Trammel Hooks
The Medieval Household

Medieval cooks used trammel hooks to suspend pots and similar cooking vessels over the cooking fire. A trammel hook is adjustable, to allow the cook to raise or lower the kettle as necessary. These links show several types of pot hangers, including trammel chains, but most show some form of a trammel hook in action.

See also La crémaillère au Moyen-âge and Crémaillère (Musée et Bibliothèque de la Gourmandise).