Steve Jackson Games Forums - Overloading a Spaceship, and volume (Spaceship rules)

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Re: Overloading a Spaceship, and volume (Spaceship rules)

Quote:

Originally Posted by PTTG (Post 2143015)

Acceleration changes, and delta-v gets worse if your ship has it. Luckily the math is easy; multiply both by (Nominal Load) / (Current Load).

Not so for delta-V unless the reaction mass fraction is initially at the low end. You could lose more than that if you're benefiting from high fuel fraction.

Re: Overloading a Spaceship, and volume (Spaceship rules)

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Originally Posted by Rupert (Post 2142989)

Minor overloading is probably not going to do much other than reduce acceleration and possibly mess with handling. Major overloading might strain the structure around the cargo hold and damage the wall and floor plating, especially if the spaceship does things like fly through atmospheres and land on planets. All cases will attract the ire of those entities in charge of ship registration, certification and, of course, of the Health & Safety people.

I'd require a Freight Handling check every week or so of operation in which the ship manoeuvres (constant acceleration wouldn't count, nor would just drifting, etc.) with a penalty for being seriously overweight. Failure would result in a minor problem (a minor repair required, something coming lose and causing a minor injury, etc.), and a critical failure causing something more severe (loose cargo crushing someone and causing broken bones, etc.). I admit my motivation for such things is as much to stop PCs getting 'free' load capacity as a desire for realism.

PC's won't really be getting free load capacity; it's just necessary to determine what the volume of a standard ton of hold is. They can only carry so much volume.

The fundamental issue I'm seeing is that Size Modifier is a function of volume, whereas Spaceships works by mass. The more I look at it, the more I realize that there should only be a need for significant extra reinforcements if the ship spends time in a gravity field, at a different orientation than its direction of flight. (Land on her jets, then nose over so the ship is in a gravity field normal to its direction of thrust.)

Handling should indeed take a penalty.

As for health and safety; I'm sure that plenty of ships have reason to haul extra heavy cargo. In the days of tramp freighters, a ship might haul lumber one way, and heavy machinery the other.

(Setting has no artificial gravity, but does have total conversion. The super total conversion drive isn't quite AS super; providing 10 G's instead of 50, and requiring 1 Power Point per G of thrust)

Re: Overloading a Spaceship, and volume (Spaceship rules)

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Originally Posted by YankeeGamer (Post 2143082)

PC's won't really be getting free load capacity; it's just necessary to determine what the volume of a standard ton of hold is. They can only carry so much volume.

Maybe.

In my setting interstellar and interplanetary cargo haulers don't land, so they aren't streamlined and don't need a fairing. They aren't aircraft so they don't need a fuselage, and they aren't watercraft so they don't need a hull. You just stack cargo containers on the front and unfurl an umbrella-like meteoroid bumper in front of that. Except for cargo that needs to be transported in pressure or to which you need access during the trip volume is unconstrained.

Quote:

The fundamental issue I'm seeing is that Size Modifier is a function of volume, whereas Spaceships works by mass.

I don't refine on that too much. GURPS Spaceships is a rough-and-ready quick-to-play system that only bothers to specify ship's masses and volumes to the nearest half an order of magnitude.

Re: Overloading a Spaceship, and volume (Spaceship rules)

Realistically, in deep space the main effect is loss of acceleration and delta-V, unless the loading is off balance or dense enough to poke holes in the cargo deck, and even that isn't a significant issue as long as you stick to low performance spacecraft.

Re: Overloading a Spaceship, and volume (Spaceship rules)

The major effects are much as people have already described.

Acceleration will be directly impacted and reduced. Delta-V will need to be significantly recalculated, since the Delta-V multiplier is based on the percentage of the ships mass that is fuel and that percentage is going to change due to the overloading.
Handling and Stability Rating should be impacted. Handling should be reduced, SR would probably actually get a bonus since a more massive ship is more stable.
In an atmosphere and a gravity well a temporary reduction of HT would be in order, since you will be overstressing the hull. Continual overloading of the ship may call for a permanent reduction in HT as damage is actually done to the hull. These won't really affect space or interstellar operations, since any overstressing is likely countered by the lower acceleration.
Even in space, it is possible a poorly loaded and imbalanced load could do damage to the hull, but this is true even if loaded within mass limits. Overloading just exacerbates the problem. Freight Handling skill is important here.
FTL drives may not work as efficiently, or may not work at all, depending on how FTL works in the campaign. An FTL-2 drive may only be able to make FTL-1 speeds, or it may not be able to travel in FTL at all.

Re: Overloading a Spaceship, and volume (Spaceship rules)

Quote:

Originally Posted by YankeeGamer (Post 2143082)

PC's won't really be getting free load capacity; it's just necessary to determine what the volume of a standard ton of hold is. They can only carry so much volume.

That's only true if their cargo isn't very dense. If, on the other hand, they're trying to haul off as much gold and platinum as they can carry volume isn't really important, while how much extra mass they can load in is.