Transfer of cargo in space

Discuss the Traveller RPG and its many settings
PsiTraveller
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Re: Transfer of cargo in space

Postby PsiTraveller » Thu Nov 26, 2020 9:57 am

Grav plate trick would have to be very low gravity to prevent 'falling' damage. Gravity may be avoided, but mass and acceleration are kept. Maybe that is what an UNREP system does, catch and release system to move items via gravitic control.

So a follow-up question. If a cargo hatch allows 10% of items to be moved at a time, does this mean my thought of putting a 10 ton figher inside a cargo bay of 60 tons will not work because it will not fit through the hatch? 10 tons being bigger than 6 tons.
AnotherDilbert
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Re: Transfer of cargo in space

Postby AnotherDilbert » Thu Nov 26, 2020 12:28 pm

PsiTraveller wrote: Grav plate trick would have to be very low gravity to prevent 'falling' damage. Gravity may be avoided, but mass and acceleration are kept. Maybe that is what an UNREP system does, catch and release system to move items via gravitic control.
Works the same way as dropping the cargo off a cliff. Using a tether to control the cargo seems advisable?

PsiTraveller wrote: So a follow-up question. If a cargo hatch allows 10% of items to be moved at a time, does this mean my thought of putting a 10 ton figher inside a cargo bay of 60 tons will not work because it will not fit through the hatch? 10 tons being bigger than 6 tons.
Some disassembly may be necessary.
Old School
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Re: Transfer of cargo in space

Postby Old School » Thu Nov 26, 2020 4:23 pm

HalC wrote:
Thu Nov 26, 2020 9:14 am
Dumb question time: in zero g of space, why can't you equip a wall with grav plates any have cargo fall towards the Grav plate from one ship towards the other?
Or just use your gravity field equipped pallet jack. Doing something “by hand” might not mean the same thing at TL12 as it does today.
HalC
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Re: Transfer of cargo in space

Postby HalC » Thu Nov 26, 2020 8:59 pm

One thing that occurs to me is that if grav plates can be installed in a starship, and in theory, one would expect that they would need a fairly substantial amount of power to operate - that "pallets" with grav fields of their own might not be slim things at all, or if they are, their power supply would be worth the while for adaptation for other uses in the field when not used as pallet power sources.

That said, what triggered the dumb thought as it were, is the idea that one could use the "Variable gravity" aspect of the grav plates for when you need to work with larger items or what have you. Mass is mass - no getting around it. But Force X mass = acceleration. A 3 G field working on attracting a mass will work faster than a 1 G field.

I remember when players rigged a grav plate in the ceiling of their passageway - playing Grav pong between the plates when pirates or what have you attempted to force their way through. They didn't like the idea of falling prey to their own tactics in case someone else gained control over the plates themselves in a hijacking attempt.

But - I suspect that we need to stop thinking in terms of working in a planetary gravity field when in Traveller, one has deck plates that generate gravity so easily. In fact? I have to wonder if there might be specialized "plates" that can generate higher gravity fields that would rival centrifuges. It might permit a level of purity in alloys than could normally be attained in normal gravity fields. One idea I had from GURPS TERRADYNE is the concept that if you had a zero G environment, you could make structurally impossible lattice work materials that would be impossible to create in a gravity field. With Traveller, two plates set above each other could create a near zero G environment inside a world's gravity well.

All in all, science fiction is sometimes about what MIGHT be possible if the technology were available. Imagine Iron with the same tensile strength as say, Titanium, but with the weight of Aluminum due to a honeycomb like lattice because it was fabricated in a zero G environment and using electrical forces (Positive/negative) for example.

**Shrug**
Condottiere
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Re: Transfer of cargo in space

Postby Condottiere » Thu Nov 26, 2020 9:50 pm

1. In regard to smallcraft, there's always been an aspect of handwavium regarding ingress and egress, if you add launch tubes to the mix; and if they have wings, which aren't foldable, it kinda widens the width.

2. A pallet jack could take a vehicle template, basically a really light air/raft, at which point, you might as well just convert that to a forklift.

3. Pretty sure OSHA takes a dim view of gravitational plate manipulation along the vertical plane, especially involving large masses.
AnotherDilbert
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Re: Transfer of cargo in space

Postby AnotherDilbert » Fri Nov 27, 2020 12:37 am

HalC wrote: One thing that occurs to me is that if grav plates can be installed in a starship, and in theory, one would expect that they would need a fairly substantial amount of power to operate - that "pallets" with grav fields of their own might not be slim things at all, or if they are, their power supply would be worth the while for adaptation for other uses in the field when not used as pallet power sources.
According to MT a grav drive for a standard container would be ~3 tonnes and use ~8 MW power.

A small fusion power plant to power it would be about ~16 tonnes at TL-12 or about half the mass of the container.

The drive and PP would cost about MCr 1.

It seems impractical for a supposedly cheap cargo container.

HalC wrote: That said, what triggered the dumb thought as it were, is the idea that one could use the "Variable gravity" aspect of the grav plates for when you need to work with larger items or what have you. Mass is mass - no getting around it. But Force X mass = acceleration. A 3 G field working on attracting a mass will work faster than a 1 G field.
Yes, but F = m × a, so a = F / m...
phavoc
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Re: Transfer of cargo in space

Postby phavoc » Tue Dec 15, 2020 6:13 pm

I would think that grav plates would not allow fast-cycling of gravity. From a safety perspective you want a grav plate to have capacitors that would slowly fail, so that passengers and freight would not suddenly be exposed to 1-XXg of acceleration. I suppose it would be possible to make it work (tech exists), but it would take some crazy wiring to bypass the built-in safety features you'd want them to have in order to NOT fail.

Moving cargo by "tossing" it works, but it's not safe and can easily lead to accidents. A light-weight frame of sorts (or even block and tackle) to move cargo along makes sense. And you'd be moving in smaller quantities, say 1-3dton containers for foodstuffs, even muntions. It makes storage easy and transfer easy. A 1dton container could contain 2 pallets (1 per grid square). That allows the cargo ship to build the containers for easy transport based on orders.
Condottiere
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Re: Transfer of cargo in space

Postby Condottiere » Tue Dec 15, 2020 9:45 pm

I suspect that current sized pallets and containers are about correctly sized for human space.

The other aspect would be cost of a anti gravity lifter, to one that just lifts the pallet or smaller container off the floor, to move it short distances.

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