Quality determinants of solid bulk cargoes in marine transport

Transkrypt

Scientific Journals
Zeszyty Naukowe
Maritime University of Szczecin
Akademia Morska w Szczecinie
2011, 26(98) pp. 66–74
2011, 26(98) s. 66–74
Determinanty jakości stałych ładunków masowych
w przewozach morskich
Ruta Leśmian-Kordas, Milena Bojanowska
Maritime University of Szczecin, Faculty of Economics and Transport Engineering
Institute of Transport Engineering, Department of Commodities Science and Quality Management
Akademia Morska w Szczecinie, Wydział Inżynieryjno-Ekonomiczny Transportu
Instytut Inżynierii Transportu, Zakład Towaroznawstwa i Zarządzania Jakością
70-507 Szczecin, ul. H. Pobożnego 11, e-mail: [email protected]
Key words: solid bulk cargoes/loads, quality determinants, marine transport/shipping, BC/IMSBC Code
Abstract
The paper deals with the most essential trends and types of changes in the last three editions (2001–2005–
2009) of BC/IMSBC Code concerning the shipment of specific group of loads such as solid bulk cargoes.
Since the general trend of changes in the content layout has been proved advantageous due to its standardized
information in relation to all types of hazardous cargoes (A, B, C groups), its continuation aimed at
facilitating the use of the Code in shipping operation is justified. Examples of detailed as well as extended
information concerning technological shipping quality determinants of solid bulk cargoes enabling a better
choice of appropriate technology of marine transport have been presented. The essence of information
relationships resulting from the knowledge of particular quality determinants with the possibility of their
practical technological application has been pointed out.
Słowa kluczowe: stałe ładunki masowe, determinanty jakości, przewóz morski, Kodeks BC/IMSBC
Abstrakt
W artykule przedstawiono najważniejsze kierunki i rodzaje zmian w trzech ostatnich wydaniach Kodeksu
BC/IMSBC (2001–2005–2009), dotyczącego przewozu morskiego bardzo specyficznej grupy ładunków,
mianowicie stałych ładunków masowych. Stwierdzono, że przy generalnie korzystnym kierunku zmian co do
układu treści, ujednolicającym formę przekazu informacyjnego w odniesieniu do wszystkich ładunków,
tj. stwarzających różnorodne zagrożenia (grupy A, B i C), uzasadnione jest ich kontynuowanie, celem ułatwienia wykorzystania Kodeksu w praktyce transportowej. Podano przykłady uszczegółowień i rozbudowy
informacji w zakresie determinantów jakości technologiczno-transportowej ładunków sypkich przewożonych
luzem, pozwalających na zwiększenie stopnia zapewnienia wyboru i zastosowania prawidłowych technologii
przewozu morskiego. Wykazano istotę powiązań informacyjnych, wynikających ze znajomości określonych
determinantów jakości z możliwością ich praktycznego, technologicznego wykorzystania.
Introduction
port in international turnover, estimated at 80% [1].
In relation to the 70s of the previous century, the
quantity of the dry cargo transported annually by
bulk carriers, considered the most significant for
world trade: iron ore, coal, bauxite, phosphates and
apatite, grains increased fourfold, reaching the
amount of 1,876 million tons in 2006 [1]. The fleet
of bulk carriers in the world increased from 186
million DWT recorded in 1980 to 276 million
DWT in 2000. The last decade turned out to be the
Over the last three decades the increase of
shipped commodities has been steadily rising by
approximately 3% per year. The growing demand
for marine transport is determined mainly by
increase of world exploitation of raw materials,
cultivation of cereal and the relation between trade
volume and fleet size. Directly stimulating, the role
of trade is linked to participation in maritime trans66
Scientific Journals 26(98)
period of the most dynamic growth in tonnage to
handle bulk cargoes by sea, the total capacity of
bulk carriers has risen by a further 209 million
DWT. Currently, the global fleet, specialized in
handling bulk, amounts to 8118 units, a total tonnage of 486 million DWT [2].
The global backlog of orders for new merchant
ships at the end of 2000 reached 99 million DWT,
with the largest share of oil tankers, bulk carriers
and container ships [3]. The order portfolio of 2010
was dominated by bulk orders (340 units), representing more than 60% of the total number of ships
ordered [2], whereas for years the combined fleet
of bulk carriers: (OB) oil-bulk carriers and (OBO)
ore-bulk-oil carriers has been declining.
