A winjammer was a type of sailing ship with a large iron or steel hull, built to carry cargo in the late nineteenth century and early twentieth century centuries. They were the grandest of cargo sailing ships, with between three and five large masts and square sails, giving them a characteristic profile. They frequently displaced several thousand tonnes, and were cheaper than their wooden hulled counterparts for three main reasons: iron was stronger, and thus could enable larger ship sizes and considerable economies of scale, iron hulls took up less space and allowed for more cargo to be carried, and iron hulls were cheaper to maintain than an equivalent wooden hull. The most common windjammer rig was four-masted barque, which was the ultimate result of science of aerodynamics and thousands of years of seamanship. The barque rig can outperform the schooner rig , can sail upwind better than full-riggers, and is easier to handle than full square rig. The usual cargo capacity was 2,000 to 5,000 tonnes. Usual windjammer cargo was bulk, such as lumber, coal, guano or grain. The largest windammer ever built was five-masted full-rigged ship Preussen, which had displacement of 11,600 tonnes. She was also one of the fastest, regularly logging 16 kn average speed on transatlantic voyages.