Types of Tankers

Oil tankers are loosely classified based on their carrying capacity in deadweight tons (DWT), which is the total weight of the ship (including cargo, crew, provisions, etc.) minus the weight of the ship if it were empty. It is likely that attackers would focus on the largest tankers to maximize their effect on the global oil market.

Very large crude carriers (VLCC), first developed in the 1960s, have a capacity of over 200,000 DWT and can carry two million barrels of oil. Ultra large crude carriers (ULCC) can carry in excess of 320,000 DWT, roughly three million barrels of oil. Other categories of tankers include: Medium Range (MR), Panamax (the largest tankers that can fit through the Panama Canal), Aframax, and Suezmax (the largest tankers that can fit through the Suez Canal).

Breakdown of Various Classifications of Oil Tankers

Size / Classification Deadweight Tonnage (DWT) Avg Dimension (Length | Height | Draft in feet) Average DWT / vessel[i] Approx # of vessels[ii] # of Orders in 2006[iii]
Medium Range 25,000 - 50,000 675 | 100 | 55 41,000 1273 330
Panamax 50,000 - 75,000 65,000 ~809 46
Aframax 75,000 - 120,000 810 | 110 | 60 106,000 ~900 160
Suezmax 120,000 - 180,000 950 | 150 | 60 161,000 ~600 83
VLCC 200,000 - 320,000 1240 | 200 | 100 306,000 474 102
ULCC 320,000+ 86,000 4056 720

 

Most of the crude oil carriers that currently travel through the Strait of Hormuz are VLCCs carrying oil to markets in East Asia. A few smaller oil tankers make "quick" runs to India and other closer destinations. But of course tankers are flexible: pretty much any ocean-going tanker can transport crude oil from the Persian Gulf to any part of the world, depending on market conditions.

[i] McQuilling Services, LLC, Orderbook Details (Apr 2006). Online. Available: http://www.mcqservices.com/McServices_repo.asp. Accessed: December 4, 2007.

[ii] McQuilling Services, LLC, Orderbook Details (Apr 2006). Online. Available: http://www.mcqservices.com/McServices_repo.asp. Accessed: December 4, 2007. Fleet sizes for Panamax, Aframax and Suezmaz were estimated based on trends in ship deliveries and orders over the past ten years.

[iii] McQuilling Services, LLC, 2006 - A Record Year for Newbuilding Orders. Online. Available: http://www.mcqservices.com/McServices_repo.asp. Accessed: December 4, 2007.

This page last modified in August 2008