ISO 13728:2020

This document specifies the types, nominal sizes, dimensions and materials, as well as construction, manufacturing and marking requirements, for Panama chocks installed to lead the mooring and towing rope of a ship. It is intended for ships passing through the Panama Canal, which are normally assisted through the locks by locomotives using steel towing wires and/or by tug boats. These chocks meet normal mooring requirements and Panama Canal requirements; they are suitable for mooring vessels inside the Panama Canal locks.
NOTE    The Panama chocks (SWL of 90 tons) for the Panamax Plus and Neopanamax vessels can be replaced by closed chocks (see ISO 13729).