 engines for more speed just isn't practical. You'd have to gut the ship just to find the room. But at 10 tons, tossing in an extra engine or 3 is not much of a problem.
I still think the best solution is to limit the speed they way planes, ships and cars are limited in real life, by a non linear increase between power and speed. |
Regarding the weight of engines. Remember that TF dont assume you are going to build a ship from scratch, but insted swap engines. The actual weight is less of an issue than the weight difference between engines. Also, we do not know the total tonnage in those rules, only the cargo capacity.
Having an engine weighs only about 4-5% of the total tonnage is perhaps a bad starting point. As you point out weight issues from stacking 'cheap' engins becomes a non-issue when so little of the total weight is from engines.
So, is the obvious solution to increase the weight of engines overall? |
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garhkal
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| Posted: Sun Jun 13, 2010 11:17 pm Post subject: |
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| ZzaphodD wrote: |
Nah, dont drop the EU. It opens up for different options and tactics like 'all power to the rear deflector shields' which are not really availible today. Also, with a damaged ship, power drops and the crew has to prioratize (is that a word in english? It is in swedish) what systems to run.
I would also add Power core to the list of ship components.
Darn I hade a lot of different options for ships made up years ago(I think 5 different versions of armor, lots of engines, etc). To bad both all my SW books and papers are gone, and the digital version disappeared in a HD swap over the years. |
Agreed. A while back when stationed in London, we had this one gm (magestones iirc was his screen name) who had this mass of rules for ship construction, including power source, fuel etc.
PS, if you want it, it is 34 pages long in a word doc. PM me your email and i can send it your way.
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Confucious sayeth, don't wash cat while drunk! |
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ZzaphodD
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Joined: 28 Nov 2009
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| Posted: Wed Jun 16, 2010 4:09 pm Post subject: Re: Benchmarking |
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| atgxtg wrote: | Does anyone know good source for cutaways or other images that can give me a hint as to how big to make the engines on ships? Some ships are easy, with A-Wings and X-Wings the engines are pretty noticeable, but for some other ships (TIE fighters) it gets tougher.
I've got several formulas that could be made to work for ships, depending no how big and efficient we want the engines to be.
For example, assuming an A-Wing masses 96 mt, do we want it to have 20 tons of engines, 16 tons, 12? or something else?
And does 18 tons of engine sound like too much for a TIE Interceptor?
Here is a table with some possible test vaules using a spqare root progression for SPACE.
Ship mt Engines Thrust SPACE MGLT SPACE
A-Wing (120MGLT) 96 16 870 12 120 12
A-Wing (J77 match) 96 18 770 12 120 12
A-Wing 20t engine 96 20 690 12 120 12
A-Wing 4.9m 39 8 700 12 120 12
A-Wing (7700 thrust engines 96 16 960 12 126 13
A-Wing (150MGLT) 96 16 1350 12 150 15
B-Wing 169 12 500 6 60 6
B-Wing (75MGLT) 169 12 800 6 75 8
Cloakshape 150 12 500 6 63 6
Cloakshape (fit) 150 12 600 6 69 7
Vulturedroid 36 8 450 10 100 10
Delta 7 80 8 600 8 77 8
Delta 7 80 8 1000 12 100 10
X-Wing 125 16 500 8 80 8
X-Wing 125 16 500 8 80 8
X-Wing (100MGLT) 125 16 750 10 98 10
X-Wing (100MGLT) 125 16 750 10 98 10
Y-Wing 160 20 450 7 75 8
Y-Wing (100MGLT) 160 20 750 7 97 10
Z-95 118 14 410 7 70 7
TIE Bomber (MGLT 60) 78 6 470 6 60 6
TIE fighter 63 12 520 10 100 10
TIE Intercetpor 96 14 800 11 108 11
TIE Intercetpor 96 18 650 11 110 11
TIE Intercetpor (125MGLT) 96 16 920 11 124 12
Nabbo Starfighter 110 10 900 9 90 9
YT-1300 267 10 400 4 39 4
Mil. Falcon 270 24 700 8 79 8
Mil. Falcon (75MGLT) 270 24 640 8 75 8
Mil Falc (16 ton engine) 270 16 950 8 75 8
SLF 250 10 400 4 40 4
Tramp Freighters Test
SLF 4 250 10 400 4 40 4
SLF 6 250 12 740 6 60 6
SLF 8 250 16 950 8 78 8
SLF 10 250 18 1380 10 100 10
SLF 12 250 24 1500 12 120 12
Tramp Freighters Revised
SLF 4 250 10 400 4 40 4
SLF 6 250 16 560 6 60 6
SLF 8 250 24 590 8 75 8
SLF 10 250 28 850 10 98 10
SLF 12 250 40 850 12 117 12
Some feedback will help me work out some engine efficiencies. Right now I can go in several different directions. |
I think we have to lower the weight of the starfighters. An A-Wing is just under 10 meters long. Compare the weight to an 15 m F16 with a fully loaded weight of 12 tons. Even though an A-wing is not really supposed to operate primarily in atmosphere by the lifting power of its wings, I think 96tons is a bit much.
