The book is the first to detail the 170-year evolution of the powered bulk carriers which continue to have a major role in the world's trades and economies. Their design and technological development is traced from the screw colliers of the 1850s which revolutionised the British coastal coal trade. The same engineering principles were applied to produce ocean-going steam and later motor tramps. By the end of the 19th century, the capabilities and economies of these 'black freighters' had captured from the sailing ship much of the world's trade in bulk commodities. In the second half of the 20th century, the tramps in turn evolved into multi-purpose, dry bulk carriers. These workhorses of the sea transport commodities including metallic ores, grain, coal, timber and other minerals. Quantities of up to 400,000 tons are carried in the largest, specialised ore carriers. In a parallel development, applying the same technical principles produced smaller yet efficient steam and later motor coasters which came to dominate short sea shipping. The book concludes with a discussion of how the economies of transportation provided by bulk carriers have had profound effects on industrialisation, globalisation and the world's economy, and discusses the environmental impact of these ships.