Stevedore

Stevedores are specialist dockers, trained to properly pack and unpack cargo holds. Loading a ship is skill-intensive and dangerous work, for vessels can overbalance and capsize if packed incorrectly, and unsecured cargoes can crush the unwary. Within the claustrophobic ship interiors, Stevedores wind "stevedore lashings" (special knots) with wedges of wood to secure and protect the heavy freight. Many Stevedores specialise in "porting" one type of cargo, as each good requires different skills to manipulate, stack and pack correctly. Thus, most larger wharfs have gangs of "porters" that identify themselves according to the goods they import or export, including fish porters, meat porters and deal porters (for timber). None are more famous than the black-liveried coal porters of Nuln, known for their anything-goes attitude and love of bawdy docker songs. Stevedores wear distinctive cloth watch caps dyed with their gang colours, both to identify their allegiances and to protect themselves from the elements. Stevedore gangs jealously guard their wharfs from rivals, and it takes little provocation for them to dish out "lashings" of a different kind.

Source
Estibador
 * Warhammer Fantasy RPD 2nd ED -- Warhammer Companion
 * pg. 23