Efficient space only freighter design

[Geir]

Agreed. But what's the price for a space-rated 10dt container with deck plating?

In High Guard a module hull is Cr25000 per dTon, so I would say MCr0.25 - and an external power source available to provide 2 power points per container for grav plating, atmosphere and the like. If you made a "power pack container" - at TL12, that would give you 100 power points, so call it one in 50 containers is a MCr 10.25 power "power cell". Or they could run off a ship's power allocation, if the ship were appropriately (up to 75%) modular.
And if there were zillions of these, the price of the 10 dton container (and probably the power cell) would get a 10% discount, maybe more.

 

[phavoc]

I haven't done might with 2300AD since it was originally published. I don't recall the currency to make a comparison (it was all in Francs wasn't it? I did like the Xwing and Kennedy class ships.).

Anything for space is going to be much more expensive than something to keep out rain. And throw in gravity control and it's going up again. Making anything vacuum proof is not cheap.

 

[Vormaerin]

Sure, but what is cheap? I mean, this is a game where a basic space motel room costs half a million credits to install, not counting the hull to put it in.

Anyway, a standard ton of High Guard starship hull costs Cr50,000. A standard ton of Aerospace Engineer's Handbook starship hull costs Lv20,000. If you consider that AEH hulls are "non gravity hulls", the High Guard cost is Cr25,000.

Admittedly, as Geir points out, High Guard lets module hulls (that do have grav, etc) cost Cr25,000 also... But they do increase the cost of the ship's hull by a significant amount.

 

[phavoc]

Sure, but what is cheap? I mean, this is a game where a basic space motel room costs half a million credits to install, not counting the hull to put it in.

Anyway, a standard ton of High Guard starship hull costs Cr50,000. A standard ton of Aerospace Engineer's Handbook starship hull costs Lv20,000. If you consider that AEH hulls are "non gravity hulls", the High Guard cost is Cr25,000.

Admittedly, as Geir points out, High Guard lets module hulls (that do have grav, etc) cost Cr25,000 also... But they do increase the cost of the ship's hull by a significant amount.

Well, an ocean-going container costs between $3-$5k USD to buy new (in China). A new 53' High-cube that are only for Road/Rail cost about $18k - $20k in the US Resale market for used ones is about $2k - $3k, with 53' ones being slightly higher.

These are the basic containers I'm thinking of, and these types of containers are going to form the backbone of your transportation network across all kinds of worlds and tech levels. Starship hulls contain a bunch of things that containers aren't going to, so maybe dropping the cost of a space-container to say Cr5k per Dton. That makes it Cr50k for a standardized 10Dton container. Entirely within the realm of possibility, but on a very high end for cost effectiveness. I'm expecting general containers to be priced at around Cr5k or Cr8k for a 10Dton container.

Having the more expensive one allows for a lot more flexibility for haulers that carry them external. And on the ground they'd make for really good bunkers or reinforced buildings. Standard containers are easily penetrated with most military weaponry - but they do make great bunkers or walls if you just fill them with dirt.

Gaming wise most won't care - it's a container - but I like to connect all the dots and build the world model correct from the start. That and I'm a railfan nut and I spend tons of time thinking about containers on the rails, getting to the ships, or on the trucks (even used as bunker/barriers in embassies or to make walls along borders). Definitely not a normal thing.

 

[MasterGwydion]

Agreed. But what's the price for a space-rated 10dt container with deck plating?

50KCr per ton or 500KCr for a 10dt container. All you need to add in now is the battery cost.

 

[Geir]

Sure, but what is cheap? I mean, this is a game where a basic space motel room costs half a million credits to install, not counting the hull to put it in.

Anyway, a standard ton of High Guard starship hull costs Cr50,000. A standard ton of Aerospace Engineer's Handbook starship hull costs Lv20,000. If you consider that AEH hulls are "non gravity hulls", the High Guard cost is Cr25,000.

Admittedly, as Geir points out, High Guard lets module hulls (that do have grav, etc) cost Cr25,000 also... But they do increase the cost of the ship's hull by a significant amount.

Can get cheaper if you use a light hull. On both the container and the ship. So the container (module) cost drops to Cr16875 with a 10% discount. And if you go with a light dispersed hull on the carrying vessel, it pays for part of the modular cost. I would argue that you could get even cheaper by skimping on the gravity on the cargo carrier and there's nothing clear in the rulebook that says you can't skimp on gravity for the module either ((does most cargo really need it - I mean, you can use some cables for interior tie-downs and call it good) and half its cost again (and half the power)... hey, by the time we're done, it's a 2300-ish ship...