Total weight aside, the jet engine of the F16 weights about 2 tons, which is about 1/6 of the total loaded weight. Looking at the picture of an A-wing one can assume that each of the A-wings engines is about the same size as the F16 engine (as the smaller version at about 1,75 tons). Id say that the A-wing engines should weight about 3,5-4,5 tons.
BTW, all the numbers above for different ship types, what do they mean? |
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ZzaphodD
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Joined: 28 Nov 2009
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| Posted: Wed Jun 16, 2010 4:18 pm Post subject: |
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| garhkal wrote: | | ZzaphodD wrote: |
Nah, dont drop the EU. It opens up for different options and tactics like 'all power to the rear deflector shields' which are not really availible today. Also, with a damaged ship, power drops and the crew has to prioratize (is that a word in english? It is in swedish) what systems to run.
I would also add Power core to the list of ship components.
Darn I hade a lot of different options for ships made up years ago(I think 5 different versions of armor, lots of engines, etc). To bad both all my SW books and papers are gone, and the digital version disappeared in a HD swap over the years. |
Agreed. A while back when stationed in London, we had this one gm (magestones iirc was his screen name) who had this mass of rules for ship construction, including power source, fuel etc.
PS, if you want it, it is 34 pages long in a word doc. PM me your email and i can send it your way. |
Thank you! I looked it over, and while its a bit too complicated than what Im comfortable with, I will definitely use it as inspiration. A lot of new ideas, and ideas of how to rewrite what I already have. |
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atgxtg
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| Posted: Thu Jun 17, 2010 12:56 pm Post subject: |
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[quote="ZzaphodD"][quote="atgxtg"] | ZzaphodD wrote: |
Regarding the weight of engines. Remember that TF dont assume you are going to build a ship from scratch, but insted swap engines. The actual weight is less of an issue than the weight difference between engines. Also, we do not know the total tonnage in those rules, only the cargo capacity.
Having an engine weighs only about 4-5% of the total tonnage is perhaps a bad starting point. As you point out weight issues from stacking 'cheap' engins becomes a non-issue when so little of the total weight is from engines. |
It7s not the starting point that I'd have chosen to go with, but I'm stuck with it, thanks to Tramp Freighters.
| ZzaphodD wrote: |
So, is the obvious solution to increase the weight of engines overall? |
Not without contracting everything in Tramp Freighters. |
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ZzaphodD
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| Posted: Thu Jun 17, 2010 1:07 pm Post subject: |
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[quote="atgxtg"][quote="ZzaphodD"] | atgxtg wrote: | | ZzaphodD wrote: |
Regarding the weight of engines. Remember that TF dont assume you are going to build a ship from scratch, but insted swap engines. The actual weight is less of an issue than the weight difference between engines. Also, we do not know the total tonnage in those rules, only the cargo capacity.
Having an engine weighs only about 4-5% of the total tonnage is perhaps a bad starting point. As you point out weight issues from stacking 'cheap' engins becomes a non-issue when so little of the total weight is from engines. |
It7s not the starting point that I'd have chosen to go with, but I'm stuck with it, thanks to Tramp Freighters.
| ZzaphodD wrote: |
So, is the obvious solution to increase the weight of engines overall? |
Not without contracting everything in Tramp Freighters. |
But what point is it to stick to tramp freighters very limited 'system' (not even a system) when your doing a complete ship building system? As allready pointed out, when doing a system where you just switch engines and other parts, without having to take into consideration the whole ship building process, they dont need to make sense. You need to if you want a complete system. If you dont change them I think your stuck. |
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atgxtg
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| Posted: Thu Jun 17, 2010 1:24 pm Post subject: Re: Benchmarking |
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| ZzaphodD wrote: |
I think we have to lower the weight of the starfighters. |
The 96 tons goes with what they used in D6 Space, and appears to be what WEG went with (19 times the length). In D6 the A-Wing is as tough as an old tank, with a 2D+2 Hull (starfighter scale).
Reducing the mass would cause one major problem:
The body STR forumula would need to be completely reworked, and t will be tough to find a forumula that fits all the vehicles as well as the current one, as it seems to be what WEG used.
