cargo handling (prelim) Flashcards
primary aim of this Code is to promote the safe stowage
and shipment of Bulk Cargoes by:
Highlighting the dangers associated with the shipment of
certain types of bulk cargoes.
Giving quidance on the procedures to be adopted when the
shipment of bulk cargoes is contemplated.
Listing typical materials currently shipped in bulk together
with advice on their properties and handling.
Describing test procedures to be employed to determine
various characteristics of the bulk cargo materials.
BC Code
The hazards associated with the shipment of materials may be
considered as falling into the following categories:
Damage
Stability
Reactions
Structural damage due to improper distribution of the cargo.
Damage
Loss or reduction of stability during a voyage due to shifting of cargo.
Stability
Chemical reactions such as production of flammable gases, toxic
gases or self-heating.
Reactions
This is the maximum slope of free-flowing granular
material. It is the angle between a horizontal plane
and the cone slope of such material.
Angle of repose
These are materials which contain at least some fine
particles and some moisture, usually water, although
they need not be visibly wet in appearance. if shipped with a moisture content in excess of their transportable moisture limit.
Cargoes which may liquefy
This is the percentage moisture content at which a flow
state develops under the prescribed method of test.
Flow moisture point
This is the state that occurs when a mass of granular
material is saturated with liquid to an extent that,
under the influence of prevailing external forces such
as ships motion it starts to behave as a liquid.
Flow state
This is the portion of a sample consisting of water,
ice or other liquid expressed as a percentage of the
total wet mass of that sample.
Moisture content
is the movement of moisture contained in materials by settling and consolidation of the material due TO vibration and ship’s motion. Water is progressively displaced, which may result in
some portions or all of the materials developing a flow state.
Moisture Migration
This is the factor which expresses the number of cubic
metes which one tonne of material will occupy:
stowage factor
This represents the maximum moisture content of the
material which is considered safe for carriage in ships
which are not specially designed for the purpose.
Transportable moisture limit
The master must be provided with information about the material to be shipped,
e.g. stowage factor, history of
shifting or any particular problems.
The hull of the vessel can be over-stressed if the cargo
is not well distributed throughout the cargo spaces.
This can either be:
sag or hog
_ on board a vessel
shows the maximum allowable weight
that can be carried in each cargo hold
and the maximum loading on the tank
top expressed in tonnes per square
metre.
capacity plan
should not be stowed to an
excessive height against bulkheads otherwise
the bulkhead may be over-stressed and the tank
top overloaded in part of the hold.
High density cargo
Most bulk carriers when carrying a high-density
cargo have a very large _
This makes the vessel excessively stiff with a
very fast roll.
metacentric height (GM).
can produce large racking
stresses which can result in structural damage.
rapid roll period
should be in good order and
special care may be required to protect cargo space fittings
from damage. It is prudent to _ after completion
of loading.
Air pipes and sounding pipes must be protected form cargo damage.
All bilge lines and sounding lines. “sound bilge”
Advice on medical matters is given in the _ for use in accidents involving Dangerous
Goods.
IMO Medical
First Aid Guide
(metal from drilling and machining industries)
rapidly uses up oxygen in the cargo space.
Steel swarf
Certain bulk cargoes are liable to react with oxygen
which may result in oxygen reduction, emission of toxic
fumes and self-heating. Others may emit toxic fumes,
particularly when wet.
These cargoes include:
Grains
Timber and forest products
Ferrous metals
Metal sulphide concentrates
Coal cargoes
Testing and sampling of stockpiles of bulk cargoes, must be done to test for moisture content,
and is given in detail in the code; the main points are that:
- The samples taken must be from a wide area of the cargo stock pile
- Samples must be taken from approximately 50 cm below the surface of the cargo pile.
- Testing for moisture content must be done not more than 7 days prior to loading.
- Competent persons must do all testing.
