Pondering Containers...

[boomslang]

I feel that I should point out that a base Forty-Foot-Equivalent Unit ("FEU"), a common -- if inexact -- standard in intermodal shipping these days, comes in right at 5dt (~67.5 cubic meters), including handling hardpoints:

<https://en.wikipedia.org/wiki/Twenty-foot_equivalent_unit>

The loading specifications are covered in ISO 668:

<https://en.wikipedia.org/wiki/ISO_668>

And our TL7.5 infrastructure here on Terra is already equipped to handle them.

 

[Spinward Flow]

I feel that I should point out that a base Forty-Foot-Equivalent Unit ("FEU"), a common -- if inexact -- standard in intermodal shipping these days, comes in right at 5dt (~67.5 cubic meters), including handling hardpoints

FEU
Exterior Dimensions (In feet) 40' long X 8' wide X 8'6” high
Exterior Dimensions (in meters) 12.19m long X 2.44m wide X 2.59m high.
Internal Dimensions (in meters): 12.025m long X 2.352m wide X 2.393m high.

For our 1.5m deck squares mapping, that comes out to being 8 squares long and 1.5 squares wide on the inside (not including bulkhead thickness). Kind of hard to fit much "Traveller useful stuff" into such a long+slender space. Even the humble Air/Raft is typically shown as being 2 deck squares wide on most deck plans.

 

[boomslang]

FEU
Exterior Dimensions (In feet) 40' long X 8' wide X 8'6” high
Exterior Dimensions (in meters) 12.19m long X 2.44m wide X 2.59m high.
Internal Dimensions (in meters): 12.025m long X 2.352m wide X 2.393m high.

For our 1.5m deck squares mapping, that comes out to being 8 squares long and 1.5 squares wide on the inside (not including bulkhead thickness). Kind of hard to fit much "Traveller useful stuff" into such a long+slender space. Even the humble Air/Raft is typically shown as being 2 deck squares wide on most deck plans.

Air/Rafts tend to be carried in dedicated bays, not cargo boxes. Also, bear in mind the old 130% of displacement rule of thumb for sub-100dt craft not in dedicated bays. And Air/Rafts sitting on cargo decks include space around them for occupants to mount and unmount.

Additionally, an FEU is noticeably wider when tipped over on its side. Even then, the volume capacity is typically stencilled right there on the end as being just under 70 cubic meters. I do not feel constrained by the 1.5-meter grid; if my cargo hold can be efficiently filled with standardized containers that do not waste precious displacement, tidy floor plans do not matter to me.

So, to ship an A/R, I would spec out a 10dt box at the same height and length but twice the width (so it fits in the same space as two regular FEUs side by side), consider stacking not one but two A/Rs in there like shoes in a shoebox, include lots of packing material, and charge a base 10KCr shipping and handling for the package.

Otherwise, the A/R would ship as loose cargo strapped to the deck for 4KCr, probably uninsured.

Remember that interstellar shipping in the 3I is a huge racket ultimately controlled by Tukera (indeed, the entire 3I is basically a vertically-integrated cash cow for the nobility) -- and with an effective monopoly, there is zero incentive to make the shipping sensible or reasonably-priced. Making customers pay Top Credit to ship easily-handled containers that are largely filled with air over parsec-scale distances is a feature, not a bug.

 

[Spinward Flow]

I would spec out a 10dt box at the same height and length but twice the width (so it fits in the same space as two regular FEUs side by side)

So basically 8 deck squares long and 3 deck squares wide for a "double wide" load using 1.5m² deck squares, meaning basically this:

 

[Silverhawk]

I feel that I should point out that a base Forty-Foot-Equivalent Unit ("FEU"), a common -- if inexact -- standard in intermodal shipping these days, comes in right at 5dt (~67.5 cubic meters), including handling hardpoints:

<https://en.wikipedia.org/wiki/Twenty-foot_equivalent_unit>

The loading specifications are covered in ISO 668:

<https://en.wikipedia.org/wiki/ISO_668>

And our TL7.5 infrastructure here on Terra is already equipped to handle them.