 

[Vormaerin]

Well, an ocean-going container costs between $3-$5k USD to buy new (in China). A new 53' High-cube that are only for Road/Rail cost about $18k - $20k in the US Resale market for used ones is about $2k - $3k, with 53' ones being slightly higher.

These are the basic containers I'm thinking of, and these types of containers are going to form the backbone of your transportation network across all kinds of worlds and tech levels. Starship hulls contain a bunch of things that containers aren't going to, so maybe dropping the cost of a space-container to say Cr5k per Dton. That makes it Cr50k for a standardized 10Dton container. Entirely within the realm of possibility, but on a very high end for cost effectiveness. I'm expecting general containers to be priced at around Cr5k or Cr8k for a 10Dton container.

Having the more expensive one allows for a lot more flexibility for haulers that carry them external. And on the ground they'd make for really good bunkers or reinforced buildings. Standard containers are easily penetrated with most military weaponry - but they do make great bunkers or walls if you just fill them with dirt.

Gaming wise most won't care - it's a container - but I like to connect all the dots and build the world model correct from the start. That and I'm a railfan nut and I spend tons of time thinking about containers on the rails, getting to the ships, or on the trucks (even used as bunker/barriers in embassies or to make walls along borders). Definitely not a normal thing.

They cost Lv5000 per ton in 2300 (double for liquid or gas). Come in 25 and 50 ton versions, plus a few weird ones. Smaller ones might make sense in Traveller because it doesn't have 2300's issues with the surface to orbit transfer because of anti grav/maneuver drives.

Container ships require a spine for the containers to be attached to.

"The structure of the spine is an accessway that connects to every pod and requires tonnage equal to 5% of the total storage of all pods. For example, 3,600 tons of pod capacity would require a spine that takes up 180 tons. This amount is added to the ship’s main body and used to compute the ship’s unloaded tonnage. This spine costs MLv0.05 per pod, which includes the necessary clamps and umbilicals."

 

[Alqualonde]

50KCr per ton or 500KCr for a 10dt container. All you need to add in now is the battery cost.

You are not required to install batteries if the container ship provides the energy (at least no batteries for a 7 days jump). When you clamp your container to the ship, just plug a power cable. It might even be integral to the clamp & fully standardised.

 

[AnotherDilbert]

In High Guard a module hull is Cr25000 per dTon, so I would say MCr0.25 - ...

Isn't a module considered internal, so covered by the ship's hull? Basically it's just a frame to keep the module together, it's not an external hull.

HG'22, p44:
Up to 75% of a ship’s internal tonnage can be designated as modular. This tonnage cannot include the bridge, power plant, drives or any structure or armour options.

The hull hatch covers the internal module on the MgT cutter.

 

[AnotherDilbert]

Sure, but what is cheap? I mean, this is a game where a basic space motel room costs half a million credits to install, not counting the hull to put it in.

Quite, that is what I meant by cheap, cheap in comparison to the ship or the shipping rates, if we use the container for decades.

Anyway, a standard ton of High Guard starship hull costs Cr50,000. A standard ton of Aerospace Engineer's Handbook starship hull costs Lv20,000. If you consider that AEH hulls are "non gravity hulls", the High Guard cost is Cr25,000.

Not much point having artificial gravity if we don't have acceleration compensators, and that requires an M-drive...


By using a basic hull, non-gravity, Light, with Dispersed configuration we get a cost of:
MCr 0.05 × 50% × 75% × 50% = MCr 0.009375 ≈ kCr 10 per dTon.

MCr 1 for a 100 Dt container, cheap as chips!

 

[AnotherDilbert]

We can get a self-piloting 100 Dt "container" with gravity, compensation, M-1, and Virtual Crew for MCr 6.5 in quantity with space for 96 Dt cargo:



At MCr 11 we can get a streamlined version with 95 Dt cargo that can land itself at the port or warehouse:


Getting a bit more expensive, but cheap enough if we write it off over 40 years?

 

[Geir]

Isn't a module considered internal, so covered by the ship's hull? Basically it's just a frame to keep the module together, it's not an external hull.



View attachment 1750
The hull hatch covers the internal module on the MgT cutter.

Agreed. That's why I said you had to pay for the modular % of the hull.
Otherwise, if you just used docking clamps or cargo mounts, you would have to pay for it as a separate 'ship' at twice the price.
Whether it's actually enclosed or not is more at the discretion of the artist, um, naval architect.

