TL;DR: A Singapore bunker barge is judged on two things at once: whether it delivers the right quantity safely, and whether its licensee keeps its MPA record clean. That makes technical management of the barge itself a compliance job. The essentials are cargo pump and hose maintenance planned around a very high delivery rate, a mass flow meter (MFM) system kept approved, sealed and calibrated under SS 648:2024, class and statutory certificates kept in step with the licence, and crew who hold the bunker-specific competencies MPA requires. Miss any one and the barge stops earning.
A bunker barge, which MPA calls a bunker tanker, is a small tanker licensed as harbour craft to deliver marine fuel to ships within the Port of Singapore. Suppliers write a lot about the fuel. Very little is written about keeping the barge itself fit for work, and that is where most off-hire comes from. This guide covers the technical side: maintenance, metering, surveys, crew and vetting. For the service overview, see our page on bunker vessel management in Singapore.
Why is bunker barge management different from managing a seagoing tanker?
The barge works harder, in a tighter regulatory box, with less slack between jobs. A seagoing product tanker might load and discharge a few times a month. A Singapore bunker tanker can make several deliveries a day, every day, so pumps, hoses, fenders and mooring gear wear on a cycle measured in deliveries rather than voyages.
The regulatory box is also unusual. A bunker tanker is licensed as harbour craft, so harbour craft licensing applies on top of bunkering rules, and each steel bunker tanker must meet MPA’s Category “A” standards for port limit bunker tankers. Its owner may be the supplier, a craft operator working for several suppliers, or an investor who charters it out. In every case, the barge’s condition feeds directly into the supplier’s licence record, which is why we think it should be managed as a compliance asset first and a hull second. If you are deciding how to structure this, our article on ship management models for tanker and bunker fleets compares the options.
Cargo pumps, hoses and the deck equipment that fails first
Cargo pumps, delivery hoses and their couplings are the items most likely to stop a bunker barge, so they need the tightest maintenance plan on board.
Cargo pumps on these craft run long hours at variable loads and often handle more than one grade. Seal wear, bearing temperatures and vibration are the early signs to trend, and a planned maintenance system (PMS) should schedule overhauls by running hours, not by the calendar. Delivery hoses need visual inspection before every operation, periodic pressure testing at the interval set by the hose manufacturer and the operator’s safety management system, and a clear retirement rule. A hose that passes its pressure test can still be condemned for kinking, flattening or flange corrosion.
The rest of the deck matters as much. Fenders, mooring lines and winches take a beating from constant alongside work in an anchorage with swell and passing traffic. Spill kits, scupper plugs and the save-all around the manifold are checked by the receiving ship’s crew and by any surveyor on board, and missing items show up in complaints. For a wider view on running-hours planning, see our planned maintenance systems guide and the case for preventive over corrective maintenance.
Keeping the mass flow meter system approved and sealed
Singapore requires bunker deliveries to be measured by an MPA-approved mass flow meter system, so the MFM is not optional equipment. It is the barge’s licence to deliver.
The history is short. MPA made MFM use mandatory for marine fuel oil deliveries from 1 January 2017 and for distillates from 1 July 2019, according to MPA’s release on the SS 648 standard. The original technical reference, TR 48 of 2015, was replaced by Singapore Standard SS 648 in November 2019. Under Port Marine Circular No. 12 of 2024, SS 648:2024 became the required standard for custody transfer to ocean-going ships from 1 April 2025. The 2024 edition brings biofuels into scope, adds a single-tanker meter-in meter-out option for system approval, sets stricter rules on data loggers and data security, replaces the minimum measured quantity with a minimum bunker quantity table, and sets out what to consider after a software update.
For the manager, that translates into a short list of standing tasks:
Keep the approval valid. MPA approves each MFM system individually, after a physical acceptance test, not by type.
Keep it calibrated. The meter undergoes an annual zero-verification test and annual stamping, carried out to an ISO/IEC 17025 standard, with any further re-calibration MPA requires planned into the docking schedule. Confirm the current requirement under SS 648:2024 and your licence.
Keep the seals intact and documented. No bypass is allowed after the meter, the vessel keeps the latest seal verification report and a metering diagram showing every sealing point, and seals are checked before and after each delivery.
Treat software updates as a controlled change. SS 648:2024 adds specific considerations after an update or upgrade, so no update should go in without checking what it triggers.
If the MFM fails mid-delivery, pumping stops, the totaliser readings are recorded, MPA is informed, and the remaining quantity is determined by tank gauging under SS 600:2022 with a separate bunker delivery note, as set out on MPA’s bunkering standards page. That is a recoverable event, but it is also a record the supplier would rather not have. Our planned article on bunker quantity disputes in Singapore covers what happens when the numbers do not agree.
Digital records now sit alongside the meter. From 1 April 2025, Singapore bunker suppliers issue electronic bunker delivery notes (e-BDNs) by default, and bunker craft operators must use an MPA-whitelisted digital bunkering solution, according to MPA’s digital bunkering page. The barge’s IT, connectivity and data logger are now part of its technical scope.
Class and statutory surveys: keeping certificates in step with the licence
A steel bunker tanker must hold a full set of statutory certificates and stay in class to keep its harbour craft licence, so the survey calendar and the licence calendar should be one plan.
MPA’s registration requirements list, for steel craft, the Cargo Ship Safety Construction, Safety Equipment, Safety Radio (or ship station licence), International Load Line and CLC 92 certificates, plus an IOPP certificate and shipboard oil pollution emergency plan for oil tankers of 150 GT and above. Tank calibration tables must be deposited with MPA. Class follows the usual five-year cycle of annual, intermediate and special surveys with bottom surveys in between. Our guide to class survey preparation explains how to avoid conditions of class.
