Bridge crew
The Bridgecrews are teams of slaves employed by Brightlords on the Shattered Plains of Roshar.
The unique geography of the Shattered Plains required the armies to cross many chasms to reach the battlefields. Brightlord Sadeas employed a large number of slaves to transport his armies temporary bridges. These slaves were also used as cannonfodder for the Parshendi bowmen.
The slaves were split into a number of bridgecrews, each carrying one bridge. The most notable crew was Bridge Four.
Crews
Gaz was the bridge overseer, reporting directly to Brightlord Lamaril and then technically to Brightlord Matal, but Brightness Hashal was the one who typically issued orders to them.
Bridge Four
Notorious for its bad luck, Bridge Four seldom kept a bridge leader for more than a few days and almost always took the highest casualties on bridge runs.
A transfer to Bridge Four was often used as a punishment for bridgemen, and the existence of a group worse off than themselves was a mental control used by Sadeas' men on the rest of the bridge crews.
Upon arrival at the bridge yard in Sadeas' war camp Kaladin managed to earn the immediate enmity of Gaz, the lieutenant in charge of the bridge crews, who then placed him in Bridge Four. Kaladin spent several weeks on the bridge crew before deciding to give leading and protecting one more try. Once the decision had been made he quickly turned Bridge Four around, and through his efforts it became the best of the bridge crews, taking the fewest casualties, treating its wounded and training for escape.
At the end of The Way of Kings Bridge Four rescues Highprince Dalinar resulting in Dalinar buying the freedom of all the bridge crews, placing Kaladin in command of all bridgemen that choose to become soldiers, and requesting Bridge Four as personal bodyguards.