Bunkering Operations: Precautions, Checklists, Calculations & Corrections Explained

Written by: sriram balu • Edited by: KennethSleight
Updated Jul 12, 2011

An actual bunkering operation is carried out with bunker checklists. In this article, emphasis is made on the checklists, safety precautions, SOPEP locker and SOPEP equipment, temperature and density correction to calculate the quantity of oil bunkered. The formula for calculation has been included

Bunkering Oil

Earlier we learned about the bunkering and what is means. Now we will study the process of actual bunkering operations and the practical details of the process of bunkering oil. All types of ships needs fuel oil, lube oil, etc. and hence it is important for everyone to understand the actual process of bunkering, so here we go.

Pre-bunkering preparations.

The most important aspect of bunkering operation are the "checklists", which form a part of company's safety management system (SMS) and I.S.M.,eliminating the possibility and negligence of human and other operational errors. The pre-bunkering checklist must be followed in-consultation with the Chief Engineer (C/E), as he is the person-in-charge for the bunkering operation. Before bunkering, usually it is 4th engineering officer, taking "soundings" of bunker tanks and calculates the volume of fuel oil available in every fuel oil tank of the ship. Then a Bunker-plan is made to plan the distribution of total quantity of bunker fuel oil.

Bunker Procurement

Ordering of Bunker oil:

The ship Managers (superintendents) monitor the performance of a fleet of ships. For example, on owning a car, we tend to keep a check on its fuel consumption widely called as "mileage." It is the distance travelled by the vehicle for a unit volume of fuel used. In the same way, as the ship consumes humungous quantity of fuel, whose costs are forming the major part of ship's operation. Managers tend to keep a check on it. This is measured in terms of specific fuel oil consumption of the main propulsion engine.

automated bunker procurement flowchart2[1] Upon knowing the fuel oil consumption for a day and the next voyage plan, the quantity of fuel oil required is calculated and compared with the available bunker tank capacity. A requisition is placed through the C/E and Master of the vessel to the Managers. The requisition is processed and evaluated for the quality and quantity of fuel to be supplied for the particular ship. Planning is done for the delivery of bunker at a particular port where the oil is available at a comparitive lesser cost. On taking all these aspects into consideration, the Managers, deliver bunker to the vessel. Upon receiving the bunker, a sample collected during bunkering operation is sent for lab analysis to confirm the delivered oil meets the required standard for the safe and efficient operation of the auxiliary engines & main propulsion engine.

Pre-Bunker Checklist

1. State of adjacent waters noticed

2. Vessel properly secured to dock

3. Check suppliers product corresponds to ordered product

4. Agree quantity to be supplied

5. Check valves open

6. Day tanks full and supply valves closed

7. Warning signs in position e.g. No Smoking

8. SOPEP plan available

9. Clean up material in place

10. Oil Boom in place

11. Foam fire extinguisher placed at bunker station

12. Alfa Laval and transfer pumps off

13. Fuel tank supply valves open

14. Agree stop/start signals between vessel and barge/truck

15. Bravo flag flying/red light showing

16. Agree pumping/transfer rate

17. Agree emergency shut down procedure

18. Specification sheet received

19. Check hose and couplings are secure and in good order

20. Fuel nozzle and hose secured to vessel

21. Check barge/truck meters Reading:

22. Check on board meters Reading:

23. Bunker Valve open

24. Unused manifold connections blanked off

25. Master informed

26. Signal pumping to commence

The above checklist has to be completely filled religiously by both the ship & barge personnel. Please move on to the next page by clicking below

Image Credits

Automated Bunker Procurement Flowchart: Calsoft Enterprise Solutions, USA

SOPEP equipments

At the bunker manifold and wherever necessary, as per the ships SOPEP plan, the SOPEP equipments should be kept in immediate readiness in order to avoid oil spill/pollution during bunkering operation.

SOPEP- Shipboard Oil Pollution Emergency Plan.

The SOPEP Locker must have minimum of the below specified items:

1. absorbent roll

2. absorbent pads

3. absorbent granules

4. absorbent materials

5. brooms

6. shovels

7. mops

8. scoops

9. empty receptacles (200 ltrs capacity)

10. portable air driven pumps

11. oil boom

12. oil spill dispersants.

These items must be stowed in an easily accessible locker, clearly marked, and is to be brought on deck ready for immediate use, prior to all oil transfer operations.

During Bunkering Procedures - Checklist

1. Witness taking and sealing of 2 representative product samples

2. Monitor fuel connections for leaks fuel flow and control tank levels

3. Change over of tanks whenever necessary.

4. Checking the rate at which bunkers are received.

5. Checking the tightness/slackness of mooring ropes.

6. Checking trim/list of the bunker barge & the ship.

7. Continuous monitoring/look outs for the vessel's position(when at anchor).

During bunkering, the above checklist must be filled up and continuous monitoring of the above secified items are required till the bunkering operation is complete.

