Bulk carrier 1

Bulk carrier

The Sabrina I is a modern Handymax bulk carrier. Class overview

Name: Freighter

Subclasses: Handymax, Handysize, Panamax, Capesize

Built: c. 1850–present

Active: 6,225 vessels over 10,000 long tons deadweight (DWT)[1]

General characteristics

Type: Cargo ship

Propulsion: 2-stroke diesel engine and 1 propeller

Capacity: up to 364,000 DWT

Notes: Rear house, full hull, series of large hatches

Plans of a geared Handymax bulker

A bulk carrier, bulk freighter, or bulker is a merchant ship specially designed to transport unpackaged bulk cargo,such as grains, coal, ore, and cement in its cargo holds. Since the first specialized bulk carrier was built in 1852,economic forces have fueled the development of these ships, causing them to grow in size and sophistication.Today's bulkers are specially designed to maximize capacity, safety, efficiency, and to be able to withstand the rigorsof their work.Today, bulkers make up 40% of the world's merchant fleets and range in size from single-hold mini-bulkers to mammoth ore ships able to carry 400,000 metric tons of deadweight (DWT). A number of specialized designs exist: some can unload their own cargo, some depend on port facilities for unloading, and some even package the cargo as it is loaded. Over half of all bulkers have Greek, Japanese, or Chinese owners and more than a quarter are registered

Bulk carrier 2

in Panama. Korea is the largest single builder of bulkers, and 82% of these ships were built in Asia.A bulk carrier's crew participates in the loading and unloading of cargo, navigating the ship, and keeping itsmachinery and equipment properly maintained. Loading and unloading the cargo is difficult, dangerous, and can takeup to 120 hours on larger ships. Crews can range in size from three people on the smallest ships to over 30 on thelargest.Bulk cargo can be very dense, corrosive, or abrasive. This can present safety problems: cargo shifting, spontaneouscombustion, and cargo saturation can threaten a ship. The use of ships that are old and have corrosion problems hasbeen linked to a spate of bulker sinkings in the 1990s, as have the bulker's large hatchways, important for efficientcargo handling. New international regulations have since been introduced to improve ship design and inspection, andto streamline the process of abandoning ship.

Definition

Cross section of a typical bulker. 1. Cargo hold2. Hatch cover 3. Upper hopper tank for water

ballast or oil 4. Double bottom 5. Lower hoppertank, for water ballast

There are various ways to define the term bulk carrier. As of 1999, theInternational Convention for the Safety of Life at Sea defines a bulkcarrier as "a ship constructed with a single deck, top side tanks andhopper side tanks in cargo spaces and intended to primarily carry drycargo in bulk; an ore carrier; or a combination carrier."[2] However,most classification societies use a broader definition where a bulker isany ship that carries dry unpackaged goods.[3] Multipurpose cargoships can carry bulk cargo, but can also carry other cargoes and are notspecifically designed for bulk carriage. The term "dry bulk carrier" isused to distinguish bulkers from bulk liquid carriers such as oil,chemical, or liquefied petroleum gas carriers. Very small bulkers arealmost indistinguishable from general cargo ships, and they are oftenclassified based more on the ship's use than its design.

A number of abbreviations are used to describe bulkers. "OBO" describes a bulker which carries a combination ofore, bulk, and oil, and "O/O" is used for combination oil and ore carriers.[4] The terms "VLOC," "VLBC," "ULOC,"and "ULBC" for very large and ultra large ore and bulk carriers were adapted from the supertanker designations verylarge crude carrier and ultra large crude carrier.[5]

History

The four-masted barque Pamir, shown here in1905, carried nitrates, corn, and barley.

Before specialized bulk carriers existed, shippers had two methods tomove bulk goods by ship. In the first method, longshoremen loaded thecargo into sacks, stacked the sacks onto pallets, and put the pallets intothe cargo hold with a crane.[6] The second method required the shipperto charter an entire ship and spend time and money to build plywoodbins into the holds.[7] Then, to guide the cargo through the smallhatches, wooden feeders and shifting boards had to be constructed.[7]

These methods were slow and labor intensive. As with the containership, the problem of efficient loading and unloading has driven theevolution of the bulk carrier.

Specialized bulk carriers began to appear as steam-powered ships became more popular.[6] The first steam ship recognized as a bulk carrier was the British coal carrier SS John Bowes in 1852.[8] [9] She featured a metal hull, a steam engine, and a ballasting system which used seawater instead of sandbags.[8] These features helped her succeed

Bulk carrier 3

in the competitive British coal market.[8] The first self-unloader was the lake freighter Hennepin in 1902 on the GreatLakes. This greatly decreased the unloading time of bulkers by using conveyor belt to move the cargo.[10] The firstbulkers with diesel propulsion began to appear in 1911.[8] [9]

Before World War II, the international shipping demand for bulk products was low—about 25 million tons for metalores[11] [12] —and most of this trade was coastal.[13] However, on the Great Lakes, bulkers hauled vast amounts ofore from the northern mines to the steel mills. In 1929, 73 million tons of iron ore was transported on the Lakes, andan almost equal amount of coal, limestone, and other products were also moved.[14] Two defining characteristics ofbulkers were already emerging: the double bottom, which was adopted in 1890,[8] and the triangular structure of theballast tanks, which was introduced in 1905.[8] After World War II, an international bulk trade began to developamong industrialized nations, particularly between the European countries, the United States and Japan.[11] Due tothe economics of this trade, ocean bulkers became larger and more specialized.[12] [15] In this period, Great Lakesfreighters increased in size, to maximize economies of scale, and self-unloaders became more common to cutturnaround time. The thousand-footers of the Great Lakes fleets, built in the 1970s, were among the longest shipsafloat and in 1979, a record 214 million ton of bulk cargo were moved on the Great Lakes.[16]

Categories

Size categories

Major bulk carrier size categories

Name Size inDWT

[17]Ships

[18]Traffic

[19]New

price[20]

Usedprice

[21]

Handysize 10,000 to 35,000 34% 18% $28M $28M

Handymax 35,000 to 59,000 37%

Panamax 60,000 to 80,000 19% 20% $35M $34M

Capesize 80,000 and over 10% 62% $59M $68.4M

Post-deepening of the Suez Canal, a capesizebulk carrier approaches the Egyptian-Japanese

Friendship Bridge

Bulkers are segregated into six major size categories: small, handysize,handymax, panamax, capesize, and very large.[22] Very large bulk andore carriers fall into the capesize category but are often consideredseparately.

