Marine Fuel Oil and Fuel Oil Bunkering Procedure

Marine Fuel Oil and Fuel Oil Bunkering
Prepared By
Md. Moynul Islam
Chemical Engineer
Expertise on Marine Fuels and Lubricants
Contact
Email : engineer@moynulislam.com
Mobile : +8801816449869
Web : www.moynulislam.com
Last Modified On: January 09, 2015
A downloadable “pdf “ version is available on author’s website

Content
PART-A: Marine Fuel Oil and Fuel Oil Specifications
PART-B: Fuel Oil Delivery and Loss Prevention

Introduction
As a buyer, you are not buying just fuels for your power plant, you are buying the energy
which is the base of your business. Every year you are spending millions of dollars behind
fuels. And your business profit is directly related to the quality fuels. Proper monitoring in
your fuel management system is vitally needed to run your power business profitably.
So, you have the right to know about the fuel specifications and also have the right to receive
actual quantity that you have ordered to the supplier. Receiving off spec fuel or less quantity
(from your ordered quantity) will ultimately impart on loss in energy. Loss in energy means
loss in generation followed by loss in revenue.
Your fuel supplier may settle your ordered quantity by manipulating some digits but the
problem arises later when you will use this fuel in your engines. The engines are very rude to
you about fuel consumption. To generate your desired power they will never compromise
even a single drop in their consumption. They will consume exactly the required amount of
fuel to generate your ordered power to them. They will consume fuels according to your fuel
quality. If the calorific value of supplied fuel is high than the fuel consumption will be low and
if the calorific value is low than the fuel consumption will be high. So, you need to understand
about bunker and bunkering procedure before entering in this world. If you supply them any
off spec fuel, it may be complicated to operate them smoothly or there may be severe damage
to engine component following breakdown maintenance. Ultimately interruption in smooth
engine operation.

Origin of Marine Fuel Oils (MFO)
Crude oil refining and stocks for marine fuel blending:
Crude oil is a mixture of many different hydrocarbons and small amounts of impurities. The
composition of crude oil can vary significantly depending on its source. Crude oils from the same
geographical area can be very different due to different petroleum formation strata. In subsequent
slides, we will see different crude oil refining process , production of marine fuel oils and how the
quality of marine fuels affected by different processing methods .
Straight run refinery: Atmospheric crude
distillation
Types of crudes:
• Paraffinic crudes
• Naphtenic crudes
• Asphaltenic (aromatic) crudes
Each crude oil contains the three
different types of hydrocarbons, but the
relative percentage may vary
depending on sources.

Straight run refinery : Atmospheric crude distillation
Diesel refers here to specific atmospheric distillation cuts, and this is not relevant for automotive engine application
Straight run stocks used for marine fuel blending: Light diesel, heavy diesel, and straight run residue
Straight run marine gasoil and distillate marine diesel (MDO): Marine gasoil and distillate marine diesel oil (MDO) are
manufactured from kero, light, and heavy gasoil fractions. For DMC distillate marine diesel up to 10–15%, residual fuel
can be added.
Straight run IFO 380 mm2/s (at 50°C): This grade is obtained by blending the atmospheric residue fraction (typical
viscosity of about 800 mm2/s at 50°C) with a gasoil fraction.
Straight run lower viscosity grade IFOs: Blending to lower grade IFOs is done from the IFO 380 mm2/s (at 50°C) using a
gasoil cutter stock or with marine diesel. All IFOs have good ignition characteristics, due to the high percentage of paraffinic
material still present in the atmospheric residue, and the paraffinic nature of the cutter-stocks used. The high amount of
paraffinic hydrocarbons in the straight run marine fuels leads to relatively low densities for these products, ensuring easy
and efficient onboard fuel purification.
The product slate of a straight run refinery, with its heavy fuel production of approximately 50% of the crude feed, does
not correspond to the product demand in industrialized countries where the ever-growing demand for light products (jet
fuel, gasoline, and gasoil) coincides with a strong reduction in the demand for heavy fuel (10 to 15% of the crude oil). This
results in the need to Convert the residue fraction into lighter, hence, more valuable, fractions and to the construction of
Complex Refineries.
Source: Everything You Need To Know About Marine Fuel

Complex refinery : ADU, VDU, FCCU, VIS-BREAKING UNIT
Complex Refinery:
A complex refinery processing scheme can be separated into two parts:
1. Crude oil distillation (atmospheric and vacuum distillation)
2. Streams from the vacuum distillation unit are converted through Catalytic (FCC) and Thermal Cracking processes.

The main marine fuel blending components from a Fluidized bed Catalytic Cracking (FCC) refinery with Vis-breaker are the
same distillates as those from a Straight run refinery (light and heavy diesel) as well as Light Cycle (gas) Oil (LCO) and
Heavy Cycle Oil (HCO) from the Cat-Cracker and vis-broken residue from the Vis-breaker unit.
Atmospheric residue is used as feedstock for the vacuum unit and will seldom be available for fuel blending. Marine fuels
produced from a catalytic cracking/ vis-breaking refinery have a composition that is markedly different from that of an
atmospheric refinery.
Light Sour Crude Refining Process

Marine Gas Oil (MGO/DMA) :
A new blend component Light Cycle Oil (LCO) which contains about 60% aromatics. Because of the high aromatic content
in LCO, the density of a marine gasoil blended with LCO will be higher than when using gasoil from a Straight run refinery.
The density will typically be close to 860 kg/m3 (at 15°C). No performance or handling differences with atmospheric
gasoil are to be expected.
Medium/Heavy Sour Crude Refining Process
Distillate marine diesel (MDO/DMB):
Distillate marine diesel typically has a lower Cetane Index than MGO, and has a higher density. With the production
slate of a Catalytic Cracking refinery, distillate marine diesel can therefore contain a higher percentage of LC(G)O than
MGO.
Blended marine diesel (MDO/DMC):
With atmospheric refining, blended marine diesel (MDO/ DMC) can contain up to 10% IFO with either marine gasoil
(MGO/DMA) or distillate marine diesel (MD)/DMB). With complex refining, MDO/DMC no longer corresponds to a
specific composition and extreme care must be used when blending this grade to prevent stability and/or combustion
problems.

IFO-380 Production:
This grade is usually manufactured at the refinery and contains visbroken residue, HCO
and LC(G)O. These three components influence the characteristics of the visbroken IF-380.
Vacuum distillation reduces the residue yield to about 20% of the crude feed, unavoidably
leading to a concentration of the heaviest molecules in this fraction. Visbreaking converts
about 25% of its vacuum residue feed into distillate fractions. This means that about 15%
of the original crude remains as vis-broken residue.
The asphaltenes1, sulphur and metal content in visbroken residue are 3 to 3.5 times higher
than in atmospheric residue. Visbreaking affects the molecular structure: Molecules are
broken thermally, and this can deteriorate the stability of the asphaltenes. HCO (typical
viscosity at 50°C: 130 mm2/s) contains approximately 60% aromatics, and is a high-density
fraction: the density at 15°C is above 1 kg/l (typically 1.02). It is the bottom fraction of the
FCC unit. The catalytic process of this unit is based on an aluminum silicate.
Some mechanical deterioration of the catalyst occurs in the FCC process, and the
resulting cat fines are removed from the HCO in the refinery. This removal, however, is not
100% efficient and a certain amount (ppm level) of cat fines remains in the HCO. From
there they end up in heavy fuel blended with HCO.
The aromaticity of HCO assists in ensuring optimum stability for the visbroken fuel blend. LC(G)O
(typical viscosity at 50°C: 2.5 mm2/s) has the same aromaticity as HCO, but is a distillate fraction of
the FCC unit, with a distillation range comparable to that of gasoil. With a typical density of 0.94 kg/l
at 15°C, it is used to fine-tune the marine heavy fuel oil blending where generally a density maximum
limit of 0.9910 kg/l has to be observed.