With the development of international trade in
solid bulk goods by sea, not only their diversity has
increased, but there are also new loads, representing
a variety of goods that have been shipped for years,
with very different physical and chemical properties. Changing technologies of production of many
bulk commodities alter the characteristics essential
for their safe transport, which is reflected in sustained development of transport regulations and
requirements, by specifying, modifying and integrating the latest results of theoretical and practical
research.
ment (gas, liquid vapor, dust, solid particles
which constitute the previous load) or a direct
adverse impact on the environment, which in the
case of goods classified as hazardous, become
a threat to the health and life of the crew as well
as to the property located on the ship and to the
cargo itself.
The listed properties are conditioned above all
by: chemical composition, water content, degree of
fragmentation, specific cohesion of the particles,
flow rate, mass density, the presence of dust and the
form of solid bulk material shaped by additional
processing (pellets, granules, blocks, meal, grits,
powders, beads, nodules). These characteristics are
usually the most important criterion for differentiating the transport requirements in relation to goods
falling under the common name of Bulk Cargo
Shipping Name – BCSN [4].
IMSBC Code
The need to develop precise rules concerning
bulk shipment in marine transport was first presented in 1960 at the International Conference on
Safety of Life at Sea (SOLAS), which resulted in
the development and adoption of the first edition of
Code of Safe Practice for Solid Bulk Cargoes – BC
Code in 1965 under the auspices of IMCO. So far
there have been a total of 13 improved and revised
editions of the BC Code. The last amendment,
adopted due to the Resolution MSC. 268 (85) from
4th December 2008, changed both the name and
status of the Code, which was replaced by the International Maritime Code for Solid Bulk Cargoes
(IMSBC Code). In accordance with amendments to
Chapter VI and VII of the SOLAS Convention,
contained in resolution MSC.269 (85), from July
2008, the IMSBC Code could be applied as binding
on a voluntary basis, but since January 2011 the
document has been mandatory. In Poland, after
a series of accidents at sea, the BC Code was introduced under the Regulation of the Minister of
Foreign Trade and Maritime Economy as binding
as early as in 1974. The final act in the national
legislation to follow the recommendations and
requirements contained in the BC Code, is the
Infrastructure Minister’s Regulation of 31 January
2003 on the safe transport of bulk cargo by sea-going vessels.
The main purpose of the IMSBC Code is to enhance safe carriage of solid bulk cargoes by administering: essential rules of conduct during loading
and unloading, trimming and sorting methods, procedures in case of emergency situations (fires and
spills) and special ones, which reveal the diverse
properties of the cargo, including dangerous ones.
Properties of solid bulk cargoes essential
in the marine transport
Solid bulk cargoes increasingly regarded as
a distinct state of matter, with their characteristics
different from other solids and in some respects
similar to fluids, exhibit many features which are
important in marine transport. These include among
others:
 the capacity of transverse shift of non-cohesive
bulk cargo (plastic flow) to side of the ship during maritime transport, leading to the loss of
vessel stability;
 the susceptibility to consolidation and subsidence during carriage by sea, resulting in increase in the free space above the surface of the
load and generating the possibility of shifting
even in the case of complete filling of the hold;
 different, often less than the vessel stowage
factor (SFS), load stowage factor (SFL), causing
the risk of overloading the vessel's structure by
allowing excessive amounts of heavy cargo;
 the susceptibility to liquefy of the wet cargo
associated with the increase in water pressure
between the lateral shift of the cargo to side, and
resulting in loss of stability;
 the possibility of the load chemicals reacting
with other substances contained in the environZeszyty Naukowe 26(98)
67
The issues raised in the Code also apply to sampling and methodology of determining the most
important, in terms of transport, safety, physical
and physical-chemical features of cargoes, transport
of solid waste harmful to humans and the marine
environment, the scope and methods of monitoring
the atmosphere in the holds and the conditions
of the crew entering the ship's enclosed spaces.
The Code sets out general procedures for proceedings before the formal adoption of the cargo to be
complied with by both the shipper and the Master
of the ship.
Threats on the part of transported cargo were
divided into three groups, corresponding successively to liquefy of the cargo containing moisture
(A), chemical hazards posed by group (B) and
transverse shift to side of the ship of dry cargo (C).
Dangerous solid cargo in bulk, with a broad spectrum of properties, are a group of special cargo,
identified with a number of other recommendations
in a variety of IMO documents, including Chapter
VII of the SOLAS Convention. In accordance with
Part A-1 of Chapter VII of the SOLAS Convention,
the “dangerous” bulk cargo shall be: “any material,
other than a liquid or gas, consisting of a combination of particles, granules or other larger pieces of
material, generally uniform in composition, which
is covered by the IMDG Code1 and is loaded
directly into the cargo spaces of the ship without
any intermediate form of containment, and includes
such materials loaded in a barge on a barge-carrying ship” [5].