Other categories occur in regional trade, such as Kamsarmax, with amaximum length of 229 meters, the maximum length that can load inthe port of Kamsar in the Republic of Guinea.[23] Other terms such asSeawaymax, Setouchmax, Dunkirkmax, and Newcastlemax alsoappear in regional trade.[22]

Mini-bulkers are prevalent in the category of small vessels with acapacity of under 10,000 DWT. Mini-bulkers carry from 500 to2,500 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.[3] These two segments represent 71% of all bulkcarriers over 10,000 DWT and also have the highest rate of growth.[24] This is partly due to new regulations cominginto effect which put greater constraints on the building of larger vessels.[24] Handymax ships are typically150–200 m in length and 52,000 – 58,000 DWT with five cargo holds and four cranes.[3] These ships are alsogeneral purpose in nature.[3]

Bulk carrier 4

The size of a Panamax vessel is limited by the Panama canal's lock chambers, which can accommodate ships with abeam of up to 32.31 m, a length overall of up to 294.13 m, and a draft of up to 12.04 m.[25]

Capesize ships are too large to traverse the Panama canal and must round Cape Horn to travel between the Pacificand Atlantic oceans. Earlier, capesize ships could not traverse the Suez and needed to go around the Cape of GoodHope. Recent deepening of the Suez canal to 66 ft (20 m) permits most capesize ships to pass through it.[26]

Capesize bulkers are specialized: 93% of their cargo is iron ore and coal.[3] Some ships on the Great LakesWaterway exceed Panamax dimensions but they are limited to use on the Great Lakes as they cannot pass throughthe smaller St. Lawrence Seaway to the ocean. Very large ore carriers and very large bulk carriers are a subset of thecapesize category reserved for vessels over 200,000 DWT.[22] Carriers of this size are almost always designed tocarry iron ore.[22]

General types

General Bulk Carrier Types

Illustration Description

Geared bulk carriers are typically in the handysize to handymax size range although there are asmall number of geared panamax vessels, like all bulkers they feature a series of holds covered byprominent hatch covers. They have cranes, derricks or conveyors that allow them to load ordischarge cargo in ports without shore-based equipment. This gives geared bulkers flexibility inthe cargoes they can carry and the routes they can travel. (Photo: A typical geared handysize bulkcarrier.)

Combined carriers are designed to transport both liquid and dry bulk cargoes. If both are carriedsimultaneously, they are segregated in separate holds and tanks. Combined carriers require specialdesign and are expensive. They were prevalent in the 1970s, but their numbers have dwindledsince 1990. (Photo: The oil pipeline and dry bulk hold aboard the Maya.)

Gearless carriers are bulkers without cranes or conveyors. These ships depend on shore-basedequipment at their ports of call for loading and discharging. They range across all sizes, the largerbulk carriers (VLOCs) can only dock at the largest ports, some of these are designed with a singleport-to-port trade in mind. The use of gearless bulkers avoids the costs of installing, operating, andmaintaining cranes. (Photo:Berge Athen, a 225,000 ton gearless bulker.)

Selfdischargers are bulkers with conveyor belts, or with the use of an excavator that is fitted on atraverse running over the vessel's entire hatch, and that is able to move sideways as well. Thisallows them to discharge their cargo quickly and efficiently. (Photo: The John B. Aird aself-discharging lake freighter.)

Lakers are the bulkers prominent on the Great Lakes, often identifiable by having a forwardhouse which helps in transiting locks. Operating in fresh water, these ships suffer much lesscorrosion damage and have a much longer lifespan than saltwater ships.[27] As of 2005, there were98 lakers of 10,000 DWT or over.[28] (Photo: Edmund Fitzgerald, a Great Lakes bulker.)

BIBO or "Bulk In, Bags Out" bulkers are equipped to bag cargo as it is unloaded. The CHLInnovator, shown in the photo, is a BIBO bulker. In one hour, this ship can unload 300 tons ofbulk sugar and package it into 50 kg sacks.[29]

Bulk carrier 5

Fleet characteristics

Growth of bulk carrier deadweight tonnage ingreen and percentage of bulkers to the entire fleet

in red, from 1977 to 1999[30]

The world's bulk transport has reached immense proportions: in 2005,1.7 billion metric tons of coal, iron ore, grain, bauxite, and phosphatewas transported by ship.[31] Today, the world's bulker fleet includes6,225 ships of over 10,000 DWT, and represent 40% of all ships interms of tonnage and 39.4% in terms of vessels.[28] Including smallerships, bulkers have a total combined capacity of almost 346 millionDWT.[32] Combined carriers are a very small portion of the fleet,representing less than 3% of this capacity.[32] The lake freighters of theGreat Lakes, with 98 ships of 3.2 million total DWT, despite forming asmall fraction of the total fleet by tonnage and only operating 10months a year, carried a tenth of the world's bulk cargo because of theshort trip distance and fast turnarounds.[28] [33]

As of 2005, the average bulker was just over 13 years old.[34] About 41% of all bulkers were less than ten years old,33% were over twenty years old, and the remaining 26% were between ten and twenty years of age.[34] All of the 98bulkers registered in the Great Lakes trade are over 20 years old and the oldest still sailing in 2009 was 106-yearsold.[35]

Bulk carriers by flag state[36] (source data)

Flag states

As of 2005, the United States Maritime Administration counted6,225 bulkers of 10,000 DWT or greater worldwide.[1] More bulkersare registered in Panama, with 1,703 ships, than any four other flagstates combined.[1] In terms of the number of bulk carriers registered,the top five flag states also include Hong Kong with 492 ships, Malta(435), Cyprus (373), and China (371).[1] Panama also dominates bulkerregistration in terms of deadweight tonnage. Positions two through fiveare held by Hong Kong, Greece, Malta, and Cyprus.[1]

Largest fleetsGreece, Japan, and China are the top three owners of bulk carriers, with 1,326, 1,041, and 979 vesselsrespectively.[37] These three nations account for over 53% of the world's fleet.[37]

Several companies have large private bulker fleets. The multinational company Gearbulk Holding Ltd. has over70 bulkers.[38] The Fednav Group in Canada operates a fleet of over 80 bulkers, including two designed to work inArctic ice.[39] Croatia's Atlantska Plovidba d.d. has a fleet of 14 bulkers.[40] The H. Vogemann Group in Hamburg,Germany operates a fleet of 19 bulkers.[41] Portline in Portugal, owns 10 bulkers.[42] Dampskibsselskabet Torm inDenmark and Elcano in Spain also own notable bulker fleets.[43] Other companies specialize in mini-bulkeroperations: England's Stephenson Clarke Shipping Limited owns a fleet of eight mini-bulkers and five smallHandysize bulkers,[44] and Cornships Management and Agency Inc. in Turkey owns a fleet of sevenmini-bulkers.[45]

Bulk carrier 6

BuildersAsian companies dominate the construction of bulk carriers. Of the world's 6,225 bulkers, almost 62% were built inJapan[46] by shipyards such as Oshima Shipbuilding and Sanoyas Hishino Meisho.[3] South Korea, with notableshipyards Daewoo and Hyundai Heavy Industries,[3] ranked second among builders, with 643 ships. The People'sRepublic of China, with large shipyards such as Dalian, Chengxi, and Shanghai Waigaoqiao, ranked third, with509 ships.[46] Taiwan, with shipyards such as China Shipbuilding Corporation,[3] ranked fourth, accounting for129 ships.[46] Shipyards in these top four countries built over 82% of the bulkers afloat.[46]

Freight chargesSeveral factors affect the cost to move a bulk cargo by ship. The bulk freight market is very volatile, and itfluctuates, along with the type of cargo, the ship's size, and the route traveled all affect the final price. Moving acapesize load of coal from South America to Europe cost anywhere from $15 to $25 per ton in 2005.[47] Hauling apanamax-sized load of aggregate materials from the Gulf of Mexico to Japan that year could cost as little as $40 perton to as much as $70 per ton.[47]