After Bunkering Procedures

On completion of the bunkering operations, with the ship-barge co-ordination, the line should be blown with air to make sure the line is not filled with oil. The after-bunker checklist is followed.

After Bunker Checklist

1. Bunker Valve closed

2. Disconnect hose (drain before disconnecting)

3. Check barge/truck meter Reading:

4. Check ships meter Reading:

5. Sign Bunker Delivery Receipt BDR No.:(Bunker Delivery Report/Note).

6. Retain BDR with product sample

7. SOPEP plan returned to bridge

8. Clean up gear stowed / Oil boom returned

9. Bravo Flag/Red light stowed/switched off

10. Remove and pack away warning/safety signs

11. Foam fire extinguisher placed back in correct location

12. Complete Oil Record Book

13. Master informed of completion

14. Confirm in Oil Record Book Bunkering checklist completed

Quantity Calculation & Temperature-Density Correction:

After bunkering of various fuel oil tanks, the quantity in each bunkered tank must be calculated to cross-check whether the received quantity of oil matches the requisition. For calculating the quantity, "sounding" of the tanks which are "bunkered" must be taken. The "Density" of the fuel oil supplied vary from place to place. It also varies with the temperature. As a thumb rule, the density of fuel oil decreases with increase in temperature. So, when the oil is supplied at a higher temperature, then the volume of oil supplied is less than what is supplied at lesser temperature.

Oil Temperature ----------------------------Density ------------------------------- Volume Of Oil Supplied

Increases--------------------------------------Decreases------------------------------------Lesser

Decreases--------------------------------- ---Increases -------------------------------------More

Also the formula which is generally used for temperature-density correction is as follows:

MT = (Temperature Corrected density * Actual Sounded Volume).

Temperature Corrected Density can be calculated with the under-mentioned fomula:

Temperature corrected Density = Density of Fuel Oil @ 15 degree Celsius * [1- {(t1-15) * 0.00064}]

where

t1 stands for temperature of oil in bunker tanks in degree celcius,

0.00064 is the correction factor,

volume of oil in m^3 (actual sounded volume), is obtained from the sounding table.

Safeties

General Safeties During Bunkering:

SOPEP locker,

Emergency shut-down arrangements,

Bunker line over-flow arrangements to overflow tank with audible & visual alarm,

Relief valve in the bunker line,

Containment trays.

Consistent & Continuous look outs.

Conclusion:

Thus bunkering operation is directly related to "MARPOL" annexes, i.e annex 1 and annex 6. When oil is spilled it causes marine pollution under annex 1. When the bunkered oil doesn't meet certain specifications, it causes pollution of air which comes under annex 6.

"MARPOL" will be dealt with in future articles.

Akarshansood Jan 2, 2012 2:42 AM

RE: Bunkering Operations: Precautions, Checklists, Calculations & Corrections Explained

GOOD INFORMATION SIR............IS THE SAME FORMULA IS USED FOR TEMPERATURE CORRECTION FOR LUBE OIL AND DIESEL OIL SOUNDINGS.

JMW Jul 19, 2011 7:44 AM

Tank Dipping

IBIA, the International Bunker Industry Association, is the user group for the bunker industry and an accredited NGO at IMO.
The FAQs and glossary are worth reading e.g. this one on tank tables:
http://ibia.net/content.cfm?page_id=86

JMW Jul 19, 2011 7:26 AM

The Chalmers Lindholmen University many years ago published some study notes on bunkering and the "errors" (inadvertent or deliberate) that can occur.
False tank tables, poor trim and list, blind dip tubes, coffer damns, false temperature reporting, false density reporting and so on.

All are a consequence of an industry with virtually no instrumentation.

In theory, and done right, the use of tank dipping ought to produce satisfactory quantity accounting.
But, as may be found from the IBIA web site and other sources, dipping the barge tanks is preferred as these have been calibrated.
Dipping vessel tanks, no matter the vessel type, is not.
Often they are not calibrated and calculations done from the geometry are unreliable as there may be many errors such as due to pipes running through the tanks.
Barges may have a set of tank tables. In some ports, as I understand it, the PSA should keep authorised/certified copies. These should be checked as one of the frauds is to substitute false tables on board.

Quantity accounting basically depends on measuring the density and correcting the volume dipped to the volume at 15degC and then finding the density at 15degC. This is the value the supplier should declare in the BDN.

