Tanker Ship Types

What is a tanker ship?

A tanker is a ship built to carry liquid cargo in bulk, held in tanks and moved on and off the vessel through cargo pumps and pipelines rather than loaded into open holds. That single design difference, liquid in tanks instead of dry cargo in holds, drives almost everything that sets a tanker apart from a dry bulk carrier: the segregated and often coated tanks, the cargo pumping system, the inert-gas plant that keeps the tank atmosphere below the flammable range, and the vetting regime that governs which ships a charterer will even consider.

Tankers are not one vessel type but a family of them, sorted first by what they carry. Crude oil tankers move unrefined crude. Product tankers carry refined products such as gasoline, diesel, jet fuel, and naphtha. Chemical and parcel tankers carry many separate liquid grades at once. Gas carriers move liquefied gas, either chilled (LNG) or under pressure (LPG). Within each family, vessels are then sized into named classes by deadweight, and those class names (VLCC, Suezmax, Aframax, LR2, LR1, MR) are the shorthand the market trades on.

This page is an at-a-glance reference to those classes and how the liquid trades work. For the commercial side, how Bulkargo brokers tanker fixtures across crude, products, and vegoils, see the tanker chartering service page.

The main tanker types at a glance

The table below sets out the principal tanker classes, the deadweight band each occupies, and the cargo each is built for. Deadweight bands are approximate and overlap at the edges, because class names are market conventions rather than strict naval-architecture limits.

Crude and product classes are sized in deadweight tonnes (DWT), the cargo-plus-stores weight a ship can carry. Gas carriers are sized differently, by the volume of liquefied gas their tanks hold in cubic metres, because gas density and the insulated containment system, not deadweight, set the practical limit.

Crude oil tankers

Crude tankers carry unrefined crude oil, a single dirty cargo that does not need a clean tank surface, so their tanks are usually uncoated. They are sorted by size, and size tracks haul length: the longer the voyage, the larger the parcel that makes economic sense.

• VLCC (Very Large Crude Carrier), 200,000 to 320,000 DWT. The long-haul workhorse. VLCCs dominate the Middle East Gulf to Far East trade and other long crude routes where one large parcel beats several small ones. The even larger ULCC sits above it but is rare in the modern fleet.
• Suezmax, 120,000 to 200,000 DWT. Named for the largest ship that historically transited the Suez Canal laden. Suezmax handles West Africa to US Gulf or Europe and Mediterranean crude on medium hauls.
• Aframax, 80,000 to 120,000 DWT. Named after the Average Freight Rate Assessment system. Aframax works regional crude and dirty products in the North Sea, the Mediterranean, the Caribbean, and intra-Asia, where draft and port size rule out the larger classes.

Product tankers

Product tankers carry refined products: gasoline, diesel and gasoil, jet fuel, naphtha, and the lighter ends of the barrel. Because these grades are clean and must not contaminate one another, product tankers have coated tanks (usually epoxy) and tight cargo segregation, with multiple separate tanks, pumps, and lines so several grades can travel on one voyage.

• LR2 (Long Range 2), 80,000 to 120,000 DWT. The same hull size as Aframax but with coated tanks for clean products. LR2 runs long-haul product arbitrages, often east of Suez to Europe.
• LR1 (Long Range 1), 55,000 to 80,000 DWT. Medium-haul clean products and larger regional parcels.
• MR (Medium Range), 25,000 to 55,000 DWT. The most numerous and flexible product class, moving clean products and vegetable oils on most regional routes.
• Handysize, 10,000 to 40,000 DWT. Smaller parcels, niche grades, and short-sea trades where a full MR cargo is too large.

Chemical and parcel tankers

Chemical tankers carry liquid chemicals, and parcel tankers are the larger, highly subdivided version built to carry many separate grades on a single voyage. Where a product tanker might run a handful of segregations, a sophisticated parcel tanker can carry dozens, each in its own stainless-steel or specially coated tank with a dedicated pump and line so grades never share equipment.

These ships handle acids, alcohols, solvents, vegetable and animal oils, and other sensitive liquids that demand strict cargo separation and a clean prior-cargo history. Tank coatings matter: stainless steel suits aggressive chemicals, while phenolic or zinc-silicate epoxy suits other grades. Chemical tonnage is vetted under CDI, the chemical-trade counterpart to the oil-trade SIRE inspection.

Gas carriers: LNG and LPG

Gas carriers move hydrocarbons that are gaseous at ambient conditions but carried as liquids to shrink their volume. They split into two trades.

• LNG carriers move liquefied natural gas, chilled to about minus 162 degrees Celsius and held in heavily insulated containment systems (membrane or spherical Moss tanks). They are sized by gas volume, commonly up to roughly 180,000 cubic metres.
• LPG carriers move liquefied petroleum gas, mainly propane and butane, kept liquid by refrigeration, pressure, or both. They range from small pressurised coasters up to Very Large Gas Carriers (VLGC) around 80,000 to 90,000 cubic metres.

Gas carriers are the most specialised tankers, with containment, boil-off handling, and safety systems well beyond those of an oil or product tanker.

How tankers differ from dry bulk carriers

The clearest way to place tankers is against the dry bulk fleet, because the two cover the bulk shipping market between them: tankers carry liquids, bulk carriers carry dry commodities such as iron ore, coal, and grain.

• Cargo containment. Tankers carry liquid in closed, often coated or stainless tanks, frequently segregated for multiple grades. Bulk carriers carry dry cargo in large open holds with hatch covers.
• Loading and discharge. Tankers load and discharge through pumps and pipelines connected to a shore manifold. Bulk carriers use grabs, conveyors, shore cranes, or the ship’s own gear to handle cargo through open hatches.
• Tank specification. Tankers manage coatings, prior-cargo compatibility, segregation, and (for heavy or waxy cargoes) heating coils. Dry holds need only be clean and dry for the next cargo.
• Safety systems. Tankers carry inert-gas plants to keep the tank atmosphere below the flammable range, plus vapour-return and gas-detection systems. Dry bulk carriers have no equivalent.
• Vetting. Tankers must clear an inspection regime (SIRE 2.0 for oil, CDI for chemicals) before most fixtures firm. Dry bulk has no comparable cargo-handling inspection.

The commercial language differs too. Crude and product voyages are usually priced on Worldscale rather than a flat per-tonne rate, while dry bulk voyages trade on a straight rate per tonne.

Chartering a tanker

Whichever class fits the cargo, a tanker is fixed under the same two core charter structures used across shipping. On a voyage charter the charterer pays for a single cargo movement between named ports, with freight on crude and products usually quoted on Worldscale; this is the standard structure for spot crude and product cargoes. On a time charter the charterer takes the ship for a period and pays a daily hire rate, which suits a trader or refiner running an ongoing programme.

The vessel-selection step that has no real dry-bulk equivalent is vetting. Before a fixture firms, the ship is screened against SIRE 2.0 or CDI, terminal acceptance lists at both ends, P&I standing, age and class limits, and prior-cargo history. A ship that fails any of these is out of the conversation regardless of price.

To take a cargo to the market, see how Bulkargo brokers tanker fixtures across crude, clean and dirty products, and vegoils on the tanker chartering service page, or send us the cargo and route directly.

Common questions