-I7ll do some number cruncing and see if I can find something that will work for a lighter A-Wing without throwing off the speeders and the larger ships off. There is only so much I can trim down the YT-1300 (it can't be smaller than it's cargo capcity).
The current formula is: log(hull mass) x5 +1 (pips, character scale).
HUll Mass is 1/3rd the total vehicle mass.
For example, the A-Wing, at 96 tons, has a hull mass of 32,000kg
log (32000) x5+1= 23 pips (7D+2 for 1D+2 toughess with +1D armor.
| ZzaphodD wrote: |
An A-Wing is just under 10 meters long. Compare the weight to an 15 m F16 with a fully loaded weight of 12 tons. Even though an A-wing is not really supposed to operate primarily in atmosphere by the lifting power of its wings, I think 96tons is a bit much. |
The A-Wing is also a lot tougher than that F16. With a Hull STR of 2D+2 (Starfighter scale) vs. about 4D+1 Speeder scale for the F16.
As for not using its wings for lift, that kind of touches upon another difficulty. No wings= faster craft. Wings slow planes down, thats one reason why high speed aircraft have short wings.
| ZzaphodD wrote: |
Total weight aside, the jet engine of the F16 weights about 2 tons, which is about 1/6 of the total loaded weight. Looking at the picture of an A-wing one can assume that each of the A-wings engines is about the same size as the F16 engine (as the smaller version at about 1,75 tons). Id say that the A-wing engines should weight about 3,5-4,5 tons. |
I like the 1/6th idea too, but I can't get it to work out with the YT-1300 and Tramp Freighters. SO compatiblity is putting me into a corner. On the plus side, the current version of the A-Wing does have engines that mass 8 tons, and maneuvering thrusters with about the same mass (for a 1/6th total)
BTW, all the numbers above for different ship types, what do they mean?[/quote]
Sorry, I should have done a better job on on posting the table. I7ll fix that with the revised table. |
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atgxtg
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| Posted: Thu Jun 17, 2010 2:12 pm Post subject: Revised Ship Table |
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Here is the latest revsion of the ship table. In a (hopefully) easier to read layout.
http://img69.imageshack.us/img69/3915/shiptable.jpg
Explantion of Terms:
Ship: Class of ship (A-Wing, YT-1300, TIE fighter, etc.).
-Ships that have "G match" in thier name mean that they were designed to match the (incredibly high)accleration rating given in the XNew Essential Guide to Ships and Vehicles.
-Ships that have "Speed match" in thier name were built to match the Speed ratings given in Star Wars D6 sourcebooks.
-Ships than have "MGLT" in thier name were desined to match the ship7s offical MGLT rating.
mt: Ship's tonnage (metric, using ten times the length for starfighter scale ships).
Gs: The ship's accleration in Gs (1G-9.81meters/secod/second accleration, not that it matters for what we are doing).
-Values in bold are the ratings given in the New Essential Guide. All others are values that will work for what other paramenters the ship was designed for (Speed or MGLT matching).
SPACE: Ship's SPACE rating. Note that for ships with conflicting data, differernt speeds are possible.
MGLT: Ship's Speed in MGLTs. This is basically 10 times the Space rating, but some ships have higher ratings that thier D& game stats would suggest (such as Lucasfilm7s X-Wings that are as fast as TIE Fighters).
Engine: The total tonnage of engines. Note that this table doesn not break the engines up by number or model. For example, the A-Wing just lists 8 tons of engines, not two four ton, Novadex J-77 "Event Horizon" engines rated at 244,000 tons of thrust each. THe latter will be on the engine table.
Rating: This is a measure of the realtive effeciency of a ship7s engines. RThe higher the rating, the more powerful the engine is for iit7s size. For example, thre A-Wings engines are rated at 61.2, so they put out nearly twice the power per ton as the Rating 32 engines on the stock YT-1300. They also cost a lot more, too.
TT: This is the ship's Total Thrust, expressed in thousands of kilograms.
Gs: This is the ship's calaulated G rating, determined as Total Thrust/Mass. IDeally, this will match the listed G rating.
SPACE: This is the ship's calculated SPACE speed. THe formula:
SPACE=(G Rating9^.75)/50, round to the nearest.
To make it easier to design ships, the following conversion table is provided.