Although in the SOLAS Convention the definition of dangerous cargoes does not invoke the concept of MHB (Materials Hazardous Only in Bulk),
they are defined in section 9 of the IMSBC Code:
Materials possessing chemical hazards.
3) changes in terminology, the refinement of concepts and terms used, attachment of explanations;
4) refining the criteria for eligibility of goods under
the common name BCSN to different subgroups
of other transport requirements and establishing
new subgroups;
5) refining and extending the information about the
properties of cargo and transport requirements
for invidual loads;
6) changes resulting from attempts to harmonize
rules concerning maritime cargo transport
with the provisions for other modes of transport,
in particular to standardize the naming of cargo
and the corresponding UN numbers.
Examples of updates listed in the above points
made over the past ten years, including three subsequent editions of the Code (2001, 2005, 2009)
[4, 6, 7] are shown in table 1.
They show considerable development and elaboration of requirements, especially for cargo posing
threats other than chemical. The tendency is also
visible to single out subsets of cargo and accurate
determination of the criteria for membership by
identifying the areas of chemical composition,
water content, cargo form and particle size. As substantial change there should be regarded the clarification of terms relating to compulsory and voluntary requirements, preventing the misinterpretation
of the rules. Another trend is the attempt to standardize the wording and application of specific
patterns such as consistently “this cargo shall not be
ventilated,” rather than those used in previous editions, the ambiguous “do not ventilate” or “should
not be ventilated.”
Changes in the requirements for cargoes
susceptible to liquefy (group A)
Changes in the Code of BC / IMSBC in
relation to the risks posed by cargoes
An example of cargo posing different threats
depending on the water content is ilmenite (titanium ore, ranging from yellow to brown, containing
about 45% titanium oxide), which in the latest edition of the Code appears as follows:
The procedure of updating successive versions
of the BC / IMSBC Code by the initiative of IMO
member states covers the amendment concerning
both form and content, within which there can be
distinguished:
1) content rearrangement (the order of chapters, the
layout of content particulars relating to the
cargo, and singling out separate additions);
2) addition of new paragraphs and chapters, which
extend the areas covered by the Code;
1
 ILMENITE CLAY: containing 10–20% of water, belongs to group (A) of cargoes susceptible
to liquefy;
 ILMENITE SAND: not classified as cohesive,
but qualified for the risk group C, because of its
high density, and only when the water content
is within 1–2%. When the water content > 2%
it is treated as a cargo susceptible to liquefy
and subject to similar transport requirements as
ilmenite CLAY (group A).
International Maritime Dangerous Goods Code, IMDG
Code – concerning the carriage of dangerous goods in
packages.
68
Table 1. Selected changes in the structure and general content of three consecutive editions of the BC / IMSBC Code [own study]
Tabela 1. Wybrane zmiany w układzie i treści ogólnej trzech kolejnych wydań Kodeksu BC/IMSBC [opracowanie własne]
Change in BC 2005 relative to 2001 BC
Change in IMSBC 2009 relative to 2005 BC
Appendices A, B, C, containing a summary table of loads
(groups A and C) and individual cards (group B) have been
replaced by individual cards for all goods covered by the Code,
and arranged alphabetically in a single Appendix 1, with indicating the risk group.
Appendices 4–8 dealing respectively with: the bulk density measurement methods, loads with a limited requirement for a fixed
gas fire-extinguishing system, the procedures for entering enclosed spaces on the ship and the use of pesticides have been
transferred to the Supplement (BLU Manual)1.
Appendices, previously identified with consecutive letters of
the alphabet, have been numbered.
A separate chapter – „Definitions‟ has been opted out with its
contents placed in Chapter 1 – „General Provisions‟; a part of the
SOLAS Convention, namely Chapter VI (Part A and B) and VII
(Part A-1) have also been cited in this chapter.
Non-cohesive cargo list has been moved into a new Appendix 3
(Properties of solid bulk cargoes).
New Appendices on: (1) list of solid bulk cargo, for which
there is no requirement for a fixed gas fire-extinguishing system (typically CO2) or for which the fire fighting system will
not be effective and (2) recommendations on the safe use of
pesticides in ships have been placed.
