It is called Document B64-9, titled "Submerged-Arc-Welded Steel Pipe." It is one of the thousands of pages of highly technical reports and papers that form part of the application by Enbridge Inc. to build its $6-billion Northern Gateway pipeline. It is not compelling reading.
It does, however, stand out for one reason: Several of its sections have been blacked-out, redacted by Enbridge, which has received permission from the federal review panel examining the Gateway project to keep proprietary commercial information private.
The full information is available in unredacted form to the panel itself, which is charged with deciding whether the project should proceed. But to those questioning Gateway's safety standards, the black ink serves as a barrier to sorting out the precise standards of a project whose controversial nature has made it the subject of withering scrutiny.
On Thursday, for example, Chris Peter, an engineer based in Prince George, pointed to deleted sections that deal with the "proven notch toughness" of the steel to be used in the pipe – a measure designed to show how well that steel will perform if it is hit, for example, with heavy equipment at different temperatures.
He called the black-outs "attempts at obfuscation," and argued that Enbridge intends to use a steel whose performance at temperatures below minus 5 Celsius will not be proven. That could leave it brittle and vulnerable to something as inconsequential as a hammer blow in a deep freeze.
"Any kind of impact at all below a certain temperature could potentially result in a fracture," he said. The risk is especially great during construction, he said, when the pipe could be exposed to frigid air and the stress of being welded together and buried.
The Enbridge response: When it gets very cold, the company uses different methods to bend and weld its pipe. And, the company said, it's virtually impossible to buy pipeline steel these days that isn't incredibly tough, even if it's not specifically tested at temperatures below minus 5, the lowest temperature expected while the pipe is operating a metre below the surface.
"Universally, pipe manufacturers have migrated to what's called high-strength low-alloy designs," said James Mihell, vice-president of engineering at Dynamic Risk Assessment Systems, which has examined the potential for failures on Gateway. He added: "One of the outcomes of this strategy is that you tend to achieve extremely high toughness levels universally, whether you request them or not."
Officials with Enbridge said the company has carried out an unusually thorough risk assessment of the pipeline, which has already led the company to commit to thicker steel. The type of pipe the company intends to use "is the appropriate design toughness for this particular pipeline," said Ray Doering, Gateway's manager of engineering.
Enbridge acknowledged, however, that many of the specifics related to Gateway remain undecided. That is not unusual for a major industrial project, since companies tend to seek regulatory approval before spending substantial sums to complete detailed final engineering.
But the lack of final plans has become a point of frustration for those seeking an extraordinary level of detail to expose any potential problems before approval is granted.
"Can you really assure the people of Canada that you are to be trusted -- your company can be trusted to do this job?" Tim Leadem, a lawyer with Ecojustice, asked on Thursday.
"What we've provided to the panel is a detailed design that we think is at the appropriate level to determine whether there are any potentially significant adverse effects," Mr. Doering replied. He pointed to the 10 years Enbridge has now spent on the project.
"We have a very full record here to help them make that decision," he said.