Fixing the Stardrive , Problem of increasing distance in Spaceships & Vehicles
uncle_jimbo Dec 28 2009, 04:07 Group: Grid Cop, 5éme Corbin Quote Post
I'm determined to post something constructive today, so decided to look at a long-standing concern I had. Starting on a suitable ship design for the Taurus contract, I'm looking at probably a Fast Transport hull that needs a 10 lightyear starfall.

However, that means using the paragraph in Warships that begins "It’s possible to increase the distances shown above..", which struck me on first reading as giving absurdly extended distances for larger ships (such as the example in the text) while not allowing the distances for small craft that we know to be achievable from the GMG.

I'll take the other Warships stats for a minimum-range stardrive (hull size, power and base starfall) to be correct. A revised rule for extended starfall distance should support about the same practical limits to the stardrive as the types of vessels described in the Star*Drive Campaign Setting and hard limits listed for different sizes of (small) vessels in the GMG and Starships - both of these as a function of the largest installation of mass reactors that a ship of that size can carry, say as 20-30% of its hull (practical) or 60-70% (maximum for some sort of experimental craft). These known extended ranges are:

GMG
Size        Maximum Starfall

1-10        10LY
11-30        15LY
31-60        25LY

Star*Drive
Size                Known Extended Starfall

Fortress Ship (Oneagle)        70LY

The campaign setting also lists dreadnoughts, cruisers and large commercial transports with 20 to 35 lightyear starfalls, but it's not clear if this refers to any sort of limit. It seems to be more of a typical distance.

There's not much scope to do anything with a fighter or launch hull. Let's say, if a 20 hull point vessel can jump 15 lightyears, a 40 hull point vessel can jump 25 lightyears, a 60 hull point vessel can jump no more than 25 lightyears and a fortress ship with a practical amount of power plants can jump 70 lightyears, the revised rule fits well enough.

One possibility that I thought about before, without really testing it:

For each increase in power factors equal to the minimum requirement listed, rounded down, add 5 lightyears to the maximum starfall distance.

Let's see how that works out for some test designs:

Hull: 20 (Small Craft)
Stardrive: 1 Hull 3 Power
Base Starfall: 5LY
Mass Reactors (70%): 14 x 3.5 = 49 Power
Extended Distance: (49 - 3) / 3 = 15 x 5 = +75LY

That is .. not going to work. Let's see the other end of the scale:

Hull: 12000 (Super-Heavy)
Stardrive: 600 Hull 1800 Power
Base Starfall: 50LY
Mass Reactors (30%): 5400 x 3.5 = 18900 Power
Extended Distance: (18900 - 1800) / 1800 = 9 x 5 = +45LY

That's too far as well. How about adding 5LY for each increase of double the initial power requirement? 20 Hull Points may be too close to the minimum to be representative:

Hull: 40 (Small Craft)
Stardrive: 2 Hull 6 Power
Base Starfall: 5LY
Mass Reactors (70%): 28 x 3.5 = 98 Power
Extended Distance: (98 - 6) / 12 = 7 x 5 = +35LY

Yup. Well, it should work out better for the Oneagle:

Hull: 12000 (Super-Heavy)
Stardrive: 600 Hull 1800 Power
Base Starfall: 50LY
Mass Reactors (30%): 5400 x 3.5 = 18900 Power
Extended Distance: (18900 - 1800) / 3600 = 4 x 5 = +20LY

Works for the top of the range. A relatively small increase in power should allow a fortress ship to outperform the state of the art in Star*Drive slightly, which I think is a healthy position for story purposes.

Now, what if each increase in distance is 10% of the base starfall, minimum 1LY? Let's try 20 or 40 Hull Points again:

Hull: 20 (Small Craft)
Stardrive: 1 Hull 3 Power
Base Starfall: 5LY
Mass Reactors (70%): 14 x 3.5 = 49 Power
Extended Distance: (49 - 3) / 6 = 7 x 1 = +7LY

Hull: 40 (Small Craft)
Stardrive: 2 Hull 6 Power
Base Starfall: 5LY
Mass Reactors (70%): 28 x 3.5 = 98 Power
Extended Distance: (98 - 6) / 12 = 7 x 1 = +7LY

Better, but now the increase is too little.