Be aware that in a recent unofficial report, in over 50% of commercial HFO samples analysed there was found a significant difference between the sample density and the the density declared in the BDN and 25% in the case of MGO/MDO samples.

This is why the spreadsheet at (http://www.cheresources.com/invision/files/file/126-density-to-temperature-correlations-for-hydrocarbons/) is laid out the way it is. You start with the density in the BDN and you can work out what the hydrometer should say. SO the very first sample you take and run you can tell at a glance if the density is what it should be.

The VDM 250.2 is an ideal tool to profile tank contents for density and viscosity variations. http://www.lemis-process.com/?mid=41&measure=42&pid=20

sathia Jul 13, 2011 10:44 AM

Procedure For Navy Ship Calculation

Hi,
I'm facing a problem with japan navy ship where they don have tank calibration book for me find the quantity. Always using level gauge on the engine room computer.
I did check the supplier tank without dispute with using my own sounding tape and density check.

Please advice me on the procedure to check on navy ship where don have table book.

Thank you

regards,

Peri Avadhani Jul 5, 2011 11:53 AM

Bunker Shortages

The best solution i have encountered to solve the bunker shortages is very simple but most of us over look.
The modus operandi of the bunker barges around world who are cheating us is as follows.
1. They show wrong soundings, use wrong tapes, wrong tables and show the quantity onboard higher at the starting soundings.
( which most of the chief engineers overlook , and leave it to 4/e or some junior engrs who are inexperienced in these functions)
2. Now the chief engr has accepted inflated fuel initial soundings and signed for it.
3. at the end of bunkering they will show the calculation by showing the ROB on the barge - the intial qty is bunkered to the vessel.

at this stage the chief engr finds he got less and tries to make noise. but nothing else he can do.

only solution to this problem is :
1. send the junior / CE with new sounding tape from the ship and take all the tanks with the tape of ship also.

This put them off from doing mischief.

i had been doing the same for some time and found a lot of improvement.

Anonymous Jun 28, 2011 8:02 AM

Please,could you recheck the formula
MT= {(t1-15)*0.00065}*volume of oil in m^3,
It seems you forgot to include the FO density at 15 degr.C

Peri avadhani Mar 5, 2011 8:17 PM

Bunkering Problems

I think it is better to add rhe practical problem of bunker shortages, capuchino bunkers, Spec Gravity overstatements etc.
Bunker shortages were there only at singapore previously, but now being noted in rotterdam, jeddah and every other bunkering ports.
If any body wants tips on these subjects contact me.

stephen Feb 23, 2011 12:31 PM

factor determining bunkering plan

sir, can you provide more information about the factor determining bunkering plan? such as time, speed, distance...???

josese Jan 9, 2011 3:24 AM

sir can u give the sequence of events and the precautions taken during bunkering.
the importance of receiving of sample of bunker oil.
the resources available and procedure of handling bunker overflow on deck.

robinson Jan 3, 2011 8:34 PM

bunker calculations

please give detail calculation and correction taken on bunker( before& after bunkering)

JMW Dec 30, 2010 5:39 AM

Densty Calculations

There are two useful spreadsheets at http://viscoanalyser.com/page8.html and further spreadsheets are available on request.
The density temperature relationship (and volume correction factor) are typically as defined in the Manual of Petroleum Measurement Standards.
Note that if the fuel is aerated (the "Cappuccino Effect") then the density measured off-line may be false low and the viscosity false high. It is important to ensure the fuel is air free. It should also be homogeneous.

erikson g. gultiano Dec 28, 2010 8:23 PM

dear sir,

i just want to ask if deck department have a role about the bunkering operation?thank you sir...more power and happy new year..

Jon watson Aug 25, 2010 6:37 AM

Bunkering

IBIA (the International Bunker Industries Association)
has some useful material on its website and runs a number of bunkering courses round the world for various aspects of bunkering.

