Category: Surveyors

Coal Spontaneous Combustion

How Coal Self-Ignites?

The coal’s temperature begins to climb above ambient. At about 150-300 degrees F, it begins to give off minute, but measurable, quantities of gas–aerosols, hydrogen, and CO (2)–precursors of combustion. As the temperature increases further–at about 600-700 degrees F–relatively, large, visible particulates are emitted. Soon, as the heating rate increases in intensity to about 750-800 degrees F, incipient combustion, and ultimately self-ignition and flame, will occur.

The risk from fire exists anywhere significant amounts of coal are in use or storage. Coal is a combustible material, making it susceptible to a variety of ignition scenarios. Preventing spontaneous combustion coal fires involves attention to many different factors. Among the most critical are the type, age, and composition of coal, how it is stored, and how it is used. Given the right kind of coal, oxygen, and a certain temperature and moisture content, coal will burn by itself.

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Negative Constant in Draft Survey

What is Ship Constant?

The ships constant is the difference between a vessels design lightship and it’s actual displacement when empty. The ships constant is determined by a draft survey. The ships constant will vary over the life of the vessel.

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Unintentional Reasons for Variations
– Sedimentation in ballast or fuel oil tanks
– Corrosion
– Fouling of hull
– Coating build-up (paintwork, tank coatings, etc.)
– Garbage collection, particularly in cargo holds
– Wear and tear of mechanical devices

Other Reasons for Variations
– Modifications to ship spaces
– Accumulation of stores (i.e., in paint locker, engineering stores, spares)
– Refit, overhauls, addition/removal of equipment.
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Inverse Draft Survey

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Few years ago, I have received the email from friend that asked regarding Inverse Draft Survey. The Inverse Draft Survey is doing when the ship has to split the cargo for two or more ports. The method is the same as common draft survey calculation, what the ship officer or surveyor needs to do is preventing cargo less or more discharge at the 1st port.

What is the purpose?
– To prevent cargo less or more discharge at one port.
– Surveyor can organize the work effectively.
– To prevent repetition of intermediate draft survey that cost a lot of time.
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Hold Cleanliness: Surveyor’s Inspection and Requirements

hold-cleanliness-marine-surveyors (2)Prior to loading grain, all ships are usually subject to a survey by an approved independent surveyor. The surveyor will require the ship’s particulars, and details of at least the last three cargoes carried. He will then inspect the holds for cleanliness and infestation, and the presence of any material that could lead to infestation or contamination.

When the surveyor is satisfied, he will issue the ship with a certificate to confirm that the holds are clean. However this is not a guarantee that the holds are perfectly clean and that no cargo claim will result.

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Hold Cleanliness: Cleaning The Hold

hold-cleanliness-marine-surveyors (14)Before loading a bulk cargo, the master has usually to declare that the ship is ready to load as per the charterparty requirements and charterer’s and owner’s instructions. Copies of the charterparty should be placed onboard so that the master is able to see exactly what are the ship’s obligations. The master can have this declaration accepted only when the holds have been inspected and accepted.

For this to happen, the master needs to know how clean the holds have to be to meet the charterer’s requirements. This will depend on the previous cargo, the next cargo, local regulations and specific cargo interest requirements.

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Petroleum Calculation Series: Gas Tanker Terms

Absolute Pressure
The absolute pressure is the total of the gauge pressure plus the pressure of the surrounding atmosphere.

Absolute Temperature
The fundamental temperature scale with its zero at absolute zero and expressed in degrees Kelvin. One degree Kelvin is equal to one degree Celsius or one degree Centigrade. For the purpose of practical calculations in order to convert Celsius to Kelvin add 273. It is normal for the degree Kelvin to be abbreviated in mathematical formulae to ‘K’ with the degree symbol being omitted.

Absolute Zero
The temperature at which the volume of a gas theoretically becomes zero and all thermal motion ceases. It is generally accepted as being -273.16°C.

Activated Alumina
A desiccant (or drying) medium which operates by adsorption of water molecules.

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Updated: Marine Survey Software

seven surveyorRecently, I have updated marine survey software for better performance and assist your fast calculation during surveying. In this version there are some updates includes:
– Clean and Larger interface with simple and easy data input for the survey.
– The software created basis Microsoft Excel files that works best with excel 2007-2013 and it could also working with excel 97-2003.
– The presentation is creates by Microsoft Power Point basis, it totally free to download. All version PP enable to open this.
– Smaller size file and performs faster file access.

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