I might have to go back to a table.

Class        Base Starfall        Extended Starfall
Small         5 LY        +1 LY / 5 Power
Light         10 LY        ..
Medium         20 LY        ..
Heavy         30 LY         ..
S-heavy         50 LY        +1 LY / 750 Power

Intermediate rows to fill in later.

There's also a problem with the base starfall for Super-Heavy ships, since in Star*Drive a dreadnought canonically has a 35 lightyear starfall (campaign setting, p. 24).

This post has been edited by uncle_jimbo on Dec 28 2009, 04:18
uncle_jimbo Dec 28 2009, 05:28 Group: Grid Cop, 5éme Corbin Quote Post
Author (uncle_jimbo @ Dec 28 2009, 15:07)
There's also a problem with the base starfall for Super-Heavy ships, since in Star*Drive a dreadnought canonically has a 35 lightyear starfall (campaign setting, p. 24).
uncle_jimbo Dec 28 2009, 07:37 Group: Grid Cop, 5éme Corbin Quote Post
I don't propose to worry too much about the dreadnought problem. Either make the assumption above, or say that a dreadnought counts as a Heavy ship for purposes of the starfall distance table.

In that case, I want either a battleship or a dreadnought easily to be able to starfall 35 lightyears, so let's say that the upper recommended power plant size in Warships, 15% of a battleship's hull, allows a 36 LY starfall (to allow for a small number of systems that need to be powered while making starfall):

Battleship stardrive: 60 Hull 180 Power
Battleship typical/high-range power plant: 180 x 3.5 = 630 Power
Power to add +6 LY = 630 - 180 = 450
Heavy ships: +1 LY / 75 Power

No need to do anything similar to ensure that a cruiser can starfall 20 LY, but maybe it would be good to ensure that a light cruiser of practical design can starfall 35 LY:

Light cruiser stardrive: 16 Hull 48 Power
Light cruiser power plant (30%): 96 Hull 336 Power
Power to add +15 LY = 336 - 48 = 288
Medium ships: +1 LY / 20 Power

The campaign setting doesn't give me any particular guidance for light warships, but says that "large commercial transports and industrial freighters can leap 20 to 35 light-years". Let's try to ensure, then, that an Industrial hull can make a 20 LY starfall:

Industrial stardrive: 5 Hull 15 Power
Industrial power plant (15%): 15 x 3.5 = 52 Power
Power to add +10 LY = 52 - 15 = 37
That doesn't work so well. I could either give light ships +1 LY/5 Power, the same as small craft, or +1 LY/10 Power which restricts an "industrial freighter" to about 15 LY. I prefer the second option.

So, the complete table:
Class                Base Starfall                Extended Starfall
Small                 5 LY                +1 LY / 5 Power
Light                 10 LY                +1 LY / 10 Power
Medium                 20 LY                +1 LY / 20 Power
Heavy                 30 LY                 +1 LY / 75 Power
S-heavy                 50 LY                +1 LY / 750 Power

Might be good to check, next, if this produces any weird corner cases.

This post has been edited by uncle_jimbo on Dec 28 2009, 07:43
uncle_jimbo Dec 28 2009, 08:08 Group: Grid Cop, 5éme Corbin Quote Post
I liked the idea of my Katydid Long-Jump Courier, but was bothered that it didn't, well, work. With the proposed change, it still doesn't have a 25 lightyear starfall as I envisaged, but it's a much more respectable advance on other small craft. edit: Corrections to life support

This post has been edited by uncle_jimbo on Jun 12 2010, 11:59


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therion Dec 28 2009, 09:44 Group: Heroes, Level 20 Quote Post
There's one critical piece of information you overlooked, concerning extending starfalls.

When designing warships, the designer calibrates the power requirements carefully to be able to cover the worst case scenario, which is always battle conditions. A ship in battle uses weapons, shields and engines, which when combined with sensors, computers and all other machinery that always needs to run then subsequently approaches 100% of the mass reactor output.

The mass reactors themselves have fuel to run 6 months without recharging, yes?

6 months of normal usage. Normal usage for a standard ship is basically 10-15% of the maximum output, since the ship doesn't need to fire all guns and have shields on all the time. In fact, most of the time while traveling it doesn't even have the engines on.

