Bulk carrier
1324895
219719192
2008-06-16T15:51:51Z
Brylaw
6003533
{|{{Infobox Ship Begin}}
{{Infobox Ship Image
|Ship image=[[Image:Sabrina I cropped.jpg|300px|The ''Sabrina I'' is a modern Handymax bulk carrier.]]
|Ship caption=The ''Sabrina I'' is a modern Handymax bulk carrier.
}}
{{Infobox Ship Class Overview
|Name=Bulk carrier
|Builders=
|Operators=
|Class before=
|Class after=
|Subclasses=[[Handymax]], [[Handysize]], [[Panamax]], [[Capesize]]
|Cost=
|Built range=''c.'' 1850–present
|In service range=
|In commission range=
|Total ships building=
|Total ships planned=
|Total ships completed=
|Total ships cancelled=
|Total ships active=6,225 vessels over {{DWT|10,000|long|first=yes}}<ref name="s6"/>
|Total ships laid up=
|Total ships lost=
|Total ships retired=
|Total ships preserved=
}}
{{Infobox Ship Characteristics
|Hide header=
|Header caption=
|Ship class=
|Ship type=[[Cargo ship]]
|Ship tonnage=
|Ship displacement=
|Ship tons burthen=
|Ship length=
|Ship beam=
|Ship height=
|Ship draught=
|Ship draft=
|Ship depth=
|Ship hold depth=
|Ship decks=
|Ship deck clearance=
|Ship ramps=
|Ship ice class=
|Ship power=
|Ship propulsion=2-stroke diesel engine and 1 propeller
|Ship speed=
|Ship range=
|Ship endurance=
|Ship boats=
|Ship capacity=up to {{DWT|364,000}}
|Ship complement=
|Ship crew=
|Ship notes=Rear house, full hull, series of large hatches
}}
{{Infobox Ship Image
|Ship image=[[Image:Bulk carrier general arrangement english.png|300px|Plans of a geared Hanydymax bulker]]
|Ship caption=Plans of a geared Handymax bulker
}}
|}
<!-- 1 Definition -->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 hold]]s. <!-- 2 History-->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. <!-- 5 Architecture--><!-- 5.1 Machinery--><!-- 5.3 Hull-->Today's bulkers are specially designed to maximize capacity, safety, efficiency, and to be able to withstand the rigors of their work.
<!-- 3 Modern bulk carriers-->Today, bulkers make up 40% of the world's [[merchant ship|merchant fleets]] <!-- 3.1 Size categories-->and range in size from single-hold mini-bulkers to mammoth ore ships able to carry 365,000 [[deadweight tonnage|metric tons of deadweight]] (DWT). <!-- 3.2 General types-->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. <!-- 3.3 Today's fleet-->Over half of all bulkers have [[Greece|Greek]], [[Japan]]ese, or [[China|Chinese]] owners and more than a quarter are registered in [[Panama]]. Japan is the largest single builder of bulkers, and 82% of these ships were built in [[Asia]].
<!-- 4.2 Voyages-->A bulk carrier's crew participates in the loading and unloading of cargo, navigating the ship, and keeping its machinery and equipment properly maintained. <!-- 4.3 Loading and unloading-->Loading and unloading the cargo is difficult, dangerous, and can take up to 120 hours on larger ships. <!-- 4 Operation--><!-- 4.1 Crew-->Crews can range in size from three people on the smallest ships to over 30 on the largest.
<!-- 5.3 Hull-->Bulk cargo can be very dense, corrosive, or abrasive, and <!-- 6 Safety--><!-- 6.1 Stability problems-->presents safety problems: [[weight distribution|cargo shifting]], spontaneous combustion, and cargo saturation can all doom a ship. <!-- 6.2 Structural problems-->The use of ships that are old and have corrosion problems has been linked to a spate of bulker sinkings in the 1990s, <!-- 5.2 Hatches-->as have the bulker's large hatchways, important for efficient cargo handling. <!-- 6.3 Crew safety-->New international regulations have since been introduced to improve ship design and inspection, and to streamline the process of abandoning ship.
==Definition==
[[Image:Bulk carrier midship section-i18.svg|right|thumb|Cross section of a typical bulker. 1. Cargo hold 2. Hatch cover 3. Upper hopper tank for water ballast or oil 4. Double bottom 5. Lower hopper tank, for water ballast]]
There are various ways to define the term bulk carrier. 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."<ref name="abs">{{cite web |url= http://www.eagle.org/regulatory/regupdate/msc70/bulk.html|title= Maritime Safety Committee's 70th Session, January 1999|accessdate=2007-04-09 | work=American Bureau of Shipping }}</ref> However, most [[Classification society|classification societies]] use a broader definition where a bulker is any ship that carries dry unpackaged goods.<ref name="SNAME"/> [[Cargo ship|Multipurpose cargo ships]] can carry bulk cargo, but can also carry other cargoes and are not specifically designed for bulk carriage. The term "dry bulk carrier" is used to distinguish bulkers from bulk liquid carriers such as [[oil tanker|oil]], [[chemical tanker|chemical]], or [[tanker (ship)|liquefied petroleum gas carriers]]. Very small bulkers are almost indistinguishable from general cargo ships, and they are often classified based more on the ship's use than its design.
A number of abbreviations are used to describe bulkers. "[[Ore-bulk-oil carrier|OBO]]" describes a bulker which carries a combination of ore, bulk, and oil, and "O/O" is used for combination oil and ore carriers.<ref>{{cite web |url=http://www.trans-inst.org/seawords.htm#o |title=Maritime Glossary |accessdate=2008-05-06 |format= |work=The Transportation Institute }}</ref> 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.<ref name="vlcc">{{cite web |url=http://www.nautinst.org/info/acrnm_abbrev.htm|title=Acronyms and Abbreviations |accessdate=2007-04-12 |format= |work=The Nautical Institute }}</ref>
==History==
[[Image:Viermastbark Pamir.jpg|thumb|right|The four-masted barque ''[[Pamir (ship)|Pamir]]'', shown here in 1905, carried nitrates, corn, and barley.]]
