Custom Search
Top Stories
Go to Site Index See "Top Stories" main page
COMMENTARY · 29th September 2012
Merv Ritchie
Double hulled bulk crude oil carriers come in a variety of sizes. The largest, ULCC’s (ultra large crude/cargo carriers) are out of fashion as they are unable to, fully loaded, sail into most ports. Today the largest being fabricated are VLCC’s (Very Large). Suezmax are the next largest, carrying up to 200,000 metric tonnes and are called as such as they are designed for navigating the Suez Canal region. Aframax Crude Carriers are typically designed for 80,000 to 120,000 metric tonnes of crude and Panamax Vessels are designed to be no larger than 32 meters wide so they can fit through the Panama Canal. Panamax can carry up to 80,000 metric tonnes. The smallest designations are called Handymax (45,000 metric tonnes) and HandySize, which carry as little as 10,000 metric tonnes. The cargo holds are divided into individual compartments. A Handymax will typically have 10 holds. A 10,000 dwt Handysize tanker might have four holds, each containing 2,500 metric tonnes.

All of these crude oil tankers are, by law, required to be doubled hulled as they are crude oil carriers. Most carry unrefined crude oil. This means the oil is shipped as a raw thick product, just as it came out of the oil well.

Dry Goods Freighters on the other hand are not designated as crude oil tankers and they are not double hulled. All freighters are designed to burn oil thicker than the raw oil shipped by crude oil tankers. The raw product is first refined to remove the profitable thinner petroleum products leaving the residue as bunker crude. The only product thicker and dirtier is what we use to pave our streets. When in port, or sailing into a habitable region, the ships switch their main engines off or over to clean burning diesel fuels. At all other times they burn the heavy bunker crude. It is the cheapest fuel available and the main engines are designed for it.

Panamax sized freighters, those sailing regularly into Prince Rupert, carry on average 2,500 metric tonnes of bunker crude. The MV Torm Saltholm is in the Prince Rupert harbour today. It is a full sized Panamax freighter at 32 meters by 229 meters and carries 2.5 million litres of bunker crude. This is the rough conversion from 2,500 tonnes of bunker crude to other measures; 16,000 barrels; 675,000 US gallons; 2,500,000 litres.

The bunker crude is carried generally in the lowest portion of the vessel, the keel hold. As there is no requirement for these vessels, which are classified as freighters, not crude oil carriers, to be double hulled. This bunker crude is generally less than the thickness of plate steel from the open ocean water. Most of these ships have a plate thickness of less than one inch. Larger bulk carriers can be found to have plate thicknesses of up to one and a half inches. Although the clean burning refined fuel is kept separate in a special hold, the bunker crude is kept altogether in one location, the very bottom of the vessel. It works great in this location for ballast and stability however it is susceptible to spillage upon any bottoming of the ship.

If a registered double hulled handy sized crude oil tanker ran aground and ripped open one hold it would spill, depending on the tanker size, between 1000 and 4500 tonnes of product. If a Panamax sized freighter ran aground such as the MV Bovec did in Prince Rupert, and ripped open the keel hold the region might be polluted with the full volume, over 2 million litres.

A double hulled Handy sized tanker would likely be carrying a fully refined product which might float, evaporate or be easier to clean up. The bunker crude from a dry goods freighter would, due to the thick tar substance it is, sink and or float up to shore lines polluting the region for generations.

Although dry goods freighters are not classified as crude oil carriers, they are. In most instances they are carrying a product more environmentally hazardous than a registered crude oil tanker. To not take the same precautions, which are taken for crude oil vessels, is irresponsible.

There are many examples across the globe where these dry goods freighters have fouled the beaches and shorelines after an accident. In BC we have been fortunate to not suffer the same fate. The Petersfield (Douglas Channel) and the Bovec (Prince Rupert) are two small examples of accidents where a major spill was narrowly avoided. It is only a matter of time until a vessel spills millions of litres, of the dirtiest crude oil product available, somewhere on a BC coastline.

And this is today, long before the Chinese build their pipeline, to transport their bitumen, from their northern Alberta bitumen mines, to fill their fleet of new VLCC tankers, to sail out Douglas Channel for China.

There is a solution, containerize the entire product; both the fuel to run the engines and the product to be shipped. It is feasible, reasonable and cost effective, as long as the environmental costs of a spill are included in the calculations. The Auto industry fought against the governments ordering them to install seatbelts; arguing the costs were too prohibitive. Today they add extra safety features and use these in promotional materials.

It is like teaching a child math, spelling or music. They might kick, scream and cry at first but then, as they mature, they learn the benefits. All we need is political leaders who can grasp the concept. Our leaders should not act like the children they are supposed to be guiding; kicking and screaming, fighting against reason, they should be taking the lead and guiding us into a better, more secure future.

The crude oil tankers are in our waters today, we simply need to remove the blinders and look out into the harbour. Every ship has millions of litres, just waiting to be released.
Oil Tankers
Comment by John Taylor on 29th September 2012
Good article on oil tankers.
The fuel used is called bunker oil or bunker fuel. It's not called 'heavy bunker crude'. Bunker comes from crude.
What do you mean about "containerized"? 'Never heard this before.
With all the (justified) concern about tankers, why do I never hear any concern about oil carrying barges, or the tugs that tow them?
There are hundreds of barges, tug boats and freighters too, hauling goods to ports big and small on the B.C. coast.
The Northern Transportation Company Ltd. An aboriginal owned company has dozens of tugs and barges sailing the waterways of the north. From Hay River to Hudson Bay. From the North Slope in Alaska to the Tar sands at Ft. McMurrey, they supply goods and equipment to the oil fields.

Every vessel on the water presents the possibility of an oil spill. Indeed it is more likely to have a 'small' spill, than a large one.
There are more oil spills during 'bunkering' (fueling) of ships and of transferring oil from vessel to shore or shore to vessel than there are of groundings or collisions.
The worry is, the occurrence of a catastrophe!

You detail the structure and engineering of the ocean going oil tankers very well. What you don't show or remark on is the internal workings. The equipment of today, used by the "supercargo" (the man or woman who looks after the oil, loading and unloading) and the Captain (in the running of the ship), are state of the art! It's quite fascinating to see.

The danger is not in the equipment or in the engineering of the ship. It never was! The danger lies with the people.
The Exxon Valdes was not defective. It's just that someone was drinking and driving.

We're pretty smart now-a-days. We can build almost anything. The only, and real, problem we have, is that people have to run it. And, people are the most unpredictable component.

Ed Note: Follow the link near the end of the article regarding containerized shipping.

As for people, Chief Ellis Ross said it best at the JRP, 'The problem with making something more idiot proof is they keep making better idiots'!