Some shippers choose instead to charter a ship, paying a daily rate instead of a set price per ton.[47] In 2005, theaverage daily rate for a Handymax ship varied between $18,000 – $30,000.[47] A Panamax ship could be charteredfor $20,000 – $50,000 per day, and a Capesize for $40,000 – $70,000 per day.[47]

Ship breakingGenerally, ships are removed from the fleet go through a process known as ship breaking or scrapping.[48]

Ship-owners and buyers negotiate scrap prices based on factors such as the ship's empty weight (called light tondisplacement or LDT) and prices in the scrap metal market.[49] In 1998, almost 700 ships were scrapped in placeslike Alang, India and Chittagong, Bangladesh[48] . This is often done by 'beaching' the ship on open sand, thencutting it apart by hand with gas torches, a dangerous operation that results in injuries and fatalities, as well asexposure to toxic materials such as asbestos, lead, and various chemicals.[50] [51] [52] Half a million deadweight tonsof worth of bulk carriers were scrapped in 2004, accounting for 4.7% of the year's scrapping.[47] That year, bulkersfetched particularly high scrap prices, between $340 and $350 per LDT.[47]

Operation

Crew

Typical bulk carrier crew

Captain/Master

Deckdepartment

Enginedepartment

Steward'sdepartment

1 -Chief Officer1 -2nd Officer1 -3rd Officer1 -Boatswain2 – 6-AbleSeamen0 – 2-Ord. Seamen

1 -Chief Engineer1 -1st Asst. Engr.1 -2nd Asst. Engr1 – 2-3rd Asst. Engr.0 – 2-QMED/Jr.Engr.1 – 3- Oiler0 – 3-Greaser/s1 – 3-Entry-level

1-ChiefSteward1-Chief Cook1-Stwd's Asst

Bulk carrier 7

The crew on a bulker typically consists of 20 to 30 people, though smaller ships can be handled by 8. The crewincludes the captain or master, the deck department, the engineering department, and the steward's department. Thepractice of taking passengers aboard cargo ships, once almost universal, is very rare today and almost non-existenton bulkers.[53]

During the 1990s, bulkers were involved in an alarming number of shipwrecks. This led ship-owners to commissiona study seeking to explain the effect of various factors on the crew's effectiveness and competence.[54] The studyshowed that crew performance aboard bulk carriers was the lowest of all groups studied.[54] Among bulker crews,the best performance was found aboard younger and larger ships.[54] Crews on better-maintained ships performedbetter, as did crews on ships where fewer languages were spoken.[54]

Fewer deck officers are employed on bulkers than on similarly sized ships of other types.[54] A mini-bulker carriestwo to three deck officers, while larger Handysize and Capesize bulkers carry four.[54] Liquid natural gas tankers ofthe same size have an additional deck officer and unlicensed mariner.[54]

VoyagesA bulker's voyages are determined by market forces; routes and cargoes often vary. A ship may engage in the graintrade during the harvest season and later move on to carry other cargoes or work on a different route. Aboard acoastal carrier in the tramp trade, the crew will often not know the next port of call until the cargo is fully loaded.Because bulk cargo is so difficult to discharge, bulkers spend more time in port than other ships. A study ofmini-bulkers found that it takes, on average, twice as much time to unload a ship as it does to load it.[54] Amini-bulker spends 55 hours at a time in port, compared to 35 hours for a lumber carrier of similar size.[54] This timein port increases to 74 hours for Handymax and 120 hours for Panamax vessels.[54] Compared with the 12-hourturnarounds common for container ships, 15-hour turnarounds for car carriers, and 26-hour turnarounds for largetankers, bulker crews have more opportunities to spend time ashore.[54]

Loading and unloadingLoading and unloading a bulker is time-consuming and dangerous. The process is planned by the ship's captain,often with assistance from the chief mate. International regulations require that the captain and terminal master agreeon a detailed plan before operations begin.[55] Deck officers and stevedores oversee the operations. Occasionallyloading errors are made that cause a ship to capsize or break in half at the pier.[56]

The loading method used depends on both the cargo and the equipment available on the ship and on the dock. In theleast advanced ports, cargo can be loaded with shovels or bags poured from the hatch cover. This system is beingreplaced with faster, less labor-intensive methods.[57] Double-articulation cranes, which can load at a rate of1,000 tons per hour, represent a widely used method,[57] and the use of shore-based gantry cranes, reaching2,000 tons per hour, is growing.[57] A crane's discharge rate is limited by the bucket's capacity (from 6 to 40 tons)and by the speed at which the crane can take a load, deposit it at the terminal, and to return to take the next. Formodern gantry cranes, the total time of the grab-deposit-return cycle is about 50 seconds.[3]

Conveyor belts offer a very efficient method of loading, with standard loading rates varying between 100 and700 tons per hour, although the most advanced ports can offer rates of 16,000 tons per hour.[57] [58] Start-up andshutdown procedures with conveyor belts, though, are complicated and require time to carry out.[58] Self-dischargingships use conveyor belts with load rates of around 1,000 tons per hour.[57]

Once the cargo is discharged, the crew begins to clean the holds. This is particularly important if the next cargo is ofa different type.[59] The immense size of cargo holds and the tendency of cargoes to be physically irritating add tothe 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.[7] As the hold is filled, machines such as excavators and bulldozers are often used to keep the cargo in check. Leveling is particularly important when

Bulk carrier 8

the hold is only partly full, since cargo is more likely to shift.[60] Extra precautions are taken, such as addinglongitudinal divisions and securing wood atop the cargo.[6] If a hold is full, a technique called tomming is used,[7]

which involves digging out a 6 feet (2 m) hole below the hatch cover and filling it with bagged cargo or weights.[7]

A typical bulker offload

1. A bulldozer is loadedinto the hold.

2. The bulldozer pushes cargoto the center of the hold.

3. The gantry cranepicks up the cargo.

4. The gantry crane removesthe cargo from the ship.

5. The gantry crane moves thecargo to a bin on the pier.

Photos courtesy of Danny Cornelissen of portpictures.nl [61].

ArchitectureExamples of bulker architectural plans

Line plan of a 1990 Capesize ore carrier.