Before specialized bulk carriers existed, shippers had two methods to move bulk goods by ship. In the first method, [[longshoremen]] loaded the cargo into sacks, stacked the sacks onto [[pallet]]s, and put the pallets into the cargo hold with a [[crane]].<ref name="un"/> The second method required the shipper to charter an entire ship and spend time and money to build plywood bins into the holds.<ref name="hay5-13"/> Then, to guide the cargo through the small hatches, wooden feeders and shifting boards had to be constructed.<ref name="hay5-13">Hayler, 2003:5–13.</ref> These methods were slow and [[Labor intensity|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 [[steamship|steam-powered ships]] became more popular.<ref name="un">{{cite web |url=http://www.oceansatlas.com/unatlas/issues/safety_at_sea/bulk_carrier/bulk_carrier.htm |title=Bulk Carrier - Improving Cargo Safety |accessdate=2007-04-09 |work=United Nations Atlas of the Oceans }}</ref> The first steam ship recognized as a bulk carrier was the [[United Kingdom|British]] coal carrier SS ''John Bowes'' in 1852.<ref name="Duron"> Bruno-Stéphane Duron, {{DOClink|''[http://junon.u-3mrs.fr/ad210w00/memoires/99/m99dubr.doc Le Transport maritime des céréales]''}}, mémoire de DESS, 1999.</ref><ref name="ship1911">{{cite web |url=http://www.1911encyclopedia.org/Ship |title= Ship |accessdate=2007-04-12 |format= |work=1911 Encoclopedia Britannica }}</ref> She featured a metal [[Hull (watercraft)|hull]], a [[steam engine]], and a [[Ballast tank|ballasting system]] which used seawater instead of sandbags.<ref name="Duron"/> These features helped her succeed in the competitive British coal market.<ref name="Duron"/> The first bulkers with [[Diesel engine|diesel propulsion]] began to appear in 1911.<ref name="Duron"/><ref name="ship1911"/>
Before [[World War II]], the demand for bulk products was low—about 25 million tons for metal ores<ref name="imo1">International Maritime Organization, 1999:1.</ref><ref name="unbc">{{cite web |url=http://www.oceansatlas.org/unatlas/uses/transportation_telecomm/maritime_trans/shipworld/cargo_car/bulk/bulk_carriers.htm |title=Bulk Carriers |accessdate=2007-04-12 |format= |work=United Nations Ocean Atlas }}</ref>—and most of this trade was [[coastal]].<ref name="reflets imo">{{cite web |url=http://www.imo.org/includes/blastDataOnly.asp/data_id%3D7987/BULK99.FIN.pdf |title=IMO and the safety of bulk carriers |accessdate=2007-04-09 |format=PDF |work=International Maritime Organization}}</ref> However, two defining characteristics of bulkers were already emerging: the [[double bottom]], which was adopted in 1890,<ref name="Duron"/> and the triangular structure of the ballast tanks, which was introduced in 1905.<ref name="Duron"/> After World War II, an international bulk trade began to develop among [[industrialized nation]]s, particularly between the [[Europe]]an countries, the [[United States]] and [[Japan]].<ref name="imo1"/> Due to the economics of this trade, bulkers became larger and more specialized.<ref name="imo1-2">International Maritime Organization, 1999: 1, 2.</ref><ref name="unbc"/>
==Categories==
===Size categories===
<!--NOTE: The numbers in this table are cited. This means they have a footnote
which points to a reference below from which the number came. If you
feel a strong urge to change one of the numbers, please find a reliable
source and place an appropriate footnote. -->
{| class="wikitable" style="float:right;width:300px;font-size:8pt; margin-left:15px"
|-bgcolor="#CCCCCC" align="center"
| colspan="6" | '''Major bulk carrier size categories'''
|- bgcolor="#CCCCCC" align="center"
!Name
!Size in<br />DWT<ref>Ranges vary slightly. MAN Diesel Group 2005, p.4. UNCTAD 2006, p. xii.</ref>
!Ships<ref name="bulkton">From Lamb, 2003 and the 2005 CIA World Factbook. See also [[:commons:Image:Bulk-carriers-by-deadweight-tonnage-2005.png|graph and table at Wikipedia commons]].</ref>
!Traffic<ref>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.</ref>
!New<br />price<ref>UNCTAD 2006, p. 41. Price for new vessel [[USD|$]][[million|M]] in 2005.</ref>
!Used<br />price<ref>UNCTAD 2006, p. 42. Five year old ship in [[USD|$]][[million|M]] in 2005.</ref>
|-
| valign="top" | [[Handysize]]
| valign="top" | 10,000 to 35,000
| valign="top" | 34%
| rowspan="2" valign="center" | 18%
| rowspan="2" valign="center" | $28M
| rowspan="2" valign="center" | $28M
|- valign="top"
|[[Handymax]]
| 35,000 to 55,000
| 37%
|- valign="top"
|[[Panamax]]
| 60,000 to 80,000
| 19%
| 20%
| $35M
| $34M
|- valign="top"
|[[Capesize]]
| 80,000 and over
| 10%
| 62%
| $59M
| $68.4M
|}
Bulkers are segregated into six major size categories: small, [[handysize]], [[handymax]], [[panamax]], [[capesize]], and very large.<ref name="mand">MAN Diesel Group, 2005, p. 3-4.</ref> Very large bulk and ore carriers fall into the capesize category but are often considered separately.
Other categories occur in [[Intra Regional Trade|regional trade]], such as Kamsarmax, with a maximum length of 229 meters, the maximum length that can load in the port of [[Kamsar]]in the [[Republic of Guinea]].<ref>{{cite web |url=http://www.tsuneishi.co.jp/tess/factbook.html |title=Kamsarmax 82BC |accessdate=2007-04-12 |format= |work=Tsuneishi Corp.}}</ref> Other terms such as Setouchmax, Dunkirkmax, and Newcastlemax also appear in regional trade.<ref name="mand"/>
Mini-bulkers are prevalent in the category of small vessels with a capacity of under {{DWT|10,000}}. Mini-bulkers 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 [[bridge]]s and have small crews of three to eight people.
Handysize and Handymax ships are general purpose in nature.<ref name="SNAME">Lamb, 2003.</ref> These two segments represent 71% of all bulk carriers over {{DWT|10,000}} and also have the highest rate of growth.<ref name="NA 0106">{{cite journal
| author =
| year = 2006
| month = January
| title = Handysize re-vamp: the next move in bulk carriers?''
| journal =The Naval Architect
| issn =
| url =
| accessdate =
| laysummary =
| laysource =
| laydate =
| quote =
}}</ref> This is partly due to new regulations coming into effect which put greater constraints on the building of larger vessels.<ref name="NA 0106"/> Handymax ships are typically 150–200 m in length and 52,000{{ndash}}{{DWT|58,000}} with five cargo holds and four cranes.<ref name="SNAME"/> These ships are also general purpose in nature.<ref name="SNAME"/>
The size of a Panamax vessel is limited by the [[Panama Canal Locks|Panama canal's lock chambers]], which can accommodate ships with a beam of up to 32.31 m, a length overall of up to 294.13 m, and a draft of up to 12.04 m.<ref>Autoridad del Canal de Panamá 2005, pp. 11{{ndash}}12.</ref>
Capesize ships are too large to traverse the [[Suez Canal|Suez]] or Panama canals and must round the [[Cape of Good Hope]] or [[Cape Horn]] to travel between oceans. Capesize bulkers are [[Specialization (functional)|specialized]]: 93% of their cargo is iron ore and coal.<ref name="SNAME"/> Very large ore carriers and very large bulk carriers are a subset of the capesize category reserved for vessels over {{DWT|200,000}}.<ref name="mand"/> Carriers of this size are almost always designed to carry iron ore.<ref name="mand"/>
<br clear="both"/>
===General types===
{| bgcolor="#f7f8ff" align="center" cellpadding="3" cellspacing="0" border="1" style="font-size: 95%; border: gray solid 1px; border-collapse: collapse;"
|-bgcolor="#CCCCCC" align="center"
| colspan="2" | '''General Bulk Carrier Types'''
|- bgcolor="#CCCCCC" align="center"
! Illustration !! Description
|- valign="top"
|[[Image:Bulk carrier arriving in port.jpg|150px]]
|'''Geared bulk carriers''' feature a series of holds (from 5 for a 35,000 ton vessel to 9 for a 250,000 ton vessel)<ref name="poster">{{cite web |url=http://www.imo.org/includes/blastData.asp/doc_id=2728/BULK.PDF |title=Improving the safety of bulk carriers|accessdate=2007-04-09 |format=PDF |work=International Maritime Organization }}</ref> covered by prominent hatch covers. They have [[crane]]s or [[derrick]]s which allow them to discharge cargo in [[port]]s without shore-based equipment. This gives geared bulkers flexibility in the cargoes they can carry and the routes they can travel. (Photo: A typical geared handysize bulk carrier.)
|- valign="top"
|[[Image:Maya OBO carrier 2.jpg|150px]]
|'''[[Ore-bulk-oil carrier|Combined carriers]]''' are designed to transport both liquid and dry bulk cargoes. If both are carried simultaneously, they are segregated in separate holds and tanks. Combined carriers require special design and are expensive. They were prevalent in the 1970s, but their numbers have dwindled since 1990. (Photo: The oil pipeline and dry bulk hold aboard the ''Maya''.)