Summary of Crude Oil Conversion
Step01: Separation of Lighter Fractions:
In this step, the crude oil is heated up to approx. 350
oC and enter to the Atmospheric Distillation Unit
(ADU) where lighters fractions are recovered via
distillation at atmospheric pressure. The bottom
residue of ADU is further heated up and sends to the
Vacuum Distillation Unit (VDU) where all of the
volatile components are recovered via distillation at
low pressure.
Step-02: Production of Marine Fuel Oil
The viscosity of heavy residue of VDU is very high. To
produce MFO, the heavy residue required further
processing like cracking with FCC , and Vis-breaker
where a cutter stocks (fuel oil heaving low viscosity) is
used to reduce viscosity to the desired level.
IFOs < 380 mm2/s Production:
These grades are generally blended starting from 380 mm2/s IFOs (at 50°C), by using a suitable cutter-
stock (marine diesel, gasoil, LC(G)O, or a mixture of these). The blend composition has to be construed in
such a way that the product stability is safeguarded, while at the same time direct or indirect density
limits are fulfilled

Classification of Marine Fuel Oil
Conventional Classification System
In maritime industry the most commonly used fuel oil classification system is as follows
MGO (Marine Gas Oil) - Roughly equivalent to No. 2 fuel oil, made from distillate
MDO (Marine Diesel Oil) - A blend of heavy gasoil that may contain very small amount of
black refinery feed stocks, but has a low viscosity up to 12 cSt and it need not be heated
for use in IC engines
IFO (Intermediate Fuel Oil) - A blend of HFO with less gasoil than MDO.
MFO (Marine Fuel Oil) - Same as HFO (just another name)
HFO(Heavy Fuel Oil) - Pure or nearly pure residual fuel oil, roughly equivalent to No. 6 fuel oil
Another classification system popular in maritime industry for fuel oil is based on their
maximum viscosity in cSt at 50oC
IFO-380 -Intermediate Fuel Oil with max viscosity of 380 cSt at 50 oC
IFO-180 -Intermediate Fuel Oil with max viscosity of 180 cSt at 50 oC
LS-380 -Los Sulfur (<1.5%) Intermediate Fuel Oil with max viscosity of 380 cSt at 50 oC
LS-180 -Los Sulfur (<1.5%) Intermediate Fuel Oil with max viscosity of 180 cSt at 50 oC
MGO -Marine Gas Oil

Serial Name Alias Type Chain Length
1 No. 1 Fuel Oil No. 1 Diesel Fuel Oil Distillate 9-16
4 No. 4 Fuel Oil No. 4 Residual Fuel Oil Distillate/Residual 12-70
5 No. 5 Fuel Oil Heavy Fuel Oil Residual 12-70
6 No. 6 Fuel Oil Heavy Fuel Oil Residual 20-70
Grade Description Max Sulfur
No. 1-D S15
No. 1-D S500
No. 1-D S5000
A special purpose light distillate fuel use in diesel engine applications with
frequent and widely varying speeds and loads or when abnormally low operating
temperatures are encountered. More volatile compared to No.2 fuels.
15 ppm
500 ppm
5000 ppm
No. 2-D S15
No. 2-D S500
No. 2-D S5000
A general purpose , middle distillate fuel for use in diesel engines especially in
applications with relatively high loads and uniform speeds, or in diesel engines
not requiring fuels having higher volatility.
15 ppm
500 ppm
5000 ppm
No. 3 D No. 3D Diesel Fuel Oil is a middle distillate having chain length 10-20
No. 4-D
A heavy distillate fuel, or blend of distillate and residual oil, for low and medium
speed diesel engines in applications involving predominantly constant speed and
load
No. 5 &6
These are the heavier fuel oils (residual) having chain length 12-70, which are
primarily used for heating purpose and in large marine engines.
According to ASTM D975:2004 Diesel fuels are classified based on Maximum sulfur content
Based on chain length and extraction process the fuel oils are classified as follows

Grade Description
DMX A special purpose light distillate intended mainly for use in emergency engines.
DMA
DMA (also called Marine Gas Oil MGO) is a general purpose marine distillate that must be
free from traces of residual fuel. DMX and DMA are mainly used in Category 1 marine
engines (< 5 liters/cylinder) .
DMB
DMB (also called Marine Diesel Oil MDO) is allowed to have traces of residual fuel ,
which can be high in sulfur. This contamination with residual fuel mainly occurs in
distribution process, when using the same supply means that are used for residual fuel.
DMB is produced when fuels such as DMA are brought on board the vessel in this manner.
DMB is typically used for Category 2 (5-30 liters/cylinder) and Category 3 (>= 30
liters/cylinder) engines.
DMC
DMC is a grade that may contain residual fuel, and often a residual fuel blend. It is similar
to No. 4-D fuel and can be used in Category 2 and Category 3 marine diesel engines.
Residual
Residual (Non-distillate) fuels are designated by the prefix RM(e.g. RMA, RME, etc). These
fuels are also identified by their nominal viscosity (e.g RMA10, RME180, etc.)
Modern Fuel Classification System:
An ASTM standard (D2069) once existed for marine fuels but it has been withdrawn. Because it was
technically equivalent to ISO 8217. ASTM D2069 covered four kinds of marine distillate fuels:

ISO 8217 : 2010 Specifications for Marine Distillate Fuels

ISO 8217:2010 Specifications for Marine Residual Fuels

Specifications of Marine Fuel Oils (MFO)
In this section, we will concentrate our mind to learn about some technical detail about Marine Fuel Oil
properties and characteristics and their Impact on the Diesel Engines. The important Parameters are listed
below.
1. Viscosity
2. Density
3. Micro Carbon Residue (MCR)
4. Aluminum + Silicon
5. Sodium
6. Ash
7. Vanadium
8. CCAI
1.0 Viscosity :
Viscosity is the most important properties of marine fuel oils. This is a measures of a fuel’s
resistance to flow. Fuel oil transfer process, fuel oil treatment system, fuel oil storage system and
fuel oil injection system, etc are directly related to fuel viscosity. The picture in next slide
showing the viscosity temperature relationship of marine fuel oils. This chart will give a quick
guide line about marine fuel oil handling like storage temperature, pumping temperature,
centrifuging temperature and injection temperature.
9. Water
10. Pour Point
11. Flash Point
12. Sulfur
13. Total Sediment Potential (TSP)
14. Acid Number
15. Used Lube Oil (ULO)
16. Hydrogen Sulfide

Viscosity Temperature Relationship for Marine Fuel Oil
Fuel oil viscosity-temperature diagram for determining the preheating temperatures of fuel
oils

Necessary Terms and Documents Used In Bunker Industry
2.0 Density :
By definition, density is the ratio of mass and volume. But volume is not an intensive properties, it is dependent on
surrounding pressure and temperature. So to measure density, the temperature must specify before. In maritime
industry the density of fuel oil is expressed at 15 oC called standard density. The standard density (density at 15 oC) is
more meaningful rather than density in any other temperatures. Because this density is used to calculate following
parameters of fuel:
CalShell Calculated Carbon Aromaticity Index (CCAI)
culation of engines specific fuel consumption
Calculation of engines peak pressure
BP Calculated Ignition Index(CII)
Higher Heating/Calorific Value (HHV)
Lower Heating/Calorific Value (LHV)
Volume Correction Factor(VCF) by ASTM 54B
Weight Correction Factor(WCF) by ASTM 56D
Volume Conversion
Density Conversion and so on…
From the commercial point of view, density is an essential parameter to measure because residual fuel is ordered by
weight but supplied by volume. If the actual value is less than that stated, there will be a proportional shortfall in the
quantity of product supplied.
Mass = Power
Cost/Tonne $800
Average Delivery 1000 MT, 8 Times/Month, 96 Times/Year
Stated Density at 15°C = 0.991
Actual Density at 15°C = 0.986
Overstatement in Density 0.005kg/l
Cost/Year in Lost Energy = $384000
Be careful! In your fuel specification contract, the maximum density is specified 991 Kg/m3 at 15 oC. If you receive a fuel
having observed density 989 at 30 oC temperature. Do not think that your fuel is within your specification. Actually this fuel
is out of specification and actual density at 15 oC is 999.14. It will create problem in fuel purification system.
Use ASTM 53B to convert observed density into standard density

3.0 Micro Carbon Residue(MCR)/Asphaltenes :
Micro Carbon Residue (MCR) also called Conradson Carbon Residue (CCR) is a measure of the tendency of a fuel
to form carbon deposits during combustion and indicates the relative coke forming tendencies of a heavy oil.
Carbon-rich fuels are more difficult to burn and have combustion characteristics which lead to the formation of
soot and carbon deposits. Since carbon deposits are a major source of abrasive wear, the CCR value is an
important parameter for a diesel engine. The type of carbon also can affect abrasive wear.
Carbon residue is the percent of coked material remaining after a sample of fuel oil has been exposed to high temperatures under
ASTM Method D-189 (Conradson) or D-524 (Ramsbottom).
Asphaltenes are those components of asphalt that are insoluble in petroleum naphtha and hot heptane but are soluble in carbon
disulfide and hot benzene. They can be hard and brittle and made up of large macromolecules of high molecular weight, consisting
of polynuclear hydrocarbon derivatives containing carbon, hydrogen, sulfur, nitrogen, oxygen and, usually, the three heavy metals
− nickel, iron and vanadium.
A high CCR/asphaltene level denotes a high residue level after combustion and may lead to ignition delay as well as after-burning
of carbon deposits leading to engine fouling and abrasive wear. Poor engine performance caused by slow burning, high boiling
point constituents results in higher thermal loading and changes in the rate of heat release in the cylinder.
The carbon residue value of a fuel depends on the refinery processes employed in its manufacture. For straight run fuels, the value
is typically 10 - 12% m/m, while for fuels from secondary refining process, the value depends on the severity of the processes
applied. On a global basis, this value is typically 15 – 16%, however in some areas it can be as high as 20% m/m.
Modern engines tolerant to a wide range of MCR valves. Operational experience has shown that the present generation of large,
medium and slow speed engines designed for residual fuel can tolerate a wide range of MCR values without any adverse effect.
> 20 % High and may be problematic and cause increased fouling
10 - 12 % Straight run fuels
15 - 16 % Average and acceptable in modern engines
Comment: Injector nozzles can become fouled using high MCR fuel. Careful control of nozzle
cooling temperature can help reduce this.

