Why are ROB and
Sludge Surveys Important?

When purchasing marine fuel, shipping companies need to carefully inspect the the fuel quantity and quality they receive from suppliers. During bunkering, some suppliers mislead their customers by conducting malpractices such as manipulation of temperatures, magic pipes, incorrect density, erroneous trim/list calculations, defective gauging tapes, faulty flowmeters and flawed strapping tables.

ROB and Sludge surveys can help shipowners and charterers avoid falling victim to such malpractices and ensure the fuel quality and quantity are in full compliance with ISO 8217 standards.

The Value of
ROB and Sludge Surveys

ROB and Sludge surveys involve investigation of various variables such as complex tank profiles, changing vessel trims and list conditions and more. Sometimes ship crews are not equipped with the knowledge and expertise to study these complex parameters, making it difficult for them to accurately measure and calculate the fuel quantity onboard when they receive the fuel from cargo officers.

Our highly trained and specialised surveyors
help customers:

  • Guarantee the vessel received exactly the same quantity of
    bunker as they purchased.
  • Ensure a true sample is collected throughout the whole period
    of bunker transfer.
  • Maintain good inventory control and prevent potential losses.
  • Avoid storing unaccounted fuel onboard.
  • Reduce fuel shortage cases.

Industries We Serve

The Viswa Group is well-reputed worldwide for being a trusted “problem-solver.” With 30 years of experience and a team of dedicated professionals, we are uniquely positioned to provide specialized ROB and Sludge surveys to our valued clients in the Marine Industry.


Benefits of Choosing The Viswa Group

Partnering with the Viswa Group means working with an independent company with the expertise and proven capabilities to inspect the fuel against various variables.

    We empower our customers with:

  • Comprehensive fuel testing including additional testing beyond ISO requirements, based on findings.
  • Independent benchmarks of fuel - Engine Friendliness Number (EFN), True Worth Index (TWI), Problem Fuel Indicating Number (PFIN), Purifier Efficiency Number (PEFN), Filter Blocking Tendency Number (FBTN).
  • Detailed report and unbiased recommendations if any faults are found and corrective measures need to be taken before the loss aggravates.
  • Experienced, well-trained and adequately professionals equipped with top-tier and calibrated equipment, including a gauging tape and an electronic thermometer, water and oil indicating paste, a flash-light, sufficient seals, sample bottles, papers and a multi-gas detector for safety.

Breakdown of our ROB and Sludge Survey Capabilities

Our expert team takes a targeted approach to provide our customers with accurate results. We analyze the fuel oil from all possible perspectives and even record quantities that may be in overflow tanks, bilge tanks, and any other hidden tanks.

Our comprehensive range of surveys include, but are not limited to:

  • Correctional (Detective) Surveys
  • Continuous (Remaining Onboard Surveys) Surveys
  • Sludge Survey
  • Bunker Pre-Delivery Sampling Surveys