OPERATIONAL SITUATION DURING DISCHARGE, LOOKING FOR OPINION REGARDING THIS MATTER

Good day to all my followers and readers, This time is to open a discussion reagring some typical operations that can occur during the discharge of a CBOB cargo, this a real scenario and some opinions differs regarding the way of how the line diplacements volumes has to be calculated. Here below a brief explanation of both scenarios: SCENARIO # 1: DISCHARGING CBOB PARCEL: The ship is arrives to Montreal for discharge two grades, CBOB and Premium Unleaded Gasoline (PUG), the 1st grade discharged was the CBOB, the shore line condition before discharge was as follows: a) A section related to the shore line was full of ULSD and its capacity was 20M3 approx, and other section of line was full of Regular Gasoline 30m3 approx, terminal decide to displace the two portion of the shore line using the product to be discharge by the ship in this way line will remain packed with CBOB. one 1st line displacement of 20m3 into a shore tank lets call it Tk-a, and a second shore line displacement of 30m3 into shore tank called "b" and after the two line displacement the full capacity of the shore line will be packed with CBOB. Then after completion of the line displacements the full discharge will go into TK-C. After completion of the discharge we had the following data to calculate our outturn figures: 1.- Open gauge and close gauge of TK-A (20m3 line displacement ULSD). 2.- Open gauge and close gauge of TK-B (30m3 line displacement RUG). 3.- Open Gauge and close gauge of TK-C (full CBOB discharge). Terminal has provide all the info regarding the product densities contained into all shore tanks for the open gauges and closing gauges. In this case the dilemma is the following: For shore quantity determination which densities we suppose to use to calculate the two shore line displacements? the ones provided by the terminal for the opening and closing gauges? or, we have to use the density corresponding to the product being discharge by the Vessel? (ship's density). I will wait for your commentaries regarding this matter, because I am in a big confusion with my supervisors regarding which densities to use and which don't, I am agree to use the densities provided by the terminal rather the ship's densities. I will wait for your commentaries regarding this matter. Have a nice weekend. Abelardo Eijesser

VESSEL EXPERIENCE FACTOR

The purpose of this bulletin is to clarify the position of IFIA member companies regarding the use and application of VEFs (Vessel Experience Factors). IFIA member companies are frequently asked to apply VEFs to vessel figures for the purpose of Custody Transfer where measurements determined by shore tank or meter are not available. Following the first issue of this bulletin in March 2002 the new standard, API MPMS Chapter 17.9/EI HM 49 Vessel Experience Factor (VEF) was issued in November 2005, “the Standard”. Appendix C in API MPMS Chapter 17.1 was withdrawn in March 2008. The VEF is primarily a loss control tool to help assess the validity of quantities derived from shore side (tanks, meters, etc.), off-shore installations or from other vessels. It should be recognized that quantities derived using vessel figures and the VEF will never have the measurement rigor of those from traditional static shore tank or meter measurements. For these reasons the Standard states that VEF adjusted vessel figures may be used for custody transfer where traditional measurements are either "not available, or are known to be inadequate". Although not well defined, "known to be inadequate" implies a general acceptance by all parties that due to poor design or obvious malfunction a shore tank or meter measurement cannot be relied upon. While in many situations when traditional measurements are questioned, a VEF adjusted vessel quantity may be the only available alternate measurement, the lack of statistics for precision and uncertainty cannot be overcome. Therefore, in these situations, it should not be automatically assumed that VEF adjusted vessel figures will provide any greater accuracy than the traditional measurements which they might replace. Limitations of the Vessel Experience Factor There are a number of factors which limit the overall accuracy of quantity calculations based on application of a VEF to vessel measurements. These factors are recognized in the Standard but a number of issues remain: • The voyage data used to compile a VEF must, by necessity, come from information supplied by the vessel. The inspector is rarely able to verify the accuracy of this data. • Most vessels only maintain records of load port data. Therefore, most vessel experience factors are load port experience factors (VEFL), even though they are frequently applied to discharge measurements. The Standard requires that data necessary for calculation of both load and discharge VEFs should be maintained by vessels. As vessels are commonly not aware of the shore outturn this data is not normally available. Data and information may be available from other reliable sources but not necessarily in sequential order. • Barge towing companies often do not maintain load or discharge records. Data may be available from other reliable sources, and which would include inspection companies and/or oil companies, but, again, not necessarily in sequential order. • There is considerable debate about whether VEFs calculated from “full” cargoes should be applied to part cargoes. The Standard allows for development of partial VEFs for “a specific set of compartments, or amount less than 75% of a vessel capacity”. However, this requires regular operation of the vessel in the same condition and it is extremely rare for there to be sufficient data to compile a partial VEF. The Standard states “if data to determine a partial cargo VEF is not available it is recommended to apply the full cargo VEF to each partial cargo”. Although the recommendation is clear the application of VEFs to part cargoes remains a contentious issue. As a consequence of the known limitations, the use of vessels figures adjusted by VEF to determine a Custody Transfer quantity (Bill of Lading or Outturn) is a commercial decision and can only be made with the agreement of the interested parties. This is clearly noted in the Standard. However it should be recognized that some regulatory authorities impose the use of a “correction” factor to vessel measurements that is not in keeping with the Standard and outside the control of inspection companies and their principals. Application of the Vessel Experience Factor Noting the above, it is recommended that IFIA member companies should calculate Custody Transfer figures by applying a VEF to vessel measurements as follows: • In accordance with the Standard, vessel experience factors will be applied for purposes of determining Custody Transfer quantities only “when agreed by interested parties”. • A full-vessel VEF will only be used for partial cargoes, as recommended in the Standard, where i) a partial VEF is not available or ii) the interested parties instruct that a full-vessel VEF is to be applied. • When data to determine a discharge VEF (VEFD) in accordance with the Standard is not available the Standard states that “a VEFL may be used”. However, in these circumstances, IFIA member companies may, with agreement of all interested parties, use data from other reliable sources to calculate a discharge VEF. Such data may not be sequential. • Where no agreement is obtained from interested parties with regard to application of a VEF for purposes of determining a Custody Transfer quantity, IFIA member companies should issue vessel figures with no factor applied.