The practical point is timing. A barge that is fully booked by its supplier cannot easily come off service for a week. We plan dry-dockings, MFM verification and stamping, and major pump overhauls into the same yard window wherever the cycles allow, because every separate stoppage is lost delivery days. If a yard period is coming, see our notes on dry-docking management.
Crew competency: the bunker-specific certificates
Bunker tanker crew need the usual STCW and harbour craft qualifications plus bunker-specific certification, and MPA enforces the second set directly.
MPA’s registration rules require manning to meet the minimum certificated levels of the craft’s manning licence, firefighting certificates for all crew, and a valid Port Limit Tanker Master Certificate for the master of a Category A bunker tanker. On metering, MPA required all in-service bunker cargo officers and bunker surveyors to complete an SS 648:2024 refresher course run by SSA and IBIA by 1 April 2025, and stated that personnel without the certification would not be allowed to conduct bunkering in the port. The cargo officer is the person who witnesses the meter, signs the delivery records and manages the operation, so their competence is the barge’s competence.
Crewing these craft is its own discipline. Rotation is frequent, the work is intensive, and fatigue across back-to-back deliveries is a real risk that the safety management system should address. Our crew management and competency development service covers this, and our article on STCW requirements for professional crew sets out the baseline.
Vetting and the licensee’s KPI score
The barge is vetted twice over: by the oil majors and charterers who buy from or charter it, and by MPA through the supplier’s licence score.
On the commercial side, OCIMF runs the Barge Inspection Report programme (BIRE), aligned with its SIRE programme for tankers, as a standard risk assessment for barges and small vessels, as described on OCIMF’s BIRE page. Which inspection scheme a particular buyer requires for a Singapore bunker tanker varies by company, so ask the supplier or charterer before you schedule anything. Our SIRE 2.0 compliance article covers inspection readiness more broadly.
On the regulatory side, MPA’s bunkering licence guidelines assess suppliers over 12 months on three KPIs: craft operations records (15 per cent), bunker supply records (70 per cent, including compliance with SS 600 and SS 648) and customer feedback (15 per cent). A supplier must keep a minimum total weighted score of 75. Craft operations records include compliance with bunker tanker standards. In plain terms, a barge’s maintenance and metering performance is scored against its supplier’s licence.
Where bunker barge owners lose time: an operator’s view
In our experience, most lost days on bunker barges come from three places, and none of them is a dramatic failure.
The first is deferred deck maintenance. Hoses, couplings and mooring gear are cheap compared with a delivery cancelled at short notice, but they get pushed back because the barge is always busy. The second is uncoordinated stoppages: a meter verification in one month, a pump overhaul in the next, a class item after that, each taking the craft off the schedule separately. The third is paperwork drift, where seal reports, calibration certificates and crew certificates fall out of date one at a time until an inspection or a surveyor catches them.
Our opinion is that a bunker barge needs a single compliance calendar that combines class, statutory, MFM, licence and crew certificate dates, owned by one superintendent and reviewed monthly with the supplier. That calendar is cheaper than any single avoidable stoppage. Fleet operators can see how we apply this across several craft in our article on the bunker fleet management approach.
Frequently Asked Questions
What is a bunker barge? A bunker barge is a small tanker that delivers marine fuel to ships at anchor or alongside. In Singapore, MPA calls these craft bunker tankers and licenses them as harbour craft. For the basics of the trade, see what is bunkering in shipping.
Is a mass flow meter mandatory on Singapore bunker tankers? Yes. MPA made MFM mandatory for marine fuel oil deliveries from 1 January 2017 and for distillates from 1 July 2019. SS 648:2024 has been the required metering standard for custody transfer to ocean-going ships since 1 April 2025.
How often must a bunker MFM be re-calibrated? In practice the meter undergoes an annual zero-verification test and annual stamping, with any further re-calibration MPA requires carried out to ISO/IEC 17025. Owners should confirm the current requirement under SS 648:2024 and their licence conditions.
What happens if the MFM fails during a delivery? Pumping stops, the meter readings are recorded and MPA is informed. The remaining quantity is measured by tank gauging under SS 600:2022, and a separate bunker delivery note is issued for that portion.
What certificate does the master of a Singapore bunker tanker need? The master of a Category A bunker tanker needs a valid Port Limit Tanker Master Certificate, and all crew need firefighting certificates. Bunker cargo officers also needed an SS 648:2024 refresher course by 1 April 2025 to keep conducting bunkering.
Quick Q&A
Can a third-party manager run a bunker barge for a licensed supplier? Yes. The supplier holds the licences, and the manager handles technical, crew and compliance work on the craft. Agree in writing who owns each licence-related record.
What should I check first when taking over an existing barge? The MFM approval, seal verification report and last calibration date, then the hose register and pump history, then crew certificates. Those three areas decide whether she can deliver next week.
Does the 2030 harbour craft electrification rule affect my barge? It affects new craft rather than existing ones, and bunker licence applicants are already asked for fully electric, B100-capable or net-zero-compatible new tankers. Our planned guide to harbour craft electrification in Singapore covers the detail.
Keep your barge delivering
Emaris Shipping manages tanker and bunker craft in Singapore, Malaysia and Indonesia, including three bunker tankers in Singapore and three in Port Klang, with maintenance, MFM upkeep, surveys and crew competency run from one compliance calendar. To discuss technical management for your bunker tankers, see our ship management service or contact our team.