4.0 Aluminum + Silicon (Catalytic Fines, CatFines) :
Hard, abrasive particles, such as alumina/silica catalyst carry-over, originate in the refinery when this
powdered catalyst is added to the charge stock of a fluidic catalytic cracking (F.C.C.) unit. Due to erosion and
fracture, some of the catalyst is not recovered but is carried over with the bottoms from the F.C.C. unit.
Larger sized catalyst particles, >10 microns, also can be carried over if there is a defect in the catalyst
removal equipment (such as cyclone separators), if there is an upset in the operation of the F.C.C. unit, or if
the heavy (low API gravity) bottoms (containing catalyst particles) are not permitted sufficient time to settle-
out in heated storage (when this method is used to control catalyst carry-over).
It is also possible to contaminate a clean marine residual fuel oil with catalyst particles during transport. For
example, if steamship fuel (frequently containing catalyst particles) has been transported by barge prior to
moving a clean heavy fuel oil for a diesel powered ship, the barge bottom sediment will be mixed with the
clean fuel oil and will contaminate it.
Because cat-fines are generally small, very hard, and quite abrasive to fuel pumps, atomizers/injectors,
piston rings and liners, a number of major diesel engine builders have concluded that 30 ppm of alumina in
the bunkered fuel oil is the upper limit for successful treatment and engine operation. The average particle
size, as well as the concentration, greatly impacts the wear rate of engine components. Small sized catalyst
particles, in the one to ten (1-10) micron range, typically cause accelerated wear in injection pumps and
injectors and only moderate increases in cylinder assembly wear, such as piston rings, piston grooves, and
liners. The larger sized catalyst particles, in the ten to seventy (10-70) micron range, typically cause very
accelerated wear rates in the cylinder assembly area. Accelerated damage can also be expected on injection
pump inlet valves, exhaust valve seating areas, and turbocharger turbine blades. These larger sized particles
have been associated with catastrophic wear rates.

5.0 Sodium(Na):
Sodium is an alkaline, chemically extremely active metallic element. The sodium found in fuel can come from several
sources. But most of it is a direct result of storing and handling procedures from the time the fuel leaves the refinery until it
is delivered to bunkers. Salt water contamination in barges used to transport the fuel is not uncommon. To some extent,
even salt air condensation in fuel tanks contributes to the overall sodium content.
Sodium acts as a paste (flux) for vanadium slag. When unfavorable quantities of vanadium and sodium are present in a fuel
they react at combustion temperatures to form (eutectic) compounds with ash melting points within operating
temperatures. In molten form sodium/vanadium ash can corrode alloy steels, and when this condition is allowed to persist
unchecked, high temperature corrosion, overheating, and eventual burning away of exhaust valves, valve faces, and piston
crowns is not uncommon.
The chief corrosive constituents in heavy fuel, oil ash formed during combustion are vanadium pentoxide, sodium sulphate,
and other complex forms of these primary compounds. The chemical nature of these compounds and their interaction with
steel surfaces on exhaust valve seats are of real concern, as the relatively low melting points of most of these compounds
make them very corrosive at normal engine exhaust temperatures. The thickness of the various oxide layers depends on the
temperature and the exhaust gas composition. In their molten states, the vanadium-sodium-sulfur compounds also act to
dissolve the exhaust valve surface ferric oxide (Fe203) layer, thus exposing the underlying steel surface to further oxidation
attack and subsequent erosion.
The oxidation attack takes place by two mechanisms: gas phase oxidation and liquid phase oxidation. In the gas phase
oxidation, the high temperature oxygen-containing exhaust gases react with steel to form oxides. Liquid phase oxidation
(corrosion) takes place when molten sulfates and pyrosulfates in the exhaust gases deposit on valve surfaces. In extreme
situations, similar sodium/vanadium ash corrosion attack can also occur downstream of the exhaust valves in the
turbocharger exhaust gas turbine and blades.

Sodium -Vanadium Phase Diagram
Vanadium present in fuel can form low melting compounds V2O5 which melts at 691 oC and which causes
severe corrossive attack on all high temperature alloys used for gas turbine blades, valves. However, if
sufficient magnesium is present in fuel, it will combine with the vanadium and forms a self-spalling
compounds with higher melting points and thus reduce the corrosion rate to an acceptable level.
Sodium and Potassium can combine with vanadium to form eutectics compounds which melt at
temperatures as low as 565 oC and with sulfur in the fuel to yield sulfates with melting points in the
operating range of the gas turbine. See the V2O5-Na2O phase diagram in Figure 07. See also the melting
temperature of different oxides of vanadium also in figure 08

Regardless of the manner of contamination, sodium in fuel is usually water soluble and can, therefore, be removed with
the centrifugal separator.
6.0 Ash
The ash contained in heavy fuel oil includes the (inorganic) metallic content, other non-combustibles and solid
contamination. The ash content after combustion of a fuel oil takes into account solid foreign material (sand, rust,
catalyst particles) and dispersed and dissolved inorganic materials, such as vanadium, nickel, iron, sodium, potassium or
calcium.
Ash deposits can cause localized overheating of metal surfaces to which they adhere and lead to the corrosion of the
exhaust valves. Excessive ash may also result in abrasive wear of cylinder liners, piston rings, valve seats and injection
pumps, and deposits which can clog fuel nozzles and injectors.
In heavy fuel oil, soluble and dispersed metal compounds cannot be removed by centrifuging. They can form hard
deposits on piston crowns, cylinder heads around exhaust valves, valve faces and valve seats and in turbocharger gas
sides.
High temperature corrosion caused by the metallic ash content can be minimized by taking these engine design factors
into consideration; (1) hardened atomizers to minimize erosion and corrosion and (2) reduction of valve seat
temperatures by better cooling.
7.0 Vanadium
Vanadium is a metallic element that chemically combines with sodium to produce very aggressive low melting point
compounds responsible for accelerated deposit formation and high temperature corrosion of engine components.
Vanadium itself is responsible for forming slag on exhaust valves and seats on 4-cycle engines, and piston crowns on both
2- and 4-cycle engines, causing localized hot spots leading eventually to burning away of exhaust valves, seats and piston
crowns. When combined with sodium, this occurs at lower temperatures and reduces exhaust valve life. As the vanadium
content (ppm) increases, so does the relative corrosion rate.

Vanadium is oil soluble. It can be neutralized during combustion by the use of chemical inhibitors (such as
magnesium or silicon). Cooling exhaust valves and/or exhaust valve seats will extend valve and seat life.
Raising fuel/air ratios also prolongs component life. Other measures which can be used to extend
component life are the use of heat resistant material, rotating exhaust valves, and the provisions of
sufficient cooling for the high temperature parts.
Vanadium content varies widely in heavy fuel oils depending on the crude oil source or crude oil
mixes used by the refinery.
The vanadium levels of future heavy fuel oils generally will be higher than today’s. This is particularly true
of fuel oils produced from Venezuelan and Mexican crude. Vanadium cannot presently be economically
reduced or removed by the refinery or the ship’s systems. The burden of coping with high vanadium levels
will continue to remain with engine builders and ship operators. This tolerance must be achieved through
advances in materials and cooling techniques and through the use of onboard treatment methods such as
chemical additives.
In general, fuel when delivered contains a small amount of sodium which is typically below 50 mg/kg. The
presence of sea water increases this value by approximately 100 mg/kg for each per cent sea water. If not
removed in the fuel treatment process, a high level of sodium will give rise to post-combustion deposits in the
turbocharger. Although potentially harmful, these can normally be removed by water washing.
High temperature corrosion and fouling can be attributed to vanadium and sodium in the fuel. During
combustion, these elements oxidize and form semi-liquid and low melting salts which adhere to exhaust valves
and turbochargers. In practice, the extent of hot corrosion and fouling are generally maintained at an acceptable
level by employing the correct design and operation of the diesel engine. Temperature control and material
selection are the principal means of minimizing hot corrosion. It is essential to ensure exhaust valve temperatures
are maintained below the temperatures at which liquid sodium and vanadium complexes are formed and for this
reason valve face and seat temperatures are usually limited to below 450°C.