|- valign="top"
|[[Image:Berge Athene.jpg|150px]]
|'''Gearless carriers''' are bulkers without cranes or conveyors. These ships depend on the shore-based equipment of the ports they visit for loading and unloading. Due to their large size, they can only dock at the largest and most advanced ports. The use of gearless bulkers avoids the costs of installing, operating, and maintaining cranes. (Photo:''Berge Athen'', a 225,000 ton gearless bulker.)
|- valign="top"
|[[Image:Welland canal john b aird.JPG|150px]]
|'''Self-dischargers''' are bulkers with [[conveyor belt]]s which allow them to discharge their cargo quickly and efficiently. (Photo: The ''John B. Aird'' a self-discharger on the Great Lakes.)
|- valign="top"
|[[Image:SSEdmundFitzgerald.jpg|150px]]
|'''Lakers''' are the bulkers prominent on the [[Great Lakes]], often identifiable by having a forward [[superstructure|house]] which helps in transiting [[Lock (device)|locks]]. Operating in fresh water, these ships suffer much less [[corrosion]] damage and have a much longer lifespan than saltwater ships.<ref name="imo6">International Maritime Organization, 1999:6.</ref> As of 2005, there were 98 lakers of {{DWT|10,000}} or over.<ref>Office of Data and Economic Analysis, 2006:1.</ref> (Photo: [[SS Edmund Fitzgerald|''Edmund Fitzgerald'']], a Great Lakes bulker.)
|- valign="top"
|[[Image:Brosen chl innovator.jpg|150px]]
|'''BIBO''' or '''"Bulk In, Bags Out"''' bulkers are equipped to bag cargo as it is loaded. The ''CHL Innovator'', shown in the photo, is a BIBO bulker. In one hour, this ship can load and package 300 tons of bulk sugar into 50 kg sacks.<ref name="rijeka">{{cite web |url=http://www.lukarijeka.hr/en/Archive/2007/july2007-1.html |title= CHL INNOVATOR |accessdate=2008-05-05 |format= |work=Port of [[Rijeka|Rijeka, Croatia]]}}</ref>
|}
==Fleet characteristics==
[[Image:Number of bulkers graphic.svg|thumb|right|Growth of bulk carrier deadweight tonnage in green and percentage of bulkers to the entire fleet in red, from 1977 to 1999<ref>{{cite book| last=| first=| authorlink=| coauthors=| title=Lloyd's Register World Fleet Statistics Tables| year= 2000| publisher= Lloyd's| location= London| isbn= |url=http://www.lrfairplay.com}}</ref>]]
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.<ref name="unctad0611">UNCTAD 2006, p.11.</ref> Today, the world's bulker 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.<ref name="s1">Office of Data and Economic Analysis, 2006:1.</ref> Including smaller ships, bulkers have a total combined capacity of almost 346 million DWT.<ref name="unctad0621">UNCTAD 2006, p. 21.</ref> Combined carriers are a very small portion of the fleet, representing less than 3% of this capacity.<ref name="unctad0621"/> The bulkers of the [[Great Lakes]], with 98 ships of 3.2 million total DWT, form another small fraction of the total fleet.<ref name="s1"/>
As of 2005, the average bulker was just over 13 years old.<ref name="unctad0623"/> About 41% of all bulkers were less than ten years old, 33% were over twenty years old, and the remaining 27% were between ten and twenty years of age.<ref name="unctad0623">UNCTAD 2006, p. 23.</ref> All of the 98 bulkers registered in the Great Lakes trade are over 20 years old.<ref name="s3">Office of Data and Economic Analysis, 2006:2.</ref>
<br clear="both"/>
[[Image:Oil-tankers-map-with-top-10.svg|thumb|right|Bulk carriers by flag state<ref name="cia05">{{cite web |url=http://www.cia.gov/cia/publications/factbook/ |title=The CIA World Factbook, 2005 |accessdate=2007-04-09 |format= |work=cia.gov }}</ref> [[:commons:Image:Bulkers-flag-state-map-with-top-10.svg|(source data)]]]]
===Flag states===
As of 2005, the [[United States Maritime Administration]] counted 6,225 bulkers of {{DWT|10,000}} or greater worldwide.<ref name="s6">Office of Data and Economic Analysis, 2006:6.</ref> More bulkers are registered in [[Panama]], with 1,703 ships, than any four other [[flag state]]s combined.<ref name="s6"/> 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 [[People's Republic of China|China]] (371).<ref name="s6"/> Panama also dominates bulker registration in terms of [[deadweight tonnage]]. Positions two through five are held by Hong Kong, [[Greece]], Malta, and Cyprus.<ref name="s6"/>
===Largest fleets===
[[Greece]], [[Japan]], and [[China]] are the top three owners of bulk carriers, with 1,326, 1,041, and 979 vessels respectively.<ref name="s4">Office of Data and Economic Analysis, 2006:4.</ref> These three nations account for <!--redundant 3,346 vessels or!--> over 53% of the world's fleet.<ref name="s4"/>
Several companies have large private bulker fleets. The multinational company [[Gearbulk Holding Ltd.]] has over 7 bulkers.<ref>{{cite web |url=http://www.gearbulk.com/company.aspx |title=About Us |accessdate=2008-04-22 |author=Gearbulk |authorlink= |coauthors= |date= |year=2008 |month= |work= |publisher=Gearbulk Holding Limited |pages= |archiveurl= |archivedate= }}</ref> [[The Fednav Group]] in [[Canada]] operates a fleet of over 80 bulkers, including two designed to work in Arctic ice.<ref>{{cite web |url=http://www2.fednav.com/anglais/fleetowned.html |title=Fleet Owned |accessdate=2008-04-21 |author=Fednav Group |year=2007 |work= |publisher=Fednav Group |pages= |archiveurl= |archivedate= }} and {{cite web |url=http://www2.fednav.com/anglais/fleetchartered.html |title=Fleet Chartered |accessdate=2008-04-21 |author=Fednav Group |year=2007 |work= |publisher=Fednav Group |pages= |archiveurl= |archivedate= }}</ref> [[Croatia]]'s [[Atlantska Plovidba d.d.]] has a fleet of 14 bulkers.<ref>{{cite web |url=http://www.atlant.hr/fleet/fleet.html |title=Atlantska Plovidba Fleet |accessdate=2007-04-15 |format= |work=Atlantska Plovidba d.d. Dubrovnik.}}</ref> The [[H. Vogemann Group]] in [[Hamburg, Germany]] operates a fleet of 19 bulkers.<ref>{{cite web |url=http://www.vogemann.de/cms/upload/download_pdf/fleetlist.pdf |title=Fleet List |accessdate=2008-05-01 |author=H. Vogemann Group |date= |year=2007 |month= |work= |publisher=H. Vogemann Group |pages= |archiveurl= |archivedate= }}</ref> [[Portline]] in [[Portugal]], owns 10 bulkers.<ref>{{cite web |url=http://www.portline.pt/ing_frota.htm |title=Portline Frota |accessdate=2007-04-15 |format= |work=PORTLINE Transportes Marítimos Internacionais, S.A.}}</ref> [[Dampskibsselskabet Torm]] in [[Denmark]] and Elcano in [[Spain]] also own notable bulker fleets.<ref>According to [http://web.archive.org/web/20070805004640/http://www.marine-marchande.net/Collection+Le+Mens/ALeMensAlpha.htm description of the main ship-owners], from the French Marine-Marchande website.</ref> Other companies specialize in mini-bulker operations: England's [[Stephenson Clarke Shipping Limited]] owns a fleet of eight mini-bulkers and five small Handysize bulkers,<ref>{{cite web |url=http://www.scsbulk.com/fleet.php |title= Stephenson Clarke Fleet|accessdate=2007-04-15 |format= |work=Stephenson Clarke Shipping Ltd }}</ref> and [[Cornships Management and Agency Inc.]] in [[Turkey]] owns a fleet of seven mini-bulkers.<ref>{{cite web |url=http://www.cornships.com/fleet.htm |title=The Cornships Fleet |accessdate=2007-04-15 |format= |work=Cornships Management & Agency Inc.}}</ref>
===Builders===