A ship extending starfall by utilizing all available power is, in effect, doing an equivalent of conducting battle for 5 entire days, and possibly burning MUCH more dark matter than it would otherwise. Some ships can, perhaps, afford this luxury if time is of the essence, but most of the normal ships, even military ones will not do this. The sheer cost of fueling all of available systems on a fortress ship for 5 days for the benefit of conducting a single extended starfall is out of the question except in war conditions.

This is why in my campaigns the ships never do this, even if they have the option.

I know this doesn't directly tie into the reworked starfall/power table, but one has to consider all the costs.
uncle_jimbo Dec 28 2009, 11:02 Group: Grid Cop, 5éme Corbin Quote Post
Does a stardrive need power for the entire 121 hours? I know the question's been raised before. For game purposes, it makes very little difference, because a ship seldom uses anything but life support and constantly-active core systems within drivespace (unless, possibly, the crew uses the time to make internal repairs, or some similar task) and Warships doesn't track fuel usage in that sort of detail. I suppose a GM could take periods of reduced power draw into account, but it's not standard.

Be that as it may, battle is only the second highest power condition for a driveship. Starfall takes all available power - everything that the reactors can produce in an intense energy spike that allows breaking the normal laws of physics. In some sense, that's flavour text, but so is the whole question of what peak output and unobtanium consumption an imaginary technology needs. A ship won't use its maximum starfall distance, whatever it is, on every journey, but a vessel designed for increased jump distance (as we know some are) has reactor power to burn for any other purpose.
Spaceman_Spiff Dec 28 2009, 19:00 Group: Heroes, Level 20 Quote Post
Yeah, I've wondered about this too--I've ended up thinking that power is only required to generate a power spike -as you mentioned- that lets it drop into drivespace, and then the ship is mainly just coasting through drivespace to its destination.
apoc527 Dec 28 2009, 19:23 Group: Heroes, Evil GM Quote Post
IMO, a stardrive only needs a spike of power--once you enter drivespace, you can basically turn off everything but the life support and entertainment systems.

I have a formula I've been using for additional power embedded within my Star*Drive Ship Design sheets. It's not perfect--it would be hard to get 10 ly starfalls with a Small Craft, but it's not bad either. I'll post the actual formulas later. One thing I found, UJ, is that you basically need different formulas for the different sizes of ships. Larger ships produce so much more power than small ones, that the scaling doesn't work otherwise.

Ok, here was my guesswork that I've been using in my Excel sheets:

Small Craft = standard rule (every 10 power is +1 ly)
Light craft = every 30 power is +1 ly
Medium craft = every 50 power is +1 ly
Heavy craft = every 100 power is +1 ly
Superheavy craft = every 500 power is +1 ly.

Now, I must admit to not having extensively tested these numbers. There's also the small matter that I have multipled power output of all power plants by 1.5 in my designs (I did this because I felt that power systems took up too much room, especially compared to other ship design systems, like Traveller).

I also don't round at all, so ships end up with stardrive performances of 7.43 ly, for example. I like it because it makes each ship somewhat unique.

This post has been edited by apoc527 on Dec 28 2009, 19:34
apoc527 Dec 28 2009, 19:42 Group: Heroes, Evil GM Quote Post
One other thing I've done is introduced grades of stardrive. So a ship can have a really cheap, a really expensive, or a standard cost stardrive. This effects the performance. For example, the above formulas I gave were for the Good stardrive (which I arbitrarily decided was Warships standard).

For an Ordinary (cheap) stardrive, they are as follows:

Sm -- every 15 power
L -- every 50 power
M -- every 80 power
H -- every 140 power
SH -- every 800 power

For an Amazing (really expensive) stardrive:

Sm -- every 7 power
L -- every 20 power
M -- every 30 power
H -- every 80 power
SH -- every 300 power

So, you can easily get a Fast Transport to jump 10 ly per starfall using these rules (it's even easier when 1 hp of mass reactor gets you 5.5 power!). However, the Amazing stardrive will cost $12,000,000, which is ~2.5 times as much as a Good model.
apoc527 Dec 28 2009, 19:45 Group: Heroes, Evil GM Quote Post
One last point,

I think I modified the base starfall distances for size classes and I also created (?? I forget which rules are original anymore) a table for max boost.



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