Ships so small they can only carry that many containers are few and far between. They are not economical to operate. OTOH, larger ships could use it as one port call among many, except that the bay and harbor area are neither large enough nor deep enough to accomodate said ships.

Like everything else, container shipping these days is based on larger ships and larger terminals to handle them. The latest container ships and those on the way carry 13,000 TEU's or more, and are 200 feet longer than a Nimitz-class aircraft carrier. Google the EMMA MAERSK if you don't believe it. In order to make money, these things have to have minimum terminal time. That means large terminals with 6 or 7 cranes working the ship at the same time. That, in turn, means much more container/chassis storage space and a lot more trains than NWP would ever be able to handle.

On yet another hand, barge container service to and from larger terminals MIGHT be a possibility, but involves double handling and thus would be costly.

I don't see it happening.