Typical midship section of a bulker with a single hull and double bottom.A bulk carrier's design is largely defined by the cargo it will carry. The cargo's density, also known as its stowagefactor, is the key factor. Densities for common bulk cargoes vary from 0.6 tons per cubic meter for light grains to3 tons per cubic meter for iron ore.[3]

The overall cargo weight is the limiting factor in the design of an ore carrier, since the cargo is so dense. Coalcarriers, on the other hand, are limited by overall volume, since most bulkers can be completely filled with coalbefore reaching their maximum draft.[3]

For a given tonnage, the second factor which governs the ship's dimensions is the size of the ports and waterways itwill travel to. For example, a vessel that will pass the Panama Canal will be limited in its beam and draft. For mostdesigns, the ratio of length-to-width ranges between 5 and 7, with an average of 6.2.[3] The ratio of length-to-heightwill be between 11 and 12.[3]

Bulk carrier 9

MachineryThe engine room on a bulker is usually near the stern, under the house and above the fuel tanks. Larger bulkers, fromHandymax up, have a two-stroke diesel engine which directly moves a single propeller. An alternator is coupleddirectly with the propeller shaft, and an auxiliary generator is used.[3] On the smallest bulkers, one or two four-strokediesels are used, and coupled with the propeller via a gear box.[3] The average design ship speed for bulkers ofHandysize and above is between 13.5 and 15 knots (28 km/h).[22] The propeller speed is relatively low, at about 90revolutions per minute.[3]

As a result of the 1973 oil crisis, the 1979 energy crisis, and the resulting rise in oil prices, experimental designsusing coal to fuel ships were tested in the late 1970s and early 1980s. The Australian National Lines (ANL)constructed 2 74,700-ton coal-burner ships called the River Boyne and River Embely.[62] along with 2 constructed byTNT called TNT Capricornia and TNT Capentaria and renamed Fitzroy River and Endeavor River. These ships werefinancially effective for the duration of their lives, and their steam engines were able to generate a shaft-power of19000 horsepower (14000 kW).[62] This strategy gave an interesting advantage to carriers of bauxite and similar fuelcargoes, but suffered from poor engine yield compared to higher maintenance cost and efficient modern diesels,maintenance problems due to the supply of ungraded coal, and high initial costs.[62]

Hatches

The sliding hatchcovers of the Zaira.

A hatch or hatchway is the opening at the top of a cargo hold. Themechanical devices which allow hatches to be opened and closed arecalled hatch covers. In general, hatch covers are between 45% and 60%of the ship's breadth, or beam, and 57% to 67% of the length of theholds.[3] To efficiently load and unload cargo, hatches must be large,but large hatches present structural problems. Hull stress isconcentrated around the edges of the hatches, and these areas must bereinforced.[58] Often, hatch areas are reinforced by locally increasingthe scantlings or by adding structural members called stiffeners. Bothof these options have the undesired effect of adding weight to the ship.

As recently as the 1950s, hatches had wooden covers that would be broken apart and rebuilt by hand, rather thanopened and closed.[63] Newer vessels have hydraulic-operated metal hatch covers that can often be operated by oneperson.[59] Hatch covers can slide forwards, backwards, or to the side, lift up or fold up. It is essential that the hatchcovers be watertight: unsealed hatches lead to accidental cargo hold flooding, which has caused many bulkers tosink.[64]

Regulations regarding hatch covers have evolved since the investigation following the loss of theMV Derbyshire.[65] The Load Line Conference of 1966 imposed a requirement that hatch covers be able towithstand 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 UnifiedRequirement S21[66] in 1998. This standard requires that the pressure due to sea water be calculated as a function offreeboard and speed, especially for hatch covers located on the forward portion of the ship.[66]

HullBulkers are designed to be easy to build and to store cargo efficiently. To facilitate construction, bulkers are built with a single hull curvature.[3] Also, while a bulbous bow allows a ship to move more efficiently through the water, designers lean towards simple vertical bows on larger ships.[3] Full hulls, with large block coefficients, are almost universal, and as a result, bulkers are inherently slow.[3] This is offset by their efficiency. Comparing a ship's carrying capacity in terms of deadweight tonnage to its weight when empty is one way to measure its efficiency.[3] A

Bulk carrier 10

small Handymax ship can carry five times its weight.[3] In larger designs, this efficiency is even more pronounced:Capesize vessels can carry over eight times their weight.[3]

Bulkers have a cross-section typical of most merchant ships. The upper and lower corners of the hold are used asballast tanks, as is the double bottom area. The corner tanks are reinforced and serve another purpose besidescontrolling the ship's trim. Designers choose the angle of the corner tanks to be less than that of the angle of reposeof the anticipated cargoes.[13] This greatly reduces side-to-side movement, or "shifting," of cargo which canendanger the ship.[13]

The double bottoms are also subject to design constraints. The primary concern is that they be high enough to allowthe passage of pipes and cables. These areas must also be roomy enough to allow people safe access to performsurveys and maintenance. On the other hand, concerns of excess weight and wasted volume keep the double bottomsvery tight spaces.Bulker hulls are made of steel, usually mild steel.[67] Some manufacturers have preferred high-tensile steel recentlyin order to reduce the tare weight.[68] However, the use of high-tensile steel for longitudinal and transversereinforcements can reduce the hull's rigidity and resistance to corrosion.[13] Forged steel is used for some ship parts,such as the propeller shaft support.[3] Transverse partitions are made of corrugated iron, reinforced at the bottom andat connections.[3] The construction of bulker hulls using a concrete-steel sandwich has been investigated.[69]

Double hulls have become popular in the past ten years.[3] Designing a vessel with double sides adds primarily to itsbreadth, since bulkers are already required to have double bottoms.[70] One of the advantages of the double hull is tomake room to place all the structural elements in the sides, removing them from the holds.[71] This increases thevolume of the holds, and simplifies their structure which helps in loading, unloading, and cleaning.[72] Double sidesalso improve a ship's capacity for ballasting, which is useful when carrying light goods: the ship may have toincrease 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 forHybrid Configuration, this design doubles the forward-most and rear-most holds and leaves the otherssingle-hulled.[73] This approach increases the ship's solidity at key points, while reducing the overall tare weight.[74]

Since the adoption of double hull has been more of an economic than a purely architectural decision, some argue thatdouble-sided ships receive less comprehensive surveys and suffer more from hidden corrosion.[75] In spite ofopposition, double hulls became a requirement for Panamax and Capesize vessels in 2005.[76]

Freighters are in continual danger of "breaking their backs"[77] and thus longitudinal strength is a primaryarchitectural concern. A naval architect uses the correlation between longitudinal strength and a set of hullthicknesses called scantlings to manage problems of longitudinal strength and stresses. A ship's hull is composed ofindividual parts called members.[77] The set of dimensions of these members is called the ship's scantlings.[77] Navalarchitects calculate the stresses a ship can be expected to be subjected to, add in safety factors, and then can calculatethe required scantlings.[77]

These analyses are conducted when traveling empty, loading and unloading, when partially and fully loaded, andunder conditions of temporary overloading.[3] Places subject to the largest stresses are studied carefully, such ashold-bottoms, hatch-covers, bulkheads between holds, and the bottoms of ballast tanks.[3] Great Lakes bulkers alsomust be designed to withstand springing, or developing resonance with the waves, which can cause fatiguefractures.[68]

Since April 1, 2006, the International Association of Classification Societies has adopted the Common StructuralRules. The rules apply to bulkers more than 90 meters in length and require that scantlings' calculations take intoaccount items such as the effect of corrosion, the harsh conditions often found in the North Atlantic, and dynamicstresses during loading. The rules also establish margins for corrosion, from 0.5 to 0.9 mm.[78]

Bulk carrier 11

SafetyThe 1980s and 1990s were a very unsafe time for bulk carriers. Many bulkers sank during this time, 99 were lostbetween 1990 and 1997 alone.[11] Most of these sinkings were sudden and quick, making it impossible for the crewto escape: more than 650 sailors were lost during this same period.[11] Due partly to the sinking of the MVDerbyshire, a series of international safety resolutions regarding bulkers were adopted during the 1990s.[79]

