Understanding tanker vessel types is essential in petroleum trade because vessel size dictates which terminals are accessible, which routes are economical, and how freight costs are calculated. Vessel selection directly affects CIF and FOB pricing.
Crude Oil Tanker Size Classes
| Class | DWT range | Capacity (barrels) | Typical routes |
|---|---|---|---|
| ULCC (Ultra Large) | 320,000–550,000 | ~3.0M bbl | Middle East → Asia (limited ports) |
| VLCC | 200,000–320,000 | ~2.0M bbl | ME Gulf → Asia, US; West Africa → Asia |
| Suezmax | 120,000–200,000 | ~1.0M bbl | West Africa → Europe, Med; Black Sea crude |
| Aframax | 80,000–120,000 | ~750,000 bbl | Med, Caribbean, Baltic, North Sea crude |
| Panamax | 55,000–80,000 | ~500,000 bbl | Americas, Pacific Basin |
Clean vs Dirty Tankers
- Dirty tanker — carries crude oil or residual fuel (HFO, VLSFO, bitumen); tanks are uncoated steel
- Clean tanker — carries refined products (EN590, Jet A-1, gasoline, naphtha); tanks are epoxy-coated to prevent contamination
- A dirty tanker can be cleaned and switched to clean service (expensive, time-consuming). Clean-to-dirty is easier.
Tanker Freight Rates
Crude tanker freight is quoted in Worldscale (WS) points — a percentage of the Worldscale flat rate (a notional USD/MT reference for each route). A WS 100 deal means the agreed rate equals the Worldscale flat rate; WS 150 is 50% above flat rate.
- VLCC TD3C (Middle East Gulf → China): key VLCC benchmark route
- Aframax TD7 (North Sea/Baltic): key European crude freight benchmark
- Product tanker MR (Medium Range) TC2 (Rotterdam → New York): key Atlantic basin clean product benchmark
Frequently Asked Questions
- What is the difference between VLCC and Aframax?
A VLCC (Very Large Crude Carrier) carries 200,000–320,000 DWT of crude oil and is restricted to deep-water ports (draught >22m). An Aframax carries 80,000–120,000 DWT and can access more ports including the Mediterranean, Baltic, and Caribbean. Aframax is the most commonly traded size class in European petroleum markets. VLCCs are used for long-haul crude routes (Middle East to Asia).
- What is the Baltic Dirty Tanker Index (BDTI)?
The Baltic Dirty Tanker Index (BDTI) is a daily freight rate index published by the Baltic Exchange in London, covering crude oil tanker routes (VLCC, Suezmax, Aframax). Similarly, the Baltic Clean Tanker Index (BCTI) covers product tanker freight. These indices are widely used as benchmarks in freight cost clauses in FOB commodity contracts.
- What is a product tanker?
A product tanker (also called a clean tanker) carries refined petroleum products — diesel, jet fuel, gasoline, naphtha — in multiple segregated coated tanks to prevent cross-contamination. Product tankers range from 10,000 DWT (coastal) to 60,000 DWT (LR2/Long Range 2). After a cargo, tanks must be cleaned (stripped and washed) before loading a different product.