Wolfgang, el pasado 1ro de Junio hizo esta aportación al respecto de "bolt".
"Bolt: a movable bar or rod that when slid into a socket fastens a door, gate, etc.
In the United States, many people bolt their doors from inside for safety reasons. These bolts can't be opened from outside, thus offering an extra protection beyond the regular lock. You might have seen some comedies in which someone has to deal with a ridiculously high number of bolts every time they open or close their door." Wolfgang.
Entonces concluí que se refería a una tranca en aquel caso en que se refería al estrépito de un pestillo. "
the clatter of bolts".