Stability problemsCargo shifting poses a great danger for bulkers. The problem is even more pronounced with grain cargoes, sincegrain settles during a voyage and creates extra space between the top of the cargo and the top of the hold.[6] Cargo isthen free to move from one side of the ship to the other as the ship rolls. This can cause the ship to list, which, inturn, causes more cargo to shift. This kind of chain reaction can capsize a bulker very quickly.[6]

The 1960 SOLAS Convention sought to control this sort of problem.[80] These regulations required the upper ballasttanks designed in a manner to prevent shifting. They also required cargoes to be leveled, or trimmed, usingexcavators in the holds.[81] The practice of trimming reduces the amount of the cargo's surface area in contact withair[82] which has a useful side-effect: reducing the chances of spontaneous combustion in cargoes such as coal, iron,and metal shavings.[82]

Another sort of risk that can affect dry cargoes, is absorption of ambient moisture.[83] When very fine concretes andaggregates mix with water, the mud created at the bottom of the hold shifts easily and can produce a free surfaceeffect.[83] The only way to control these risks is by good ventilation practices and careful monitoring for the presenceof water.[83]

Structural problems

Diagram showing the wreck of the Selendang Ayu, and the double-bottom tank leaks.

In 1990 alone, 20 bulk carriers sank, taking with them 94 crewmen. In 1991, 24 bulkers sank, killing 154.[84] Thislevel of loss focused attention on the safety aspects of bulk carriers, and a great deal was learned. The AmericanBureau of Shipping concluded that the losses were "directly traceable to failure of the cargo hold structure"[27] andLloyd's Register of Shipping added that the hull sides could not withstand "the combination of local corrosion,fatigue cracking and operational damage."[84]

The accident studies showed a clear pattern:[64]

1. Sea water enters the forward hatch, due to a large wave, a poor seal, corrosion, etc.[64]

Bulk carrier 12

2. The extra water weight in hold number one compromises the partition to hold number two,[64]

3. Water enters hold number two and alters the trim so much that more water enters the holds[64]

4. With two holds rapidly filling with water, the bow submerges and the ship quickly sinks, leaving little time forthe crew to react.[64]

Previous practices had required ships to withstand the flooding of a single forward hold, but did not guard againstsituations where two holds would flood. The case where two after (rear) holds are flooded is no better, because theengine room is quickly flooded, leaving the ship without propulsion. If two holds in the middle of the ship areflooded, the stress on the hull can become so great that the ship snaps in two.

Selendang Ayu suffered a catastrophic fracture innumber 4 hold in December 2004.

Other contributing factors were identified:• Most shipwrecks involved ships over 20 years in age. A glut of

ships of this age occurred in the 1980s, caused by an overestimateof the growth of international trade. Rather than replace themprematurely, shipping companies were compelled on cost groundsto keep their aging vessels in service.[6]

• Corrosion, due to a lack of maintenance, affected the seals of thehatch covers and the strength of the bulkheads which separate holds.The corrosion is difficult to detect due do the immense size of thesurfaces involved.[85] [86]

• Advanced methods of loading were not foreseen when the shipswere designed. While the new processes are more efficient, loadingis more difficult to control (it can take over an hour just to halt the operation), occasionally resulting inoverloading the ship. These unexpected shocks, over time, can damage the hull's structural integrity.[58]

• Recent use of high-tensile steel in construction enables buildings to retain the similar strength with less materialand weight. However, because it is thinner than regular steel, HT steel can corrode though more easily, plus it candevelop metal fatigue in choppy seas.[68]

• According to Lloyd's Register, a principal cause was the attitude of ship-owners, who sent ships with knownproblems to sea.[87]

The new rules adopted in the 1997 annexes to the SOLAS convention focused on problems such as reinforcingbulkheads and the longitudinal frame, more stringent inspections (with a particular focus on corrosion) and routinein-port inspections.[6] The 1997 additions also required bulkers with restrictions (for instance, forbidden fromcarrying certain types of cargoes) to mark their hulls with large, easy-to-see triangles.[88]

Crew safety

Launch of a free-fall lifeboat.

Since December 2004, Panamax and Capesize bulkers have beenrequired to carry free-fall lifeboats located on the stern, behind thehouse.[6] This arrangement allows the crew to abandon ship quickly incase of a catastrophic emergency.[89] One argument against the use offree-fall lifeboats is that the evacuees require "some degree of physicalmobility, even fitness" to enter and launch the boat.[90] Also, injurieshave occurred during launches, for example, in the case of incorrectlysecured safety belts.[90]

In December 2002, Chapter XII of the SOLAS convention wasamended to require the installation of high-level water alarms and

Bulk carrier 13

monitoring systems on all bulkers. This safety measure quickly alerts watch standers on the bridge and in the engineroom in case of flooding in the holds.[6] In cases of catastrophic flooding, these detectors could speed the process ofabandoning ship.

Notes[1] Office of Data and Economic Analysis, 2006:6.[2] "Maritime Safety Committee's 70th Session, January 1999" (http:/ / web. archive. org/ web/ 20070904190443/ http:/ / www. eagle. org/

regulatory/ regupdate/ msc70/ bulk. html). American Bureau of Shipping. Archived from the original (http:/ / www. eagle. org/ regulatory/regupdate/ msc70/ bulk. html) on September 4, 2007. . Retrieved 2007-04-09.

[3] Lamb, 2003.[4] "Maritime Glossary" (http:/ / web. archive. org/ web/ 20080415134847/ http:/ / www. trans-inst. org/ seawords. htm#o). The Transportation

Institute. Archived from the original (http:/ / www. trans-inst. org/ seawords. htm#o) on April 15, 2008. . Retrieved 2008-05-06.[5] "Acronyms and Abbreviations" (http:/ / www. nautinst. org/ info/ acrnm_abbrev. htm). The Nautical Institute. . Retrieved 2007-04-12.[6] "Bulk Carrier - Improving Cargo Safety" (http:/ / www. oceansatlas. com/ unatlas/ issues/ safety_at_sea/ bulk_carrier/ bulk_carrier. htm).

United Nations Atlas of the Oceans. . Retrieved 2007-04-09.[7] Hayler, 2003:5–13.[8] Bruno-Stéphane Duron, Le Transport maritime des céréales (http:/ / junon. u-3mrs. fr/ ad210w00/ memoires/ 99/ m99dubr. doc) DOC,

mémoire de DESS, 1999.[9] "Ship" (http:/ / www. 1911encyclopedia. org/ Ship). 1911 Encoclopedia Britannica. . Retrieved 2007-04-12.[10] Shipwrecks - A Deep Look, The Rise of the Self-unloading Freighter (http:/ / www. perryballard. com/ pdfs/ curriculum_guide. pdf), The

Heritage Museum and Cultural Center (HMCC) and Michigan Shipwreck Research Associates[11] International Maritime Organization, 1999:1.[12] "Bulk Carriers" (http:/ / www. oceansatlas. org/ unatlas/ uses/ transportation_telecomm/ maritime_trans/ shipworld/ cargo_car/ bulk/

bulk_carriers. htm). United Nations Ocean Atlas. . Retrieved 2007-04-12.[13] "IMO and the safety of bulk carriers" (http:/ / www. imo. org/ includes/ blastDataOnly. asp/ data_id=7987/ BULK99. FIN. pdf) (PDF).