A new Chapter 12 has been introduced - expressing in tabular
form specified in the Code references to the other requirements
of the IMO (SOLAS, IMDG Code, FSS Code1 and others).
The terms static angle of repose and dynamic natural angle of
repose have been replaced by angle of repose, indicating in the
definition that it refers to non-cohesive cargoes.
There has been placed a new chapter (Chapter 11), relating to
hazards resulting from terrorist actions, which may be aggravated
by the direct use of the transported bulk cargo of dangerous properties, or as a result of the impact of weapons on the cargo.
Examples of such loads are: ammonium nitrate UN 1942 (Class
5.1) and ammonium nitrate fertilizers containing UN 2067.
Due to the obligatory nature of the Code, the significance of the
following words in the text of the Code has been specified as:
Shall – mandatory
Should – recommendatory,
May – optional.
In the latest edition of the Code, the requirements for carriage of ilmenite clay were significantly expanded. The requirement to determine
the moisture content in the cargo before taking
on-board to ensure that the TML2 is not exceeded,
was supplemented by the need to maintain the
moisture content of the load at its baseline levels
throughout the duration of the voyage. The possibility of loading during rainfall was restricted to
exceptional circumstances, when the moisture content of the load is low enough not to cause the risk
of its growth to a value close to TML. Discharging
during precipitation was determined as possible on
the condition that the total amount of cargo is
unloaded in the port. The requirement to survey the
surface appearance of the cargo during carriage was
added with indication that in case of the presence of
free water on the surface or the surface condition in
the form of fluid, the captain is obliged to take appropriate measures to prevent the shift of cargo and
loss of vessel stability. Undoubtedly, the requirements became stricter due to incidents of accidents,
including numerous cases of liquefy of the loads of
ilmenite. In November 2000, the M/V Maria VG,
carrying 2.662 tones of ilmenite in the form of clay,
from the port Tahkoluoto (Finland) to Slite (Sweden), had a dangerous heel on starboard beam of
2
20 as a result of liquefy of cargo, which contained
moisture in amounts well above the TML set for
this material part (38.9–46.5% vs. TML = 22.7%).
In a report on the causes of the incident the important role of reducing external sources of additional
moisture was highlighted. The cargo, before loading, was stored for 5 days in the open air, during
which heavy rainfall occurred [8].
For a better understanding of the phenomenon
of liquefy, only for cargoes of specified degree
of fineness and moisture content, starting from the
2005 edition of the BC Code, Chapter 7 presents
an overview of the phenomenon and the reasons
for the importance of interdependence between
the degree of fragmentation and the water content
in the process. It was noted that there is a threat
of liquefy of the loads in group A also when they
are cohesive and trimmed in accordance with
the recommendations of the Code. There were
distinguished three phases of liquefy:
1) decrease in the volume between the particles, as
a result of subsidence, and consolidation of
cargo during movement of the ship;
2) increase in pressure of water contained in the
cargo, due to the decreasing volume between the
particles;
3) decrease in the coefficient of friction between
particles, due to the increase in water pressure,
resulting in decrease in shear strength.
TML – Transportable Moisture Limit
Zeszyty Naukowe 26(98)
69
According to the BC / IMSBC Code [4, 5],
liquefy refers neither to loads of very small particles (dust) as strong cohesion between such particles prevents them from moving and thereby
increase the water pressure, nor cargo in the form
of larger particles, between which water moves
without an increase in pressure.
name but different carriage conditions is due to
their different characteristics:
 chemical (e.g., content of hazardous component
and organic pollutants in nitrogen fertilizers
based on ammonium nitrate);
 physical (e.g., the degree of fragmentation, or its
form as in the case of sulphur);
 set of physical, chemical and physical-chemical
properties, due to different production technologies (e.g., water and fat content depending on
the de-oiling process and to a certain degree on
plants species the oil-cake is obtained from, particle size and methods of preparation in the case
of directly reduced iron).
possessing chemical hazards (group B)
One of the factors to ensure the safe carriage
of goods that can be dangerous for their chemical
hazards is the correct classification of transported
cargoes. The use of cargo divisions with a common
Table 2. Selected changes in the detailed content of the cargoes contained in three consecutive editions of the BC/IMSBC Code
[own study]
Tabela 2. Wybrane zmiany w treści szczegółowej dotyczącej ładunków, zawartej w trzech kolejnych wydaniach Kodeksu
BC/IMSBC [opracowanie własne]
Change in BC 2005 relative to 2001 BC
Change in IMSBC 2009 relative to 2005 BC
For all loads the range of basic information on: the particle size, form (granules, beads, lumps, powders, etc.) and
bulk density has been expanded and standardized.
