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COMMENTARY · 25th April 2012
Merv Ritchie
Almost every Ocean Cargo Vessel, regardless of what it is designed to haul has a fatal flaw, one which exposes the ocean environment to serious long term pollution. One very simple modification to the design and fabrication would solve almost all of it.

Most readers will not be aware that all Ocean Vessels are crude oil carriers. The engines are designed to run on the cheapest fuel available; crude bunker fuel, the thickest, dirtiest oil available. It is what is left after primary refining. It cannot be pumped without heating it. It has the consistency of roofing tar. All Ocean vessels load up this bunker crude fuel in massive quantities and store it in the bottom of the Vessel called the “Keel Hold”.

For readers concerned about VLCC (Very Large Crude Carriers) bitumen tankers planned for Kitimat and Douglas Channel another subject should be of greater concern. Currently single hulled vessels arrive with enough crude to foul all the beaches and shorelines. At the Methanex facility next to Rio Tinto Alcan since 2006, tankers arrive loaded with a highly volatile Natural Gas fuel by-product similar to butane or white gas called condensate. It is then loaded onto rail cars for transport, first to Terrace (for rail yard switching), and then to Northern Alberta via CN to add to the crude bitumen for pipeline shipping. The current real danger to the land environment as well as the population is an accident involving this very poisonous and explosive substance.

The Ocean environment is, and always has been, subject to the poor design of all vessels. Any vessel that runs aground is exposed to ripping open the large bunker crude holds, which is separated by only an inch of steel from the water. The current tankers entering Douglas Channel bound for Kitimat are generally Panamax sized vessels. Like the Rena, which fouled the beaches of New Zealand as it broke up, these hold approximately half a million gallons of this thick raw bunker crude on the exposed bottom of the vessel. Very little of these vessels are double hulled as they are not considered crude oil carriers.

This is why all tankers need to be redesigned.

Rail car tankers such as the condensate tankers currently used to deliver the thinner to Alberta from Kitimat each hold 30,000 gallons (125 tonnes) and are approximately 55 feet long.

Twenty of these rail tankers would hold more than the average fuel carried by a Panamax tanker. Ten of these rail containers on each side of the vessel placed in the lower holds, end to end, could easily fit in any Panamax tanker. A forward or rear opening for lowering these tanks to an internally fabricated sliding rail system for the fuel tank placement would leave the remaining tanker uninhibited for extra cargo.

The placement of these could accommodate electrical solenoid valves which could be opened and closed on demand and quickly closed during a grounding or other such disaster scenario. The removal of the on board fuel would be a much simpler operation as the tanks would only need to be extracted as individual tanks.

If these rail car tankers were fabricated with a double skin similar to the above ground fuel tanks seen at various service stations, with an internal vacuum seal protection, the potential for environmental degradation during a mishap, (such as even a CN derailment), would be greatly reduced.

Currently double hulled tanker vessels are fabricated with up to ten feet of space between the water and the crude oil holds. This is on both the bottom and the sides of the vessel. Therefore if all the oil shipped in VLCC or even ULCC tankers were contained in the same size and design, double skinned railcars, detached like Cosco containers from the rail beds, the requirement for double hulls would not be necessary and likely the volume of product carried would be similar, or at least not so greatly reduced the financial viability would be harmed.

Within the space now occupied by the double skinning of an average sized VLCC, almost 1000 more rail cars of crude could be added to the voyage. This extra capacity of 30 million gallons should at least open this discussion up for consideration.

The cost in fabricating a double hulled vessel is much greater than a single hulled vessel. A single hulled vessel only has a single sheet of steel separating it from the water; on average less than an inch and a half thick.

Designing and fabricating vessels with gussets throughout the vessel spaced the length (55 feet) and the width (10 feet) of double skinned crude oil rail container cars and designing the vessels fuel system to accommodate similar containers to hold the fuel would reduce potential environmental degradation on innumerable levels.

Tank farms and pipelines would no longer be necessary. Fuel spillage at the loading and unloading terminal would be avoided. No crude oil or fuel oil would be openly exposed to the environment except at the production facilities (ie the Tar/Oil Sands) and at the delivery location such as the Dalian Chinese refinery.

Products such as refined diesel or even the condensate required for today’s existing pipelines could be return shipped via the same container rail cars.

It is so simple; likely very cost effective, and most certainly more environmentally responsible.

Now we just need to find a solution to our present lack of leadership.

To research and understand more on this topic follow this link to a story which contains more than a dozen further links, all related to this single issue.
The Bovec Carrier sitting on a reef near Prince Rupert
The Bovec Carrier sitting on a reef near Prince Rupert
The Rena as it was splitting in two off the coast of New Zealand
The Rena as it was splitting in two off the coast of New Zealand
of ships and shipping
Comment by blocky bear on 25th April 2012
Thank you for the explanation and diagrams along with the pictures I would think even the dullest of us readers can grasp the potential of spillage that exists. What kind of fuel has the Queen of the North been hiccuping these past years? Has the federal government done anything to mitigate this pollution? Certainly they would be doing something to pump the tanks? d.b.