Overloading a Spaceship, and volume (Spaceship rules)
 

The spaceship rules are purely weight related, which can make sense, and certainly makes designing a ship easy. However, there can be some concerns that I'm seeing already.

How much volume is in a cargo hold of a certain rated weight? And, then, what happens if you FILL that hold with something extremely dense, such as lead. Acceleration will, naturally, drop for reaction engines, but what happens to things like the ship's handling? Are other effects likely, besides awkward scenes like landing in the ocean and sinking instead of floating?

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

I would reduce Handling and HT by one for every 50% above optimal load (representing the inability of the ship to maneuver in the case of the former and the strain on the structural elements of the ship in the case of the latter). In addition, I would also have the ship start suffering damage to the structural elements buckling under the strain if mass exceeds optimal load by more than 100% (10% of HP per month of acceleration for 101%-200%, 10% of HP per week of acceleration for 201%-300%, and 10% of HP per day of acceleration for 301%+).

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

Any suggestions on how to build a spaceship with the expectation that it might be overloaded? If a ship is going to be small, but heavy, armor should weigh proportionally less, since it's enclosing a smaller volume. Perhaps a system or two devoted to structural reinforcement (Volume per armor, but doesn't add to DR or handling. Instead, it's bracing--reinforcement between the source of thrust and the heavy hold, etc.)

That wouldn't help handling, but should help with HT.

Spaceships is elegant, but a small ship with a BIG engine could haul a lot of serious weight.

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

I would suggest designing a Reinforced Hull Component. It would cost as much as a Habitat and would give +1 HT and +50% HP per component.

Structural reinforcement
 

Rather than building structural reinforcement at the price of habitat, perhaps buying it as armor would make more sense. It needs to be in a core section, in either the midship or aft section. The tougher the armor, the more HT benefit and the more overloading the ship can take. (Also, the more expensive!)

Specs, of course, to be developed at a later time.

Could this work?

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

Would it matter when you are not in orbit? Artificial grav can compensate and there is no gravity to speak of in space. If you put to much in it will strain the bulwarks but presumably they are built to withstand radiation, ultraspeed atmospheric friction and micrometeoroids.

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

Seems fair. You should also reduce acceleration and delta-vee in due proportion.

I would not do that, because the stress on a ship in space consists of the thrust of its motors. Overloading a ship will not increase the thrust of its motors and therefore will not increase the stress on the structure. there is no increase in weight where there is no weight.

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

Whatever handles smaller systems, also has a guideline how much of a handling penalty a ship suffers if its control room is smaller than is appropriate for its tonnage.

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

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.

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

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

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

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)
 

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)
 

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.

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)
 

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.