Freelance Traveller

Fixing Standard Cargo Containers

by Jason Barnabas

This article originally appeared in the April 2014 issue and was reprinted in the July/August 2024 issue.

Why are standard cargo containers in Traveller 3m wide, 3m high and 6m long? Because no one consider the implications of containerized cargo on Earth when they wrote that description decades ago. Nor did they consider the standards for starships in Traveller. The standard cargo container, as written, is unusable in the standard starships, as written, in Classic Traveller.

A subsidized merchant (Type R) cannot stack two standard cargo containers in its hold because the deck height is only 6m. There would be no room to maneuver them about. From past experience working in steel yards and manufacturing plants, I would say as a minimum the decks would need to be 6.3m apart in order to safely stack two 3m containers, and it seems the writers of Fire, Fusion, & Steel 2 (Marc Miller’s Traveller [T4]) would agree because they suggest a minimum door size that is 10% larger in dimension than the corresponding dimension of anything that will be moved through it.

So let’s take a fresh look at containerized cargo for Traveller. On Earth, while there are occasionally containers dented by mishandling, it is rare, so a Traveller armor rating of 1 seems to be a reasonable ‘guesstimate’. This is also the standard minimum for grav vehicles, probably for much the same reason.

If the deck heights will be 3m then the maximum height of cargo containers should be 2.7m since starships will be the primary mode of transport. Does anyone know the Imperium’s standard axle size? Never mind, we’ll leave the other two dimensions at 3m and 6m. An Imperial standard shipping container would have a surface area of 84.6m² and an external volume of 48.6 m³. Other important measurements depend on composition, per the table below.

Containers are inexpensive and finding them “repurposed” to other functions would be quite likely. Researching “container architecture” might offer some ideas.

None of these would be vacuum resistant and the TL 0 and 1 containers couldn’t be made so. Adding a cargo door (e.g. one that was proof against vacuum) would add to the cost. Since most starships maintain shirt-sleeve environments in cargo areas this usually won’t be a problem; however, for high end cargos it might be worth a shipper’s while to pop for the added protection.

A container could hold a kiloton of high density material so planetary standards bodies would probably call for a maximum gross mass. What that would be IYTU would depend on what standards exist for cargo moving equipment. Present-day ISO standards call for a maximum net load of 28.2 tonnes but present-day standard cargo containers are 21% smaller than those described here, so 38 tonnes would be comparable on a volume for volume basis.

There are probably sub-containers available as well. These would be designed to fit inside the main container with little wiggle room. They might be standardized or not IYTU. Because they are protected by the main container they would have no minimum standards and could be as simple as plastic or cardboard boxes. Standard widths would be 2.8, 1.4, 0.93, 0.7, 0.56, 0.46, 0.4, 0.35, and possibly 0.31, 0.28, 0.25, and 0.23. Standard lengths would be 5.8, 2.9, 1.93, 1.45, 1.16, 0.96, 0.82, 0.72, 0.64, 0.58, 0.52, and 0.48. Standard heights would be less likely, especially on the smaller end, but if you had them they would probably be on the order of 2.4, 1.2, 0.8, 0.6, 0.48, 0.4, 0.34, 0.3, 0.26, 0.24, 0.21, and 0.2.

Note that the widths and lengths refer to their placement within the main container. One could have sub-containers that were longer from side to side of the main container than they were front to back, relatively speaking.

Most PCs won’t know or care what’s inside the shipping containers in the hull, but if you have PCs that do something other than standard merchant type activities this information could be useful. There are actually companies that arrange sub cargos for small concerns that cannot afford to ship full containers and they make good money saving their customers money on shipping by bundling their shipments with others to form full containers.