TVA. Lasers. Spaghetti?

Today, TVA surveyors deploy the latest technology—3-D laser scanning—capable of mapping the spaghetti of piping and conduits in engineering spaces with millimeter accuracy.

When Keith Elder, senior manager of TVA Transmission Line Engineering, was asked to map the Shawnee Fossil Plant in Kentucky, he might have been intimidated. After all, it was a big job—TVA engineers needed to run new water lines and other piping through a sub-basement that looked like a maze already filled with ducting, piping and electrical components.

“Think of a plate of spaghetti,” Elder suggests. “Then try to put your finger though it without touching a noodle.” That just about sums up the task he had at hand.

High definition 3-D laser scanning devises (pictured at left) are a continuation of TVA's surveying mission, but allow complicated jobs to be accomplished in a fraction of the time.

Luckily, Elder also had resources: a team of 50 surveyors and two high-definition 3-D laser scanning (HDS) devices, each of which cost about $100,000. HDS was originally designed for the petrochemical industry to map large complex piping networks in hazardous and sometimes remote environments. But TVA applies it elsewhere in the utility industry.

“With old drawings and traditional surveying methods, it would have taken months to map everything the engineers needed to know,” says Elder. “With HDS we had a preliminary map of the section they wanted to start with ready much sooner than we could have had with any other method.” This allowed the engineers to begin the planning process almost immediately.

Elder’s team gave the Shawnee engineers a detailed computerized 3-D model mapped down to the millimeter. This allowed the designers to precisely position and move the new equipment through the maze easily.

Image of Swanee Fossil Plant sub-basement rendered using high-definition 3-D laser scanning (HDS), above; that same basement in real life, below.

“Because HDS allows us to capture data that you could not get with traditional surveying methods, the technology pays for itself through saved man hours and safety,” says Elder.

Elder’s work is an extension of the original surveying teams who arrived in the Tennessee Valley in the 1930s, a time in which the region was gripped in poverty and the mighty Tennessee river regularly flooded, destroying crops, homes and lives.

“Some of the very first TVA employees were surveyors, and I’m proud to keep that tradition alive today at TVA,” says Elder. “Back then there were few roads. You hiked into the wilderness with the latest technology of the day: transit, calibrated steel tape, plane table to supplement photogrammetry, pencil and field book.”

“The basic roll of the surveyor has remained unchanged over time,” Elder. “We provide our clients accurate situational awareness in order to help them make the best decisions possible. Only the technology has changed.”