In case the specified feature is not translated into safety
(e.g. particle size, angle of repose) or does not apply – the
single phrase “not applicable” has been adopted.
Previously, these properties were given selectively or
generally for a large group of similar cargoes.
Verbal description of the properties (water content, total fat content) of
cargoes under the common name SEED CAKE has been supplemented
with a graphic representation of these characteristics and their scope in
order to avoid erroneous interpretation and correct classification of the
cargo to a group of UN 1386 (a) or UN 1386 (b).
A number of detailed features have been described due to
defining ranges of values for specific cargoes, which
allowed separate cards for each of them.
For example, given in the 2001 edition of the stowage
factor (SF) based on all ores and concentrates was 0.33–
0.57 m3/t. In the 2005 edition, its value was specified for
each of the loads from the group.
Both ilmenite SAND and ilmenite CLAY are very heavy
loads, but their range of stowage factors is completely
different and is suitably SF = 0.31–0.42 m3/t (Sand) and
SF = 0.4–0.5 m3/t (Clay).
Water content range for a load of ilmenite SAND has been supplemented with > 2%, qualifying it as a hazard of liquefy, that is, belonging to group A.
In the previous classification, the extent of ilmenite SAND includes
the water content of 1–2% (group C), while ilmenite CLAY 10–20%
(group A).
Currently, ilmenite SAND may belong to a risk group C or A.
Other relevant information and a set of additional properties for multiple loads have been added. For example, with
respect to ilmenite CLAY its water content was determined, the ability to pollination, non-flammability and
high density indicated.
In addition to loads of sulphur SULPHUR UN 1350 (Class 4.1, Group
B), a new tab for sulphur SULPHUR (former, solid) was created and
classified into risk group C.
There have been created separate cards for loads of ilmenite SAND and ilmenite CLAY, taking into account other
hazards (C or A), due to their different content of water.
In addition to the existing DRI cargo cards: DIRECT REDUCED
IRON (Briquettes, hot-moulded) and DIRECT REDUCED IRON
(lumps, pellets, cold-moulded briquettes), there has been created a new,
card for DRI (By-product Fines).
The creation of individual cards for all cargoes (also from
groups A and C), has increased the amount of information
concerning the individual loads, and thus the details of the
transport requirements, particularly in relation to goods of
non-hazardous chemical (B).
For example, for ilmenite CLAY there have been developed requirements for safety precautions when loading in
conjunction with very low SF.
Transport requirements for cement have been extended by more detailed information about the trimming of the cargo, and attention has
been drawn to its characteristics (form of fluid, a variable angle of
repose, subsidence, dusting), especially important if the ship is not
designed for transporting cement.
Requirements for the cargo of ILMENITE CLAY concerning precautions when loading at the time of rainfall have been extended, and the
scope of the compulsory care of cargo during transport in order to avoid
liquefy of the load has been increased.
70
Oil cake and meal, which are residues of mechanically expelling or extracting oil seeds, belong
to a group of self-heating loads (Class 4.2, Group
B), at the specified water content and residual fat.
These properties, in addition to production technology, are essential to distinguish four subgroups of
cargo, including three dangerous ones (UN 1386,
UN 1386 b, UN 2217) and a non-hazardous one.
Within the subgroup classified as hazardous, there
are also exemptions from the sharpened transport
requirements for specific commodities (plant species) as well as load form. A seemingly insignificant change in the descriptions of the cargo SEED
CAKE UN 1386 (a) and SEED CAKE UN 1386
(b), definitely facilitates the correct classification of
loads into one of these groups. The record repeated
in subsequent editions of the Code, for UN 1386
(b), reads as follows: “solvent extractions and expelled seeds, containing NOT MORE than 10% of
oil AND, when the amount of moisture is 10%
higher than, not more than 20% of oil and moisture
combined”, could be interpreted in two ways. The
load containing: Oil (O) < 10%, Moisture (M)
< 10%, O + M < 20%, could be excluded from the
requirements for UN 1386 (b) and regarded as safe
for an equivalent reading of a total of three conditions (due to M < 10%) or as subject to the criteria,
if the overriding adopted criterion was only the fat
content (about < 10%).
In case of the second possible interpretation, all
the cake with a fat content below 10% was attributable to a group of UN 1386 (b), except those containing M > 10% and M + O > 20%, which put
them in a group of UN 1386 (a) [9]. Currently, the
graphic treatment of these interdependencies, supplemented by a precise verbal description, provides
a unique solution of the problem presented.
