# Question on Stowage Factor and Ballast Arrangements

Hey Folks,

Recently ventured into the shipping industry, so please excuse my rudimentary questions:

1. Can anyone explain / give a rough overview of how carrying different types of ores in different holds of a single general purpose bulk carrier will affect ballast arrangements? (e.g. some holds carrying Iron Ore. others carrying coal).

and

1. Also, Is it right to say that the higher the stowage factor, the more space is needed to store 1 metric tonne of a cargo. As such, if coal’s Storage Factor is 1.40 and iron ore’s is 0.40 m3/MT, for every tonne of coal placed into a hold, I could actually have 3.5 Tonnnes of Iron Ore?

and

1. Also, what does having a “strengthened bulkhead” have to do with allowing a vessel to carry a much wider range of bulk cargoes?

[QUOTE=Imperium;148019]Hey Folks,

Recently ventured into the shipping industry, so please excuse my rudimentary questions:

1. Can anyone explain / give a rough overview of how carrying different types of ores in different holds of a single general purpose bulk carrier will affect ballast arrangements? (e.g. some holds carrying Iron Ore. others carrying coal).

and

1. Also, Is it right to say that the higher the stowage factor, the more space is needed to store 1 metric tonne of a cargo. As such, if coal’s Storage Factor is 1.40 and iron ore’s is 0.40 m3/MT, for every tonne of coal placed into a hold, I could actually have 3.5 Tonnnes of Iron Ore?

and

1. Also, what does having a “strengthened bulkhead” have to do with allowing a vessel to carry a much wider range of bulk cargoes?

1. Don’t know, I would think hull stress might be an issue.

2.Given those SF numbers 1 ton of coal would take up the same cubic metes as 3.5 tons of Ore. Basically it’s the reciprocal of density.

1. Don’t know.

an ore strengthened bulk carrier will be classed as such, where alternate holds may be left empty to raise the center of gravity of the heavy ore cargo due to the low angle of repose (less then 35 degrees), as to improve the stability of the vessel at sea and give a level trim, where steep angles could be unsafe and cause the cargo to shift with sudden force, IMO has specific guidelines for loading iron ores in the IMBC code as well as the IMO BLU (bulk loading guide) which are available for purchase in print and digital in the IMO’s online bookstore

iron ore your talking 15-20 cuft/lt where as coal 41-44 cut/lt depending on grade, green delayed petcoke is 46-48’ cuft/lt coking coal 50-55 cuft/lt, where wheat may be 42.5-45 cut/lt, corn 49-51 cuft/lt, HSS 48cuft/lt

conversion m3/mt to cuft/lt is one m3/mt is equal to 35.87 cuft/lt, often shippers give stowage factors on cuft/mt which is not correct, but only a slight adjustment

so yes, heavier and more dense the cargo, the less space utilized which is a ‘deadweight cargo’ so would typically load to load line marks and/or disport, or load port draft, where a lighter cargo like soft grains may “cube out” where all available cubic capacity has been utilized, or the perfect case of a “full and down” vessel would be all cubics and load line draft utilized

you should always refer the the vessels classification and statutory cargo certificates when planning a lift, as well as the IMBC code and the vessels load line certificates and loadlines zones the vessel will transit on her voyage

as for ballast arrangements, that would depend on the vessel, trim and stability, draft loading to, etc…thats a technical issue specific to the vessel, but sure, with alternate holds empty, even with iron ore, she may have some aft or forepeak, wing tanks or double bottoms requiring ballasting, the ships stability books/program would guide the mate in planning ballast required

hope this helps