Bulk carrier

The term bulk carrier has been defined in varying ways. As of 1999, the International Convention for the Safety of Life at Sea defines a bulk carrier as "a ship constructed with a single deck, top side tanks and hopper side tanks in cargo spaces and intended to primarily carry dry cargo in bulk; an ore carrier; or a combination carrier." Most classification societies use a broader definition, by which a bulk carrier is any ship that carries dry unpackaged goods. The terms "VLOC", "VLBC", "ULOC", and "ULBC" for very large and ultra-large ore and bulk carriers were adapted from the supertanker designations very large crude carrier and ultra-large crude carrier. == History ==

from Chile to Maryland Before specialized bulk carriers were developed, shippers had two methods to move bulk goods by ship. In the first method, longshoremen loaded the cargo into sacks, stacked the sacks onto pallets, and put the pallets into the cargo hold with a crane. These methods were slow and labor-intensive. As with the container ship, the problem of efficient loading and unloading has driven the evolution of the bulk carrier. Specialized bulk carriers began to appear as steam-powered ships became more popular. The first steam ship recognized as a bulk carrier was the British collier John Bowes, built in 1852. She featured a metal hull, a steam engine, and a ballasting system which used seawater instead of sandbags. The first bulk carriers with diesel propulsion began to appear in 1911.—and most of this trade was coastal. However, on the Great Lakes, bulk carriers hauled vast amounts of iron ore from Minnesota and Michigan's northern mines to the steel mills. In 1929, 73 million tons of iron ore was transported on the Lakes, and an almost equal amount of coal, limestone, and other products were also moved. Two defining characteristics of bulk carriers were already emerging: the double bottom, which was adopted in 1890, In this period, Great Lakes freighters increased in size, to maximize economies of scale, and self-unloaders became more common to cut turnaround time. The thousand-footers of the Great Lakes fleets, built in the 1970s, were among the longest ships afloat, and, in 1979, a record 214 million tons of bulk cargo were moved on the Great Lakes. == Categories ==

Size categories , a capesize bulk carrier approaches the Egyptian-Japanese Friendship Bridge|313x313px Bulk carriers are segregated into six major size categories: small, handysize, handymax, panamax, capesize, and very large. Very large bulk and ore carriers fall into the capesize category but are often considered separately. Categories as per regions Categories occur in regional trade, such as Kamsarmax, Seawaymax, Setouchmax, Dunkirkmax, and Newcastlemax. • "Newcastlemax": Maximum beam 50 meters, and maximum length overall of 300 meters Refers to the largest vessel able to enter the port of Newcastle, Australia at about 185,000 DWT • "Setouchmax": About 203,000 DWT, being the largest vessels able to navigate the Setouchi Sea, Japan • "Seawaymax": LOA 226 m max / 7.92 m draft. Refers to the largest vessel that can pass through the canal locks of the St. Lawrence Seaway (Great Lakes, Canada) • "Malaccamax": LOA 330 m / 20 m draft / 300,000 DWT, Refers to the largest vessel that can pass through the Straits of Malacca. • "Dunkirkmax": Maximum allowable beam = 45 m / LOA 289 m. max (175,000 DWT approx) for the eastern harbour lock in the Port of Dunkirk (France) Mini-bulk carriers are prevalent in the category of small vessels with a capacity of under . Mini-bulk carriers carry from 500 to 2,500 tons, have a single hold, and are designed for river transport. They are often built to be able to pass under bridges and have small crews of three to eight people. Handysize and Handymax ships are general purpose in nature. These two segments represent 71% of all bulk carriers over and also have the highest rate of growth. This is partly due to new regulations coming into effect which put greater constraints on the building of larger vessels. Capesize ships are too large to traverse the Panama canal and must round Cape Horn to travel between the Pacific and Atlantic oceans. Earlier, Capesize ships could not traverse the Suez and needed to go around the Cape of Good Hope. Recent deepening of the Suez canal to 66 ft (20 m) permits most Capesize ships to pass through it. Capesize bulk carriers are specialized: 93% of their cargo is iron ore and coal. General types == Fleet characteristics ==

