Tag: marine surveyor

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.

Continue reading “Coal Spontaneous Combustion”

VNET in Bunker Survey

bunker-survey-vnet
What is VNET in Terms of Bunker Survey?

Remembered that unanswered question about Bunker Survey VNET by Surveyor on this site. We have collected two similar information to solve it.

QUESTION: Recently, many Chinese built vessels using the VNET calibration table for calculation of the bunker received on board and many a time, ended with dispute. What is VNET?

Continue reading “VNET in Bunker Survey”

Procedure of Calculations Using Density, API & Relative Density

Marine Surveyor Information 1602282

 

Working with Density at 15°C in air:
1) Observed Ullage – apply corrections – get Corrected Ullage
2) Observed Interface – apply corrections – get Corrected Interface
3) From Corrected Ullage, find Total Observed Volume TOV (in cubic metres)
4) From Corrected Interface, find Volume of Water (in cubic metres)
5) TOV – Water = Gross Observed Volume (GOV) of Cargo (in cubic metres)
6) Use Density at 15°C and Observed Temperature (°C) and find Volume Correction Factor (VCF) from Table 54
7) Gross Standard Volume (GSV) = GOV x VCF (cubic metres)
8) Weight Correction Factor (WCF) = Density at 15°C in vacuum – 0.0011 (or the Density at 15°C in air)
9) Weight in Air (Metric Ton) = GSV x WCF(Density at 15°C in air)
10) Weight in Vaccum (Metric Ton) = GSV x Density at 15°C in vacuum
Continue reading “Procedure of Calculations Using Density, API & Relative Density”

Bunkering Tricks

tape-measure
Even though the procedure has been tightened, we may see some bunker tanker are still trying to play their tricks, therefore it is very important for Chief Engineer, Vessel’s Crew and Surveyor to know well their tricks.

Below are the Tricks of Bunker Supply, trust that most of our Chief Engineers might known the trick very well, or even know more other tricks. Hopefully by knowing these tricks we can do some prevention, counteract or countermeasure to protect our interest:

1. Manipulating the sounding result
It is very easy for the bunker barge operator to manipulate the sounding result.

Counteract/Countermeasure: Chief Engineer or bunker surveyor appointed should sound the bunker barge tanks himself
Continue reading “Bunkering Tricks”

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.

calculator
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.
Continue reading “Negative Constant in Draft Survey”

Inverse Draft Survey

contact
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.
Continue reading “Inverse Draft Survey”

IIMS 2014 Conference

marine-surveying
The International Institute of Marine Surveying is proud to announce its 2014 Conference and AGM

Presenting ‘New Energies in Marine Surveying’

Date: 09 June 2014 (2 Days)
Location: Hilton Hotel, Chilworth, Southampton, UK

Description:
The 2014 Conference (including Dinner and AGM) will be held on the 9th and 10th June 2014 at the Hilton Hotel, Chilworth, Southampton. The Conference theme will be “New Energies in Marine Surveying”.

Click here to view the Brochure PDF or visit the website http://www.iims.org.uk for more info.

The event will coincide with the SeaWork Exhibition in Southampton running from the 10th – 12th June.