Spaceships series: Electrical Batteries module?

[Ulzgoroth]

Originally Posted by jacobmuller

Were any actual per ton values worked out? eg Fuel Cell 5Mw Fusion 10Mw Antimatter 20Mw?

None of that is officially provided.

Physics can give you minimums for how much power a power point must be based on the various power-consuming systems. You can get some maximums too but I think that's a bit hairier.

[Anthony]

Originally Posted by Ulzgoroth

Physics can give you minimums for how much power a power point must be based on the various power-consuming systems.

Which are somewhat inconsistent. I'm fond of 1 ep = 50 kW/ton, as generates reasonably plausible power densities, but to do that you need to reduce ion drive thrust by a factor of 5 and mass driver by a factor of 10.

[Flyndaran]

Originally Posted by Anthony

Which are somewhat inconsistent. I'm fond of 1 ep = 50 kW/ton, as generates reasonably plausible power densities, but to do that you need to reduce ion drive thrust by a factor of 5 and mass driver by a factor of 10.

I can live with that. TL8 anything is going to be painfully inefficient. Mass drivers are by their nature horrible at everything unless you have free mass and really long term power.

I don't expect TPTB to ever clearly state it, but I still like having a ballpark figure for adding new house rule tech.
Unless anyone disagrees, I'm going to steal the 50 kW/ton guideline.

[Anthony]

Originally Posted by Flyndaran

I can live with that. TL8 anything is going to be painfully inefficient.

For clarity, by reasonable, I mean 'reasonable at TL 9'. TL8 space-rated power plants have fairly horrible performance.

Incidentally, 50 kW/ton is 100 horsepower on a 3,000 lb car; a modern car is likely to have 2 ep, a sports car will be 3-4.

[Fred Brackin]

Originally Posted by Anthony

For clarity, by reasonable, I mean 'reasonable at TL 9'. TL8 space-rated power plants have fairly horrible performance.

Incidentally, 50 kW/ton is 100 horsepower on a 3,000 lb car; a modern car is likely to have 2 ep, a sports car will be 3-4.

That is a rather modest defintion of "sports car". Modern super cars don't really start til you go over 600 hp and there's a very significant number of vehicles in the 400-500 range.

[Anthony]

Originally Posted by Fred Brackin

That is a rather modest defintion of "sports car". Modern super cars don't really start til you go over 600 hp and there's a very significant number of vehicles in the 400-500 range.

They're also usually over 3,000 lb loaded weight. For example, a 2010 Camaro SS is 426 hp (318 kW), but it has a curb weight of 3,860 lb, which will exceed 4,000 lb with a driver; thus, that's 3 ep. Going with lighter sports cars, the Lotus Elise SC is 218 HP (163 kW) on a weight of 1,987 lb; that's marginally over 3 ep as well. Can you give me an example of a 600 horsepower car with a curb weight of less than 4,300 lb, or 500 hp at less than 3,555 lb, or 400 hp at less than 2,810 lb? (in all cases, adding 170 lb to curb weight for a driver).

[DouglasCole]

Originally Posted by Anthony

Can you give me an example of a 600 horsepower car with a curb weight of less than 4,300 lb, or 500 hp at less than 3,555 lb, or 400 hp at less than 2,810 lb? (in all cases, adding 170 lb to curb weight for a driver).

Including modified cars? The Subaru WRX STi can hit 500-600hp on less than 3,000lbs curb weight, I believe. Some extreme mods have hit 1,000hp.

There's a 1,500hp modification to a Porsche out there with a curb weight of 3,200-3,600lbs. http://ast-usa.com/blog/2011/04/

[Fred Brackin]

Originally Posted by Anthony

. Can you give me an example of a 600 horsepower car with a curb weight of less than 4,300 lb, or 500 hp at less than 3,555 lb, or 400 hp at less than 2,810 lb? (in all cases, adding 170 lb to curb weight for a driver).

Bugatti Veyron

http://en.wikipedia.org/wiki/Bugatti_Veyron

This is taking things right to the limit but the weights of high performance cars tend to be tied to many other factors than engine size.

Note that the Veyron for example gives all the luxury you'd expect in a $ million car. If it had been designed with the sorts of weight savings seen in previous stretch the limits cars (i.e. no floor mats much less air con and stereo) it would be much lighter.

[David L Pulver]

Originally Posted by Flyndaran

I can live with that. TL8 anything is going to be painfully inefficient. Mass drivers are by their nature horrible at everything unless you have free mass and really long term power.

I don't expect TPTB to ever clearly state it, but I still like having a ballpark figure for adding new house rule tech.
Unless anyone disagrees, I'm going to steal the 50 kW/ton guideline.

SPACESHIPS is a system with numerous simplifications and short cuts designed to produce even whole numbers for things like power points and for weapons, to make the turn sequencing work. Note, for example, that many systems do not improve at higher TLs, and how structures are ignored.

In particular the power point numbers for fuel cells etc. and electric drive drive thrusts are abstracted to make them "worth using" in manned designs and avoid having to deal with 1/1000G thrusts and the like. I think they are deliberately about 10x as effective as they should be.

[David L Pulver]

Originally Posted by Ulzgoroth

None of that is officially provided.

Physics can give you minimums for how much power a power point must be based on the various power-consuming systems. You can get some maximums too but I think that's a bit hairier.

That is correct. I worked out some numbers that I used, but Spaceships is intended to be fairly abstract. The only reason the weapons have megajoule values is because I needed to call each level of weapon SOMETHING and would have run out adjectives if I stuck with things like "very large" or whatever.

It is worth saying that Spaceships is intended as a "thing in itself" and is not specifically intended as a modular system for upcoming Vehicle Design books or the like. It's a simple system in which some things are reasonably realistic given its simplicity, like the treatment of fuel, but the more layers of detail you try to add to it, the more you are likely to break it.