Quote from: John MorrowThe problem is, from a role-playing perspective, that if a horrible accident happens on a ship carrying all of the PCs, the next session will consist of everyone rolling up new characters or playing a different game.

True.
Talking about this, I got the idea of the characters being the Insurance Investigators or the survivors avoiding the "Fixers".

Also stumbled on some interesting stories of ship repossession by companies like Maritime Resolve. While not directly related, it did give some good ideas.
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Quote from: GreentongueWhile I'm sure there is an effective load limit for a starship...

In terms of tonnage, there is no limit in a real-world spacegoing vehicle that doesn't have to land. If you've gravity of some sort, the limit would be the spaceframe of the vehicle, in other words, the weight it takes for your cargo to fall through the floor. Beyond scales in the deck, I know of no convenient and immediate visual representation of this, although in theory the weight and its distribution could be inferred by moving the ship and determining the rate of acceleration versus pounds of thrust.

Really, I'm just posting this to make sure you know that, unlike on oceangoing vessels, there's no medium-based limitation to mass. You could fill your entire ship with lead, and as long as the frame could withstand the stress, the engines couldn't care less; you'll just get going proportionately slower. Your maximum speed won't change, either, although your increased mass will start to matter...around 99.9 percent lightspeed. Or so.

As for cube-out - when you fill the hold without transcending its mass limits - that's generally indicated in holds with paint or gaffers tape, if the hold cannot for whatever reason just be filled completely full. Many warehouses and cargo holds do not include such lines, and simply expect the lumpers or other unloaders to know "how much and where" is the limit.

Quote from: EngineIn terms of tonnage, there is no limit in a real-world spacegoing vehicle that doesn't have to land. If you've gravity of some sort, the limit would be the spaceframe of the vehicle, in other words, the weight it takes for your cargo to fall through the floor.

QuoteReally, I'm just posting this to make sure you know that, unlike on oceangoing vessels, there's no medium-based limitation to mass. You could fill your entire ship with lead, and as long as the frame could withstand the stress, the engines couldn't care less; you'll just get going proportionately slower. Your maximum speed won't change, either, although your increased mass will start to matter...around 99.9 percent lightspeed. Or so.

Yes, I do understand this. Rather well actually.
You may have hit on what I was looking for. Frame Stress. I would have to believe that this would be an issue over time. Sinking and breaking apart may be close enough to the same end effect. Loss of the ship that could have been prevented.

QuoteAs for cube-out - when you fill the hold without transcending its mass limits - that's generally indicated in holds with paint or gaffers tape, if the hold cannot for whatever reason just be filled completely full. Many warehouses and cargo holds do not include such lines, and simply expect the lumpers or other unloaders to know "how much and where" is the limit.

So official loading zones would serve the same effective purpose as a Plimsol mark.
Correct?
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One assumption that needs to be addressed that has only been slightly touched upon is what are the normal operating peramators of the ship?

In real design, its impractical to make a ship that travels deep space, maybe even FTL and yet also lands and takes off from worlds.  Space 'dry docks' (where the ship 'lands' inside the station) are impractical from many many standpoints...

.... yet from a fictive or especially Gaming perspectives ships may be designed to do all of that.  Or not.

Realistically I've heard 'futurists' claim that the only practical design for a pure space vessel (the most logical sort for interstellar work) is an erector set design. I find that slightly laughable from a material aspect (more surface area exposed to space that way...), but they make several good points. Of course, such a vehicle is impossible to 'land' anywhere.

Which makes rating the 'cargo' slightly problematic.  


So I assume you'll ditch the 'pure space' aspect of the design, which is where 'cargo mass' becomes more important.  An over-loaded vessel won't be able to acheive escape velocity, and 'illegal loading' falls into the grey band between 'unable to leave planet' and 'legally safe'.  

In all likelihood, ships are rated in terms of tonnes of thrust they can generate.  Certain berths (space docks inside ships) and landing pads (dirtside) might be rated on how many tonnes of thrust they can tolerate (meaning a larger vessel might have to lift off underloaded to avoid damaging the facilities), and either way the cargo limit could be violated easily by picking up additional cargo in orbit... which might create other problems.

Of course, as has been stated: how your FTL technology 'works' is also pretty important here.  Wormhole travel (Bujold's setting, fer ex) might not give a god damn, provided your ship isn't so damn big it exceeds the astronomical dimensions of the wormhole, but the 'drive rods' that keep your ship from being atomized by the trip might.  A 'warp bubble' a la Startrek probably also doesn't care a whit about mass, seeing as the ship is functionally motionless (thus smaller vessels can occasionally, secretly, tag along inside the bubble...seen in the movies notably).

Hyperspace (8th dimensional travel?) probably DOES care, as the vessel is still operating under fairly normal physics, just outside the normal 3 dimensional movement.

Jump drive? Mass probably does have a factor in power consumption, etc...

In short, without a better understanding of 'how your setting works' its hard to really answer the question.

Quote from: GreentongueYou may have hit on what I was looking for. Frame Stress. I would have to believe that this would be an issue over time.

On an immediate basis, if frame stress is the concern, I'd go with a system like, John Morrow mentioned with the tugs, or, if the owner of the vessel wanted to know his tonnage, the ship's own thrusters. As long as you know the exact force your engines can produce, and can fix your position in space with reasonable accuracy, you should be able to determine mass just by working f=ma backward.

Quote from: GreentongueSo official loading zones would serve the same effective purpose as a Plimsol mark.
Correct?

Oh, how I wish. But some cargoes are much heavier than others, so you'd "weigh out before you cube out." As a rule, this is prevented simply by accounting for all the mass you've loaded before you put it on the ship. Modern loading docks do this, so there's no surprise when the trucker gets up to the scales. [Which there won't be anyway, since he's got relatively accurate gages on the trailer.]

Quote from: SpikeIn short, without a better understanding of 'how your setting works' its hard to really answer the question.

An excellent point. It should be noted that my answers all presume physics and technology that work precisely as we understand those things today; I've deliberately avoided FTL travel or anything of the sort, as answers to your question in those terms will end up being, "However you want, since you're inventing the physics anyway."