Safety Bulk carrier

1 safety

1.1 stability problems
1.2 structural problems
1.3 crew safety

safety

the 1980s , 1990s unsafe time bulk carriers. many bulkers sank during time, 99 lost between 1990 , 1997 alone. of these sinkings sudden , quick, making impossible crew escape: more 650 sailors lost during same period. due partly sinking of mv derbyshire, series of international safety resolutions regarding bulkers adopted during 1990s.

stability problems

cargo shifting poses great danger bulkers. problem more pronounced grain cargoes, since grain settles during voyage , creates space between top of cargo , top of hold. cargo free move 1 side of ship other ship rolls. can cause ship list, which, in turn, causes more cargo shift. kind of chain reaction can capsize bulker quickly.

the 1960 solas convention sought control sort of problem. these regulations required upper ballast tanks designed in manner prevent shifting. required cargoes leveled, or trimmed, using excavators in holds. practice of trimming reduces amount of cargo s surface area in contact air has useful side-effect: reducing chances of spontaneous combustion in cargoes such coal, iron, , metal shavings.

another sort of risk can affect dry cargoes, absorption of ambient moisture. when fine concretes , aggregates mix water, mud created @ bottom of hold shifts , can produce free surface effect. way control these risks ventilation practices , careful monitoring presence of water.

structural problems

diagram showing wreck of selendang ayu, , double-bottom tank leaks.

in 1990 alone, 20 bulk carriers sank, taking them 94 crewmen. in 1991, 24 bulkers sank, killing 154. level of loss focused attention on safety aspects of bulk carriers, , great deal learned. american bureau of shipping concluded losses directly traceable failure of cargo hold structure , lloyd s register of shipping added hull sides not withstand combination of local corrosion, fatigue cracking , operational damage.

the accident studies showed clear pattern:

previous practices had required ships withstand flooding of single forward hold, did not guard against situations 2 holds flood. case 2 after (rear) holds flooded no better, because engine room flooded, leaving ship without propulsion. if 2 holds in middle of ship flooded, stress on hull can become great ship snaps in two.

selendang ayu suffered catastrophic fracture in number 4 hold in december 2004.

other contributing factors identified:

most shipwrecks involved ships on 20 years in age. glut of ships of age occurred in 1980s, caused overestimate of growth of international trade. rather replace them prematurely, shipping companies compelled on cost grounds keep aging vessels in service.
corrosion, due lack of maintenance, affected seals of hatch covers , strength of bulkheads separate holds. corrosion difficult detect due immense size of surfaces involved.
advanced methods of loading not foreseen when ships designed. while new processes more efficient, loading more difficult control (it can take on hour halt operation), resulting in overloading ship. these unexpected shocks, on time, can damage hull s structural integrity.
recent use of high-tensile steel allows building structure less material , weight while retaining similar strength. however, because thinner regular steel, ht steel can corrode more easily, plus can develop metal fatigue in choppy seas.
according lloyd s register, principal cause of sinkings attitude of ship-owners, sent ships known problems sea.

the new rules adopted in 1997 annexes solas convention focused on problems such reinforcing bulkheads , longitudinal frame, more stringent inspections (with particular focus on corrosion) , routine in-port inspections. 1997 additions required bulkers restrictions (for instance, forbidden carrying types of cargoes) mark hulls large, easy-to-see triangles.

crew safety

launch of free-fall lifeboat.

since december 2004, panamax , capesize bulkers have been required carry free-fall lifeboats located on stern, behind deckhouse. arrangement allows crew abandon ship in case of catastrophic emergency. 1 argument against use of free-fall lifeboats evacuees require degree of physical mobility, fitness enter , launch boat. also, injuries have occurred during launches, example, in case of incorrectly secured safety belts.

in december 2002, chapter xii of solas convention amended require installation of high-level water alarms , monitoring systems on bulkers. safety measure alerts watch standers on bridge , in engine room in case of flooding in holds. in cases of catastrophic flooding, these detectors speed process of abandoning ship.