So while you are correct that a 40 foot container is one FEU, the standard is to quote capacity in terms of the 20 foot container or TEU. This makes a 40 foot container 2 TEU.

There are also 10 foot containers out there that can be transported in pairs like one 20 foot unit.

 

[Spinward Flow]

quote capacity in terms of the 20 foot container or TEU.

4 squares by 1.5 squares = 6 squares = 13.5m² of usable deck area (for our starship wargaming purposes)
Throw in a 2.4m high interior ceiling and you're looking at 32.4m³ of usable interior volume ... which sounds suspiciously close to being 2.3 displacement tons (for those playing the home game) per TEU.

If that sounds "pretty rinky dink" for starship cargo hold commerce modules (falling into the "incidental cargo" category) ... well ... you'd be right!

 

[giant.robot]

I think it's only worth bringing Earth containers into the equation as a concept.

Make your life easier, the "standard" Traveller pallet is a .5 dTon pallet that's a 1.5m^3 cube. Two cubes is a dTon and if they're stacked two high that means you get a dTon per standard grid square. The .5dTon cube is the smallest freight load you'll ever mess with and multiples of those cubes is what small freighters will ever deal with. A 1x1x2 square 1dTon container is very common.

Larger ships will do bigger intermodal containers that are 2x6x2 square (roughly an Earth TEU) sized containers. Because we're in the Far Future the containers are made out of cheap but sturdy Plastanium. They have attach points at corners and edges to work with cargo loading systems and tie-downs. Most can safely stack two high in normal 1G and are rated to 4G, 6G can cause stress on the attach points and they might go flying. Military grade pallets are more expensive but rated to 6G.

 

[Spinward Flow]

2x6x2 square

9m long x 3m wide x 3m high = 81m³ / 14 = 5.785 displacement tons
5 tons * 14m³ = 70m³ ... so there's some "margin" around the edges there for a 5 ton Minor Cargo Container to fit into such a "volume slot" in a cargo hold.

A "closer" fit would be 7.5m long x 3m wide x 3m high (5x2x2 squares) = 67.5m³ / 14 = 4.821 displacement tons

Point being that there are ways to ... finesse ... the solution to this problem of form factors.
Speaking just for myself, I'd prefer to have "square blocks of floor space" rather than long rectangles be the standardization for cargo module containers. That way orientation doesn't have to be an issue, they all just "stack squarely" regardless of how each module gets spun around. Depending on what you put into the modules when they're loaded into a cargo hold/hangar bay that might be important (for reasons of access while in flight, if nothing else), but otherwise the modules just fit together in repeating squares with regards to containment spacing. Makes certain things a little easier when you start playing Tetris with the contents of your load capacity.

 

[kilemall]

The attach point part is important. I would expect to attach to floors, stacks, ceilings, walls and container stacks next to each other. No chance of floating/flying.

 

[kilemall]

9m long x 3m wide x 3m high = 81m³ / 14 = 5.785 displacement tons
5 tons * 14m³ = 70m³ ... so there's some "margin" around the edges there for a 5 ton Minor Cargo Container to fit into such a "volume slot" in a cargo hold.

A "closer" fit would be 7.5m long x 3m wide x 3m high (5x2x2 squares) = 67.5m³ / 14 = 4.821 displacement tons

Point being that there are ways to ... finesse ... the solution to this problem of form factors.
Speaking just for myself, I'd prefer to have "square blocks of floor space" rather than long rectangles be the standardization for cargo module containers. That way orientation doesn't have to be an issue, they all just "stack squarely" regardless of how each module gets spun around. Depending on what you put into the modules when they're loaded into a cargo hold/hangar bay that might be important (for reasons of access while in flight, if nothing else), but otherwise the modules just fit together in repeating squares with regards to containment spacing. Makes certain things a little easier when you start playing Tetris with the contents of your load capacity.