Especially noteworthy are changes on the sulphur contained in the successive editions of the
Code as SULPHUR UN 1350, lumps or coarse-grained powder, classified as Class 4.1, Group B.
Sulphur ignites easily, releasing toxic, very irritating and choking sulphur dioxide. Sulphur bulk
cargo is also susceptible to dust explosion, which
may occur, especially during loading and unloading, and when cleaning the hold. Changes in the
classification of sulphur and its placements in the
risk group B or C, depending on its form, result
from the harmonization of the Code IMSBC with
the IMDG Code, where solid sulphur formed in
specific shapes is excluded from the requirements
of Class 4.1, by the Special Provision 242 [10].
The 2005 edition of the BC Code also contains
different sizes of particles of sulphur in lumps or
coarse powder, in addition, dividing them into
flakes (up to 10 mm) and pellets and lumps (up to
5 mm), while according to the IMDG Code (2008),
the sulphur formed into specific shapes such as
nodules, granules, pellets, pastilles or flakes, is not
considered as dangerous cargo. The effect of uniform definitions of cargo under the same name
BCSN and UN number on the card is the removal
for individual sulphur UN 1350 in the new edition
of the IMSBC Code of the information about the
dimensions and highlighting its heterogeneous
shape and dimensions by adding the word
“crushed” (crushed lump and coarse-grained).
Separation of sulphur in the moulded form and
declaring it as chemically safe cargo is the result of
over 15-year successful experience in transport by
sea as well as many independent laboratory tests,
excluding its placement to Class 4.1, group B.
An example of distinguishing a new variation of
cargo is directly reduced iron in the smallest form
(Direct Reduced Iron, By-product Fines), which is
a by-product formed during the production of iron
pellets fused hot (DRI A Briquettes, hot-moulded)
or cold-formed lumps, briquettes and pellets
(DRI B Lumps, pellets, cold-moulded briquettes)
included in previous editions of the BC Code.
Discussion on the introduction of this variety to the
IMSBC Code was launched due to a series of accidents involving the cargo, described in various
documents by Venezuela and France [11]. In November 2004, Ythan bulk carrier, carrying cargo of
DRI Fines from Venezuela to China, experienced
a series of catastrophic explosions in four of the
five holds, which resulted in six casualties of the
crew members and the ship sank 45 minutes after
the event [12]. A new variant of the cargo, commonly and similarly hazardous as the DRI (A) and
DRI (B) in respect of: the possibility of self-heating
and the emission of hydrogen in dangerous
amounts, above the Lower Explosion Limit (4% in
a mixture with air), was differentiated by the particle size so that experience in the transport of the
first two varieties proved inadequate. Therefore,
countries with experience in shipping a new variety
of directly reduced iron, which is the finest form of
this cargo, were asked to provide any information
about: properties, grain composition and bulk density, emerging hazards during transport, the type of
ships on which the cargo is transported, the use of
inert gas, type of ventilation, equipment for monitoring the cargo during transport and the temperature and moisture content during transport. The
result of international work and consultation is an
individual card for a cargo being recognized as
a DIRECT REDUCED IRON (C) (By-product
Fines) in IMSBC 2009, showing in detail the risks,
71
requirements, including conditions during loading,
transport requirements and the precautions that
should be taken before the adoption of the cargo on
board. The cargo was included in class MHB,
group B, because of the threat of self-heating, ignition and explosion during transport. It was pointed
out that the sources of these threats are chemical
reactions with oxygen and water (fresh or sea) and
even water vapour in the air, which lead to the
release of hydrogen and generate heat. Despite the
great similarity of other characteristics and requirements for the transport of DRI (A), DRI (B)
and DRI (C), dimensions and particle size (from
DRI in the form of briquettes – A to fine grained,
with an average particle size of 6.35 mm – C) determine the conditions for admission to the ship
because of the conditioning period required before:
0 days (DRI A), 3 days (DRI B), 30 days (DRI C).
Moreover, because of the known relationship between water content and degree of fragmentation of
the cargo, and the rate of chemical reactions posing
a risk of explosion, DRI (C), as well as DRI (B),
may be transported only in an atmosphere of inert
gas, a maximum oxygen content in air 5% by
volume, at continuously maintained water content
of less than 0.3% of the cargo at all stages of transport, including loading. In addition, each time before loading there should be checked the waterproofness of the hatches, and a sea journey can be
started only after ensuring that the holds are tight
and inert, the temperature of the cargo is stable and
the hydrogen concentration in the holds does not
exceed 0.2% by volume. During transport, a permanent, documented monitoring of the cargo temperature, water content, concentration of hydrogen
and oxygen in the cargo spaces is required. Records
of monitoring must be kept in the ship's records for
2 years.
