On Aug 25, 2014, at 11:13 AM, David Shaw <xxxxxx@btconnect.com> wrote:

>
> Which assumes that you need to send cargo in nice, convenient, 200kDt loads at *just* the same intervals that your superfreighter arrives in system.
>
> On the other hand, if you're needing to send 10kDt loads pretty much constantly, then multiple, smaller ships make sense - especially if what you're shipping is perishable or the receiving system can only *handle* 10kDt at a time.
>
> IRL, we have superfreighters plying the oceans, to be sure - but there are also a lot of smaller cargo vessels making a living as well.

Which is, pretty much, exactly what everyone BUT Phil is arguing. Phil is arguing that the smaller cargo vessels are all you need, because that's all that CT lets you build.

Lets approach it from the other side.

A Liberty ship could carry 4380 register tons, which is roughly 2.83 cubic meters (I'm reading that the 'net tonnage' is the same as 'register tonnage' . <http://en.wikipedia.org/wiki/Liberty_ship> <http://www.unc.edu/~rowlett/units/dictT.html>)

Modern containerized transports are measured in TEU, 'twenty foot unit's' or a standard 20' cargo container.

One TEU is 38.5 cubic meter. A Liberty ship could carry ~12400 cubic meters or ~322 TEU. (note this is roughly 880dT of cargo capacity in Traveller terms. For example, an Empress Marava 200T Far Trader can carry 78, or roughly *two* TEU)

The 2012 global container fleet capacity is 15406610 TEU,

<http://www.statista.com/statistics/254004/gloobal-cellular-container-ship-fleet-capacity/>

representing 5754 vessels of all sizes.<http://www.statista.com/statistics/264011/number-of-container-vessels-in-the-container-fleet-by-2013/>

Therefore the average modern container ship has 2677 TEU of capacity.

To replace that volume with Liberty Ships, you would need 47,857 ships, 8 times the size of the existing fleet.

Yes, there is room in the OTU for small traders of PC scale; even 10Kt ships. But no way in hell does the total tonnage needed to generate the income for an entity the size of the 3I survive on liberty ship scale.

The largest container ships, (Maersk currently holds the record with several ships of this class) hold 18270 TEU. In Traveller terms this is 50KdT of cargo space alone. This would represent ~200KdT ship, at a *very* rough guess.

Larger Traveller ships have been designed: <http://dbdev2.pharmacy.arizona.edu/Majesta.html>

These are the ships, as Alvin's write up describes, that the Imperial Navy is there to protect...not dinky free traders or subsidized merchants.

--
Bruce Johnson

"Wherever you go, there you are." B. Banzai, PhD