But... that assumes a cargo container has to be treated like a spacecraft/module etc. in the first place. For many items all you have to do is vacuum-seal (in both meanings of the term) the cargo. There's also a reference to the cost of 'surface modules' in the Drinaxian Companion's construction rules (which might be a bit flakey as I recall, and I'm not going to hunt down the reference this morning to double-check) that quarter the cost of a space-rated enclosed environment.

 

[phavoc]

The prices are gonna be too high for bulk containerization. You just need a box to put the stuff in, and then those boxes get moved around all over the place - often far from starships.

The space-rated container to HOLD a basic container is different than the container itself. Just like the ship that will take that space-rated container between star systems is different than the space-rated container.

 

[MasterGwydion]

You are not required to install batteries if the container ship provides the energy (at least no batteries for a 7 days jump). When you clamp your container to the ship, just plug a power cable. It might even be integral to the clamp & fully standardised.

The batteries are so you do not lose gravity when you disconnect from the transport ship and before the container is connected or inside of something with it's own gravity.

 

[phavoc]

The batteries are so you do not lose gravity when you disconnect from the transport ship and before the container is connected or inside of something with it's own gravity.

Agreed. You'd need some sort of battery system if you ever moved it into zero-G or were carrying cargo inside while disconnecting it from external power supply.

Typical reefers today generally have a 2-3 day fuel supply (tractor trailers). Specialized reefer containers for container ships are electrically powered and plug into the ships power supply. They can also have their own power system and plug into the ship (they typically cost 5-6 times the cost of a normal ocean container).

While you COULD use capacitors to do a slow discharge, unless they were super-capacitors that had a fair amount of power in them you'd not be able to account for a myriad of possible delays that reality would throw at you.

And using space as your freezer isn't recommended for a lot of different types of cargo's because of the freezing/thawing process (ice crystals, too cold, etc).

 

[MasterGwydion]

and guys just remember, a semi-truck costs about 100k and a shipping container to go on the semi truck costs about 2k. So you should never spend more than 2-4% of the cost of the ship in shipping containers. For a 50MCr ship, you'd average between 1MCr and 2MCr on containers. My problem with My idea, is that only covers the price comparison for a truck that only holds one 5Dton cargo container versus a ship that can hold a dozen or more. So, We may have to look into the cost of a, modern day, cargo ship, how many 40' cargo containers they can hold, and then compare that to the price of the cargo containers. Then We could have a rough percentage of ship's cost versus container cost. That might, might give Us a decent starting point to figure out what additional percentage of the cost of your ship, should be used for containers. Then if they are "space-worthy" containers, multiply that cost by 10ish

Modern "Adventure-Class" container ships cost about 30 million dollars and containers cost roughly 2,000 dollars. The ships can hold an average of 300 FEUs or 600,000 dollars in containers. 30M dollars for the ship and roughly 2% for the cargo containers puts Us in the right ballpark at 600k.

This is just My 2 cents first thing in the morning before I have had My caffeine.

 

[AnotherDilbert]

and guys just remember, a semi-truck costs about 100k and a shipping container to go on the semi truck costs about 2k. So you should never spend more than 2-4% of the cost of the ship in shipping containers.

So, you mean current containers are impossible, because of the cost amphorae compared to Greek galleys?

Both have about as much to do with each other as with 57th century spaceships.

 

[Geir]

This entire discussion is, I believe(d?), predicated on containers needing to be fully "space rated". In default scenarios, they need be nothing more than boxes of 57th century plastic, to the point at which they are ignored - or it assumed that whatever container exists for a 5 or 10 lot is part of the "delivery".

Only in special cases does it matter, like the equivalent of a container ship needing to store containers on the hull and under the waterline, but not the standard, "I have a cargo hold. Let's load load it up." scenario - that would be like saying every passenger needs a vacc suit that they have to wear for the entire journey - and don't forget the jump space visor, because they'll be sitting on the hull. So costs for a metal box on the back of a truck or for most of the boxes stacked on a panamax ship are not at all the same thing in anything other than, perhaps, shape.

 

[Nelphine]

Right, but were specifically trying to design an efficient transport, and two things have cropped up as possible problems that need spaceworthy cargo:

One, dont store cargo in your hull, lash it to the outside instead. But in this case, its needs to be space rated, becsuse there is no ship protecting it.

Two, what if your ship is designed in an unusual fashion (which includes lashing to the outside, but could also include other designs, including just.. a ship way larger than the station its docked with) where unloading the cargo won't occur through a cargo bay door, but will of necessity need to pass through space before reaching the loading dock.

 

[Sigtrygg]

If the cargo is lashed to the outside as you put it then it needs jump cabling running through its structure, grav plates and acceleration compensation.