AnotherDilbert
SOC-14 1K
No rule has ever stated that.
Some people infer that as mass is not specified in detail.
Last edited:
Cargo Capacity and volume and mass
- Thread starter Badenov
- Start date
Some people infer that as mass is not specified in detail.
In MT, gravitic (ant-grav) and thruster Drives are those detailed in page 65 of the RM and do not care about mass. Gravitic plates, detailed in page 66 do, giving tons of thrust that must overcome the mass.
The Drives are used by small crafts (20-99 dtons) and spaceships/starships (100+dtons), while the Plates for Grav vehicles (though this may be missleading, as there are larger grav vehicles)
Redefining the dton as a unit of mass (equaling 10 metric tons, "dton" standing for deca-ton) and moving the volume side of the equation into the "fuzzy, simplified" area solves more problems than it causes IMHO (though it does still cause a few problems.)
You can leave the classic design systems unchanged, but you can use additional considerations in gameplay. For example recalculating acceleration with less load, enabling PCs to throw valuable cargo and redshirts overboard in that desperate run from the chasing Vargr pirates.
You can leave the classic design systems unchanged, but you can use additional considerations in gameplay. For example recalculating acceleration with less load, enabling PCs to throw valuable cargo and redshirts overboard in that desperate run from the chasing Vargr pirates.
AnotherDilbert
SOC-14 1K
Vehicles use detailed thrust and mass, MT RM, p66:
Note that TL-9 anti-grav M-drive units (p65) is exactly the same technology as TL-9 Standard grav on p.66, just rescaled. See Overview of Technology, p56.
Spacecraft are simplified to be just like LBB5, the same drive percentages. That makes spacecraft much simpler to build than grav vehicles.
mike wightman
SOC-14 10K
Hmm.
If we set cargo and fuel as 1 ton per mdt
and all other components at 14 tons per mdt how would that work out, (mass1)
Or the more sensible fuel is 1 ton per mdt, while everything else is 14 tons per mdt how does that work out.(mass2)
If we set cargo and fuel as 1 ton per mdt
and all other components at 14 tons per mdt how would that work out, (mass1)
Or the more sensible fuel is 1 ton per mdt, while everything else is 14 tons per mdt how does that work out.(mass2)
| Ship | fuel | cargo | rest of ship | mass(1) | mass(2) |
| type S | 40 | 3 | 57 | 841 | 880 |
| type A | 30 | 82 | 88 | 1344 | 2410 |
| patrol cruiser | 120 | 50 | 230 | 3390 | 4040 |
Side note:
see that in fact the formula should be (Total thrust / vehicle's loaded mass)-gravity.
Assuming you have 100 tons of trust and 100 tons of mass, in a planet with a gravity of 0.66 G, the formula given by the book sould be 100/66-1, so 0.51 G.
With the correct formula it would be 100/100-0.66, so 0.34 G.
And in zero gravity, the formula given by the boos would mean infinite Gs...
I'm a bit confused about the 1000kg/m^3 thing. That's the density of water. Rock, so mined ore, is wildly variable, but can easily get over 5000kg/m^3. The more valuable stuff is denser, of course. Iron is about 7800kg/m^3, and Lead is 11300kg/m^3. A ground car might be about 145kg/m^3, since a car is largely air (passenger/cargo space), so it'd be OK to carry cars as cargo, but carrying ore would be a problem using that as a limitation.
I mean it’s a game.
The reason mass and volume and the relationship they have with ship acceleration and movement and centre of mass and the like is all vastly simplified is that it’s a game not an accurate simulation of space travel. Even the most in-depth and autistically detailed ship building, economic, or socio-political supplements to the game don’t make pretence of 100% accurate simulation.
