Real life comparisons for dtonnage?

[phavoc]

The whole idea of containers is a cheap means of shipping, with the ability to drop it off and pick it up latter, while it can be transported by truck or train as well. Depending on how heavy you view spacecraft hulls, a container built to under 100 dTons spacecraft standard is neither going to be cheap or light, and clearly is subject to being modified into a space craft. As a first cut, a circa 100 dTon hull is going to weigh about 140 to 175 mass tons or so.

We don't know the cost of the hull materials itself, as the pricing for small ships includes a whole host of things not applicable to building a container.

Also mass, unless you are playing GURPS, is meaningless in Traveller. It's all focused on displacement tonnage.

An ocean-going container is more structurally sound than a standard container that only travels by truck or rail. But beyond having to operate in a sea environment they aren't much different. All intermodal containers are built to be picked up and stacked.

An ocean-going 40' one costs about $4,000 new. Used ones are cheaper. Layering tougher materials on the frame isn't the same as having to build an entire ship. It's not unreasonable to assume crystal-iron would be as common and as cheap as steel is today, which ocean-going containers are made out of.

 

[Timerover51]

We don't know the cost of the hull materials itself, as the pricing for small ships includes a whole host of things not applicable to building a container.

Also mass, unless you are playing GURPS, is meaningless in Traveller. It's all focused on displacement tonnage.

An ocean-going container is more structurally sound than a standard container that only travels by truck or rail. But beyond having to operate in a sea environment they aren't much different. All intermodal containers are built to be picked up and stacked.

An ocean-going 40' one costs about $4,000 new. Used ones are cheaper. Layering tougher materials on the frame isn't the same as having to build an entire ship. It's not unreasonable to assume crystal-iron would be as common and as cheap as steel is today, which ocean-going containers are made out of.

Mass is not meaningless when you have to move these things in a gravity well, and you do have inertia to deal with as well. You are only thinking about the space end, you are not thinking about what happens when the container is not being carried by a space ship. Put that large and heavy container on un-reinforced ground and watch what happens.

As for being seized and used for other things, you do have a loss rate of containers which once delivered, never are returned. Third World countries find that they make nice homes, small stores and other quick buildings, as well as storage space in rainy climates. A friend of mine who works with Congo Refugees on Lake Tanganyika states that there are entire villages where every home is a shipping container.

I will not get into the cost of hull materials.

 

[phavoc]

Mass is not meaningless when you have to move these things in a gravity well, and you do have inertia to deal with as well. You are only thinking about the space end, you are not thinking about what happens when the container is not being carried by a space ship. Put that large and heavy container on un-reinforced ground and watch what happens.

As for being seized and used for other things, you do have a loss rate of containers which once delivered, never are returned. Third World countries find that they make nice homes, small stores and other quick buildings, as well as storage space in rainy climates. A friend of mine who works with Congo Refugees on Lake Tanganyika states that there are entire villages where every home is a shipping container.

I will not get into the cost of hull materials.

It's not that I'm NOT thinking of it. The RULES don't accommodate it at all (unless you are talking about GURPS - then mass AND displacement matter).

I'm well aware that 10Dtons of lead masses more than 10Dtons of feathers, and if we were interjecting reality into things, the mass of 10 tons of lead would occupy a smaller space than 10 tons of feathers (assuming you don't crush them into an indistinct mass, and even then the sizes would be different).

As to the re-use of containers, it's nothing new. In Afghanistan they fill them with dirt and they become impenetrable earth berms you can stack. In the Australian outback they are used as homes. There is an entire industry dedicated to purchasing used/retired shipping containers and repurposing them.

I still don't see where anything I mentioned disputes the idea that (a) containers remain an extremely inexpensive way to ship goods, and (b) that containerization would logically continue to be used thousands of years from now since it's the (current) apex of efficiently moving cargo from point A to point B (aside from using say teleportation technology). I suppose if you mastered energy to matter issue containers as a form of transport would probably fall along the wayside.