When a fuel is bunkered with a vanadium level greater than that recommended by the
engine designer, there is a risk that hot corrosion and fouling may occur. One operational
solution is by the use of a fuel additive, and numerous ash-modifying compounds are
available. They should be used with care as situations can arise where the effect of the ash-
modifier, by incorrect application, can cause further problems in the downstream post-
combustion phase.
Comment: Do not run on V levels above spec for extended intervals. Watch for Na:V of 1:3
ratio. Vanadium, Sodium and Ash will cause fouling in the Turbocharger.
8.0 CCAI
The most common method of assessing this aspect is by an empirical equation involving
density and viscosity, known as the Calculated Carbon Aromaticity Index (CCAI). Of the two
parameters, density has the major effect. The incidence of fuels with a CCAI exceeding 870
is in the order of 0.2% , whilst those in the range 870-860 are less than 3%.

Combustion of a residual fuel is a multi-stage process of which one part is the ignition quality of the
fuel. Fuel takes a finite time from the start of the injection to the start of combustion. During this period,
fuel is intimately mixed with the hot compressed air in the cylinder where it begins to vaporize. After a
short delay known as the ignition delay, the heat of compression causes spontaneous ignition to occur.
Rapid uncontrolled combustion follows as the accumulated vapor formed during the initial injection
phase is vigorously burned. The longer the ignition delay, the more fuel will have been injected and
vaporized during this “pre-mixed” phase and the more explosive will be the initial combustion. The
second phase or “diffusion burning” phase of combustion is controlled by how rapidly the oxygen and
remaining vaporized fuel can be mixed as the initial supply of oxygen near the fuel droplets has been
used during the pre-mixed combustion. Rapid pre-mixed combustion causes very rapid rates of pressure
rise in the cylinder resulting in shock waves, broken piston rings and overheating of metal surfaces.
Large diesel engines are designed to withstand a certain rate of pressure rise within the cylinder although
the figure will vary between different designs.
Ignition performance requirements of residual fuels in large diesel engines are primarily determined by
engine type and, more significantly, engine operating conditions. Fuel factors influence ignition
characteristics to a much lesser extent. It is for this reason that no general limits for ignition quality can
be applied, since a value which may be problematical to one engine under adverse conditions may
perform quite satisfactorily in many other circumstances. Engine operation under part load conditions
using high CCAI fuel should be avoided.
CCAI and CII are empirical attempts to estimate how long the fuel will take from injection to ignition and
by implication the likelihood of engine damage. After calculating the CCAI or CII of a fuel, the operator
must then judge the acceptability of that fuel for effective operation in the engine. Variations of engine
load, rated speed and design affect the likelihood of poor combustion, hence it is impossible to give
precise figures that apply to all engines. The figure above gives guidance in relation to CCAI for a number
of engine types. This data is derived from the results of engine simulations and published performance
criteria.

PART-B
Fuel Oil Delivery and Loss
Prevention
Do not think for Discrepancy in Quantity only
Think about the Discrepancy in Quality also

PART-B: Fuel Oil Delivery and Loss Prevention
Fuel Oil Bunkering is a fuel oil transfer process, where a large quantity of fuel is transferred from one vessel (supplier
vessel) to another vessel (receiver tank or vessel) in a systematic way. In bunker industry the well established trading unit
of bunker fuel is metric tones(MT). There has some technical advantages to use this unit in purchasing bunker.(1) MT is a
unit of mass which is not dependent on temperature, (2) All types of energy calculations are directly related to the mass
of fuel rather than volume.
For the sellers, you are selling fuels, and you have to be clean and reliable in your business by supplying actual
information and technical data about the fuel which you are supplying/delivering to your customer.
Due to the complexity in calculation procedure and limitation of time standard procedure of bunkering is rarely followed.
But without a standard measurement system, attaining accurate result is quite impossible. This is the main reason of
discrepancies in bunkering.
1. The key objectives of this effort:
2. To automate the bunker calculation processes using computer.
3. To establish IBIA standard procedure in bunkering in Bangladesh.
4. To visualize the sources of error in bunkering in Bangladesh
5. To minimize discrepancies in bunkering by removing erroneous procedures in bunkering
6. Enhancing the fuel system monitoring in HFO/LFO based power plant

Density :
We know that volume is an extensive properties which is dependent on the temperature and the pressure. So, to
measure density of fuel oil, the temperature and pressure must consider. In maritime industry the density of fuel oil is
expressed at 15 oC called density at standard temperature. The standard density (density at 15 oC) is more meaningful
rather than density in any other temperature. Because this density is used to calculate following parameters of fuel;
1. Shell Calculated Carbon Aromaticity Index (CCAI)
2. BP Calculated Ignition Index(CII)
3. Higher Heating/Calorific Value (HHV)
4. Lower Heating/Calorific Value (LHV)
5. Volume Correction Factor(VCF) by ASTM 54B
6. Weight Correction Factor(WCF) by ASTM 56D
7. Volume Conversion
8. Density Conversion and so on…
Be careful! In your fuel specification contract, the maximum density is specified 991 Kg/m3 at 15 oC. If you receive
a fuel having observed density 989 at 30 oC temperature. Do not think that your fuel is within your specification. Actually
this fuel is out of specification and actual density at 15 oC is 999.14
TABLE ASTM 53B is used for density correction from observed density to standard density

Use of Density, API Gravity and Specific Gravity in Bunker Survey:
Density, API Gravity and Specific Gravity (Also called Relative Density R.D) all are used by the bunker
surveyor to calculate VCF and WCF.
VCF Calculation:
Table 54B is specified for Density, Table 6B is specified for API Gravity and Table 24B is specified for S.G. to
calculate VCF.
WCF Calculation:
Again Table 56 is specified for Density and Table 13 is specified for API Gravity to calculate WCF.
Comments: Sometimes the surveyors convert the density at 15 oC kg/m3 expressed in BDR in to Specific
Gravity (S.G) to facilitate it with Table 54B and Table 56 to calculate VCF and WCF. Suppose, 978  0.978
Are they actually converting from Density at 15 oC in to Specific Gravity?
They are not converting the Density in to S.G. They are actually converting the density unit from kg/m3
to kg/L. Because, some version of VCF and WCF tables are calculated based on the density expressed
in kg/L unit rather than kg/m3. That is the reason for conversion of density unit from kg/m3 to kg/L.
So be careful about the use of Density and Specific Gravity. Do not mess up with density in kg/L with S.G
To avoid all kinds of conversion problems in bunker survey, a specialized software is available which will
automate your bunker quantity calculation. Visit author’s website www.moynulislam.com and see the
demo

Purchase Bunker by Mass rather than by Volume
Observe the pictures below, fuel oil is being shipped from a hotter region to a cooler region. The volume
is different but the mass is remaining the same. So trading fuel by mass is more convenient rather than
by volume. As a large volume of fuel is involved in bunkering and its quite impossible to measure the
fuel quantity by mass using a weight measuring machine. That’s why the mass (an intensive properties)
of fuel is measured indirectly from volume and density (two extensive properties of fuel). Converting
fuel volume into mass is not an easy job just by multiplying the observed volume with observed density.
It’s a critical job. Mass should be calculated following standard procedure. Accuracy in calculation
procedure is important as fuel oil is not a low valued product like water. Hence, care should be taken
before calculating the mass. The cost of small error in calculation procedure is much more higher than
spending small effort in standard measurement.

Purchase Bunker by Mass rather than by Volume
Observe the column chart below, an oil tanker carrying fuel oil from one location to another location.
Location 01:
Temperature in Location 01 = 50 oC
Quantity by Mass in Location 01 = 1413.09 MT
Quantity by Volume in Location 01 = 1500 m3
Location 02:
Quantity by Volume in Location 02 = 1478.48 m3
Location 03:
Quantity by Volume in Location 03 = 1462.85 m3
1500
1478.48
1462.85
1413.09 1413.09 1413.09
1350
1400
1450
1500
1550
50 30 15
Volume(m^3) Mass (MT)

Sounding Tape
How To Take Sounding?
Follow the steps mentioned below to take sounding on a ship using
the sounding tape.
1.) Make sure the bob is tightly held with the tape using a strap hook.
Ensure that the tape is not damaged anywhere in between to
avoid dropping of bob or tape inside the pipe.
2.) Know the last reading (reference height) of the tank in order to
have a rough idea whether to take sounding or ullage.
3.) Apply water/ oil finding paste to get exact readings.
4.) Drop the tape inside the pipe and make sure it strikes the striker
plate.
5.) Coil up the tape and check for impression of paste and then note
the sounding.
6.) Check the trim and list of the ship to read the correct reading for
volumetric content of the ship.
7.) Note down the sounding in the record book with signature of the
officer in charge.
Sounding Measuring Tape
 For Manual measurement of sounding, a measuring tape normally
made up of brass and steel with a weighted bob attached at the
end of the tape is used.
 Sounding pastes are also available for both water and gas oil
which highlights the level of fluid in tape.