FAME CONTAMINATION IN AVIATION FUEL

With increased levels of FAME being allowed in the EN590 Gas Oil (#2 Diesel) specification, the presence and concentration of FAME components in these cargoes may not be known by the vessel. This can create a major problem if a subsequent cargo is Aviation Fuel. Current Jet Fuel specifications have a very low tolerance to FAME and, although not currently reflected in specifications, AVGAS is also critical with regard to FAME as noted in the Energy Institute publication HM50 Guidelines for the cleaning of tanks and lines for marine tank vessels carrying petroleum or refined products. (HM50) Companies are sometimes asked to inspect ships tanks for cleanliness prior to receipt of cargo and to issue a respective Tank Inspection document. With increasing environmental restrictions, many of these inspections must be performed from deck level only as the tanks remain under inert gas. Any retained cargo must be determined by manual gauging and sampling through vapour control valves. It is therefore necessary to rely heavily on information provided by the vessel as to previous cargoes and tank cleaning methods. While IFIA members can review records of previous cargoes and tank cleaning methods they cannot attest to the accuracy of information provided by the vessel and clearly this may be critical in relation to FAME contamination of Aviation Fuel. IFIA members should report the conditions under which tank cleanliness and/or OBQ is determined and note where information is provided by the vessel. There is an inherent problem in obtaining uncontaminated samples from cargoes which follow Bio diesels as FAME has a tendency to adhere to internal surfaces. This may lead to increased concentrations at sampling points, as they are difficult to clean. HM50 states under section 2.12.7 that the cleaning regime employed by the vessel should include sampling equipment, stand pipes and stilling wells. However, the Inspector normally has to rely on cleaning information provided by the vessel and cannot verify whether this operation has been carried out. When a previous cargo has contained FAME and samples are drawn through the vessel sampling system their integrity may be in doubt due to the inherent difficulties in removing FAME residues from sampling fittings on the vessel. Therefore, in cases where analysis of samples obtained via closed or restricted systems indicates that FAME limits have been exceeded in a following cargo, it is recommended principals are advised accordingly and arrangements are made to take additional samples under open sampling conditions to confirm the results. The responsibility for cleanliness and suitability of the vessel rests with the vessel and its charterer. It is recommended that charterers confirm whether FAME has been present in previous cargoes and ensure that appropriate cleaning procedures are adopted prior to considering the vessel for the carriage of Aviation Fuel. Where part cargoes are involved charterers should treat any non-nominated cargo tanks carrying FAME or Bio diesel in the same manner as the nominated cargo tanks to avoid the possibility of cross-contamination. HM50 recommends three intermediate cargoes between FAME or Bio-diesel with a FAME content of 15% or above (B15) and an Aviation Fuel cargo, together with rigorous cleaning procedures for prior cargoes with lower FAME levels. IFIA members would consider the presence of FAME or Bio diesel in the three prior cargoes a reason to decline the vessel as fit for the loading of Aviation Fuel. Therefore, it is recommended that any charterer choosing to utilize such a vessel should inform the Inspector of its agreements with the vessel in advance of its arrival for inspection to reduce the chance of delay. There is significant evidence to show that shore loading systems can retain enough residual FAME to contaminate an Aviation Fuel cargo. It is therefore recommended that the party with contractual responsibility for the loading operation verify with the terminal that manifolds, loading arms and hoses have not been used to transfer FAME or Bio diesels for the last three operations. IFIA members are not in a position to obtain and verify such information and cannot accept any duty or responsibility in this regard.