Asian companies dominate the construction of bulk carriers. Of the world's 6,225 bulkers, <!--redundant 3,841 or!--> almost 62% were built in Japan<ref name="s5">Office of Data and Economic Analysis, 2006:5.</ref> by shipyards such as [[Oshima Shipbuilding]] and [[Sanoyas Hishino Meisho]].<ref name="SNAME"/> [[South Korea]], with notable shipyards [[Daewoo]] and [[Hyundai Heavy Industries]],<ref name="SNAME"/> ranked second among builders, with 643 ships. The People's Republic of China, with large shipyards such as Dalian, Chengxi, and Shanghai Waigaoqiao, ranked third, with 509 ships.<ref name="s5"/> [[Taiwan]], with shipyards such as [[China Shipbuilding Corporation]],<ref name="SNAME"/> ranked fourth, accounting for 129 ships.<ref name="s5"/> Shipyards in these top four countries built over 82% of the bulkers afloat.<ref name="s5"/>
===Freight charges===
Several factors affect the cost to move a bulk cargo by ship. The bulk freight market is very volatile, and it fluctuates, along with the type of cargo, the ship's size, and the route traveled all affect the final price. Moving a capesize load of coal from [[South America]] to Europe cost anywhere from $15 to $25 per ton in 2005.<ref name="UNCTAD"/> Hauling a panamax-sized load of [[Aggregate (composite)|aggregate materials]] from the [[Gulf of Mexico]] to Japan that year could cost as little as $40 per ton to as much as $70 per ton.<ref name="UNCTAD"/>
Some shippers choose instead to [[Chartering (shipping)|charter]] a ship, paying a daily rate instead of a set price per ton.<ref name="UNCTAD"/> In 2005, the average daily rate for a Handymax ship varied between $18,000{{ndash}}$30,000.<ref name="UNCTAD"/> A Panamax ship could be chartered for $20,000{{ndash}}$50,000 per day, and a Capesize for $40,000{{ndash}}$70,000 per day.<ref name="UNCTAD">UNCTAD 2005.</ref>
===Ship breaking===
Generally, ships are removed from the fleet go through a process known as [[ship breaking]] or scrapping.<ref name="ilo-breaking">{{cite web |url=http://www.ilo.org/public/english/dialogue/sector/papers/shpbreak/index.htm |title=Is there a decent way to break up ships? |accessdate=2007-05-29 |last=Bailey |first=Paul J. |authorlink= |coauthors= |date= |year=2000 |month= |format= |work=Sectoral Activities Programme |publisher=International Labour Organization |pages= |language= |archiveurl= |archivedate= |quote= }}</ref> [[Ship-owner]]s 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.<ref name="mtcp">{{cite book
| author = Maritime Transport Coordination Platform
| authorlink =
| coauthors =
| editor =
| others =
| title = Tonnage Measurement Study
| url = http://ec.europa.eu/transport/maritime/studies/doc/2006_11_tonnage_measurement_study.pdf
| format = pdf
| accessdate = 2007-05-29
| edition =
| series = MTCP Work Package 2.1, Quality and Efficiency
| date =
| year = 2006
| month = November
| publisher =
| location = Bremen/Brussels
| language =
| isbn =
| oclc =
| doi =
| id =
| pages = 3.3
| chapter = 3: The London Tonnage Convention
| chapterurl =
}}</ref> In 1998, almost 700 ships were scrapped in places like [[Alang, India]] and [[Chittagong|Chittagong, Bangladesh]].<ref name="ilo-breaking"/> Half a million deadweight tons of worth of bulk carriers were scrapped in 2004, accounting for 4.7% of the year's scrapping.<ref name="UNCTAD"/> That year, bulkers fetched particularly high scrap prices, between $340 and $350 per LDT.<ref name="UNCTAD"/>
<br clear="both"/>
==Operation==
===Crew===
{| class="wikitable" style="float:right;width:300px;font-size:8pt; margin-left:15px"
|+ Typical bulk carrier crew
| colspan="3" align="center" | '''[[Captain (nautical)|Captain/Master]]'''
|-
! Deck<br />department !! Engine<br />department !! Steward's<br />department
|- valign="top"
|
1 -[[Chief Mate|Chief Officer]]<br />
1 -[[Second Mate|2nd Officer]]<br />
1 -[[Third Mate|3rd Officer]]<br />
1 -[[Boatswain]]<br />
2{{ndash}}6-[[Able Seaman (occupation)|Able Seamen]]<br />
0{{ndash}}2-[[Ordinary Seaman (occupation)|Ord. Seamen]]<br />
|
1 -[[Chief Engineer]]<br />
1 -[[Second Engineer|1st Asst. Engr.]]<br />
1 -[[Third Engineer|2nd Asst. Engr]]<br />
1{{ndash}}2-[[Third Assistant Engineer|3rd Asst. Engr.]]<br />
0{{ndash}}2-[[Qualified Member of the Engine Department|QMED]]/Jr. Engr.<br />
1{{ndash}}3- [[Oiler (occupation)|Oiler]]<br />
0{{ndash}}3-Greaser/s <br />
1{{ndash}}3-Entry-level<br />
|
1-[[Chief Steward]]<br />
1-[[Chief Cook]] <br />
1-[[Steward's Assistant|Stwd's Asst]]<br />
|}The crew on a bulker 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 [[engineering department]], and the [[steward's department]]. The practice of taking [[passenger]]s aboard cargo ships, once almost universal, is very rare today and almost non-existent on bulkers.<ref>Some companies specialize in providing cruises on various kinds of freighters, for example [http://www.freighterworld.com/ Freighter World Cruises].</ref>
During the 1990s, bulkers were involved in an alarming number of [[shipwreck]]s. This led ship-owners to commission a study seeking to explain the effect of various factors on the crew's effectiveness and competence.<ref name="TL">{{cite book
|last= Lane
|first= Tony
|authorlink=
|coauthors=
|title= Bulk Carrier Crews; Competence, Crew composition & Voyage Cycles
|year= 2001
|publisher= Cardiff University
|location=
|isbn= }}</ref> The study showed that crew performance aboard bulk carriers was the lowest of all groups studied.<ref name="TL"/> Among bulker crews, the best performance was found aboard younger and larger ships.<ref name="TL"/> Crews on better-maintained ships performed better, as did crews on ships where fewer languages were spoken.<ref name="TL"/>
Fewer [[deck officer]]s are employed on bulkers than on similarly sized ships of other types.<ref name="TL"/> A mini-bulker carries two to three deck officers, while larger Handysize and Capesize bulkers carry four.<ref name="TL"/> [[LNG carrier|Liquid natural gas tankers]] of the same size have an additional deck officer and [[sailor|unlicensed mariner]].<ref name="TL"/>
===Voyages===
A bulker's voyages are determined by market forces; routes and cargoes often vary. A ship may engage in the grain trade during the [[harvest]] season and later move on to carry other cargoes or work on a different route. Aboard a [[Coastal trading vessel|coastal 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 of mini-bulkers found that it takes, on average, twice as much time to unload a ship as it does to load it.<ref name="TL"/> A mini-bulker spends 55 hours at a time in port, compared to 35 hours for a lumber carrier of similar size.<ref name="TL" /> This time in port increases to 74 hours for Handymax and 120 hours for Panamax vessels.<ref name="TL"/> Compared with the 12-hour turnarounds common for container ships, 15-hour turnarounds for car carriers, and 26-hour turnarounds for large tankers, bulker crews have more opportunities to spend time ashore.<ref name="TL" />
<br clear="both"/>
===Loading and unloading===
Loading and unloading a bulker is time-consuming and dangerous. The process is planned by the ship's [[captain (nautical)|captain]], often with assistance from the [[chief mate]]. International regulations require that the captain and terminal master agree on a detailed plan before operations begin.<ref>{{cite web |url=http://www.imo.org/includes/blastDataOnly.asp/data_id%3D1836/947.pdf |title=MSC Circular 947: Safe Loading and Unloading of Bulk Carriers |accessdate=2007-04-15 |format=PDF |work=International Maritime Organization }}</ref> [[Deck officer]]s and [[stevedore]]s oversee the operations. Occasionally loading errors are made that cause a ship to capsize or break in half at the pier.<ref>George, 2005:245.</ref>
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.<ref name="packard">{{cite book
|last=Packard
|first= William V.