Reading Draft Marks
Why accuracy in drafts
reading is important?
The reason is that, the tanks
of a tanker is calibrated
based on précised
measurement. The capacity
table is generated by using
accurately measured drafts.
Your unintentional mistakes
in drafts measurement will
affect your entire
calculation. So, try to collect
data as accurate as possible
by avoiding common error
in measurement.
Procedure for Reading Draft Marks: Draft marks are numbers marked on each side of the bow and stern of
the vessel. Draft marks show the distance from the bottom of the keel to the waterline. Use the small boat
to go around the ship and get as near as possible to the draft mark for best viewing. This process is hard to
do and involves many rules of conduct to gain the correctness and accuracy of Draft Survey itself

Types of Hydrometers
Hydrometers for Oil: A hydrometer is an instrument used to measure the specific
gravity(or relative density) of liquids. Hydrometers for oils are specifically designed
for the testing of oil and petroleum products, and are made in accordance with
national and international standards. They can be supplied with calibration
certificates, or certificates showing traceability to national NAMAS standards.
Hydrometers varies depending on the scales and field of applications. The common
types of hydrometers are as follows:
 Specific Gravity Hydrometers (spgr 60/60 oF) calibrated at 60 oF
 Density Hydrometers calibrated at 20 oC (at 68 oF)
 API/ASTM Hydrometers
 Baume Hydrometers
 Brix Hydrometers
 Twaddle Hydrometers
 Plain Form Hydrometers
How to use a hydrometer: Before using the hydrometer
 Make sure both the hydrometer and hydrometer jar are clean.
 If the liquid to be tested is not at room temperature, allow it to reach room
temperature before testing.
 Pour the liquid carefully into the hydrometer jar to avoid the formation of air
bubbles. Do this by pouring it slowly down the side of the jar.
 Stir the liquid gently, avoiding the formation of air bubbles.
Comment: Visually, Density Hydrometer and Specific Gravity Hydrometer are same but differ in
scale and calibration temperatures. Before using the hydrometer be sure about the type so that
you can select right ASTM tables for density/specific gravity correction. Because the ASTM
tables for density and specific gravity correction are different. For density hydrometer ASTM53B
and for specific gravity hydrometer ASTM 23B are used.

How to take reading from a hydrometer?
How to take reading from a hydrometer:
 Carefully insert the hydrometer into the liquid, holding it at the top of
the stem, and release it when it is approximately at its position of
equilibrium.
 Note the reading approximately, and then by pressing on the top of the
stem push the hydrometer into the liquid a few millimetres and no more
beyond its equilibrium position. Do not grip the stem, but allow it to rest
lightly between finger and thumb. Excess liquid on the stem above the
surface can affect the reading.
 Release the hydrometer; it should rise steadily and after a few
oscillations settle down to its position of equilibrium.
 If during these oscillations the meniscus is crinkled or dragged out of
shape by the motion of the hydrometer, this indicates that either the
hydrometer or the surface of the liquid is not clean. Carefully clean the
hydrometer stem. If the meniscus remains unchanged as the
hydrometer rises and falls, then the hydrometer and liquid surface are
clean, and a reading can be taken.
 The correct scale reading is that corresponding to the plane of
intersection of the horizontal liquid surface and the stem. This is not the
point where the surface of the liquid actually touches the hydrometer
stem. Take the reading by viewing the scale through the liquid, and
adjusting your line of sight until it is in the plane of the horizontal liquid
surface. Do not take a reading if the hydrometer is touching the side of
the hydrometer jar.

Measuring The Temperature
Measuring The Temperature:
 Using a suitable thermometer, take the temperature of the liquid immediately after
taking the hydrometer reading.
 If there is any chance of a change in the temperature of the liquid it is safer to take the
temperature both before and after the hydrometer reading. A difference of more than
1°C means that the temperature is not stable, and the liquid should be left to reach
room temperature.
 If the temperature of the liquid is not the same as that on the hydrometer scale, the
hydrometer reading should have a correction due to temperature applied.
Handling the Hydrometer
 The hydrometer should never be held by the stem, except when it is being held
vertically.
 When holding the stem, always hold it by the top, as finger-marks lower down can affect
the accuracy of the instrument.
 Always handle with care.

LIST and TRIM Correction Table: A certified calibration table for LIST and TRIM correction table.
Calibration Tables:
A certified capacity table derived from the tank dimension to measure the bulk volume by providing tank
sounding/ullage data. Make sure that the calibration table is original and accurate. It is not unknown for
duplicate barge tables to be used. At first sight they appear in order but have, in fact, been modified to
the advantage of the supplier. Inserted pages, photocopies, corrections, different print and paper types
are all indications of tampering.
Meter Readings:
If fuel oil delivery is determined by a meter reading, air may be pumped which will reduce the amount
actually delivered. Meter readings record a volume which has to be converted to weight by knowledge of
the density.
Ullage:
The delivery barge contends that seals on sounding pipes cannot be broken. The statement is usually
backed by excuses such as customs seals or a seized sounding cock. As an alternative to gauging the tanks.
fuel oil is delivered by meter and air is pumped through the meter to increase the measured
delivery displayed
Counter measures - don’t agree to meter only fuel oil deliveries.

ASTM D1250: Standard Guide for Use of the Petroleum Measurement Tables
ASTM D1250: This guide explains in detail about use of the following petroleum measurement tables
TABLE VOLUME NAME
5A VOLUME I GENERALIZED CRUDE OILS CORRECTION OF OBSERVED API GRAVITY TO API GRAVITY AT 60 oF
5B VOLUME II GENERALIZED PRODUCTS CORECTION OF OBSERVED API GRAVITY TO API GRAVITY AT 60oF
6A VOLUME I GENERALIZED CRUDE OILS CORRECTION OF VOLUME TO 60oF AGAINST API GRAVITY AT 60oF
6B VOLUME II GENERALIZED PRODUCTS CORRECTION OF VOLUME TO 60oF AGAINST API GRAVITY AT 60oF
6C VOLUME III
VOLUME CORRECTION FACTORS FOR INDIVIDUAL AND SPECIAL APPLICATIONS VOLUME CORRECTION TO 60oF
AGAINST THERMAL COEFFICIENTS A 60oF
23A VOLUME IV GENERALIZED CRUDE OILS CORRECTION OF OBSERVED RELATIVE DENSITY TO RELATIVE DENSITY AT 60/60oF
23B VOLUME V GENERALIZED PRODUCTS CORRECTION OF OBSERVED RELATIVE DENSITY TO RELATIVE DENSITY AT 60/60oF
24A VOLUME IV GENERALIZED CRUDE OILS CORRECTION OF VOLUME TO 60oF AGAINST RELATIVE DENSITY 60/60oF
24B VOLUME V GENERALIZED PRODUCTS CORRECTION OF VOLUME TO 60oF AGAINST RELATIVE DENSITY 60/60oF
24C VOLUME VI
VOLUME CORRECTION FACTORS FOR INDIVIDUAL AND SPECIAL APPLICATIONS VOLUME CORRECTION TO 60oF
AGAINST THERMAL COEFFICIENTS A 60oF
53A VOLUME VII GENERALIZED CRUDE OILS CORRECTION OF OBSERVED DENSITY TO DENSITY AT 15oC
53B VOLUME VIII GENERALIZED PRODUCTS CORRECTION OF OBSERVED DENSITY TO DENSITY AT 15oC
54A VOLUME VII GENERALIZED CRUDE OILS CORRECTION OF VOLUME TO 15oC AGAINST DENSITY AT 15oC
54B VOLUME VIII GENERALIZED PRODUCTS CORRECTION OF VOLUME TO 15oC AGAINST DENSITY AT 15oC
54C VOLUME IX
VOLUME CORRECTION FACTORS FOR INDIVIDUAL AND SPECIAL APPLICATIONS VOLUME CORRECTION TO 15oC
AGAINST THERMAL COEFFICIENTS A T 15oC
56D WEIGHT CORRECTION FACTOR AGAINST DENSITY AT 15oC