The more time players spend calculating mass to thrust ratios and balancing the centre of mass of the ship so the thrust doesn’t unbalance it the less time they have to play the game. Cargo is measured in volume because it means that players and referees can easily tell from ship sheets how much cargo space they have. Does it make 100% sense that the actual mass of the cargo being transported doesn’t matter? No, but it does mean that the trading part of the game is quick and easy for players to understand meaning they have more time to play the game.
The reason mass and volume and the relationship they have with ship acceleration and movement and centre of mass and the like is all vastly simplified is that it’s a game not an accurate simulation of space travel. Even the most in-depth and autistically detailed ship building, economic, or socio-political supplements to the game don’t make pretence of 100% accurate simulation.
The more time players spend calculating mass to thrust ratios and balancing the centre of mass of the ship so the thrust doesn’t unbalance it the less time they have to play the game. Cargo is measured in volume because it means that players and referees can easily tell from ship sheets how much cargo space they have. Does it make 100% sense that the actual mass of the cargo being transported doesn’t matter? No, but it does mean that the trading part of the game is quick and easy for players to understand meaning they have more time to play the game.
AnotherDilbert
SOC-14 1K
Agreed, it should be, and is in CT Striker, but sloppy in MT.
MT RM does not really distinguish between mass and weight, as far as I can see. I assume they actually mean mass.
AnotherDilbert
SOC-14 1K
Why would we set everything to 1 tonne per m³? By all the rulesets that care, machinery and armour are heavier, fuel and staterooms are lighter.
AnotherDilbert
SOC-14 1K
Compare to a current container.
1 TEU ≈ 33 m³ and max ~22 tonnes (plus the container itself).
Not 1 tonne per m³, but not that far off. If you want to ship heavier stuff, you don't fill the container.
It's a general approximation, for generic freighters. The 90% case, not the rare exception.
If you ship lead in a generic freighter, you can't fill the cargo-hold completely, or even remotely. Add some light cargo on top?
If you want to ship cars, the volume limits before the mass limits.
Exactly, it’s only when players are trying to make the getaway with something like that radioactives heist that I would be looking at imposing density/mass effects. Especially if they got greedy stuffing the hold with the heavy stuff.
For what it's worth, long containers and high-volume have only slightly higher gross weight limits than standard ones, so the 1 tonne per cubic metre is slightly more than the maximum for containerised cargo.
For general cargo the old rule of thumb was one ton per 100 cubic feet (roughly 1 tonne per 3 cubic metres), and for a mixed load of general cargo it is a good rule of thumb (which would be why it survived so long). Unless your ship is a bulk carrier of something like ore, assuming 1 t/m^3 means you can ignore mass except in extreme cases. If using rules like CT and MgT that don't track mass, I'd rule that cargoes that mass more than than say [15 x cargo hold capacity (in DTons)] tonnes would cause the ship to have issues - lower acceleration, poor handling, liability to take strain and damage on even minor failures in piloting, etc. Not coincidentally, that's the threshold TNE/FF&S used for spaceship density when shifting from 'assume 10 tonnes per DTon' to 'use actual mass'.
For general cargo the old rule of thumb was one ton per 100 cubic feet (roughly 1 tonne per 3 cubic metres), and for a mixed load of general cargo it is a good rule of thumb (which would be why it survived so long). Unless your ship is a bulk carrier of something like ore, assuming 1 t/m^3 means you can ignore mass except in extreme cases. If using rules like CT and MgT that don't track mass, I'd rule that cargoes that mass more than than say [15 x cargo hold capacity (in DTons)] tonnes would cause the ship to have issues - lower acceleration, poor handling, liability to take strain and damage on even minor failures in piloting, etc. Not coincidentally, that's the threshold TNE/FF&S used for spaceship density when shifting from 'assume 10 tonnes per DTon' to 'use actual mass'.