|authorlink=
|coauthors=
|title= Sea-trading
|year= 1985
|publisher= Fairplay Publications
|location=
|isbn= }}</ref>
[[Crane (machine)|Double-articulation cranes]], which can load at a rate of 1,000 tons per hour, represent a widely used method,<ref name="packard"/> and the use of shore-based [[gantry crane]]s, reaching 2,000 tons per hour, is growing.<ref name="packard"/> 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. For modern gantry cranes, the total time of the grab-deposit-return cycle is about 50 seconds.<ref name="SNAME"/>
Conveyor belts offer a very efficient method of loading, with standard loading rates varying between 100 and 700 tons per hour, although the most advanced ports can offer rates of 16,000 tons per hour.<ref name="imo7">International Maritime Organization, 1999:7.</ref><ref name="packard"/> Start-up and shutdown procedures with conveyor belts, though, are complicated and require time to carry out.<ref name="imo7"/> Self-discharging ships use conveyor belts with load rates of around 1,000 tons per hour.<ref name="packard"/>
Once the cargo is discharged, the crew begins to clean the holds. This is particularly important if the next cargo is of a different type.<ref name="halyer5-11">Hayler, 2003:5–11.</ref> 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.<ref name="halyer5-13">Hayler, 2003:5–13.</ref> As the hold is filled, machines such as [[excavator]]s and [[bulldozer]]s are often used to keep the cargo in check. Leveling is particularly important when the hold is only partly full, since cargo is more likely to shift.<ref>George, 2005:341, 344.</ref> Extra precautions are taken, such as adding longitudinal divisions and securing wood atop the cargo.<ref name="un"/> If a hold is full, a technique called tomming is used,<ref name="halyer5-13"/> which involves digging out a {{convert|6|ft|m|0}} hole below the hatch cover and filling it bagged cargo or weights.<ref name="halyer5-13"/>
<center>
{| class="wikitable" style="width:620px;"
|+ A typical bulker offload
|-
|[[Image:Bulldozer loaded on bulk carrier.jpg|120px]] || [[Image:Bulker-unload-sequence-2.jpg|120px]] ||[[Image:Bulker-unload-sequence-3.jpg|120px]]|| [[Image:Bulker-unload-sequence-4.jpg|120px]] || [[Image:Grab unloaded into hopper.jpg|120px]]
|- valign="top"
|'''1.''' A bulldozer is loaded into the hold.||'''2.''' The bulldozer pushes cargo to the center of the hold.||'''3.''' The gantry crane picks up the cargo.||'''4.''' The gantry crane removes the cargo from the ship.||'''5.''' The gantry crane moves the cargo to a bin on the pier.
|-
| colspan="5" align="center" | <font size="-1">''Photos [[:commons:User:Korrigan/Autorisation portpictures.nl|courtesy of Danny Cornelissen]] of [http://www.portpictures.nl portpictures.nl].''</font>
|}
</center>
==Architecture==
<div class="thumb tright">
<div class="thumbinner" style="width:152px;"><div class="thumbcaption" style="text-align:center;">'''Examples of bulker architectural plans'''</div><div class="thumbimage">[[Image:Capesize bulk carrier lines plan.svg|150px|Line plan of a 1990 Capesize ore carrier.]]</div><div class="thumbcaption">Line plan of a 1990 Capesize ore carrier.</div><span style="display: block; height: 2px; font-size: 1px;"> </span>
<div class="thumbimage">[[Image:Bulk carrier midship section en.svg|150px|Line plan of a 1990 Capesize ore carrier.]]</div><div class="thumbcaption">Typical midship section of a bulker with a single hull and double bottom.</div>
</div>
</div>
</div>
A bulk carrier's [[Naval architecture|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.<ref name="SNAME"/>
The overall cargo weight is the limiting factor in the design of an ore carrier, since the cargo is so dense. Coal carriers, on the other hand, are limited by overall volume, since most bulkers can be completely filled with coal before reaching their maximum draft.<ref name="SNAME"/>
For a given tonnage, the second factor which governs the ship's dimensions is the size of the ports and [[waterway]]s it will travel to. For example, a vessel that will pass the Panama Canal will be limited in its [[Beam (nautical)|beam]] and [[Draft (hull)|draft]]. For most designs, the ratio of length-to-width ranges between 5 and 7, with an average of 6.2.<ref name="SNAME"/> The ratio of length-to-height will be between 11 and 12.<ref name="SNAME"/>
===Machinery===
The [[engine room]] on a bulker is usually near the [[stern]], under the [[Superstructure|house]] and above the [[fuel tank]]s. Larger bulkers, from Handymax up, have a [[Two-stroke cycle|two-stroke]] [[diesel engine]] which directly moves a single [[propeller]]. An [[alternator]] is coupled directly with the [[propeller shaft]], and an auxiliary [[generator]] is used.<ref name="SNAME"/> On the smallest bulkers, one or two [[Four-stroke cycle|four-stroke]] diesels are used, and coupled with the propeller via a [[gear box]].<ref name="SNAME"/> The average design ship speed for bulkers of Handysize and above is between 13.5 and {{convert|15|kn|km/h|0}}.<ref name="mand"/> The propeller speed is relatively low, at about 90 revolutions per minute.<ref name="SNAME"/>
As a result of the [[1973 oil crisis]], the [[1979 energy crisis]], and the resulting rise in oil prices, experimental designs using coal to fuel ships were tested in the late 1970s and early 1980s. The Australian company New Lines constructed a 74,700-ton coal-burner called the ''River Boyne''.<ref name="Ewart"/> The ship was marginally effective, and its [[steam engine]] was able to generate a shaft-power of {{convert|19000|hp}}.<ref name="Ewart"/> This strategy gave an interesting advantage to carriers of [[bauxite]] and similar fuel cargoes, but suffered from poor engine yield, maintenance problems, and high initial costs.<ref name="Ewart">{{cite book
|last= Ewart
|first= W.D.
|authorlink=
|coauthors=
|title= Bulk Carriers
|year= 1984
|publisher= Fairplay Publications Ltd,
|location=
|isbn=0-905045-42-4 }}</ref>
===Hatches===
[[Image:Hatch covers on bulk carrier.jpg|left|thumb|The sliding hatchcovers of the ''Zaira.'']]