Jon Watson Aug 25, 2010 6:35 AM

Correction factors, density and temperature

The usual procedure to find the necessary density values and the volume correction factors is to note the fuel temperature when bunkering or in the tanks and then measure the sample density.
The density of the sample is usually measured with a hydrometer for 15degC but actually measured at a higher temperature e.g. 50degC. This is the "Observed Density".
Applying the hydrometer correction (for the fact it is calibrated for 15degC and is being used at 50degC) and then tables, the density at 15degC is found. This is the "base density". This is the density that the supplier quotes on the BDN.
Tables are again used to find the density at the temperature in the tanks. This is the "alternative density".
The next thing is to calculate the volume correction factor which is to convert the volume at the storage temperature to the volume at 15degC.
This is simply a ratio of the alternative density to the base density.
There are many calculators available for use on a PC which will simplify these calculations. It seems to be general practise to round density values to the nearest 0.5kg/m3, no doubt to speed the measurement and calculations because you need these answers pretty quickly during bunkering.
You might also need to know the fuel density at 98deegC which is the temperature it will go through the centrifuges and you want the Ignition Index value.
Most usually the key concerns for an engineer are "Can I clean it?" i.e. will this fuel pass through the treatment stages and be rendered suitable for burning, and "Can I burn it?" which is to say, is the viscosity within the limits of my fuel heaters so I can get the right EVT (equi-viscous temperature or injection temperature).
Some engines will quote an operating envelope which involves three parameters, density, viscosity and ignition index.
Spreadsheet for density calculations (Density 12MF.xls) and viscosity (RMI ASTM D341 revo1.xls) are found here www.viscoanalyser.com/page8.html

Sudhir Aug 22, 2010 7:45 AM

Pre Bunkering.

Please note that, along with the Pre Bunkering Preparations and start of Bunkering (as explained above), one should fill / exchange and agree with the safety requirements between the delivering and receiving vessels. This will help and save you from unhealthy situation in case there is an eventuality.

Thanks.

radsque May 17, 2010 4:59 AM

bunkering calculation

sir
can you give me a problem for bunkering calculation with its formula and solutions? thanks

juan carlos May 3, 2010 5:28 AM

Calculations

go into details on how to obtain corrected soundings if there are trim & list and free water present,then how to obtain the GOV & GSV then subsequently weight in metric tons based on the density & temp..tks

Darragh O'Reilly Apr 11, 2010 6:12 AM

Volume vs Temperature

Thanks for the article but I'm a little confused about something.

I would have normally said that just about any substance would increase in VOLUME when you increase its temperature. The density does go down because the molecules of the substance move further apart as they gain more heat energy. When the molecules move further apart they obviously take up more space and thus increase in volume.

jerome tingzon Mar 28, 2010 8:51 AM

volume correction factor table

hello gd day sir,
I would like to ask if you can send my a volume correction table for fuel calculation thx.
respectfully yours,
jerome tingzon

samir khoueldi Mar 24, 2010 2:46 PM

I want to ask you about how many samples shall we take per bunker operation, and if you have any idea about regulation governing the location of samples locker on board the ship.

mark bolongs Feb 23, 2010 8:47 AM

how about if the S.G. @ 15 deg celcius is o.9900 what is the corection factor should i use?is there any formula for solving the correction factor?is there any table for getting correction factor?where can find it if any?

Sunam Suwim Jan 15, 2010 12:00 AM

Good one buddy. I am lecturing at one of the maritime training in Sarawak. malaysia. lecturing Near coastal students This is good article. thanks for sharing. more please.

fuentesandy Jan 10, 2010 2:16 AM

crank shaft deflectin how to read the gauge

sir please guide me how read crank shaft defiection on dial gauge is there any video i can watch

Panjeshah Jan 2, 2010 6:37 AM

Article is helpful and it would ne great if analytical treatment is added and relevant formulas also provided

naveen Dec 25, 2009 2:10 AM

hi anna,it is very useful 2 me,.thanks
i m ur junior in our college.2003-2007 batch

basuka55 Oct 31, 2009 2:51 PM

BUNKERING OPERATIONS

This is a nice article regarding bunker operations.Here i want to add few things which i think relevant for safe bunker operations from the safety point of view.
* The air vents of the tanks concerned to be checked for any blockage, as several accidents took place , during bunkering operations, as due to the blockage of air vents, the sounding was improper causing overflowing and accidental spillage.Also the flame arrestors fitted in the air vents should be in good condition.

* During bunker operations, the sight glass in the engine room, for observing any overflow taking place to be monitored extensively and precautionary measures to be taken immediately.
* There should be no hot work in the engine room as well as in the decks during bunkering operations.As the vapors of the bunkering fuel is highly inflammable.
* The sounding pipes caps should be of self closing type,Whenever sounding is not checked, it should be in closed condition.

tharaka Oct 30, 2009 6:15 AM

thank you.absoliutly this is a very imfortent article for self study.

Amulya Verekar Sep 15, 2009 2:27 PM

nice informative article

hey balu it was a pleasurable and knowledgeable experience reading this article. i m about to sail as a junior engineer and this was of gr8 help to me.. thnx..

JACKMAY RAWLINGS Sep 11, 2009 5:35 PM

Great article Balu

This is really a nice article for home study. Well i'm a marine operations deck cadet at WMA southampton. I would love to an article on "how ISM and ISPS codes are met during delivery of ship's stores" especially at security levels 1 anmd 2. Thanks.