Rupert mentioned the containerized cargo limits. You could presumably move masses of metal rather than be limited to the restrictions placed on containerized cargo, but presumably those restrictions exist for a reason. The stuff has to be moved to and away from your ship in something, and that something is going to have a limit on what it can carry, whether it's a wheeled or rail or grav vehicle. The client isn't getting any advantage if they're moving the same amount of mass whether it's containerized or a dense lump of lead - they'd still need the same number of vehicles and trips to get it to you or from you to someplace else because the vehicles have load limits regardless of the density of the product. The loading dock on the other hand now has to have staff and equipment capable of moving containerized cargo AND equipment capable of moving small dense blocks of lead or other nonstandard cargo; they'd probably prefer the shipper put everything in containers (securely tied down), even if there's a lot of empty space left, because they then only need to deal with, and train staff to handle, containers.
The only issue I can think of is armor for spacecraft, since armor's some really dense stuff, but someone pointed out that the armor for spacecraft might not be what they use for tanks and such. I'm still thinking that one through since I can't see a reason why the armor for spacecraft couldn't be used on tanks and such if it was both as effective as and less dense than the Striker-style armor tanks were using, but there may be something I haven't considered.
I think the conclusion that I'm drawing at the end of this discussion is that the game designers really hadn't thought this out at the beginning, they tried to interject various reasonable-sounding but ultimately not very harmonious rulings when the situation was specifically asked about, and that people just houserule their own game for whatever seems reasonable. It's sci fi anyhow, and I will just have to press the 'I believe in space magic' button. The times to orbit are wildly unusable for reaction-powered craft that are not able to continuously burn engines to maintain orbit as fusion, grav thruster craft would have to do to make use of the time tables in the book.
The comparison between ground and space armor is not really usesful, the only similarity is the names. Space armor is less bulky, lighter, and cheaper for the same protection (considering 50:1 between space and ground scale damage), and can be layered on so much more heavily that ground fighting vehicles are essentially a waste of effort. You are generally better off designing a small craft in High Guard than anything out of the military vehicles supplement, unless you're specifically going for like an air/raft-scale non-fighting vehicle.
The comparison between ground and space armor is not really usesful, the only similarity is the names. Space armor is less bulky, lighter, and cheaper for the same protection (considering 50:1 between space and ground scale damage), and can be layered on so much more heavily that ground fighting vehicles are essentially a waste of effort. You are generally better off designing a small craft in High Guard than anything out of the military vehicles supplement, unless you're specifically going for like an air/raft-scale non-fighting vehicle.
Marcatlas
SOC-12
The travel times were not made for craft with limited Δv . That's why they are wildly unusable for lower tech craft.
If my players stuffed thier hold with radioactives, As they delivered each pallet of material and put them touching the pallets around then I would give them a chance to notice a blue glow if there was air in the cargo area. No air, no warning. suddenly the guy running the grav lift falls over as he put the 9th pallet in a 3x3 grid of touching pallets (a few minutes later he gets back up, loading continues). Even better once they have a 3x3x3 stack of 27 pallets... everybody in the cargo bay falls down and this time none of them get back up. Anybody going into the cargo bay falls down. Anybody in adjacent compartments fall down. Eventually the ship's engineer calls the bridge: "Captian we have radation alarms going off in the engineering spaces we have 5 minutes to get everybody off this ship or we are all dead men walking."
Marcatlas
SOC-12
I doubt spaceship operators would be that uneducated when most of us here and now would know to check for radioactivity and leaks in such cargo
It's not dangerous till you put the radioactives in close proximity to a lot more radioactives. We store plutonium in a gell that suspends tiny flakes apart from one another, mass per m3 is a lot closer to 1kg/m3 of plutonium with the rest of the m3 having water density. On earth we have naturally formed fission reactors, the area fills with water, the radioactive particles start splitting faster, rocks get hot, water departs as steam, reaction stops. stacking pallets of plutotinium gell in a grid with water moderating is a recipie to start up a chain reaction, likley not enough to run away and destroy the gell, but a hell of a problem to deal with in your cargo hold. This is one area where you might want to actually pack your haul of plutonium at densities of 1mt/DT.