Petroleum Measurement Tables
53A CRUDE OILS 53B OIL PRODUCTS
DENSITY AT OBSERVED TEMPERATURE DENSITY AT OBSERVED TEMPERATURE
950.0 952.0 954.0 956.0 958.0 960.0 997 999.0 1001.0 1003.0 1005.0 1007.0
TEMP ˚C CORRESPONDING DENSITY AT 15˚C TEMP ˚C CORRESPONDING DENSITY AT 15˚C
-18 929.1 931.1 933.1 935.2 937.3 939.3 -0.5 986.9 988.9 990.9 992.9 994.9 996.9
-17.75 929.2 931.3 933.3 935.4 937.4 939.5 -0.25 987.1 989.1 991.1 993.1 995.1 997.1
-17.5 929.4 931.4 933.5 935.5 937.6 939.6 0 987.2 989.2 991.2 993.3 995.3 997.3
-17.25 929.5 931.6 933.6 935.7 937.7 939.8 0.25 987.4 989.4 991.4 993.4 995.4 997.4
-17 929.7 931.7 933.8 935.8 937.9 939.9 0.5 987.6 989.6 991.6 993.6 995.6 997.6
-16.75 929.9 931.9 934 936 938 940.1 0.75 987.7 989.7 991.7 993.7 995.8 997.8
DENSITY AT 15 ˚C DENSITY AT 15 ˚C
990 992.0 994.0 996.0 998.0 1000.0 730 732.0 734.0 736.0 738.0 740.0
TEMP ˚C FACTOR FOR CORRECTING VOLUME TO 15 ˚C TEMP ˚C CORRESPONDING DENSITY AT 15˚C
14 1.0006 1.0006 1.0006 1.0006 1.0006 1.0006 40 0.9684 0.9686 0.9687 0.9688 0.969 0.9691
14.25 1.0005 1.0005 1.0005 1.0005 1.0005 1.0005 40.25 0.9681 0.9683 0.9684 0.9685 0.9687 0.9688
14.5 1.0003 1.0003 1.0003 1.0003 1.0003 1.0003 40.5 0.9678 0.9679 0.9681 0.9682 0.9683 0.9685
14.75 1.0002 1.0002 1.0002 1.0002 1.0002 1.0002 40.75 0.9675 0.9676 0.9678 0.9679 0.968 0.9682
15 1 1 1 1 1 1 41 0.9672 0.9673 0.9674 0.9676 0.9677 0.9679
15.25 0.9998 0.9998 0.9998 0.9998 0.9998 0.9998 41.25 0.9669 0.967 0.9671 0.9673 0.9674 0.9675
RELATIVE DENSITY 60/60˚F RELATIVE DENSITY 60/60˚F
0.612 0.614 0.616 0.618 0.62 0.622 0.89 0.892 0.894 0.896 0.898 0.9
TEMP ˚F CORRESPONDING RELATIVE DENSITY 60/60˚F TEMP ˚F FACTOR FOR CORRECTING VOLUME TO 60˚F
75 0.9863 0.9863 0.9864 0.9865 0.9866 0.9867 135 0.9671 0.9672 0.9673 0.9674 0.9675 0.9675
75.5 0.9858 0.9859 0.986 0.9861 0.9862 0.9863 135.5 0.9668 0.9669 0.967 0.9671 0.9672 0.9673
76 0.9853 0.9854 0.9855 0.9856 0.9857 0.9858 136 0.9666 0.9667 0.9668 0.9669 0.967 0.9671
76.5 0.9849 0.985 0.9851 0.9852 0.9853 0.9854 136.5 0.9664 0.9665 0.9666 0.9667 0.9668 0.9669
77 0.9844 0.9845 0.9846 0.9847 0.9848 0.9849 137 0.9662 0.9663 0.9664 0.9665 0.9666 0.9667
77.5 0.984 0.9841 0.9842 0.9843 0.9844 0.9845 137.5 0.966 0.9661 0.9662 0.9663 0.9664 0.9665
RELATIVE DENSITY AT OBSERVED TEMPERATURE RELATIVE DENSITY AT OBSERVED TEMPERATURE
0.827 0.829 0.831 0.833 0.835 0.837 0.941 0.943 0.945 0.947 0.949 0.951
TEMP ˚F CORRESPONDING RELATIVE DENSITY 60/60˚F TEMP ˚F CORRESPONDING RELATIVE DENSITY 60/60˚F
90 0.8389 0.8409 0.8429 0.8449 0.8468 0.8488 195 0.9906 0.9926 0.9946 0.9965 0.9985 1.0005
90.5 0.8391 0.8411 0.8431 0.8451 0.847 0.849 195.5 0.9908 0.9928 0.9948 0.9967 0.9987 1.0007
91 0.8393 0.8413 0.8433 0.8453 0.8472 0.8492 196 0.991 0.993 0.995 0.9969 0.9989 1.0008
91.5 0.8395 0.8415 0.8435 0.8455 0.8474 0.8494 196.5 0.9912 0.9932 0.9951 0.9971 0.9991 1.001
92 0.8397 0.8417 0.8437 0.8456 0.8476 0.8496 197 0.9914 0.9933 0.9953 0.9973 0.9992 1.0012
92.5 0.8399 0.8419 0.8439 0.8458 0.8478 0.8498 197.5 0.9916 0.0035 0.9955 0.9975 0.9994 1.0014

Bunker Delivery Receipt/Bunker Delivery Note:
Bunker Delivery Receipt/Bunker Delivery Note:
This a standard document originated from the fuel supplier for the purchaser containing
necessary and most important information regarding the fuel that has been purchased.
The purpose of the Bunker Delivery Receipt (BDR) is to record what has been
transferred. Various factors are recorded in this document including:
 Location and time of transfer
 Details of product delivered
 Temperature of product delivered
 Product density at standard reference temperature
 Sample seal numbers
Care should be taken before signing the BDR. For example, the bunkers should not be
signed for in weight form, only for volume at observed temperature. The actual weight
can only be calculated after a representative sample of the delivery has been tested for
density.
IBIA Standard Bunker Delivery Note/Receipt

IBIA Standard Bunker Delivery Note/Receipt

An Existing Bunker Delivery Note/Receipt
Extracted from IBIA Standard Form for comparison

Bunker Checklist
Bunker Checklist:
Bunkering is often carried out when the engineering staff are under pressure in both time and
manpower. Key checks are often missed and only come to light when it is too late. A few relevant
points are detailed below:
1. The purchaser should obtain specification acceptance from the supplier.
2. Purchaser needs to advise ship’s Staffs what grade of fuel will be delivered and how transferred.
3. Fuels from different deliveries should be segregated as far as practical.
4. All receiving tanks need to be gauged prior to taking fuel.
5. Don’t sign any documentation unless you have witnessed the actual event.
6. Always take up witness offers made by the supplier
7. If the suppliers sampling method is unknown, then sign adding the words “for receipt only - source
unknown”.
8. Always take a fuel sample using a continuous drip method.
9. Take one sample per barge/ delivery
10. Sign the BDR for volume only, if necessary adding the words “for volume only - weight to be
determined after density tests”.
11. Ensure good records are kept throughout the bunkering.
12. Keep accurate engine logs in the event of any subsequent problems
13. Keep fuel samples for at least 12 months.
14. Test all fuel on delivery for Viscosity, Density, Water,Stability, Pour Point and Salt (if water present).
15. Use a laboratory to check results in the event of any discrepancies being indicated by on-site test
equipment.

MARPOL Annex VI Summery:
MARPOL: MARPOL 73/78 is the International Convention for the Prevention of Pollution From Ships, 1973
as modified by the Protocol of 1978. (MARPOL is short form of Marine Pollution and 73/78 short for
the years 1973 and 1978)
MARPOL Annex VI Summery:
 Fuel oil purchasers need to advise the ship’s staff what grade of fuel they will receive and how it will be
transferred.
 Fuels from different deliveries should be segregated as far as is practicable
 All receiving fuel oil tanks need to be gauged and the results recorded prior to taking delivery of fuel
 Don’t sign any documentation before you have witnessed the actual event
 Always take up witness offers made by the supplier’s representatives.
 If the origin and method by which the supplier’s sample was obtained is unknown then sign for it
adding the words “for receipt only - source unknown”
 Fuel oil samples should always be taken by continuous-drip method throughout the bunkering.
 If the fuel oil delivered is supplied by more than one barge, a sample should be taken of each fuel oil
from the supplying barges.
 Sign the bunker delivery receipt only for volume delivered. If the supplier insists on a signature for
weight add “for volume only - weight to be determined after density testing of representative sample”.
Comment : Make sure that what you sign for is what you get. Be certain that the bunker receipt reflects the facts
as witnessed. Do not sign anything unless you have witnessed it. Always take a representative sample.

