Ships carrying military cargo needed to unload with their own gear when suitable shore equipment was unavailable. Mercogliano links the Sherman's roughly thirty-ton weight to the lifting capacity of common cargo booms: a heavier tank could create an unloading problem at its destination. Time in port also limited how much a cargo vessel could deliver over a year. An 11.5-knot Liberty ship might make only four Atlantic crossings annually in wartime, compared with an estimated six or eight in peacetime, because convoy departures and congested ports delayed its return to sea. A convoy's arrival could bring forty or fifty ships into Liverpool together, creating a large loading and unloading task.
Notable Point · 1:15:19-1:16:44
A cargo boom could limit the weight of an army's tank
The Sherman's weight illustrates a proposed link between shipboard lifting limits and tank design, while port turnaround restricted wartime cargo delivery.