Annex I- Regulations for the Prevention of Pollution by Oil Chapter 4 - Requirements for the cargo area of oil tankers. Part A - Construction Regulation 27 - Intact stability 1 Every oil tanker of 5,000 tonnes deadweight and above delivered on or after 1 February 2002 shall comply with the intact stability criteria specified for any operating draught under the worst possible conditions of cargo and ballast loading, consistent with good operational practice, including intermediate stages of liquid transfer operations. Under all conditions, the ballast tanks shall be assumed slack..1 In … [Read more...]
Tankscopes – Tanker Instruments
Non-Catalytic Heated Filament Gas Indicators (Tankscopes) Operating Principle The sensing element of this instrument is usually a non-catalytic hot filament. The composition of the surrounding gas determines the rate of loss of heat from the filament, and hence its temperature and resistance. The sensor filament forms one arm of a Wheatstone Bridge The Initial zeroing operation balances the bridge and establishes the correct voltage across the filament, thus ensuring the correct operating temperature During zeroing, the sensor filament is purged with air or inert gas that is free from … [Read more...]
Combustible Gas Indicator or (Explosimeter) – Tanker Instruments
Principle The Combustible Gas Indicator (CGI) or Explosimeter is used to measure the volume of flammable gas in a gas/air mixture. It gives the result as a percentage of the lower flammable limit. It is used to ascertain the atmosphere in a cargo tank when planning tank cleaning in a too lean atmosphere or for evaluation of C/H gas prior to man entry, hot work or other operations.Marine Safety Appliances MSA 40 is a commonly used CCI. It works on the Catalytic Combustion Principle. A catalytic filament is heated by an electric current. A sample of the atmosphere to be tested is drawn over … [Read more...]
Types of Double Hull Tankers
Double hull tankers The double hull design has many advantages over the more traditional single-hull designs, performing better in the low-speed collision or grounding situations. Looking at 30 tanker groundings between 1969 and 1973, a study by the U.S. Coast Guard concluded that 96 percent of the spills could have been prevented with double hulls. How these monstrous tankers can so successfully avoid oil spillage is a direct outcome of their engineering and design. There are two types of double-hull ballast arrangements:The first is the "L" type arrangement, where the ballast is the … [Read more...]
Multi-Gas Detector – Tanker Instruments
Working This is an instrument used for evaluating the tank atmosphere, prior to man entry, specifically for the presence of toxic gas. Hollow, glass tubes are inserted into a hand-held bellows pump through which a metered volume of the sample to be tested is drawn.The tubes are coated internally with a reagent and sealed at both ends. Different tubes are required for each type of toxic gas. The tubes are graduated externally. Just before use, the sealed ends are broken and the tube is fitted to the pump.As the sample is drawn through the tube by a recommended number of strokes of the … [Read more...]
Recommended Practices for Storage and Transport of Edible Oils and Fats
Introduction The international trade in oils and fats increases every year in volume and diversity. It included some 18 million tonnes of shipped cargo in 1984. The system involved in bringing the products from the harvest field to the end user is complex and inevitably a number of independent management is involved in processing, storage, and transport. It is clearly in the interest of all the parties involved that any deterioration in the products should be minimised. To this end, a number of trade associations have published advice for the benefit of their members. Individual sources … [Read more...]
Molasses – Carriage on Tankers
GENERAL Molasses is the thick dark brown syrupy liquid left after sucrose has been removed from the mother liquid in sugar manufacture. There is two type of molasses – cane molasses and beet molasses. Blackstrap molasses is the syrup from which no more sugar can be obtained economically.Synonym of molasses – Treacle.Main composition of molasses at 75 % Dry MatterCane molasses Beet molassesSucrose 30 – 40 % 48 – 52 %Reducing sugars 15 – 20 % 0.2 – 1.2 %Organic non-sugar matter 9 – 12 % 12 – 17 %Sulphated ash 3 – 11 % 3 – 10 % … [Read more...]
Vegetable, Palm and Soybean/Sunflower Oils – Carriage on Tankers
VEGETABLE OILS Prior loading of any Veg Oil cargoes, it should be noted that the last three cargoes must be lead-free.Also, ensure all Cargo Tanks, pipelines and pumps must be well drained and dried.The Veg Oils are very susceptible to Salt Water. Any contact with Sea water will result in rotting /damage of cargo.It should be ensured that after loading is completed; all cargo tanks are checked by Ship’s Officer along with attending surveyor, with a bottom sampler to ensure no water is trapped/loaded at Load Port.All Butterworth openings should have Oil resistant packing’s. … [Read more...]
What is VEF (Vessel Experience Factor) ?
The VEF is a factor to account for residual inherent measurement imprecision associated with ships's calibration and residual random measurement variations (both ship and shore). The VEF is a computation of the history of the Total Calculated Volume (TCV) loaded by the vessel adjusted for OBQ or ROB, compared with the TCV of shore measurements, typically a Bill of Lading in order to compute a load port VEF for the vessel.The VEF should always be used by the vessel to assess if the Bill of Lading quantity is reliable. It may also provide an indication of potential shortages on outturn at … [Read more...]
Cargo Calculations – Tanker Work
General An oil volume can only be measured at its prevailing temperature and it, therefore, follows that the standard volume must usually be calculated. Unfortunately, different countries have different standard (reference) temperatures.Generally, the reference temperatures are:In Eastern Bloc, Brazil 20oC; In Western Europe 15oC; In the USA 60oF. The situation is further confused in that there are primarily two volumetric units, which are:In metric countries the cubic meter (m ) In non-metric countries the barrel (Bbl).Combining a statement of volume … [Read more...]