Guidelines for the Sampling of Fuel Oil for Determination of Compliance with ANNEX VI of
MARPOL 73/78
Definitions:
Supplier’s representative: Supplier’s representative is the individual from the bunker tanker who is responsible for the
delivery and documentation or, in the case of deliveries direct from the shore to the ship, the person who is responsible
for the delivery and documentation.
Ship’s representative: Ship’s representative is the ship’s master or officer in charge who is responsible for receiving
bunkers and documentation.
Representative Sample: Representative sample is a product specimen having its physical and chemical characteristics
identical to the average characteristics of the total volume being sampled.
Primary Sample: Primary Sample is the representative sample of the fuel delivered to the ship collected throughout the
bunkering period obtained by the sampling equipment positioned at the bunker manifold of the receiving ship.
Retained sample: Retained sample is the representative sample in accordance with regulation 18(6) of Annex VI to
MARPOL 73/78, of the fuel delivered to the ship derived from the primary sample.
Sampling Method: The primary sample should be obtained by one of the following methods.
1. Manual valve-setting continuous-drip sampler
2. Time-Proportional automatic sampler
3. Flow-Proportional automatic sampler
Sampling equipment should be used in accordance with manufacturer’s instructions or guidelines as appropriate.

Guidelines for the Sampling of Fuel Oil for Determination of Compliance with ANNEX VI of
MARPOL 73/78
AUTOMATIC
SAMPLER
Manual Continuous Drip
Sampler
Sampling and Sample Integrity:
1. A means should be provided to seal the sampling equipment throughout the period of supply.
2. Attention should be given to:
a) The form of set up of the sampler
b) The form of primary sample container
c) The cleanliness and dryness of the sampler and the primary sample container prior to use
d) The setting of the means used to control the flow to the sample container
e) The method to be used to secure the sample from tampering or contamination during the bunker
operation
3. The primary sample receiving container should be attached to the sampling equipment and sealed so as to
prevent tampering or contamination of the sample throughout the bunker delivery period.
Sampling location: For the purpose of these guidelines a sample of the fuel delivered to the ship should be
obtained at the receiving ship’s inlet bunker manifold and should be drawn continuously throughout the bunker
delivery period.

Guidelines for the Sampling of Fuel Oil for Determination of Compliance with ANNEX
VI of MARPOL 73/78
Retained sample handling:
1. The retained sample container should be clean and dry
2. Immediately prior to filling the retained sample container, the primary sample quantity should be thoroughly
agitated to ensure that it is homogenous
3. The retained sample should be sufficient quantity to perform the tests required but should not be less than 400 ml.
The container should be filled to 90% +/-5% capacity and sealed.
Sealing of the retained sample: Immediately following collection of the retained sample, a tamper proof security
seal with a unique means of identification should be installed by the supplier’s representative in the presence of ship’s
representative. A label containing the following information should be secured
To the retained sample.
1. Location at which, and the method by which the sample was drawn
2. Date of commencement of delivery
3. Name of bunker tanker/installation
4. Name and IMO number of the receiving ship
5. Signature over the printed name of supplier’s and ship’s representative
6. Details of seal identification, and
7. The bunker grade
Retained sample storage:
1. The retained sample should be kept in a safe storage location.
2. The retained sample should be stored in a sheltered location where it will not be subject to elevated temperatures,
preferably at a cool/ambient temperature, and where it will not be exposed direct sunlight.
3. Pursuant to regulation 18(6) of Annex VI of MARPOL 73/78, the retained sample should be retained under the ship’s
control until the fuel oil is substantially consumed, but in any case for a period of not less than 12 months from the
date of delivery

Dubious Practices Summery
Dubious Practices Summery:
 Fuel oil purchasers need to advise the ship’s staff what grade of fuel they will receive and
how it will be transferred.
 Fuels from different deliveries should be segregated as far as is practicable
 All receiving fuel oil tanks need to be gauged and the results recorded prior to taking
delivery of fuel
 Don’t sign any documentation before you have witnessed the actual event
 Always take up witness offers made by the supplier’s representatives.
 If the origin and method by which the supplier’s sample was obtained is unknown then
sign for it adding the words “for receipt only - source unknown”
 Fuel oil samples should always be taken by continuous-drip method throughout the
bunkering.
 If the fuel oil delivered is supplied by more than one barge, a sample should be taken of
each fuel oil from the supplying barges.
 Sign the bunker delivery receipt only for volume delivered. If the supplier insists on a
signature for weight add “for volume only - weight to be determined after density testing of
representative sample”.
Comment : Make sure that what you sign for is what you get. Be certain that the bunker
receipt reflects the facts as witnessed. Do not sign anything unless you have witnessed
it. Always take a representative sample.

Necessary Tools/Documents Required for Bunker Calculation
 Sounding Tape
 Thermometer
 Density Hydrometer
 Water Finding Paste(For MDO)
 Bunker Delivery Notes (BDN)
 ASTM 53B table for density correction
 ASTM 54B table for VCF calculation
 ASTM 56D table for weight correction
 Calculator
 Sample bottles

Pre-Bunker Data Collection in Existing Bunkering
Measuring The Density: To measure the density, a fuel sample is drawn from randomly selected tank of
the tanker. Sometimes average density of multiple tanks are used.
Measuring The Temperature: The Temperature is measured using a mercury thermometer.
Pre-bunker Tank Gauging/Sounding: Using a suitable sounding tape the soundings of associated tanks
of the tanker are taken and calculate the corresponding volumes from the tank capacity/calibration
tables.
Existing Calculation Sheet:
Tank No
Tank
Sounding
cm
Observed
Volume in
m3
Observed
Density
Kg/m3
Observed
Temp.
o
C
1P 301 115.471
1S 299 116.723
2P 333.9 195.201
2S 339 198.752 977.4 26.25
3P 337 117.175
3S 338 118.89
4P 320 129.295
4S 323 132.376
Total Obs. Vol : 1123.883 m3
Observed Density: 977.4 oC
Quantity in MT(obs vol. x obs density/1000): 1098.48 MT

Existing Bunker Quantity Calculation Flow Chart
Observed Volume (m3)
Quantity in
(Kg)
Observed Density (Kg/m3)
Tank Calibration/Capacity
Tables
Sounding of Desired Tanks
Observed Temperature (oC)
1000
Quantity in Metric Tones (MT)

IBIA Standard Procedure for Bunker Quantity Calculation Flow Chart
Observed Volume (m3)
Observed Density of Representative Sample (Kg/m3)
Tank Calibration/Capacity Tables
Sounding of Desired Tanks
Observed Temperature of Representative Sample oC
Quantity in Metric Tones (MT)
ASTM53B
Density at 15oC (Kg/m3)
ASTM 54B
Volume Correction Factor (VCF)
Standard Volume at 15 oC (m3) Weight Correction Factor (WCF)
ASTM
56D
Tank Temperature oC
Actually, the density of a representative sample at 15oC
should be specified in Bunker Delivery Receipt (BDR). If not
specified, then use this method to calculate standard density.

Case Study 01:
Basic Information Supplied in the Bunker Delivery Receipt.
Product Name : Heavy Fuel Oil
Density in BDN at 15oC : 989.999 Kg/m3
Density of Representative Sample after Bunkering at 15oC = 980.019 Kg/m3

Basic Information Supplied in the Bunker Delivery Receipt.
Product Name : Heavy Fuel Oil
Density in BDN at 15oC : 989.999 Kg/m3
Case Study 01 (Cont’d):

Opening Observed Volume (m3) = 1236.76
Opening Standard Volume (m3) = 1208.75 (VCF calculated from ASTM 54B)
Closing Observed Volume (m3) = 144.949
Closing Standard Volume (m3) = 141.826 (VCF calculated from ASTM 54B)
Observed Volume Transferred = 1236.76 – 144.949 = 1091.81 m3
Standard Volume Transferred = 1208.75 – 141.867 = 1066.88 m3
The theoretical weight transferred in air: = Density (kg/m3) * Standard volume at 15°C(m3) x Factor = kg * kg/1000
= 990.0*1066.88*0.988899/1000 (MT) (The Factor is calculated from ASTM 56D)
= 1055.04 MT
The transferred weight of the fuel based on the density provided in Bunker Delivery Receipt(BDR) is = 1055.04 MT
As the density determined from a representative sample of the bunkering is 984.994 kg/m3;
the actual weight transferred in air = 980.019 * 1066.88/1000 * 0.978919
= 1044.07 MT
If the density is not determined from a representative sample, the BDR should be signed only for volume. If the supplier
insists on a signature for weight, add “for volume only - weight to be determined after density testing of a
representative sample”.
Comment: The example calculation given for a fuel delivery changed the actual delivery from:
1055.04 Changes to 1044.07 MT a savings of 10.97 MT or $8776 at $800/MT
Case Study 01 (Cont’d):