A hatch or hatchway is the opening at the top of a [[hold (ship)|cargo hold]]. The mechanical devices which allow hatches to be opened and closed are called 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 the holds.<ref name="SNAME"/> To efficiently load and unload cargo, hatches must be large, but large hatches present structural problems. Hull stress is concentrated around the edges of the hatches, and these areas must be reinforced.<ref >International Maritime Organization, 1999:7.</ref> Often, hatch areas are reinforced by locally increasing the scantlings or by adding structural members called stiffeners. Both of 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 than opened and closed.<ref>Hayler, 2003:5–9.</ref> Newer vessels have hydraulic-operated metal hatch covers that can often be operated by one person.<ref>Hayler, 2003:5–11.</ref> Hatch covers can slide forwards, backwards, or to the side, lift up or fold up. It is essential that the hatch covers be watertight: unsealed hatches lead to accidental cargo hold flooding, which has caused many bulkers to sink.<ref name="imo-imp"/>
Regulations regarding hatch covers have evolved since the investigation following the loss of the {{MV|Derbyshire}}.<ref>{{cite conference
| first = David
| last = Byrne
| authorlink =
| coauthors =
| title = Hatch Covers on Bulk Carriers: The Effect on Procurement Costs of Changes in Design Pressure
| booktitle =
| pages =
| publisher =
| month = October
| date = 10
| year=2001
| location = Conférence internationale RINA
| url =
| accessdate =
| id =
}}</ref> 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''<ref name="ur21">International Association of Classification Societies 2007, p. 21-1.</ref> 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.<ref name="ur21"/>
===Hull===
Bulkers are designed to be easy to build and to store cargo efficiently. To facilitate [[ship construction|construction]], bulkers are built with a single hull curvature.<ref name="SNAME"/> Also, while a [[bulbous bow]] allows a ship to move more efficiently through the water, designers lean towards simple vertical bows on larger ships.<ref name="SNAME"/> Full hulls, with large [[block coefficient]]s, are almost universal, and as a result, bulkers are inherently slow.<ref name="SNAME"/> 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.<ref name="SNAME"/> A small Handymax ship can carry five times its weight.<ref name="SNAME"/> In larger designs, this efficiency is even more pronounced: Capesize vessels can carry over eight times their weight.<ref name="SNAME"/>
Bulkers have a cross-section typical of most merchant ships. The upper and lower corners of the hold are used as [[ballast tank]]s, as is the [[double bottom]] area. The corner tanks are reinforced and serve another purpose besides controlling the ship's trim. Designers choose the angle of the corner tanks to be less than that of the [[angle of repose]] of the anticipated cargoes.<ref name="reflets imo"/> This greatly reduces side-to-side movement, or "shifting," of cargo which can endanger the ship.<ref name="reflets imo"/>
The double bottoms are also subject to design constraints. The primary concern is that they be high enough to allow the passage of pipes and cables. These areas must also be roomy enough to allow people safe access to perform surveys and maintenance. On the other hand, concerns of excess weight and wasted volume keep the double bottoms very tight spaces.
Bulker hulls are made of steel, usually [[mild steel]].<ref>George, 2005:221.</ref> Some manufacturers have preferred high-tensile steel recently in order to reduce the tare weight.<ref name="iimo8">International Maritime Organization, 1999:8.</ref> However, the use of high-tensile steel for longitudinal and transverse reinforcements can reduce the hull's rigidity and resistance to corrosion.<ref name="reflets imo"/> Forged steel is used for some ship parts, such as the propeller shaft support.<ref name="SNAME"/> Transverse partitions are made of [[corrugated iron]], reinforced at the bottom and at connections.<ref name="SNAME"/> The construction of bulker hulls using a [[concrete]]-steel sandwich has been investigated.<ref>{{cite journal
| author =
| year = 2005
| month = February
| title = Concrete sandwiches: structural strength and safety for bulk carriers
| journal =The Naval Architect
| issn =
| url =
| accessdate =
| laysummary =
| laysource =
| laydate =
| quote =
}}</ref>
Double hulls have become popular in the past ten years.<ref name="SNAME"/> Designing a vessel with double sides adds primarily to its breadth, since bulkers are already required to have [[double bottom]]s.<ref>{{cite web |url=http://www.imo.org/Safety/mainframe.asp?topic_id=69&doc_id=588 |title=New IMO bulk carrier regulations enter into force on 1 July 1999 |accessdate=2007-04-10 |format= |work=International Maritime Organization}}</ref> 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 [[cargo hold|holds]].<ref>{{cite journal
| author =
| year = 2005
| month = November
| title = NG-Bulk20: a new Turkish double-skin bulker design
| journal =The Naval Architect
| issn =
| url =
| accessdate =
| laysummary =
| laysource =
| laydate =
| quote =
}}</ref> This increases the volume of the holds, and simplifies their structure which helps in loading, unloading, and cleaning.<ref>{{cite web |url=http://www.dnv.com/publications/classification_news/class_news_2003_02/Oshimalooksahead.asp |title=Oshima looks ahead |accessdate=2007-04-15 |author=Det Norske Veritas |authorlink=Det Norske Veritas |coauthors= |date=28 |year=2003 |month=May |format= |work= |publisher= |pages= |language= |archiveurl= |archivedate= |quote= }}</ref> 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.<ref name="hycon">{{cite web |url=http://www.osy.co.jp/en/bc_lineup/hy-con.html |title=Oshima Hy-Con Bulker |accessdate=2007-04-14 |format= |work=Oshima Shipbuilding Co., Ltd.}}</ref> This approach increases the ship's solidity at key points, while reducing the overall tare weight.<ref>{{cite web |url=http://www.osy.co.jp/en/bc_lineup/handymax.html |title="Ultra Handymax" Semi-Double Hull Handymax Bulk Carrier |accessdate=2007-04-10 |format= |work=Oshima Shipbuilding Co., Ltd. }}</ref>
Since the adoption of double hull has been more of an economic than a purely architectural decision, some argue that double-sided ships receive less comprehensive surveys and suffer more from hidden corrosion.<ref>{{cite web |url=http://books.nap.edu/openbook.php?record_id=5798&page=261 |title=Double-Hull Tanker Legislation: An Assessment of the Oil Pollution Act of 1990 (1998) |accessdate=2007-04-10 |format= |work=Marine Board Commission on Engineering and Technical Systems }}</ref> In spite of opposition, double hulls became a requirement for Panamax and Capesize vessels in 2005.<ref>{{cite journal
| author =
| year = 2003
| month = May
| title = Double-skin bulkers: paradise or problem?
