Weighlock n. : A lock, as on a canal, in which boats are weighed and their tonnage is settled.

Example:


Taxonomy
Weighlock Building, the Erie Canal, boats, Tolls, Erie Canal Museum, canal, lock chamber, downtown Syracuse, weigh, Albany, History of the Erie Canal, Barge Canal, canal boat captains, second floor, engineers, scale, the Barge, canal boat.

Defination from the web:
weighlock, "little more than a guess pond. ... The third weighlock, built in 1834, was the first weighing station to have a building along with it. ...