The world's bulk transport has reached immense proportions: in 2005, 1.7 billion metric tons of coal, iron ore, grain, bauxite, and phosphate was transported by ship. Today, the world's bulk carrier fleet includes 6,225 ships of over 10,000 DWT, and represent 40% of all ships in terms of tonnage and 39.4% in terms of vessels. Including smaller ships, bulk carriers have a total combined capacity of almost 346 million DWT. Combined carriers are a very small portion of the fleet, representing less than 3% of this capacity. As of 2005, the average bulk carrier was just over 13 years old. All of the 98 bulk carriers registered in the Great Lakes trade are over 20 years old and the oldest still sailing in 2009, the St. Mary's Challenger, was 106 years old. )|402x402px Flag states As of 2005, the United States Maritime Administration counted 6,225 bulk carriers of or greater worldwide. More bulk carriers are registered in Panama, with 1,703 ships, more than any four other flag states combined. These three nations account for over 53% of the world's fleet. The Fednav Group in Canada operates a fleet of over 80 bulk carriers, including two designed to work in Arctic ice. Croatia's Atlantska Plovidba d.d. has a fleet of 14 bulk carriers. The H. Vogemann Group in Hamburg, Germany operates a fleet of 19 bulk carriers. Portline in Portugal, owns 10 bulk carriers. Dampskibsselskabet Torm in Denmark and Elcano in Spain also own notable bulk carrier fleets. Other companies specialize in mini-bulk carrier operations: England's Stephenson Clarke Shipping Limited owns a fleet of eight mini-bulk carriers and five small Handysize bulk carriers, and Cornships Management and Agency Inc. in Turkey owns a fleet of seven mini-bulk carriers. Builders Asian companies dominate the construction of bulk carriers. Of the world's 6,225 bulk carriers, almost 62% were built in Japan by shipyards such as Oshima Shipbuilding and Sanoyas Hishino Meisho. Ship breaking Generally, ships are removed from the fleet by going through a process known as ship breaking or scrapping. Ship-owners and buyers negotiate scrap prices based on factors such as the ship's empty weight (called light ton displacement or LDT) and prices in the scrap metal market. In 1998, almost 700 ships were scrapped in places like Alang, India and Chittagong, Bangladesh. Half a million deadweight tons worth of bulk carriers were scrapped in 2004, accounting for 4.7% of the year's scrapping. That year, bulk carriers fetched particularly high scrap prices, between $340 and $350 per LDT. == Operation ==

Crew The crew on a bulk carrier typically consists of 20 to 30 people, though smaller ships can be handled by 8. The crew includes the captain or master, the deck department, the engine department, and the steward's department. The practice of taking passengers aboard cargo ships, once almost universal, is very rare today and almost non-existent on bulk carriers. During the 1990s, bulk carriers were involved in an alarming number of shipwrecks. This led ship-owners to commission a study seeking to explain the effect of various factors on the crew's effectiveness and competence. The study showed that crew performance aboard bulk carriers was the lowest of all groups studied. Deck officers and stevedores oversee the operations. Occasionally loading errors are made that cause a ship to capsize or break in half at the pier. The loading method used depends on both the cargo and the equipment available on the ship and on the dock. In the least advanced ports, cargo can be loaded with shovels or bags poured from the hatch cover. This system is being replaced with faster, less labor-intensive methods. Double-articulation cranes, which can load at a rate of 1,000 tons per hour, represent a widely used method, Start-up and shutdown procedures with conveyor belts, though, are complicated and require time to carry out. The immense size of cargo holds and the tendency of cargoes to be physically irritating add to the difficulty of cleaning the holds. When the holds are clean, the process of loading begins. It is crucial to keep the cargo level during loading in order to maintain stability. Extra precautions are taken, such as adding longitudinal divisions and securing wood atop the cargo. If a hold is full, a technique called tomming is used, which involves digging out a hole below the hatch cover and filling it with bagged cargo or weights. Bulldozer loaded on bulk carrier.jpg|1. A bulldozer is loaded into the hold. Bulker-unload-sequence-2.jpg|2. The bulldozer pushes cargo to the center of the hold. Velox cargo ship unloading rapeseed.jpg|3. The gantry crane picks up the cargo. Bulker-unload-sequence-4.jpg|4. The gantry crane removes the cargo from the ship. Grab unloaded into hopper.jpg|5. The gantry crane moves the cargo to a bin on the pier. == Architecture ==