| journal =The Naval Architect
| issn =
| url =
| accessdate =
| laysummary =
| laysource =
| laydate =
| quote =
}}</ref>
Freighters are in continual danger of "breaking their back"<ref name="gstruct">George, 2005:217.</ref> 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 [[scantling]]s to manage problems of longitudinal strength and stresses. A ship's hull is composed of individual parts called ''members.''<ref name="gstruct">George, 2005:218.</ref> The set of dimensions of these members is called the ship's scantlings.<ref name="gstruct"/> Naval architects calculate the stresses a ship can be expected to be subjected to, add in safety factors, and then can calculate the required scantlings.<ref name="gstruct"/>
These analyses are conducted when traveling empty, loading and unloading, when partially and fully loaded, and under conditions of temporary overloading.<ref name="SNAME"/> Places subject to the largest stresses are studied carefully, such as hold-bottoms, hatch-covers, bulkheads between holds, and the bottoms of ballast tanks.<ref name="SNAME"/> Great Lakes bulkers also must be designed to withstand [[springing]], or developing [[resonance]] with the [[ocean surface wave|waves]], which can cause [[fatigue (material)|fatigue fractures]].<ref name="imo8"/>
Since [[April 1]], [[2006]], the International Association of Classification Societies has adopted the ''Common Structural Rules.'' The rules apply to bulkers more than 90 meters in length and require that scantlings' calculations take into account items such as the effect of corrosion, the harsh conditions often found in the [[North Atlantic]], and dynamic stresses during loading. The rules also establish margins for corrosion, from 0.5 to 0.9 mm.<ref name="NA 0306">{{cite journal
| year = 2006
| month = March
| title = Implications of commons structural rules
| journal =The Naval Architect
}}</ref>
==Safety==
The 1980s and 1990s were a very unsafe time for bulk carriers. Many bulkers sank during this time, 99 were lost between 1990 and 1997 alone.<ref name="imo1"/> Most of these sinkings were sudden and quick, making it impossible for the crew to escape: more than 650 sailors were lost during this same period.<ref name="imo1"/> Due partly to the sinking of the [[MV Derbyshire|MV ''Derbyshire'']], a series of international safety resolutions regarding bulkers were adopted during the 1990s.<ref name="poster"/>
===Stability problems===
Cargo shifting poses a great danger for bulkers. The problem is even more pronounced with grain cargoes, since grain settles during a voyage and creates extra space between the top of the cargo and the top of the hold.<ref name="un"/> Cargo is then free to move from one side of the ship to the other as the ship rolls. This can cause the ship to list, which, in turn, causes more cargo to shift. This kind of chain reaction can capsize a bulker very quickly.<ref name="un"/>
The 1960 SOLAS Convention sought to control this sort of problem.<ref name="imo2">International Maritime Organization, 1999:2.</ref> 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.<ref >International Maritime Organization, 1999:1,2.</ref> The practice of trimming reduces the amount of the cargo's surface area in contact with air<ref name="imo4">International Maritime Organization, 1999:4.</ref> which has a useful side-effect: reducing the chances of spontaneous combustion in cargoes such as coal, iron, and metal shavings.<ref name="imo4"/>
Another sort of risk that can effect dry cargoes, is absorption of ambient moisture.<ref name="kemp">{{cite book
|last=Kemp
|first= John F.
|authorlink=
|coauthors=
|title= Notes on Cargo Work
|year= 1971
|publisher= Kandy Publications
|edition=3rd
|location=
|isbn= 0853090408 }}</ref> When very fine concretes and aggregates mix with water, the mud created at the bottom of the hold shifts easily and can produce a [[free surface effect]].<ref name="kemp"/> The only way to control these risks is by good ventilation practices and careful monitoring for the presence of water.<ref name="kemp"/>
===Structural problems===
[[Image:Seledang Ayu.jpeg|center|600px|thumb|Diagram showing the wreck of the ''Seledang 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.<ref name="imo5">International Maritime Organization, 1999:5.</ref> 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"<ref name="imo6">International Maritime Organization, 1999:6.</ref> and [[Lloyd's Register of Shipping]] added that the hull sides could not withstand "the combination of local corrosion, fatigue cracking and operational damage."<ref name="imo5"/>
The accident studies showed a clear pattern:<ref name="imo-imp">{{cite web |url=http://www.imo.org/includes/blastDataOnly.asp/data_id%3D6609/BULK.PDF |title=Improving the safety of bulk carriers |accessdate=2007-04-09 |format=PDF |work=International Maritime Organization }}</ref>
# Sea water enters the forward hatch, due to a large wave, a poor seal, corrosion, etc.<ref name="imo-imp"/>
# The extra water weight in hold number one compromises the partition to hold number two,<ref name="imo-imp"/>
# Water enters hold number two and alters the trim so much that more water enters the holds<ref name="imo-imp"/>
# With two holds rapidly filling with water, the bow submerges and the ship quickly sinks, leaving little time for the crew to react.<ref name="imo-imp"/>
Previous practices had required ships to withstand the flooding of a single forward hold, but did not guard against situations where two holds would flood. The case where two after (rear) holds are flooded is no better, because the engine room is quickly flooded, leaving the ship without propulsion. If two holds in the middle of the ship are flooded, the stress on the hull can become so great that the ship snaps in two.
[[Image:Seledang Ayu 2.jpeg|thumb|right|''Seledang Ayu'' suffered a catastrophic fracture in number 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 overestimate of the growth of international trade.<ref name="un"/>
* Corrosion, due to a lack of maintenance, affected the seals of the hatch covers and the strength of the bulkheads which separate holds. The corrosion is difficult to detect due do the immense size of the surfaces involved.<ref>{{cite web |url=http://www.iacs.org.uk/fsa/wp5/main.htm |title=Formal Safety Assessment of Bulk Carriers, Fore-End Watertight Integrity' |accessdate=2007-04-09 |format= |work=International Association of Classification Societies |archiveurl=http://web.archive.org/web/20070206175021/http://www.iacs.org.uk/fsa/wp5/main.htm
|archivedate=2007-02-06 }}</ref><ref name="imo5-6">International Maritime Organization, 1999:5,6.</ref>
* Advanced methods of loading were not foreseen when the ships were designed. These unexpected shocks, over time, can damage the hull's structural integrity.<ref name="imo7">International Maritime Organization, 1999:7.</ref>
* Recent use of high-tensile steel in construction has negative side-effects. This material is prone to corrosion and can develop metal fatigue in choppy seas.<ref name="imo8">International Maritime Organization, 1999:8.</ref>
* According to Lloyd's Register, a principal cause was the attitude of ship-owners, who sent ships with known problems to sea.<ref name="imo7-8">International Maritime Organization, 1999:7,8.</ref>
The new rules adopted in the 1997 annexes to the [[Safety of Life at Sea|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.<ref name="un"/> The 1997 additions also required bulkers with restrictions (for instance, forbidden from carrying certain types of cargoes) to mark their hulls with large, easy-to-see triangles.<ref>{{cite web |url=http://www.eagle.org/regulatory/regupdate/msc71/bulk.html |title=Maritime Safety Committee's 71st Session, May 1999 |accessdate=2007-04-10 |format=PDF |work=American Bureau of Shipping }}</ref>
===Crew safety===
[[Image:Abgang rettungsboot.gif|left|thumb|Launch of a free-fall lifeboat.]]Since December 2004, Panamax and Capesize bulkers have been required to carry free-fall [[Lifeboat (shipboard)|lifeboats]] located on the stern, behind the house.<ref name="un"/> This arrangement allows the crew to abandon ship quickly in case of a catastrophic emergency.<ref>{{cite web |url = http://www.pbs.org/wgbh/nova/escape/pioship.html | title = Pioneers of Survival |accessdate=2007-04-10 |format= |work=NOVA }}</ref> 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.<ref name="lb">{{cite web |url=http://www.maib.gov.uk/cms_resources/Review_of_%20lifeboat_and_launching_systems_accidents.pdf |title=Review of Lifeboat and Launching System Accidents |accessdate=2007-04-10 |format=PDF |work=Marine Accident Investigation Branch }}</ref> Also, injuries have occurred during launches, for example, in the case of incorrectly secured safety belts.<ref name="lb"/>
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 bulkers. This safety measure quickly alerts watch standers on the bridge and in the engine room in case of flooding in the holds.<ref name="un"/> In cases of catastrophic flooding, these detectors could speed the process of abandoning ship. Nevertheless, every two months, somewhere in the worlds ocean's, an average of one bulk carrier goes down with total loss of life.
