by Dr. R. (Vis) Visweswaran

Analytical Services & Materials, Inc.

Hampton, Virginia U.S.A.

"The crown of all faculties is common sense. It is not enough to do the right thing;

it must be done at the right time and place. Talent knows what to do;

tact knows when and how to do it."

- William Mathews

Common sense is not such a commonly available commodity!

Every day in ship operations, one is required to make decisions. Though a lot of data is made available to make those decisions, mere numbers cannot dictate decisions. An undercurrent of common sense, previous experience, and general feel for the situation are the factors that will dictate the decisions. Some of the items on which decisions have to be made are listed below. Common sense solutions are provided for the guidance of the ship manager. These are based on the many years of experience of the author on all three aspects of the bunker-user (ship’s engineer), impartial observer (surveyor), and analyst (lab in charge). It is hoped that this common sense approach will be useful for practical situations that arise in ship operations. These are only suggestions, not recommendations. Obviously, decisions have to be based on actual situations.

4. Costs of testing and not testing.

The above concerns are discussed below.

Grade 180 - 7-15% distillate content

Grade 380 - 2-5% distillate content

Price of grade 180 is at least $3 - $5 more than grade 380

Engine Maker recommendation

Perception that 180 is better than 380

Sulphur More of the 180 grade samples (0.7%) had more sulphur than 380 grade

But the perception of many ship managers is that grade 180 is a better fuel and they are therefore willing to pay a higher price to get an inferior fuel. (This argument assumes that the engine manufacturer permits the use of both grades of fuel in the engine.)

Say a vessel bunkers 8 times per year.

Annual cost per ship - AS&M Program: 8 x $250 = $2000

Say you bunker 1000 tons each time: @ $100 per ton

Total bunker cost is 8 x 1000 x 100 = $800,000

Testing cost as a proportion of bunker cost = 1/400

Testing cost as additional cost on a ton of bunkers = $100.25, i.e. 25 cents more per ton

Say ship operation cost is $8,000 per day --

Bunker test cost per day = 2000 = $5.5

365

Bunker test cost as proportion of operation cost: 5.5 = 1

8000 1500

CONCLUSION: TESTING COST IS A PITTANCE, AND THE QUESTION IS

NOT IF YOU CAN AFFORD TO TEST, BUT CAN YOU AFFORD NOT TO TEST!

1. Buy 380 grade if engine manufacturer permits use of this grade

2. Do test, it costs only 25¢ per ton of fuel

The table below lists the various parameters and their values, as specified by the various grades of bunker fuel. The question is, how much out of specification can be tolerated? Here are some suggestions:

The standards give ranges for "out of specification" under two categories:

Repeatability - defined as the variance in results when the same sample is tested in the same lab, using the same method, by two different analysts.

Reproducability - defined as the variance in results when the same sample is tested in two different labs, by two different analysts, using the same method.

Bunker fuel as received at custody point is the bunker fuel that gets into the engine. What can shipboard treatment do? Every ship has considerable capability for fuel treatment onboard, and these well-known facilities are listed below, along with suggestions for imaginatively combining the facilities to obtain the desired fuel treatment:

• Heat the fuel, settle it, drain the water

• Purify it, remove water and heavier particles

• Clarify it and remove solid particles

• Two purifiers in series (remove excess water)

• Two clarifiers in parallel

• Various filters

• Heaters and automatic viscosity controllers

• Routine draining of water and particulates from service tanks

• Compatibility and stability tests

• Shipboard test kit

• Fuel additives

• Blending fuels on board

It is hoped that the above analysis will help generate decisions that make sense; common sense!