n. pl. su·per·nu·mer·ar·ies

1. A person or thing beyond the number stated, one that is in excess of the regular, necessary, or usual number.

2. A person or thing beyond what is necessary or usual; especially, a person employed not for regular service, but to fill the place of another in case of need.

3. An actor without a speaking part, as one who appears in a crowd scene.

The seizure of land and labour in England, Ireland, Africa and the America laid the military, commercial and financial foundations for capitalism and imperialism, which could be organized and maintained only through Braithwaite’s hydrarchy, the maritime state.

[…]

The ship, whose milieu of action made it both universal and sui generis, provided a setting in which large numbers of workers cooperated on complex and synchronized tasks, under slavish, hierarchical discipline in which human will was subordinated to mechanical equipment, for a money wage. The work, cooperation and discipline of the ship made it a prototype of the factory. Indeed, the very term factory evolved etymologically from factor, “a trading representative,” and specifically one associated with West Africa, where factories were originally located.