Friday, January 25, 2008

Example: Synthesis and the Obvious Solution

At the eastern end of the Mediterranean Sea oil tankers would pull into the Sidon Oil Terminus to fill up with crude oil and other petroleum products. The turn around time for loading a tanker was dependent upon the capacity of the undersea pipe, which led from the shore to the off-shore berth, about a mile out. As tanker ships got larger the need for higher capacity undersea cargo pipelines also increased. Every hour the tanker remained at berth tens of thousands of dollars were wasted.

The largest diameter pipe on the seabed was 24 inches. By increasing the diameter by 50% to 36 inches the line capacity would increase by 225%. Unfortunately, welding sections of 36 in pipe underwater was very dangerous, expensive, and it was hard to control the quality of the welds. Even small undersea currents easily nudged a section of pipe that broad. But the opportunity was great, and the company wanted the 36 inch-line installed.

Their young Chief Pipeline Engineer was an expert on structural properties of pipelines, fluid-dynamics, electrical engineering, and petroleum products. After thinking about the problem for a little while he came up with a simple solution – build the pipeline on shore, tow it into place, and sink it. The reason this obvious solution had not been considered before is that as a pipeline is filled with water and starts to submerge it is hard to keep it from sinking irregularly and snapping welds or crimping the pipe. The solution took into account the properties of the pipe, and the properties of liquids.

Once the empty and capped pipe was floated into place, the shore end was opened and a 36 inch rubber ball was inserted followed by 15 feet of water and another 36 inch ball. Behind that, 1000 feet of gasoline (which is lighter than water, but with the pipe, weighed more than seawater) was pumped in, followed by another 36 in ball. The balls kept the liquids separated. Lastly seawater was pumped in behind the gasoline. This method allowed the pipe to flex only slightly as sections sank, and put no dangerous stresses on the welds. The whole operation took just 2 days to complete.

The synthesis took place in the engineer’s brain. Existing knowledge about fluids and structural properties of pipe were combined in his brain along with the characteristics of the problem and a solution presented itself. A couple of years earlier, his son had received a ping-pong ball burp gun as a gift. The engineer had picked up the clear tube of the gun and by restricting the open end, he could see how the ball held positive air pressure behind it. This may have formed the model for the pipeline solution.

Typically, people with this capability are able to see the whole problem at once. It is having both the ‘big picture’ and all the little details in the forefront at the same time. The solution involved no experimentation. Nobody built a little pipeline in a bathtub and tested the concept. Once the other engineers in the company understood the solution they were each able to use their own knowledge to understand that it would work. For them, it became the ‘obvious’ solution.

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