International Maritime Organization. . Retrieved 2007-04-09.[14] Steamboats & sailors of the Great Lakes (http:/ / books. google. com/ books?id=KRLZDXIEWCsC& pg=PA26& lpg=PA26& dq=great+

lakes+ ore+ 1930+ ton& source=bl& ots=Pd2uSk2sEn& sig=ERNy-XXWpnZ9GWfeWgWUZp8Pwnc& hl=en&ei=xykMS87OFtWCnQevvuDCAw& sa=X& oi=book_result& ct=result& resnum=4& ved=0CBgQ6AEwAw#v=onepage& q=great lakes ore1930 ton& f=false), Mark L. Thompson, p. 26, 1991, ISBN 978-0-8143-2359-5

[15] International Maritime Organization, 1999: 1, 2.[16] Steamboats & sailors of the Great Lakes (http:/ / books. google. com/ books?id=KRLZDXIEWCsC& pg=PA26& lpg=PA26& dq=great+

lakes+ ore+ 1930+ ton& source=bl& ots=Pd2uSk2sEn& sig=ERNy-XXWpnZ9GWfeWgWUZp8Pwnc& hl=en&ei=xykMS87OFtWCnQevvuDCAw& sa=X& oi=book_result& ct=result& resnum=4& ved=0CBgQ6AEwAw#v=onepage& q=great lakes ore1930 ton& f=false), Mark L. Thompson, p. 28, 1991, ISBN 978-0-8143-2359-5

[17] Ranges vary slightly. MAN Diesel Group 2005, p.4. UNCTAD 2006, p. xii.[18] From Lamb, 2003 and the 2005 CIA World Factbook. See also graph and table at Wikipedia commons.[19] From Lamb, 2003. This is measured in terms of the tonnage of cargo carried multiplied by the distance traveled, and could be expressed in

terms of (miles x tons), for example.[20] UNCTAD 2006, p. 41. Price for new vessel $M in 2005.[21] UNCTAD 2006, p. 42. Five year old ship in $M in 2005.[22] MAN Diesel Group, 2005, p. 3-4.[23] "Kamsarmax 82BC" (http:/ / www. tsuneishi. co. jp/ tess/ factbook. html). Tsuneishi Corp.. . Retrieved 2007-04-12.[24] "Handysize re-vamp: the next move in bulk carriers?". The Naval Architect. January 2006.[25] Autoridad del Canal de Panamá 2005, pp. 11 – 12.[26] "Egypt's Suez canal H1 revenue, traffic up; upgrade helps" (http:/ / af. reuters. com/ article/ idAFJOE66P09P20100726). Reuters Africa.

Thomson Reuters (af.reuters.com). 26 July 2010. . Retrieved 26 March 2011.[27] International Maritime Organization, 1999:6.[28] Office of Data and Economic Analysis, 2006:1.[29] "CHL INNOVATOR" (http:/ / www. lukarijeka. hr/ en/ Archive/ 2007/ july2007-1. html). Port of Rijeka, Croatia. . Retrieved 2008-05-05.[30] Lloyd's Register World Fleet Statistics Tables (http:/ / www. lrfairplay. com). London: Lloyd's. 2000. .[31] UNCTAD 2006, p.11.[32] UNCTAD 2006, p. 21.[33] Great Lakes Navigation System: Economic Strength to the Nation (http:/ / www. lre. usace. army. mil/ ETSPubs/ HFS/ Great Lakes

Navigation-Economic Strength to the Nation. pdf), US Army Corps of Engineers, 2006[34] UNCTAD 2006, p. 23.[35] Office of Data and Economic Analysis, 2006:2.

Bulk carrier 14

[36] "The CIA World Factbook, 2005" (https:/ / www. cia. gov/ library/ publications/ the-world-factbook/ ). cia.gov. . Retrieved 2007-04-09.[37] Office of Data and Economic Analysis, 2006:4.[38] Gearbulk (2008). "About Us" (http:/ / www. gearbulk. com/ company. aspx). Gearbulk Holding Limited. . Retrieved 2008-04-22.[39] Fednav Group (2007). "Fleet Owned" (http:/ / www2. fednav. com/ anglais/ fleetowned. html). Fednav Group. . Retrieved 2008-04-21. and

Fednav Group (2007). "Fleet Chartered" (http:/ / www2. fednav. com/ anglais/ fleetchartered. html). Fednav Group. . Retrieved 2008-04-21.[40] "Atlantska Plovidba Fleet" (http:/ / web. archive. org/ web/ 20070407070302/ http:/ / www. atlant. hr/ fleet/ fleet. html). Atlantska Plovidba

d.d. Dubrovnik.. Archived from the original (http:/ / www. atlant. hr/ fleet/ fleet. html) on April 7, 2007. . Retrieved 2007-04-15.[41] H. Vogemann Group (2007). "Fleet List" (http:/ / www. vogemann. de/ cms/ upload/ download_pdf/ fleetlist. pdf) (PDF). H. Vogemann

Group. . Retrieved 2008-05-01.[42] "Portline Frota" (http:/ / www. portline. pt/ ing_frota. htm). PORTLINE Transportes Marítimos Internacionais, S.A.. . Retrieved 2007-04-15.[43] According to description of the main ship-owners (http:/ / web. archive. org/ web/ 20070805004640/ http:/ / www. marine-marchande. net/

Collection+ Le+ Mens/ ALeMensAlpha. htm), from the French Marine-Marchande website.[44] "Stephenson Clarke Fleet" (http:/ / www. scsbulk. com/ fleet. php). Stephenson Clarke Shipping Ltd. . Retrieved 2007-04-15.[45] "The Cornships Fleet" (http:/ / www. cornships. com/ fleet. htm). Cornships Management & Agency Inc.. . Retrieved 2007-04-15.[46] Office of Data and Economic Analysis, 2006:5.[47] UNCTAD 2005.[48] Bailey, Paul J. (2000). "Is there a decent way to break up ships?" (http:/ / www. ilo. org/ public/ english/ dialogue/ sector/ papers/ shpbreak/

index. htm). Sectoral Activities Programme. International Labour Organization. . Retrieved 2007-05-29.[49] Maritime Transport Coordination Platform (November 2006). "3: The London Tonnage Convention" (http:/ / ec. europa. eu/ transport/

maritime/ studies/ doc/ 2006_11_tonnage_measurement_study. pdf) (pdf). Tonnage Measurement Study. MTCP Work Package 2.1, Qualityand Efficiency. Bremen/Brussels. p. 3.3. . Retrieved 2007-05-29.

[50] Staff Correspondent, Ctg (2009-09-06). "Safety still missing" (http:/ / www. thedailystar. net/ newDesign/ news-details. php?nid=104585).The Daily Star (Bangladesh). . Retrieved 2009 9 12.

[51] OSHA (US Govt). "Shipbreaking » Inventory of Hazardous Materials" (http:/ / www. osha. gov/ SLTC/ etools/ shipyard/ ship_breaking/survey_hm. html). . Retrieved 2009 9 12.

