Open-Top Container ship

An open-top container ship is a cellular vessel whose forward or amidships holds have no hatch covers, so cell guides run continuously from the tank top to above the weather deck. Boxes load and discharge straight down into the guides without removing covers, which cuts crane cycle time and removes the cover-stowage step. The trade-off is rainwater and green-water ingress, so open-top holds carry high-capacity bilge pumping and rely on the cell guides for all stowage support. The hatchless design was used on dedicated high-turnover liner ships such as the Bremen Express and Norasia types of the 1990s. Most modern container ships keep conventional hatch covers because the pumping and structural penalties outweigh the time saving on longer routes.