Part of the cargo, under the common name, is
not a hazardous cargo, if it meets certain criteria to
exclude and ease the transport requirements. Examples are nitrogen-based fertilizers containing ammonium nitrate (AMMONIUM NITRATE BASED
Fertilizers Non-Hazardous). Nitrogen fertilizers
containing ammonium nitrate may exhibit explosive properties, especially in the case of the content
of combustible organic pollutants such as oil. At the
content of this type of contamination above 0.4%,
ammonium nitrate is counted among one of the
explosives. Also, mixtures of ammonium nitrate,
though unclassified as explosives, may explode
during incineration. Fertilizers, which are mixtures
containing at least 45% of ammonium nitrate, exhibit oxidizing properties, if also composed of ammonium sulphate, and their total amount exceeds
70% (UN 2067, Class 5.1, Group B). In addition,
fertilizers containing ammonium nitrate may be
prone to spontaneous decomposition (UN 2071,
Class 9, Group B). Currently, according to IMSBC
2009, fertilizers containing ammonium nitrate in
quantities not exceeding the limits set for UN 2067
and UN 2071 are not included in the dangerous but
only in the risk group C, because of the low value
of the angle of repose 27–42. The United States,
during the 11th session of the Subcommittee on the
carriage of dangerous goods, solid cargoes and
containers of IMO (document DSC 11/4/7) proposed that the cargo should be reclassified as MHB.
This type of amendment, however, was not included in the new edition of the Code. A similar
proposal was sent in relation to chromite ore, which
is a cargo belonging now to group C, which poses
a threat mainly due to high density, but generates
toxic dust, and also in respect to the cargo of tapioca obtained from cassava – forming a dry mixture
of powder and granules, with an angle of repose
32 C (group C), but also easily reacting with oxygen, which can lead to cargo heat and reduction of
the amount of oxygen in the cargo hold. Lack of
any conclusive basis for verification of an existing
list of goods of MHB-class and unified criteria for
assigning cargoes to the IMO class limits the introduction of these changes, since there are no experimental data or actual threats observed in practice.
(group C) which are neither liable to liquefy
(group A) nor possess chemical hazards
(group B)
The threats assigning cargo to group C are
usually associated with dry cargoes ranked among
non-cohesive ones, characterized by low values of
the angle of repose, that readily shift due to sliding
during transport. Different angles of repose for
individual cargoes, which are within three ranges:
up to 30, 30–35 and above 35, determine different rules of trimming and allow the classification
of cargo to be high, medium or low susceptible to
readily shift due to sliding during transport. Group
C covers also cargoes of high specific gravity,
which include mainly concentrated ore, causing
a risk of exceeding the permissible loads and
stresses of the hull, up to its deformation, cracking
the shell, and in extremely difficult weather conditions, even breaking the ship in waves. Recent
changes in the requirements to reduce such risks
include mainly the extension of specific requirements on the conditions under which the loading is
run and how a particular shipment is trimmed.
72
CEMENT, one of group C loads, is characterized by low values of the angle of repose in the
aerated state. During the deposition of cement
while loading which is almost immediately followed by deaeration, the load changes its characteristics, becoming relatively stable, cohesive granular
material with no fixed range of values of the angle
of repose. In the new edition of the Code special
attention was paid to a very low angle of repose of
cement in the form of fluid, actually containing
more than 12% of the air occurring during loading,
until the total consolidation. Although cement is not
classified as non-cohesive group of cargo, with a
fixed range of angle of repose, and, in respect of
which there are additional requirements for the
trim, detailed information appears in the IMSBC
Code on how to align the cargo area. Cement must
be trimmed to a level so that the angle between the
surface of the cargo and the horizontal plane does
not exceed 25. An important change in relation to
multiple loads of Group C is supplementing the
basic information about their ability to pollination,
including an indication of the essential characteristics of these particles, mainly flammability, toxicity
and harmfulness. Requirements for the precautionary measures in reference to the crew clothing,
goggles and masks with filters, are often included
as mandatory.