[52] Andrew Buncombe (2009-08-31). "Alang: The place where ships go to die" (http:/ / www. independent. co. uk/ news/ world/ asia/alang-the-place-where-ships-go-to-die-1779656. html). The Independent (UK). . Retrieved 2009 9 12.

[53] Some companies specialize in providing cruises on various kinds of freighters, for example Freighter World Cruises (http:/ / www.freighterworld. com/ ).

[54] Lane, Tony (2001). Bulk Carrier Crews; Competence, Crew composition & Voyage Cycles. Cardiff University.[55] "MSC Circular 947: Safe Loading and Unloading of Bulk Carriers" (http:/ / www. imo. org/ includes/ blastDataOnly. asp/ data_id=1836/

947. pdf) (PDF). International Maritime Organization. . Retrieved 2007-04-15.[56] George, 2005:245.[57] Packard, William V. (1985). Sea-trading. Fairplay Publications.[58] International Maritime Organization, 1999:7.[59] Hayler, 2003:5–11.[60] George, 2005:341, 344.[61] http:/ / www. portpictures. nl[62] Ewart, W.D. (1984). Bulk Carriers. Fairplay Publications Ltd,. ISBN 0-905045-42-4.[63] Hayler, 2003:5–9.[64] "Improving the safety of bulk carriers" (http:/ / www. imo. org/ includes/ blastDataOnly. asp/ data_id=6609/ BULK. PDF) (PDF).

International Maritime Organization. . Retrieved 2007-04-09.[65] Byrne, David (10). "Hatch Covers on Bulk Carriers: The Effect on Procurement Costs of Changes in Design Pressure". Conférence

internationale RINA.[66] International Association of Classification Societies 2007, p. 21-1.[67] George, 2005:221.[68] International Maritime Organization, 1999:8.[69] "Concrete sandwiches: structural strength and safety for bulk carriers". The Naval Architect. February 2005.[70] "New IMO bulk carrier regulations enter into force on 1 July 1999" (http:/ / www. imo. org/ Safety/ mainframe. asp?topic_id=69&

doc_id=588). International Maritime Organization. . Retrieved 2007-04-10.[71] "NG-Bulk20: a new Turkish double-skin bulker design". The Naval Architect. November 2005.[72] Det Norske Veritas (28). "Oshima looks ahead" (http:/ / www. dnv. com/ publications/ classification_news/ class_news_2003_02/

Oshimalooksahead. asp). . Retrieved 2007-04-15.[73] "Oshima Hy-Con Bulker" (http:/ / web. archive. org/ web/ 20060430180139/ http:/ / www. osy. co. jp/ en/ bc_lineup/ hy-con. html). Oshima

Shipbuilding Co., Ltd.. Archived from the original (http:/ / www. osy. co. jp/ en/ bc_lineup/ hy-con. html) on April 30, 2006. . Retrieved2007-04-14.

[74] ""Ultra Handymax" Semi-Double Hull Handymax Bulk Carrier" (http:/ / web. archive. org/ web/ 20060430004211/ http:/ / www. osy. co. jp/en/ bc_lineup/ handymax. html). Oshima Shipbuilding Co., Ltd.. Archived from the original (http:/ / www. osy. co. jp/ en/ bc_lineup/handymax. html) on April 30, 2006. . Retrieved 2007-04-10.

Bulk carrier 15

[75] "Double-Hull Tanker Legislation: An Assessment of the Oil Pollution Act of 1990 (1998)" (http:/ / books. nap. edu/ openbook.php?record_id=5798& page=261). Marine Board Commission on Engineering and Technical Systems. . Retrieved 2007-04-10.

[76] "Double-skin bulkers: paradise or problem?". The Naval Architect. May 2003.[77] George, 2005:217.[78] "Implications of commons structural rules". The Naval Architect. March 2006.[79] "Improving the safety of bulk carriers" (http:/ / www. imo. org/ includes/ blastData. asp/ doc_id=2728/ BULK. PDF) (PDF). International

Maritime Organization. . Retrieved 2007-04-09.[80] International Maritime Organization, 1999:2.[81] International Maritime Organization, 1999: 1, 2.[82] International Maritime Organization, 1999:4.[83] Kemp, John F. (1971). Notes on Cargo Work (3rd ed.). Kandy Publications. ISBN 0853090408.[84] International Maritime Organization, 1999:5.[85] "Formal Safety Assessment of Bulk Carriers, Fore-End Watertight Integrity'" (http:/ / web. archive. org/ web/ 20070206175021/ http:/ /

www. iacs. org. uk/ fsa/ wp5/ main. htm). International Association of Classification Societies. Archived from the original (http:/ / www. iacs.org. uk/ fsa/ wp5/ main. htm) on 2007-02-06. . Retrieved 2007-04-09.

[86] International Maritime Organization, 1999:5,6.[87] International Maritime Organization, 1999:7,8.[88] "Maritime Safety Committee's 71st Session, May 1999" (http:/ / web. archive. org/ web/ 20070930043825/ http:/ / www. eagle. org/

regulatory/ regupdate/ msc71/ bulk. html) (PDF). American Bureau of Shipping. Archived from the original (http:/ / www. eagle. org/regulatory/ regupdate/ msc71/ bulk. html) on September 30, 2007. . Retrieved 2007-04-10.

[89] "Pioneers of Survival" (http:/ / www. pbs. org/ wgbh/ nova/ escape/ pioship. html). NOVA. . Retrieved 2007-04-10.[90] "Review of Lifeboat and Launching System Accidents" (http:/ / www. maib. gov. uk/ cms_resources/ Review_of_

lifeboat_and_launching_systems_accidents. pdf) (PDF). Marine Accident Investigation Branch. . Retrieved 2007-04-10.

References• Autoridad del Canal de Panamá (2005). MR Notice to Shipping Number N-1-2005. (http:/ / www. pancanal. com/

eng/ maritime/ notices/ n01-05. pdf). Notices to Shipping. Balboa-Ancon: Autoridad del Canal de Panamá.pp. 11–12. Retrieved 2008-04-01.

• Frankel, Ernst G. (1985). Bulk Shipping and Terminal Logistics. Washington, D.C., U.S.A.: World Bank.ISBN 082130531X.

• George, William (2005). Stability and Trim for the Ship's Officer. Centreville, MD: Cornell Maritime Press.ISBN 978-0-87033-564-8.

• Hayler, William B. (2003). American Merchant Seaman's Manual. Cornell Maritime Pr. ISBN 0-87033-549-9.• International Maritime Organization (September 1999). "IMO and the safety of bulk carriers" (http:/ / www. imo.

org/ includes/ blastDataOnly. asp/ data_id=7987/ BULK99. FIN. pdf) (PDF). Focus on IMO. Retrieved2007-04-09.