Problem with squares is it limits your container size to what fits in the hatch, longer rectangles are going to need smaller hatches.

You can go star citizen style, the floor IS the hatch/elevator, but most of our classic floor plans aren’t wired that way.

 

[Spinward Flow]

Problem with squares is it limits your container size to what fits in the hatch, longer rectangles are going to need smaller hatches.

True.

This is why I really like the sweet spot of the 7.5m x 7.5m x 3m = 12.05 tons module form factor that I found, since it's 5x5 deck squares. So you need bay doors that are 5 squares wide, but once you've got that on your deck plans, you're good to go.

Curiously enough, a 6m x 6m x 6m = 15.43 tons "double decker cube" is another option if you can afford the bay doors and the double deck height stacking involved. The downside is that you only have 4x4x4 deck squares to work with, which often times isn't "floor space-y enough" for the form factor of a lot of larger vehicles (ATVs, GCarriers, Speeders, etc.)

9m x 9m x 3m = 17.35 tons module form factor (6x6 deck squares)
10.5m x 10.5m x 3m = 23.63 tons module form factor (7x7 deck squares)

But as far as bay doors go, a 3m x 3m door area just seems too small for a starship (5 squares wide, 1 deck tall).
A 7.5m x 3m door area makes for a decent compromise (5 squares wide, 1 deck tall).

 

[Silverhawk]

The attach point part is important. I would expect to attach to floors, stacks, ceilings, walls and container stacks next to each other. No chance of floating/flying.

Having seen pictures of derailed railcars with double stacks where the top container is still on top even with severe tilt, I suspect that it is just an engineering/design problem.

 

[whartung]

You can go star citizen style, the floor IS the hatch/elevator, but most of our classic floor plans aren’t wired that way.

 

[willtron3030]

ot on how conservative humanitii is about such things and how much influence the Solomani have had on containers within the Imperium. If they had a lot of influence and there was a strong conservative trend, then we'd expect to see 3m, 6m and 12m long containers; assuming those are 3m wide and 3m high that would give approximately 2, 4 and 8 dTons.
However, those don't mesh particularly well with the freight lot sizes in Traveller. The dimensions we generally see in the rules also don't mesh with the reality of cargo handling, deck heights, need for space for "lashing" and visual inspection

Adventure-class merchant ships and freighters seem very nearly break-bulk haulers by comparison to existing surface vessels.

 

[infojunky]

Adventure-class merchant ships and freighters seem very nearly break-bulk haulers by comparison to existing surface vessels.

Well, Yes... Considering how small most of them are.

 

[Spinward Flow]

Adventure-class merchant ships and freighters seem very nearly break-bulk haulers by comparison to existing surface vessels.

Very much so.

 

[Grav_Moped]

Adventure-class merchant ships and freighters seem very nearly break-bulk haulers by comparison to existing surface vessels.

Well, Yes... Considering how small most of them are.

Very much so.

The archetypes for the merchant ships in Traveller pre-date containerization.

 

[Condottiere]

Re engine them, and externalize the containers.

 

[TamsinP]

Adventure-class merchant ships and freighters seem very nearly break-bulk haulers by comparison to existing surface vessels.

Very much so. Based on the annual World Fleet stats published by Equasis, they would fall into the lower end of the "Medium" (500 to 24,999 GT; converts to 140 to 6205 dTons) size category; which would mostly be short haul vessels operating the minor feeder routes.
Interestingly, in the medium size category, bulk carriers (ie, grain, ore, etc) account for a slightly higher total tonnage than general cargo (= break-bulk) but with fewer, larger vessels; container ships account for about half the tonnage of that for general cargo, again with fewer, larger vessels. Tankers have a total tonnage just below that of the bulkers, but from a larger number of smaller vessels (about the same number as general cargo).

 

[Spinward Flow]

Re engine them, and externalize the containers.

Already ahead of you.
Way WAY ahead of you ...