(Ship Taken Up From Trade)

A merchant ship employed in support of the fleet. Usually taken into the fleet in times of emergency to enhance the logistic support capability.

Usually this is a long standing arrangment for supplementing the fleet in time of war, and the merchant ship takes aboard a naval officer to command, and sometimes a few other naval personnel to help run the ship.

In some cases, governments take on emergency powers and can commandeer merchant ships for military use - though this is naturally unpopular with the shipping corporations.