• Isbester, Jack (1993). Bulk Carrier Practice. London: The Nautical Institute. ISBN 1870077164.• Lamb, Thomas (2003). Ship Design and Construction Vol. I. Jersey City: Society of Naval Architects and Marine

Engineers. ISBN 0-939773-40-6.• MAN Diesel Group (2005). "Propulsion Trends in Bulk Carriers" (http:/ / www. manbw. com/ files/ news/

filesof5479/ 5510-0007-00ppr. pdf) (PDF). MAN Diesel Group. p. 4. Retrieved 2007-04-12.• International Association of Classification Societies (2007). "21: Evaluation of Scantlings of Hatch Covers and

Hatch Coamings of Cargo Holds of Bulk Carriers, Ore Carriers and Combination Carriers (Rev. 4)" (http:/ /www. iacs. org. uk/ document/ public/ Publications/ Unified_requirements/ PDF/ UR_S_pdf158. PDF).Requirements Concerning Strength of Ships. Unified Requirements. International Association of ClassificationSocieties. pp. 21–1.

• Office of Data and Economic Analysis (July 2006). "World Merchant Fleet 2001–2005" (http:/ / www. marad.dot. gov/ MARAD_statistics/ 2005 STATISTICS/ World Merchant Fleet 2005. pdf) (PDF). United StatesMaritime Administration. Retrieved March 13, 2007.

• Thompson, Mark L. (1994). Queen of the Lakes. Detroit: Wayne State Univ. Press. ISBN 0814323936.

Bulk carrier 16

• United Nations Council on Trade and Development (UNCTAD) (2005). Review of Maritime Transport, 2005(http:/ / www. unctad. org/ Templates/ StartPage. asp?intItemID=2614& lang=1). New York and Geneva: UnitedNations.

• United Nations Council on Trade and Development (UNCTAD) (2006). Review of Maritime Transport, 2006(http:/ / www. unctad. org/ en/ docs/ rmt2006_en. pdf). New York and Geneva: United Nations.

• Zera, Thomas F. (1996). Ore-Oil Bulk: Pictorial History of Bulk Shipping Losses of the 1980s. Bethel, CT:Rutledge Books. ISBN 0964393778.

External links• Bulk Carriers @ United Nations Atlas of the Oceans (http:/ / www. oceansatlas. com/ unatlas/ uses/

transportation_telecomm/ maritime_trans/ shipworld/ cargo_car/ bulk/ bulk_carriers. htm)• Bulk Carriers at MRI Netherlands (http:/ / www. marin. nl/ web/ show/ id=77616)• Histories of WWII Bulkers (http:/ / www. t2tanker. org/ ships/ nashbulk. html)

Article Sources and Contributors 17

Article Sources and ContributorsBulk carrier  Source: http://en.wikipedia.org/w/index.php?oldid=449582063  Contributors: -

Image Sources, Licenses and ContributorsImage:Sabrina I cropped.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Sabrina_I_cropped.jpg  License: Public domain  Contributors: Original uploader was Nsandel aten.wikipediaImage:Bulk carrier general arrangement english.png  Source: http://en.wikipedia.org/w/index.php?title=File:Bulk_carrier_general_arrangement_english.png  License: Creative CommonsAttribution-ShareAlike 3.0 Unported  Contributors: Rémi Kaupp for the original drawing, Calips for clean-upImage:Bulk carrier midship section-i18.svg  Source: http://en.wikipedia.org/w/index.php?title=File:Bulk_carrier_midship_section-i18.svg  License: Creative Commons Attribution-ShareAlike3.0 Unported  Contributors: Rémi Kaupp and Funakoshi, words removed by Haus.Image:Viermastbark Pamir.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Viermastbark_Pamir.jpg  License: Public Domain  Contributors: -File:Capesize bulk carrier at Suez Canal Bridge.JPG  Source: http://en.wikipedia.org/w/index.php?title=File:Capesize_bulk_carrier_at_Suez_Canal_Bridge.JPG  License: Creative CommonsAttribution-Sharealike 3.0  Contributors: AashayBaindurImage:Bulk carrier arriving in port.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Bulk_carrier_arriving_in_port.jpg  License: unknown  Contributors: Danny CornelissenImage:Maya OBO carrier 2.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Maya_OBO_carrier_2.jpg  License: unknown  Contributors: Hervé CozanetImage:Berge Athene.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Berge_Athene.jpg  License: Creative Commons Attribution-Sharealike 2.0  Contributors: Capt. Jan MelchersImage:Welland canal john b aird.JPG  Source: http://en.wikipedia.org/w/index.php?title=File:Welland_canal_john_b_aird.JPG  License: Public Domain  Contributors: Own workImage:Edmund Fitzgerald NOAA.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Edmund_Fitzgerald_NOAA.jpg  License: Public Domain  Contributors: Bob Campbell, GrandLedge, MichiganImage:Brosen chl innovator.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Brosen_chl_innovator.jpg  License: Creative Commons Attribution-ShareAlike 3.0 Unported Contributors: BrosenImage:Number of bulkers graphic.svg  Source: http://en.wikipedia.org/w/index.php?title=File:Number_of_bulkers_graphic.svg  License: Creative Commons Attribution-ShareAlike 3.0Unported  Contributors: Rémi Kaupp, words removed and converted to SVG by User:HausImage:Oil-tankers-map-with-top-10.svg  Source: http://en.wikipedia.org/w/index.php?title=File:Oil-tankers-map-with-top-10.svg  License: Public Domain  Contributors: HausImage:Bulldozer loaded on bulk carrier.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Bulldozer_loaded_on_bulk_carrier.jpg  License: unknown  Contributors: DannyCornelissenImage:Bulker-unload-sequence-2.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Bulker-unload-sequence-2.jpg  License: unknown  Contributors: Danny CornelissenImage:Bulker-unload-sequence-3.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Bulker-unload-sequence-3.jpg  License: unknown  Contributors: Hervé CozanetImage:Bulker-unload-sequence-4.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Bulker-unload-sequence-4.jpg  License: unknown  Contributors: Danny CornelissenImage:Grab unloaded into hopper.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Grab_unloaded_into_hopper.jpg  License: unknown  Contributors: Danny CornelissenImage:Capesize bulk carrier lines plan.svg  Source: http://en.wikipedia.org/w/index.php?title=File:Capesize_bulk_carrier_lines_plan.svg  License: Creative Commons Attribution-ShareAlike3.0 Unported  Contributors: Rémi KauppImage:Bulk carrier midship section en.svg  Source: http://en.wikipedia.org/w/index.php?title=File:Bulk_carrier_midship_section_en.svg  License: Creative Commons Attribution-ShareAlike3.0 Unported  Contributors: Rémi KauppImage:Hatch covers on bulk carrier.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Hatch_covers_on_bulk_carrier.jpg  License: unknown  Contributors: Danny CornelissenImage:Seledang Ayu.jpeg  Source: http://en.wikipedia.org/w/index.php?title=File:Seledang_Ayu.jpeg  License: Public Domain  Contributors: UNIFIED COMMANDImage:Seledang Ayu 2.jpeg  Source: http://en.wikipedia.org/w/index.php?title=File:Seledang_Ayu_2.jpeg  License: Public Domain  Contributors: UNIFIED COMMAND PHOTO PLSImageID 242791Image:Abgang rettungsboot.gif  Source: http://en.wikipedia.org/w/index.php?title=File:Abgang_rettungsboot.gif  License: Creative Commons Attribution-Sharealike 2.5  Contributors: -

LicenseCreative Commons Attribution-Share Alike 3.0 Unportedhttp:/ / creativecommons. org/ licenses/ by-sa/ 3. 0/