 

[Timerover51]

My error on my initial estimate of the weight of a 100 dTon cargo container similar to a 100 dTon space craft hull. A 100 dTon container of that type equals 500 measurement tons in the Real World of shipping, or about 1400 displacement tons in terms of water displacement. By rule of thumb, 500 measurement tons would equate to a total weight of about 250 tons for a sea-going ship, so about 160 tons or so for hull mass. Fourteen hundred displacement tons would make it a bit smaller than a British World War 2 T-class submarine (surface displacement of 1090 tons, submerged displacement of 1579 tons). Hull weight for the T-class went about 400 tons for pressure hull. As the container can handle a vacuum, it has to handle an internal pressure of 14.7 pounds per square inch, less than a sub, but more than a surface ship, and a lot more than a Real World container. Allowing for some internal subdivisions (a T-class sub was 265 by 26.5 feet roughly), figure the mass of the container, empty, is probably about 200 tons. That does not include cargo, which could easily be 500 to 1000 tons. Moving that in space is a lot of inertial mass to deal with. Handling it on the ground, assuming that is is a dumb container, is another story.

I am not saying that it could not be done, just that you might want to think about how you are handling this once landed on a planet.

As I have said many times before, it is your universe, and you can do whatever you want.

 

[infojunky]

How so? What I stated is exactly how it is today. Today's modern containers are comprised of two types - ocean going, which are characterized by their external appearance, and non-ocean going, which are indistinguishable from the containers that are built into the frames of trucks and trailers. The addition of the hazards of space would naturally mean a third type would be necessary to deal with radiation, micro-metoroids, etc.

Unless you are explicitly referring to Swapbody containers I think you might off in left field. In that Yes there are some containers that aren't commonly supported for transhipment by ship. They are very visually different from Standard Containers. Note these generally are 40+ ft containers....

Generally a space going container would be assumed to somewhat more robust than a current Container. One the whole Vacuum thing, which is less of an issue than you are making it out to be. Consider said space going box is going have to be able to support its load in any direction. Plus the load of the surrounding boxes as well. (Note modern Containers strong axis is horizontal with a great deal of their strength being in the corrugated steel walls). As for radiation, that is simple, do it like today, containers that are vulnerable to radiation will be shipped in the inner layers, and I suspect if it is a worry the shipper will take appropriate steps when packing the container as well.

What you are referring to is more of the LASH (Lighter Aboard Ship) idea that came about in the 70s, where mini-barges were hoisted on to the ship that could then be distributed elsewhere via water after they had been transported across the ocean. There's nothing to say that this wouldn't work in the Traveller universe. Having a large container that held say 50 to 100 other smaller containers would allow for the expensive ship to arrive in-system at the 100D limit, drop off the larger container that has the cargo destined for this system, refuel and pickup new ones and then jump out. It would shave days off a normal port rendezvous process.

Well, yes, but couldn't all container operations be considered a form of LASH operation? In light of some of the Cited Fiction a'la BSG can't you see those ships with containers being 100 dTons?

 

[infojunky]

It's not that I'm NOT thinking of it. The RULES don't accommodate it at all (unless you are talking about GURPS - then mass AND displacement matter).

Correction, as this a general Traveller discussion area whether the "rules" deal with mass or not is a moot point is you do not specify which rules set you are referring to. As several rules sets have dealt with mass.

 

[phavoc]

Unless you are explicitly referring to Swapbody containers I think you might off in left field. In that Yes there are some containers that aren't commonly supported for transhipment by ship. They are very visually different from Standard Containers. Note these generally are 40+ ft containers....

