A large merchant ship falls under a few different classifications, two of the largest being the "Capesize" and "Chinamax" ship sizes or types, which both allow up to 400,000 DWT vessel tonnage. A large merchant ship is also called a cargo vessel or merchant vessel.
The "Aframax" is another large merchant ship type. While it averages only approximately 120,000 DWT vessel tonnage, it has few size restrictions according to About.com. Other large merchant ship types include Malaccamax, Panamax, Seawaymax, Supermax, Handymax and Suezmax. These ship size classifications can also be applied to military and cruise ships, but the most common reference is to cargo vessels, according to About.com.