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Opinion: Powerful tugs will protect B.C. coast


Opinion: Powerful tugs will protect B.C. coast
Locally designed escort tugs should prevent another Exxon Valdez disaster

Written by Robert Allan for The Vancouver Sun, July 25, 2014 

Escort tugs will accompany every oil tanker to and from Kitimat should the Northern Gateway pipeline be constructed. Photograph by: HELGE HANSEN , HELGE HANSEN

Escort tugs will accompany every oil tanker to and from Kitimat should the Northern Gateway pipeline be constructed.

The federal government’s recent approval of the Northern Gateway pipeline requires the company to meet 209 tough conditions.

Some of those conditions specify marine and tanker safety requirements, including provisions for both oil spill recovery and, more critically, oil spill prevention. As someone who frequently kayaks along our beautiful mid-coast, I’m well aware of the need to ensure we protect this unique region.

That’s why I’ve spent much of my life designing — right here in Vancouver — vessels focused on oil spill prevention.

These vessels, called escort tugs, are large and powerful, providing emergency steering capability in the unlikely event of a tanker rudder failure. Escort tugs will also act as a very powerful handbrake in case a tanker’s propulsion system fails.

It’s important to note that tanker safety has improved dramatically since the 1989 Exxon Valdez spill and the subsequent enactment of a range of international laws and the U.S. Oil Pollution Act of 1990.

Modern-day tankers are some of the safest ships ever built. All single-hulled tankers (such as Exxon Valdez) have been mandated out of service since 2010 by the enactment of the International Maritime Organization Marine Pollution Act Annex 1, and as affirmed by Canada under the Canada Shipping Act; Vessel Pollution and Dangerous Chemicals Regulations.

By law, double-hulled tankers are now the norm and that means in the unlikely event of a grounding, it’s much more difficult than was previously the case to breach an inner cargo tank and cause a spill.

Tankers can, however, occasionally have mechanical problems with propulsion or steering systems. If problems occur well out to sea, there is almost no risk — the crew should be able to fix the problem quickly. If however that failure occurs in a near-coastal environment, there must be systems in place to ensure the tanker does not go aground.

That’s where the high-performance escort tug comes in.

Worldwide, a significant majority of these escort tugs in the past two decades have been designed in Vancouver by Robert Allan Ltd., and operate at major oil and gas terminals throughout Europe, the U.S., South America, the Middle East, Africa and Asia.

Escort tugs should not be mistaken for the small log- or barge-towing tugs with which many British Columbians are familiar. Escort tugs are large and immensely more powerful, featuring unique hull forms that can generate very high hydrodynamic forces, and with powerful 360-degree steerable thrusters. The capabilities of these tugs have been verified by extensive scale-model testing and research, and by full-scale trials.

An escort tug typically operates tethered to the tanker and is immediately available to exert very high steering or braking forces as required. Our innovative escort tug design allows for the boat to apply forces equivalent to or higher than the tanker’s own steering and braking capabilities at high operating speeds.

Based on our extensive experience designing the world’s most capable high-performance escort tugs, we have recommended to the Northern Gateway pipeline project the largest and most capable tugs of this class operating anywhere in the world.

These escort tugs will dwarf any existing tugs on the B.C. coast.

Fifty metres long and with more than 10,000 horsepower, they can generate corrective steering and braking forces up to 200 tonnes at 10 knots.

These tugs are also designed to perform rescue towing should an unescorted tanker be disabled anywhere within the 320-kilometre limit of Canadian waters off the B.C. coast.

Two of these Raincoast Guardian-class tugs will escort every laden tanker en route from Kitimat. Laden tankers will have one free-running tug checking the route ahead of the ship and one tug tethered astern. Empty tankers will have one free-running escort. No less important to the huge safety margin provided by using escort tugs is the extra number of trained eyes and ears available within the escort system to detect a potential incident.

The lead tugs will identify any potential marine hazards, suggesting course or speed corrections as necessary. The master of the stern escort tug is uniquely positioned to detect any potential off-course error of the tanker, where he can exert corrective action within seconds. In addition, the presence of two B.C. Coast Pilots aboard the tanker itself, plus the ship’s captain, means no less than five professional mariners are paying attention to the tanker course at all times.

The use of innovative, high-performance escort tugs as part of an extensive tanker escort system will provide as close to a zero-risk operation as is possible.

Robert Allan is the executive chairman of Robert Allan Ltd., one of the world’s leading naval architecture and marine engineering firms specializing in high-performance workboat designs, based in Vancouver since 1930.

Read the original article.

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