Bunker Quantity Determination Software Package
This is the software Package designed to automate entire bunker calculation process
without compromising with any standard. All of the petroleum measurement
tables required to work with Density, API Gravity or Specific Gravity are embedded
in this software. This is light weight and can be used without installation in any windows based
system.
To download a demo visit author’s personal website www.moynulislam.com and see under
“Application “ tab.
Applicability: Crude Oils, Gasolenes, Transition Zone, Jet Fuels, Fuel Oils and Lubricants
The main feature of this software is interactive conversion capabilities. With a single click one can
switch from one measurement standard (say, Density based measurement to APIG based
measurement) to another standard without changing the existing values. The accuracy of the
calculation has been tested by comparing with DNVPS software “Bunker Master 2.0” and with
Shell’s “BunkerCalc”. This software can be used universally to calculate the actual fuel quantity.
Additionally this software contains energy calculation tools, density conversion tools, VCF
calculation tools, WCF calculation tools, MT calculation tools etc. and much more.
The VB based software is featured with OFF HIRE BUNKER SURVEY, BUNKER ROB
SURVEY, ULLAGE REPORT GENERATION, and BUNKER STEM SURVEY
To try it out please visit www.moynulislam.com under Applications tab

Bunker Quantity Determination Software Package
SN Description Version
Database
Availability
01 Bunker ROB Survey + Bunker Detective Survey (221B survey) Workbook DENS/M3/oC Yes
02 Bunker Stem Survey Workbook DENS/M3/oC Yes
03 ON-OFF-HIRE Survey Workbook DENS/M3/oC Yes
04 Bunker ROB Survey + Bunker Detective Survey (221B survey) Workbook APIG/US, bbl/oF Yes
05 Bunker Stem Survey Workbook APIG/US, bbl/oF Yes
06 ON-OFF-HIRE Workbook APIG/US, bbl/oF Yes
07 Bunker ROB Survey + Bunker Detective Survey (221B survey) Workbook DENS/M3/oC No
08 Bunker Stem Survey Workbook DENS/M3/oC No
09 ON-OFF-HIRE Survey Workbook DENS/M3/oC No
10 Bunker ROB Survey + Bunker Detective Survey (221B survey) Workbook APIG/US, bbl/oF No
11 Bunker Stem Survey Workbook APIG/US, bbl/oF No
12 ON-OFF-HIRE Survey Workbook APIG/US, bbl/oF No
Above workbooks are designed for HSFO, LSFO, MDO, LSMDO, MGO and LSMGO. But it is possible to customize for other
refined products like Gasolenes, Naphtha, Jet Fuels and Lube Oils and also for Crude Oil.
13 Draught Survey Workbook and Wedge Volume Calculation
14 Workbook with necessary tools (1D, 2D Interpolation, Density<> APIG<> SG<> conversion, Blended Density
Calculation, Temperature Conversion etc and much more) required by bunker surveyors

PIFMS | BUNKER MANAGER – ROB+221B SURVEY
This program is designed, considering Bunker ROB Surveyor’s requirements. With a single click you can generate your all
survey reports like VESSEL GAUGING REPORT, BUNKER ROB CERTIFICATE, 221B REPORT, TIME LOG, SURVEYOR’S
COMMENTS etc in excel or pdf format. You can directly print or email reports from the program.
To download the demo, visit author’s webpage www.moynulislam.com and you will get it under Applications tab.
This is a database embedded customized workbook for Bunker ROB and Bunker Detective
Survey (221B Survey) where a surveyor can store his all survey related information in a
built-in database which one can retrieve for further processing.

PIFMS | BUNKER MANAGER generated Vessel gauging report

This is a database embedded customized workbook for Bunker STEM SURVEY where a surveyor can store his all survey
related information in a built-in database which one can retrieve for further processing. It has also built-in report
generation capabilities like ROB SURVEY program. You can generate SUPPLY VESSEL and RECEIVING VESSEL GAUGING REPORTS,
FINAL SURVEY SUMMARY , COQ, TIME LOG, TEMPERATURE LOG, DOCUMENTS CHECKLIST, FUEL SAMPLE INFO, SURVEYOR COMMENTS etc.
PIFMS | BUNKER MANAGER – BUNKER STEM SURVEY
To try the demo, visit author’s webpage www.moynulislam.com and you will get it under Applications tab.

PIFMS | BUNKER MANAGER generated receiving vessel gauging report

PIFMS | BUNKER MANAGER generated Final Survey Summary Report

PIFMS | BUNKER MANAGER generated COQ report

PIFMS | BUNKER MANAGER generated document checklist

PIFMS | BUNKER MANAGER Print Panel and fuel sample information

PIFMS | BUNKER MANAGER ON-HIRE SURVEY CERTIFICATE

PIFMS | DRAUGHTS MASTER – Certificate of draughts survey

Shore Based Fuel Storage System
3D layout of a shore based power station fuel storage system. This software can
be customized for any tank firm/terminal to automate fuel calculation process.

Shore Based Fuel Storage System Monitoring
This is also another semi-automatic fuel storage monitoring system designed to observe the content of
individual storage tanks. You will need to put the dip and tank temperature manually. This is
customizable for any liquid storage system. Using data acquisition system, it can be made
completely automatic (no human operator is required to show the fuel quantity).

Bunker Delivery in Shore Tanks
It seems that, bunkering in a shore tank is much easier than that of a ship/barge. The transferred fuel volume
(observed volume) is determined from the initial and final tank sounding. The initial and final tank
temperatures are not being considered. But the temperature differences influences the entire calculation
process. In the software below we will estimate, how the differences in temperature participates on
transferred quantity.
Bunker delivery in a shore based storage tank

Effect of Temperature Variation in Bunkering
Effect of Temperature Variation in Bunkering :
Average temperature of Shore based fuel storage tanks are maintained around 45 to 50 oC to keep the
fuel temperature above their pour point. Another reason of heating is to enhance the transfer
process by lowering the viscosity of the oil. Hence, elevated temperature will greatly impart on
received quantity during bunkering if the temperature correction is not considered. As the
capacities of shore based storage tanks are normally high compared to other storage tanks (like in
barge/oil tanker), So the variation in temperature by few degrees will change the entire scenario of
bunkering. Please see the subsequent slides regarding volumetric expansion or volumetric
shrinkage due to the variation in temperature during bunkering.

This is another useful tool for bunker handling in shore tanks. It consider all factors related to bunker quantity and use
dynamic material balance to determine the volume shrinkage/expansion due to the temperature difference of incoming
and receiving vessel. The above picture showing an oil tanker delivering bunker in a shore tank possessing temperature
30oC and after delivery the tank temperature increases to say 40 oC. According to the calculation, the receiving vessel will
pay for 13.83 MT (Expanded quantity) that they have not received if they ignore the temperature correction.
Bunker Handling in Shore Based Storage Tank

The above picture showing an oil tanker delivering bunker in a shore tank possessing temperature
40oC and after delivery the tank temperature drops to say 30 oC. According to the calculation, the
incoming vessel won’t find 13.73 MT (Shrinkage quantity) oil if they ignore the temperature
correction.
Bunker Handling in Shore Based Storage Tank

Prepared By
Md. Moynul Islam
Chemical Engineer
Expertise on Marine Fuels and Lubricants
Contact:
Cell : +8801816449869
Inventory
Control
Bunker
Manager
Quick Volume
Tools

How BargeCalc Works?
Input Variables
•Barge Drafts
•Tank Sounding
•Tank Temperature
•Density at 15oC
LOAD DATABASE
Select TRIM Correction Table
Select LIST Correction Table
Run 2D-Linear Interpolation For
Given Sounding, TRIM and LIST
Values
LIST and TRIM Corrected
Volume
Call ASTM 54B Table For
VCF Calculation
Call ASTM 56D For
WCF Calculation
Calculate Quantity in Metric
Tones
You can customize this application for your own vessel
by integrating your own vessel calibration tables. It
will definitely reduce your time to manage your OBQ
and also to monitor your fuel consumption.
To customize it for your own vessel, please contact
with the author.

Using Flow Meters in Bunkering
An worrying comment made in the Control Engineering article ”Flow meter selection: Right size, right design”
that “Worlds 70% of installed flow meters are either the wrong technology or the wrong size ”.
There are three types of flow meters are commonly used in oil and gas industry. They
are the PD (Positive Displacement) flow meter, Ultrasonic Flow meter, and
Coriolis Flow meter. None of the above are universal. All of them have some
advantages and disadvantages depending on the field of application.
Ultrasonic Flow Meter
Ultrasonic Flow Meter
Ultrasonic Flow Meter Measurement Technology

The Coriolis Mass Flow meter
Among the above flow meters, Coriolis Mass Flow Meter is the best choice in
bunker industry. The main reason is its accuracy in mass measurement and
entrained air compensation technology made it unique in flow measurement.
It can measure the density, volumetric flow rate and the mass flow rate.

Expecting your valuable suggestion about this presentation
This presentation is under continuous development. Most of the
resources are from internet. Thanks to all who have uploaded the
materials/information for the web learner.. Expecting your valuable
suggestion/comments about further improvement of this
presentation.
For more information about the customized bunker fuel
calculation software please visit authors personal website
Mobile: +8801816449869
Skype : moynulbd

Marine Fuel Oil and Fuel Oil Bunkering Procedure

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