When the interiors of five jet fuel tanks at Portsmouth International Airport at Pease needed to be blasted and recoated, contractor L. A. Mangum & Son, Inc.'s confined space blasting and painting experience made them the best choice for the job.
The L. A. Mangum & Son crew used Sponge-Jet’s Robotica robotic abrasive blasting system to remove the old coating and achieve the proper cleanliness and surface profile required in the job specifications. Use of Robotica reduced confined space entry, ensuring the safety of the L. A. Mangum & Son team, as well as providing unparalleled productivity and consistent surface preparation quality.
To watch a recap of the project, view the video below:
Job Background
Portsmouth International Airport at Pease, formerly known as Pease International Airport, is a joint civil and military airport located near the business district of Portsmouth, New Hampshire. In 1989, Pease Air Force Base was closed by the Department of Defense, and New Hampshire leadership began to develop plans to turn the shuttered base into an economic hub called the Pease International Tradeport.
Within the Tradeport, Port City Air is the full-service operator that provides ground service for the passenger terminal, the cargo facility, runways, ramps, hangers and corresponding infrastructure, including fuel tanks.
As part of ground support role, Port City Air manages several 20,000 gallon Jet A fuel tanks. After 20 years of service, the tanks need to be drained, blasted, and recoated. Each of the five tanks measures 10.5 feet in diameter by 30-feet long for a total of 1,200 square feet each.
Safer and More Effective Blasting with Robotica
With Sponge Media™ chosen as the abrasive blasting media, L. A. Mangum & Son worked with Sponge-Jet to utilize the Robotica robotic abrasive blasting system for this job. Garnet would have been the crews second choice, but according to Gary Mangum, President of L. A. Mangum & Son, Inc., there would have been definite disadvantages to using garnet, including the generation of four times more waste than the Sponge Media.
Using a robotic blasting system has many advantages, not the least of which is reducing confined space entry and keeping the crew safe. “It’s all about reducing the wear and tear on my staff,” explained Mangum, who tries to keep confined space entry to a minimum whenever possible.
In addition to Robotica being a safer blasting alternative, there are also productivity and consistency advantages. The goal for the job was to abrasive blast the interior of one tank per day, as Port City Air was anxious to return the fuel tanks to service.
Using Robotica, the L. A. Mangum & Son crew was able to achieve this goal, even with inconsistent condition of the steel substrate. In some areas, there were spots of corrosion and peeled coating, and in others the existing coating was extremely thick. Given the high variation in the thickness of the existing coating (ranging from 12 mils to 40 mils) the operator had to make adjustments in the speed of robot. However, when all was said and done, the crew was able to blast each tank in about 5 to 6 hours, at a rate of 247.2 square feet per hour.
The project's specification called for an SP-10 (NACE – Near-White Blast cleaning), but by using the Robotica system, the DMV team was able to prepare the steel substrates closer to the more stringent level of SP-5 (NACE 1 – White Metal Blast) while meeting all surface profile depth requirements.