 "Hydro" was larger than its predecessor, at with a capacity of 493.60 gross tonnes.Like all the railway ferries it had two parallel tracks, which merged at the front to allow a single track to enter the ship; total track length was , allowing twelve wagons weighing 300 tonnes as well as 120 passengers.It was equipped with two steam engines, each at 190 kW (250 hp), giving it a cruise speed of .