==See also==
{{nautical portal}}
*[[MV Bright Field|MV ''Bright Field'']]
*[[MV Lake Illawarra|MV ''Lake Illawarra'']]
*[[MV Flare|MV ''Flare'']]
*''[[Sygna]]'' (shipwreck)
*[[SS Edmund Fitzgerald|SS ''Edmund Fitzgerald'']]
==Notes==
{{reflist|2}}
==References==
*{{cite book |author=Autoridad del Canal de Panamá |authorlink=Panama Canal Authority |coauthors= |editor= |others= |title=MR Notice to Shipping Number N-1-2005. |origdate= |origyear= |origmonth= |url=http://www.pancanal.com/eng/maritime/notices/n01-05.pdf |format= |accessdate=2008-04-01 |edition= |series=Notices to Shipping |volume= |date= |year=2005 |month= |publisher=Autoridad del Canal de Panamá |location=Balboa-Ancon |language= |isbn= |oclc= |doi= |id= |pages=pp. 11-12 |chapter= |chapterurl= |quote= }}
*{{cite book
|last= Frankel
|first= Ernst G.
|authorlink=
|coauthors=
|title= Bulk Shipping and Terminal Logistics
|year= 1985
|publisher=
|location=
|isbn= 082130531X
}}
*{{cite book |last=George| first=William |authorlink= |coauthors= |title=Stability and Trim for the Ship's Officer |year= 2005|publisher=Cornell Maritime Press |location=Centreville, MD |isbn=978-0-87033-564-8 }}
* {{cite book |last=Hayler |first=William B. |title=American Merchant Seaman's Manual |year=2003 |publisher= Cornell Maritime Pr |isbn= 0-87033-549-9 }}
*{{cite web
| url = http://www.imo.org/includes/blastDataOnly.asp/data_id%3D7987/BULK99.FIN.pdf
| title = IMO and the safety of bulk carriers
| accessdate=2007-04-09
| author = International Maritime Organization
| authorlink = International Maritime Organization
| year = 1999
| month = September
| format = PDF
| work = Focus on IMO
| publisher =
| pages =
| language =
| archiveurl =
| archivedate =
| quote =
}}
*{{cite book
|last= Isbester
|first= Jack
|authorlink=
|coauthors=
|title= Bulk Carrier Practice
|year= 1993
|publisher=
|location=
|isbn= 1870077164
}}
*{{cite book |author=Lamb, Thomas |title=Ship Design and Construction Vol. I |publisher=Society of Naval Architects and Marine Engineers |location=Jersey City | |year=2003 |pages= |isbn=0-939773-40-6 |oclc= |doi= |accessdate=}}
*{{cite web |author=MAN Diesel Group |title=Propulsion Trends in Bulk Carriers |year=2005 |url=http://www.manbw.com/files/news/filesof5479/5510-0007-00ppr.pdf |accessdate=2007-04-12 |pages=p. 4 |format=PDF |work= MAN Diesel Group}}
*{{cite book |author=International Association of Classification Societies |authorlink=International Association of Classification Societies |editor= |others= |title=Requirements Concerning Strength of Ships |origdate= |origyear= |origmonth= |url=http://www.iacs.org.uk/document/public/Publications/Unified_requirements/PDF/UR_S_pdf158.PDF |format= |accessdate= |accessyear= |accessmonth= |edition= |series=Unified Requirements |volume= |date= |year=2007 |month= |publisher=International Association of Classification Societies |location= |language= |isbn= |oclc= |doi= |id= |pages=p. 21-1 |chapter=21: Evaluation of Scantlings of Hatch Covers and Hatch Coamings of Cargo Holds of Bulk Carriers, Ore Carriers and Combination Carriers (Rev. 4) |chapterurl= |quote= }}
*{{cite web
| url = http://www.marad.dot.gov/MARAD_statistics/2005%20STATISTICS/World%20Merchant%20Fleet%202005.pdf
| title = World Merchant Fleet 2001–2005
| accessdate = March 13
| accessyear = 2007
| author = Office of Data and Economic Analysis
| last =
| first =
| authorlink =
| coauthors =
| date =
| year = 2006
| month = July
| format = PDF
| work =
| publisher = United States Maritime Administration
| pages =
| language =
| archiveurl =
| archivedate =
| quote =
}}
*{{cite book
|last= Thompson
|first= Mark L.
|authorlink=
|coauthors=
|title= Queen of the Lakes
|year= 1994
|publisher=
|location=
|isbn= 0814323936
}}
*{{cite book |author=United Nations Council on Trade and Development (UNCTAD) |authorlinkUnited Nations Council on Trade and Development= |coauthors= |editor= |others= |title=Review of Maritime Transport, 2005 |origdate= |origyear= |origmonth= |url=http://www.unctad.org/Templates/StartPage.asp?intItemID=2614&lang=1 |format= |accessdate= |accessyear= |accessmonth= |edition= |series= |volume= |date= |year=2005 |month= |publisher=United Nations |location=New York and Geneva |language= |isbn= |oclc= |doi= |id= |pages= |chapter= |chapterurl= |quote= }}
*{{cite book |author=United Nations Council on Trade and Development (UNCTAD) |authorlinkUnited Nations Council on Trade and Development= |coauthors= |editor= |others= |title=Review of Maritime Transport, 2006 |origdate= |origyear= |origmonth= |url=http://www.unctad.org/en/docs/rmt2006_en.pdf |format= |accessdate= |accessyear= |accessmonth= |edition= |series= |volume= |date= |year=2006 |month= |publisher=United Nations |location=New York and Geneva |language= |isbn= |oclc= |doi= |id= |pages= |chapter= |chapterurl= |quote= }}
*{{cite book
|last= Zera
|first= Thomas F.
|authorlink=
|coauthors=
|title= Ore-Oil Bulk: Pictorial History of Bulk Shipping Losses of the 1980s
|year= 1996
|publisher=
|location=
|isbn= 0964393778
}}
==External links==
{{commons|bulker}}
*[http://www.oceansatlas.com/unatlas/uses/transportation_telecomm/maritime_trans/shipworld/cargo_car/bulk/bulk_carriers.htm Bulk Carriers @ United Nations Atlas of the Oceans]
*[http://www.ship-photos.de categorized ship photographs]
*[http://www.motorbooks.com/Store/ProductDetails_7997.ncm Super Cargo Ships book]
*[http://www.google.com/maps?f=l&hl=en&q=6%C2%B06%2727%3FS105%C2%B025%273%3FE&near=&ie=UTF8&t=h&om=1&ll=-5.952911,105.914243&spn=0.002316,0.003573 Google Maps Satellite Image] of bulk carrier in Sunda Strait, Indonesia
*[http://www.marin.nl/web/show/id=77616 Bulk Carriers at MRI Netherlands]
*[http://www.t2tanker.org/ships/nashbulk.html Histories of WWII Bulkers]
*[http://shipphoto.exblog.jp shipphoto]
<br clear="both"/>
{{ModernMerchantShipTypes}}
[[Category:Ship types]]
[[Category:Bulk freighters|Bulk freighters]]
{{Link FA|fr}}
[[da:Bulk carrier]]
[[de:Massengutfrachter]]
[[el:Μπαλκ κάριερ]]
[[es:Buque de transporte de carga sólida a granel]]
[[fa:کشتی فلهبر]]
[[fr:Vraquier]]
[[ko:화물선]]
[[it:Porta rinfuse]]
[[he:אוניית צובר]]
[[lv:Balkeris]]
[[nl:Bulkcarrier]]
[[no:Tørrlasteskip]]
[[pl:Masowiec]]
[[ru:Балкер]]
[[fi:Irtolastialus]]
[[sv:Bulkfartyg]]