Sampling & Testing Cargoes Blended On Board Marine Vessels

IFIA AC member companies are often assigned to inspect cargoes of petroleum that are blended on
board marine vessels at the loading port with the intention to meet certain contractual quality specifications of buyers and sellers. These cargoes are usually blended from two or more shore tanks, each containing a different component. The target composition of the final blend is typically based on a composite of shore tank samples, proportionally blended in a loading port laboratory. Shippers and receivers then rely on agitation of the cargo during proportional transfer into each of the vessel’s tanks to mix all of the components to contract quality specifications.
IFIA AC members’ experience has consistently indicated that, for many physical reasons, thorough
mixing of these components does not always occur as intended. Therefore, when the blended cargo
reaches the discharge port, manual samples taken from the vessel do not yield the same test results that were obtained at the loading port.

The American Petroleum Institute (API), in its Manual of Petroleum Measurement Standards (MPMS),
has recognized the difficulties of obtaining representative samples from cargoes that are not uniform throughout their profile and cross-section in a tank. API MPMS Chapter 8.1.8.3.3.1 states that “A running/all-levels sample is not necessarily representative (because of the difficulties of ensuring proportional filling of the sampler).” API MPMS Chapter 17.1.9.7 Note: states that “...on blended cargoes, vessel tank samples often will not be representative of proportional hand-blended samples that were tested at the port of loading.”
All work performed by IFIA AC member companies is subject to regulatory audit for conformance to
industry standards. Therefore, consistent with API and ASTM standards, IFIA AC member companies
have resolved to take the following position:
1. All manual samples, shore tank and vessel tank, will be taken in accordance with methods
prescribed in API MPMS, Chapter 8.1;
2. Laboratory analysis of all samples will be performed using standard industry test procedures,
usually as specified by the American Society for Testing and Materials (ASTM);
3. If analysis results indicate a possible problem with a cargo, blending, sampling and testing procedures will be carefully reviewed and findings promptly reported to the customer(s);
4. Test method precision limits (repeatability and reproducibility) will not be used to adjust the analysis results of any sample except as specifically authorized in ASTM method D3244.

CARGO RETENTION CLAUSES.

Cargo retention clauses provide a means for interested parties to account for the quantity of cargo
remaining in a vessel’s tank/s when discharge is concluded. This quantity is reported as ROB


[Remaining on Board] on completion of discharge.
Such clauses may require the inspector conducting the ROB inspection to offer, in addition to a record
of volume, a description to be applied to the ROB material.
In accordance with internationally accepted petroleum measurement documents produced by
API/ISO/EI (previously IP), the only standard terms which IFIA member companies are prepared to
use when describing ROB are “liquid”, “non-liquid” or “free water”. The use of any other terms for the characterization of ROB material, would be subject to a written definition agreed to in writing prior to the transaction, by all interested parties.
The requirement to operate under closed or restricted conditions is becoming more common and
under these conditions it is not possible to carry out direct visual examination of retained volumes in cargo tanks. This impairs the ability of the Inspector to describe the nature of any ROB, as the assessment is limited to small amounts of material which may be retrieved via vapour lock valves.
Where a description is made, particularly under these conditions, it may not necessarily be
representative of the total volume of ROB.
Irrespective of the operating conditions, when the terms, liquid, non-liquid and free water are used by Inspectors to describe ROB, it should be noted that they apply only:

1. To the material observed by the inspector
2. At the time of measurement
3. To the material at the point of measurement


ROB - Quantity remaining on board
Sum of liquid volume, including free water and non-liquid volume in cargo tanks just after discharge has been completed, excluding clingage, hydrocarbon vapours and the contents of associated lines and pump