Nope, just the normal kind. More detail than necessary, but containers destined for truck/rail shipments are now standardized in 48' and 53' foot lengths, and seagoing ones are 40' and 45' in length. Then there are the tractor trailers that have similar features to containers, except they aren't removable from the trailer. Most older models of road/rail containers are visually indistinguishable from normal tractor trailers unless you look at the corners or the trailers and see the tell-tale signs of it being a container, or not. There are exceptions to this. If you are a railfan you may notice the blue Pacer stacktrain containers (you can see similar JB Hunt ones, too). These are similar in appearance to the standard 40' & 45' containers transported via container ships. However these newer containers are in 48' and 53' lengths and don't get loaded onto a ship.

Generally a space going container would be assumed to somewhat more robust than a current Container. One the whole Vacuum thing, which is less of an issue than you are making it out to be. Consider said space going box is going have to be able to support its load in any direction. Plus the load of the surrounding boxes as well. (Note modern Containers strong axis is horizontal with a great deal of their strength being in the corrugated steel walls). As for radiation, that is simple, do it like today, containers that are vulnerable to radiation will be shipped in the inner layers, and I suspect if it is a worry the shipper will take appropriate steps when packing the container as well.

I would also assume a space-rated container to be structurally more robust than one today, but that's pretty reasonable considering containers today aren't built for vacuum standards.

The reason I mentioned three different types is because there would be variations on where you would be using the container, and the simplest version would be the cheapest. A container that is never going to be exposed to space is obviously the cheapest. It means you just need to keep the rain out. No need for a more expensive structure to keep atmosphere in, to protect against radical pressure changes, or the hazards of space. Basically the common slab-sided container you see today. These types of containers would always be carried in pressurized cargo holds.

The space type would obviously be more expensive, but handy if you need to bring it up from a planet or move them around in orbit or a vacuum. The addition of protecting against the rigors of space would require more materials and structural reinforcement.

The final type would be the kind you could strap onto a ship and deliver anywhere in a system. Or leave them on the surface of a vacuum world and not worry about their cargo being damaged by space hazards (within reason of course). Probably not as much call for them, but perhaps. Making them the same size as the other containers means you don't need special equipment to transport them around. Which is the same reason you see specialized types of containers for transporting liquids in frames that mimic the standard container. Being able to deliver that container anywhere makes for great economics. Same as we have today.

Well, yes, but couldn't all container operations be considered a form of LASH operation? In light of some of the Cited Fiction a'la BSG can't you see those ships with containers being 100 dTons?

I would say not. The concept behind the LASH idea was to merge ships and barges with the cargo. The ship takes it across the ocean to a port or river, and then the lighter is directed towards its final water destination and the lighter is unloaded. Containers weren't really big at the time, but in theory you could have loaded containerized cargo on the LASH and moved them that way.

I do see where the LASH concept is getting mixed up. They are very similar in their operations. I suppose the dividing line is that the LASH lighter is actually a vessel, but unpowered, itself. And the big 100 Dton container would not be. There was a similar idea for a modular starship in GURPS that had the primary mover equipped with a J6 drive and as each module was attached the jump went down by one. Each module was self-contained (don't remember if they had thrusters or not though).

 

[phavoc]

Correction, as this a general Traveller discussion area whether the "rules" deal with mass or not is a moot point is you do not specify which rules set you are referring to. As several rules sets have dealt with mass.

Ah, you are right. I had forgotten that MT added mass for the starships. I wasn't addressing it since most of the other versions are more concerned with displacement tonnage when it comes to what you can cram inside a cargo hold.

 

[GypsyComet]

Ah, you are right. I had forgotten that MT added mass for the starships. I wasn't addressing it since most of the other versions are more concerned with displacement tonnage when it comes to what you can cram inside a cargo hold.

In most editions volume remains the only *concern* after the design phase, but mass is there as a detail to be used or not. MT, TNE, some of T4, and maybe one of the late editions all have mass as a detail for ships. CT only uses mass for smaller vehicles, per Striker, because ground pressure is a possible factor. The editions that use mass for starships do relatively little with it, with the notable exception being TNE, which forces a recalculation of maneuver Gs if a ship is too dense.