Trunk Deck Ship - Advantages and Disadvantages

Advantages and Disadvantages

As with turret deck ships, the design of the trunk deck ships was said to maximize strength while reducing the amount of steel needed for construction. Disadvantages included the narrow hatches atop the trunk, which inhibited efficient loading and unloading. The low freeboard meant smaller waves could board the ship, and the bridge and superstructure therefore had to be stronger to resist wave action.

Trunk deck ships had a low net tonnage (an approximate measure of cargo space) in comparison to their deadweight tonnage capacity (weight of cargo). Net tonnage is a computation of volume, and the method of measurement used at the Suez Canal to determine tolls was based on a measure of net tonnage which excluded some of the cargo spaces of these unconventional hulls. Trunk deck ships therefore paid less in tolls. In 1911 the toll measure changed at Suez, and construction of the type ceased.