Birth of the bulk carrier

The evolution of a shipping stalwart from a coal mining commission in 1852.

Bulk carriers, together with tankers and container ships, make up the three ‘pillars’ of global shipping. As of 2021, the world's bulk carrier fleet included 6,225 ships of over 10,000 deadweight tonnes (dwt), equivalent to 40% of world tonnage and 39.4% of vessel numbers. In total, the 12,700 vessels over 500 gross tons have a combined capacity of almost 346 million dwt. Some vessels have been constructed with deadweights as large as 400,000 dwt, for example the Vale ships built to carry iron ore from Brazil to China. The first vessels that could be called bulk carriers were, however, very much smaller.

The earliest examples

Specialised bulk carriers started to appear as soon as steam-powered ships became more popular. The first example recognised as such dates back to 1852. In that year, the coal mine owner John Bowes commissioned Palmer Brothers & Co. shipyard at Jarrow on the River Tyne, to build a steam collier, the John Bowes. Designed to carry coal to London, it had a cargo deadweight of 630 tons. It was 45.4m long with a beam of 7.8m and was equipped with a two-cylinder steam engine from Robert Stephenson that gave her a speed of 9 knots. Typically for a vessel at this time, she was also rigged as a topsail schooner to provide alternative propulsion in case of machinery failure etc. The vessel was a great success and in the first week of operations, transported more coal than, it was claimed, two sailing colliers would have done in a month. As a result, many similar vessels were then constructed. 

Interestingly, the John Bowes was later fitted with water ballast tanks below her single hold, a feature retained in today’s bulkers. Despite the early design, the vessel survived until October 1933 when she sank off Spain in a storm. 

Bulk shipping also developed on the Great Lakes starting with the 748 gross ton R J Hackett of 1869, designed to carry iron ore. Constructed of wood at the Peck & Masters shipyard in Cleveland, she was 68m long and is said to be one of the first vessels specifically designed to carry iron ore. Re-built in 1881 as a two-deck ship, she survived until 1905 when a cargo of coal caught fire, resulting in her loss. 

Water features

Around this time the defining characteristics of the modern ocean-going bulker were beginning to emerge with the double bottom, which was generally adopted from 1890 for the carrying of water as ballast or for trimming. The familiar triangular structure of the tanks was introduced around 1905, initially for self-trimming but also to carry water ballast when transporting high density cargoes. 

Initially coal was the main cargo carried deep sea, but a series of turret-deck steamers were built for ore-carrying purposes between 1904 and 1910. Later, however, to overcome the disadvantage that the ore carrier was only usefully employed on one leg of the voyage, the oil/ore carrier was developed. The latter ship type carried oil in the wing tanks.

Long-term charters

In 1924, Cardiff owners Owen and Watkin Williams took delivery of the Silurian, at the time the world’s largest ocean-going bulk carrier with a deadweight of 11,000 tonnes. She also features an all-aft machinery arrangement. 

Another important step in the evolution of the bulk carrier came in 1925 when the Brostrom company A/B Tirfing took delivery of the Amerikaland and the Svealand, from the Hamburg shipbuilder Deutsche Werft. Able to load up to 26,600 tons, they were 174m long, diesel-powered with a service speed of 11.5 knots and specifically designed to ship iron ore from Chile to Bethlehem Steel’s Sparrow Point works in Maryland. This was a long-term charter, the first of its kind in the bulk ore trade. Progressively other cargoes moved to bulk shipment including grain and bauxite.

The Swedish ore carrier Svealand - one of two vessels built in Germany in 1925 that set the pattern for long-term charters (Credit: shipspotting.com)

Post-war proponent

Two figures who played key roles in the evolution and diversification of the bulk carrier after World War 2 were the American businessman Daniel Ludwig and Norway’s Erling Naess. 

Ludwig will be remembered for building the largest tankers at any given time, but he also invested in dry bulkers. In 1954, he designed and built three twin-screw, 60,000 dwt ore carriers to move Venezuelan iron ore, the 56,000 dwt self-unloading ore/oil carrier Sinclair Petrolore in 1955, and then in 1969 the Universe Aztec, of 160,245 dwt, for the carriage of industrial salt from Mexico to Japan. 

Naess would pioneer the OBO (ore/bulk/oil) in 1964 with the development of a vessel type that would have increased flexibility in trading. Construction of the first example, the 71,000 dwt Naess Norseman, at AG Weser in Bremerhaven, was completed in 1965. Popular in the 1970s and 80s, the type has fallen from favour more recently due to higher costs and various operational difficulties. 

John Barnes is a journalist and author and former editor of Marine Engineers Review