A straight decker is a ship built with its pilothouse forward and engines aft to provide continuous hold between. This design originated to meet the navigational demands on lake freighters on the U.S./Canadian Great Lakes routes. The term "Straight Decker" is commonly used upon the Great Lakes to denote a bulk/ore freighter which has not been equipped with self-unloading machinery.[1]
Straight Deckers are mainly owned by the Canadian fleets, such as Upper Lakes Shipping (ULS). One exception can be made, though. The U.S. freighter Edward L. Ryerson came out of long term layup, and joined the fleet once again in 2006. Straight deckers are loaded and unloaded by gantry cranes or Hulett Unloaders. These giants used a clamshell bucket and counterweight system to scoop the cargo out of the holds, one load at a time.
Self-unloading equipment is usually in the form of a boom on deck. The boom is usually positioned on the back half of the vessel, pointing forward. The boom is swung out to either side of the vessel, a conveyor system is started, and the offloading process begins. The boom is a much more efficient method of unloading and allows the boat to serve a wider variety of ports which have no shoreshide unloading gear. This also allows a greater variety of cargoes to be hauled and therefore, the opportunity to run more trips each season. Many historic straight deckers have been converted to self-unloaders or retired from service. For instance, the steam-powered straight decker James Norris was converted to a self-unloader in 1980 but, in 2008, still had not been converted from steam to diesel. The largest straight-decker, the 806-foot John Sherwin has not sailed under its own power since 1981 and its conversion to a diesel self-unloader in 2008 was suspended because of the world economic downturn.
Some self unloaders can have a rather straight decker look. For example, the 1000-foot Stewart J. Cort has a shuttle boom inside the aft deckhouse. The shuttle boom can be extended to reach hoppers on the docks, specially designed for the purpose.