SPACE G Range
20 9668.06 - 10334.71
19 9012.72 - 9668.06
18 8369.07 - 9012.72
17 7737.58 - 8369.07
16 7118.73 - 7737.58
15 6513.04 - 7118.73
14 5921.14 - 6513.04
13 5343.67 - 5921.14
12 4781.42 - 5343.67
11 4235.25 - 4781.42
10 3706.17 - 4235.25
9 3195.35 - 3706.17
8 2704.22 - 3195.35
7 2234.49 - 2704.22
6 1788.31 - 2234.49
5 1368.5 - 1788.31
4 978.85 - 1368.5
3 625 - 978.85
2 316.29 - 625
MGLT: The ship7s Speed expressed in MGLT units. This is 10 times the SPace rating, without any rounding.
I7ve got some fomulas for other types of vehicles too. Eventually we should be able to use this system for designing up amyhting from a cutting edge starfighter to a old pistol engine biplane. |
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atgxtg
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| Posted: Thu Jun 17, 2010 2:22 pm Post subject: |
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| ZzaphodD wrote: |
But what point is it to stick to tramp freighters very limited 'system' (not even a system) when your doing a complete ship building system? As allready pointed out, when doing a system where you just switch engines and other parts, without having to take into consideration the whole ship building process, they dont need to make sense. You need to if you want a complete system. If you dont change them I think your stuck. |
The main point is compatiblity.
If I do this right, I should be able to do the design system without being "stuck". For example, by having the A-Wing's engines being twice as powerful per ton that the engines on the YT-1300, I should be able to allow for the various replacement engines in TF.
By using a power curve equation for SPACE speed, I should be able to sidestep the problem of engine stacking. As it stands, a YT-1300 could match the SPACE speed of an A-wing by stacking 4 standard drives, but doing so would eat up 30 tons of cargo space, and double the cost for restocking and increase the cost for engine maitentance and repairs fourfold. |
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ZzaphodD
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| Posted: Fri Jun 18, 2010 4:46 pm Post subject: |
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| atgxtg wrote: | | ZzaphodD wrote: |
But what point is it to stick to tramp freighters very limited 'system' (not even a system) when your doing a complete ship building system? As allready pointed out, when doing a system where you just switch engines and other parts, without having to take into consideration the whole ship building process, they dont need to make sense. You need to if you want a complete system. If you dont change them I think your stuck. |
The main point is compatiblity.
If I do this right, I should be able to do the design system without being "stuck". For example, by having the A-Wing's engines being twice as powerful per ton that the engines on the YT-1300, I should be able to allow for the various replacement engines in TF.
By using a power curve equation for SPACE speed, I should be able to sidestep the problem of engine stacking. As it stands, a YT-1300 could match the SPACE speed of an A-wing by stacking 4 standard drives, but doing so would eat up 30 tons of cargo space, and double the cost for restocking and increase the cost for engine maitentance and repairs fourfold. |
I see no problem with a cutting edge starfighter having twice the power per ton than an old tramp freighter.
Also, what is not represented in the rules very good is agility of different spacecraft. All spacecraft are very much alike when it comes to maneuverability. Stacking cheap engines might get you a very fast ship in a straight line even compared to a fast starfighter. However, turning all that mass is another thing, whereas the starfighter is light and maneuverable. However, I think Fun must win over Realism here.
If you want to follow TF, how do you handle the rule about switching speed for lifting power (more cargo weight)? |
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ZzaphodD
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| Posted: Fri Jun 18, 2010 5:16 pm Post subject: |
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As close as Ive gotten so far with the YT1300
| Code: |
YT1300
Weight Spaces Cost Power Effect Notes
******************************************************************************************************************
Hull 50 200 12500 0 0 250 ton ship
Crew 4 8 4000 1+1
Passengers30 30 6000 5t/pass, 5 spaces, 500 cr
Cargo 100 50 5000
Ion Engine 20 12 10000 100 Space 4 T: 1000
Hyperdrive 15 5 10000 25 x2
Backup 2 1 2500 5 x12
Power Core 15 10 10000 P: 300
Nav comp 1 1 7500 1
Escape pod8 8 7500 8 prs
Life supp 5 10 4800
Shields 6 5 7500 50 1D
Turret 2 4 5000 2
Laser can 2 2 10000 40 4d damage
260 146 102300 223
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atgxtg
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Posts: 2460
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| Posted: Tue Jun 22, 2010 2:46 pm Post subject: |
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| ZzaphodD wrote: | | I see no problem with a cutting edge starfighter having twice the power per ton than an old tramp freighter. |
Niether do I, and that Is why it did it the way that way. As it worked out, the Space 12 engine for the six J-77 (A-Wing) engines.