With regard to terminology, the concepts of
cone angle (called static angle of repose) and the
angle of repose (angle of repose, kinetic angle of
repose), as in the Code of 2001 closely reflecting
the methodology for their determination, have been
replaced by a single term “angle of repose” and
single definition not referring to any of the laboratory methods. According to the IMSBC Code (as
well as the BC Code of 2005): „Angle of repose
means the maximum slope angle of non-cohesive
(i.e. free-flowing) granular material. It is measured
as the angle between a horizontal plane and the
cone slope of such material”.
3. Ensuring the safety and unchanged quality of
goods favours the introduction of the Code of conduct based on individual cards for all cargoes
(Groups A, B and C), containing the following: –
characteristics of the determinants of quality (in the
form of table headers) – arising from the characteristics transport recommendations, including the
sequence of provided information about the following areas: Hazard –Stowage & Segregation – Hold
cleanliness – Weather precautions – Loading –
Precautions –Ventilation – Carriage – Discharge –
Clean-up.
4. Adoption of the alphabetical arrangement (in
reference to the technical names) of individual
cards of cargo to some extent makes it difficult to
quickly find the necessary information in emergency situations. It seems that a further stage in the
development of the Code should be an alphabetically arranged assortment of cargo according to the
type of risks, with the information on possible simultaneous risks enclosed in the table header of
individual cards.
5. With regard to the determinants of the quality
of transport – technology of solid bulk cargo, the
changes made in recent editions of the Code related
to: the introduction of a new definition of the angle
of repose, clarification of the particle size and the
various forms of structural loads, that are in direct
relation with the degree of shipment risks, dividing
the loads of the same kind according to different
types due to the water and stowage factor, resulting
in classifying risks for different groups (A, B or C),
additions to the clarification of the requirements for
water content, determining the dusty, consolidating,
and cohesive properties and graphic representation
of some of the more complex interactions between
the susceptibility to self-heating and the chemical
composition of cargo.
6. The selection of the examples of precise
specification of the data relating to the various
characteristics of loads is a proof of recognition for
the significance of detailed clarification and taking
into account the determinants of quality in the
processes of cargo transport, especially as specific
as solid bulk, which is based on long experience
and its appreciation in practical use.
Conclusions
1. The Code for the shipment of solid bulk cargo
is constantly enriched with new information and
more detailed determinants of the quality of these
goods.
2. The introduction of these changes in the Code
in relation to all groups of goods presenting a transport hazard (may liquefy, possess chemical hazard,
readily shift to the side of the ship, the deformation
of the hull) provide a significant impact on the
selection and use of proper, safe techniques and
transport technologies.
References
1. International Shipping and World Trade, Facts and Figures,
October 2009, Maritime Knowledge Centre, IMO 2009.
2. ISL Shipping Statistics and Market Review, 2010, vol. 54,
No 8.
3. Rocznik Statystyczny Gospodarki Morskiej 2001, Instytut
Morski, Gdańsk 2001.
4. International Maritime Solid Bulk Cargoes Code, 2009
Edition and Supplement, IMO, London 2009.
73
5. Międzynarodowa Konwencja o bezpieczeństwie życia na
morzu, 1974 SOLAS, Tekst jednolity, PRS Gdańsk 2006.
6. Code of Safe Practice for Solid Bulk Cargoes 2004, 2005
Edition, IMO, London 2005.
7. Code of Safe Practice for Solid Bulk Cargoes, 2001 Edition
with MSC/Circ. 908, IMO, London 2001.
8. Investigation report B 4/2000 M, Mv. Maria VG, incident
at Sea of Bothnia off Pori, November 7, 2000. Edita Prima
Oy, Helsinki 2002.
9. Review of the BC Code, including evaluation of properties
of solid bulk cargoes. Clarification on classification of seed
cake. Submitted by BIMCO, DSC/9/10, IMO 2004.
of solid bulk cargoes. Classification of formed solid sulphur. Submitted by Germany and Canada. DSC/12/4/16,
IMO, 2007.
11. Sprawozdanie z 11 sesji Podkomitetu ds. przewozu towarów niebezpiecznych, ładunków stałych i kontenerów
(DSC) IMO Delegacji Polskiej, 02.01.2007.
of solid bulk cargoes. Information needed for the definition
of DRI Fines, other than DRI (A) briquettes, hot moulded.
Submitted by the Republic of Marshall Islands, Malta, and
INTERCARGO, DSC 12/4/14, IMO, 2007.
Recenzent:
prof. dr hab. Hieronim Kubera
Uniwersytet Ekonomiczny w Poznaniu
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Quality determinants of solid bulk cargoes in marine transport

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