Bunkering: Maritime Glossary

Bunkering is the supply of fuel, known as bunkers, to a ship, and the operation of transferring that fuel on board. The name comes from the coal bunkers of early steamships; today it refers mainly to marine fuel oil, marine gas oil and, increasingly, LNG and other alternative fuels.

How bunkering works

Bunkers are usually delivered by a bunker barge alongside, by a road tanker at the quay, or from a shore pipeline. The operation is planned around the vessel port call, with the quantity, grade and specification agreed in advance and the delivered fuel sampled and measured for quality and volume.

Bunkering and ship procurement

Fuel is one of the largest running costs of a ship, so bunkering is often handled by specialist suppliers and traders rather than general chandlers. It still sits within the wider maritime procurement picture, alongside provisions, stores and spares, as one of the key supplies a vessel arranges around each port call.

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Related terms

Port call Port agent Disbursement account Agency fee Ship chandler All glossary terms →

Frequently asked questions

What is bunkering?

Bunkering is the supply of fuel, called bunkers, to a ship and the operation of loading that fuel on board, whether by barge, road tanker or shore pipeline.

Why is ship fuel called bunkers?

The term dates from the age of steam, when coal was stored in shipboard compartments called bunkers. The name carried over to liquid marine fuels and the act of supplying them, bunkering.

What fuels are used for bunkering?

Common marine fuels include heavy fuel oil, very low sulphur fuel oil, marine gas oil and marine diesel oil, with LNG and other alternative fuels increasingly used to meet emissions rules.

How is bunker fuel delivered?

Bunkers are typically delivered by a bunker barge coming alongside the vessel, by road tanker at the berth, or through a shore pipeline, with the fuel sampled and measured on delivery.