A bulk carrier's design is largely defined by the cargo it will carry. The cargo's density, also known as its stowage factor, is the key factor. Densities for common bulk cargoes vary from 0.6 tons per cubic meter for light grains to 3 tons per cubic meter for iron ore. Hatches A hatch or hatchway is the opening at the top of a cargo hold. The mechanical devices which allow hatches to be opened and closed are called hatch cover. In general, hatch covers are between 45% and 60% of the ship's breadth, or beam, and 57% to 67% of the length of the holds. Newer vessels have hydraulic-operated metal hatch covers that can often be operated by one person. The Load Line Conference of 1966 imposed a requirement that hatch covers be able to withstand load of 1.74 tons/m2 due to sea water, and a minimum scantling of 6 mm for the tops of the hatch covers. The International Association of Classification Societies then increased this strength standard by creating its Unified Requirement S21 in 1998. This standard requires that the pressure due to sea water be calculated as a function of freeboard and speed, especially for hatch covers located on the forward portion of the ship. Some manufacturers have preferred high-tensile steel recently in order to reduce the tare weight. However, the use of high-tensile steel for longitudinal and transverse reinforcements can reduce the hull's rigidity and resistance to corrosion. Double hulls have become popular in the past ten years. One of the advantages of the double hull is to make room to place all the structural elements in the sides, removing them from the holds. This increases the volume of the holds, and simplifies their structure which helps in loading, unloading, and cleaning. Double sides also improve a ship's capacity for ballasting, which is useful when carrying light goods: the ship may have to increase its draft for stability or seakeeping reasons, which is done by adding ballast water. A recent design, called Hy-Con, seeks to combine the strengths of single-hull and double-hull construction. Short for Hybrid Configuration, this design doubles the forward-most and rear-most holds and leaves the others single-hulled. This approach increases the ship's solidity at key points, while reducing the overall tare weight. Since the adoption of double hull has been more of an economic than a purely architectural decision, some argue that double-sided ships receive fewer comprehensive surveys and suffer more from hidden corrosion. In spite of opposition, double hulls became a requirement for Panamax and Capesize vessels in 2005. Freighters are in continual danger of "breaking their backs" and thus longitudinal strength is a primary architectural concern. A naval architect uses the correlation between longitudinal strength and a set of hull thicknesses called scantlings to manage problems of longitudinal strength and stresses. A ship's hull is composed of individual parts called members. The set of dimensions of these members is called the ship's scantlings. == Safety ==

The 1980s and 1990s were a very unsafe time for bulk carriers. Many bulk carriers sank during this time; 99 were lost between 1990 and 1997 alone. These regulations required the upper ballast tanks designed in a manner to prevent shifting. They also required cargoes to be leveled, or trimmed, using excavators in the holds. The practice of trimming reduces the amount of the cargo's surface area in contact with air which has a useful side-effect: reducing the chances of spontaneous combustion in cargoes such as coal, iron, and metal shavings. Structural problems In 1990 alone, 20 bulk carriers sank, taking with them 94 crewmen. In 1991, 24 bulk carriers sank, killing 154. This level of loss focused attention on the safety aspects of bulk carriers, and a great deal was learned. The American Bureau of Shipping concluded that the losses were "directly traceable to failure of the cargo hold structure" • Sea water enters the forward hatch, due to a large wave, a poor seal, corrosion, etc. The new rules adopted in the 1997 annexes to the SOLAS convention focused on problems such as reinforcing bulkheads and the longitudinal frame, more stringent inspections (with a particular focus on corrosion) and routine in-port inspections. Crew safety Since December 2004, Panamax and Capesize bulk carriers have been required to carry free-fall lifeboats located on the stern, behind the deckhouse. One argument against the use of free-fall lifeboats is that the evacuees require "some degree of physical mobility, even fitness" to enter and launch the boat. Also, injuries have occurred during launches, for example, in the case of incorrectly secured safety belts. In December 2002, Chapter XII of the SOLAS convention was amended to require the installation of high-level water alarms and monitoring systems on all bulk carriers. This safety measure quickly alerts watch standers on the bridge and in the engine room in case of flooding in the holds. In cases of catastrophic flooding, these detectors could speed the process of abandoning ship. == See also ==