The difficulty with making the A-Wing lighter is that it will in turn make the enines of the freighters more powerful. Basically, if the YT-1300 has ten times the mass of an A-Wing, then it7s engines will need to be more powerful to get the right thrust/mass ratios.
| ZzaphodD wrote: |
Also, what is not represented in the rules very good is agility of different spacecraft. All spacecraft are very much alike when it comes to maneuverability. Stacking cheap engines might get you a very fast ship in a straight line even compared to a fast starfighter. However, turning all that mass is another thing, whereas the starfighter is light and maneuverable. However, I think Fun must win over Realism here |
That is factored in the RPG with the Maneuverability stats. I7ll admit that .
Star Warriors did it in more detail, and IMO, better, but the aRAPG uses maneuverability. So the A-Wing benefits from having a much higher Maneuverability score.
In my design rules, the way I7ve worked it out is that maneuver thrusters are just like Ion Drives. The SPACE speed is treated as pips for Maneuverability purposes. So the A-Wing (at 96mt) would have 8 tons (two four ton) of engines, and 8 more tons of thrusters. IF someone wanted to get the Maneuverability of a YT-1300 up to 4D (12 pip) they will need to put in 24 tons of A-Win grade thrusters, of 48 tons of "standard" thrusters.
In addtion, all the systems require power, and power generators provide 8 EU per ton (I might upo it to 10 EU/ton to make ithe math more "user-freindly". Engines require 1 EU per 10K thrust (I've got guidelines for designing engines, and someone can make engines that are more energy effcient, but they will cost more credits). The net result is that trippling the speed of a YT-1300 will mean adding a bigger power plant (another 17 tons or so), as will upping it7s maneuverability to 4D.
So with my design rules, you can make a YT-1300 as frast an maneuverable as an A-Wing, but it will mean sacrficing 94 tons of cargo to do it. Not to mention that it will cost a bundle and raise the operating cvosts of ship.
| ZzaphodD wrote: |
If you want to follow TF, how do you handle the rule about switching speed for lifting power (more cargo weight)? |
Two ways:
The first method is to take the mass off the cargo capaicty as in the past. Tis means that the owners are trying to keep a constant mass.
But, since Speed is determined by the thrust to mass ration (G's accleration)MR), ssomeone could alter the mass of a ship and figure out the new speed by diving the total thrust by the ship's new mass.
For example, let7s say you havre a light freighter with a mass of 270mt, a cargo capacity of 100mt, with a 10 ton engine that provides 270kilotons of thrust, for an accleration of 1000Gs and a Space Speed of 4.
You mkae some extensive modfications to the ship, that take up 50mt. You can just sacrfice 50mt of cargo space and be fine, since the ship's total mass hasn't changed.
Or you could opt to keep 100mt of cargo, and recaculate the ship's new accleration at 320mt of mass (the base of 270 plus the 50 tons of modfications). 270 kilotons of thrust divided by the new ship mass of 320 tons is a G rating of 843.75. Looing that up on the G table I posted earlier, we see that 874Gs falls in the range for SPACE 3, so the ship will be slower.
It would also suffer a proportial drop in maneuverability, and the hyperdrive will draw more power, and require manitenance more often (after every 14-17 jumps instead of every 20).
Note that the first option is the suggested one, and is certainly easier, buy if someone is willing to do the math, they can alter mass if they want to. You can even figure out G rating for the ship when the cargo hold is empty, or just partially full, and get a speed and maneuverabilty boost (the freighter above goues to to SPACE 5 empty), if you want. Or you can just ingore it, as the GMs descretion. The only time you need to work out the math is when you design the ship, or do extensive mods.
Did that manke sense? THe hard part about explaining this is that I've got the luxury of my notes, and D& Space to fall back on, plus an idea of what direction I'm heading towards. I suspect a lot of this looks arcane to someone looking in from the outside. |
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ZzaphodD
Rear Admiral
Joined: 28 Nov 2009
Posts: 2426
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| Posted: Tue Jun 22, 2010 3:07 pm Post subject: |
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What I mean with maneuverability is actually that the system favours the heavier (engine stacked) freighter. A 3D maneuverability freighter is not very hard or expensive if one uses the (limping) TF rules (you can even find on 'as is' i think). This means that the A-Wing has only a 1D advantage. With two pilots at 5D thats only 8D vs 9D. This does not really represent the difficulty of changing direction with a freighter full of stacked engines.
WEG moved away from Space speed die codes because the speed of the ship meant so little compared to the skill of the pilot. Strange they didnt do the same thing with maneuverability, which suffers from the same problem.
Regarding you table. It says that an A-Wing accelerates at 5100G if I read this correctly. So, if I understand your 1G example, means that one second of acceleration moves this ship about 50 km? |
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