Lights out: How to design a new airfield electrical system at New Orleans' biggest airport

Benedikt Goebel | 07 Jun 2017 | Comments

Large, highly-visible infrastructure projects typically receive the most attention from the public. We watch new structures being built, wondering what the finished product will look like and how it might improve our lives. In airport construction, that usually means new passenger terminals, runways, or ground transportation hubs—the visible structures we interact with that can make or break our traveling experience. But what about the behind-the-scenes infrastructure that airports rely on to run safely and efficiently? What would happen if the runway lights suddenly went out while aircraft were preparing to take off or land?

Louis Armstrong New Orleans International Airport (MSY) is no stranger to large airport improvements. Construction began recently on replacement of its 54-year-old terminal with a new, nearly $950 million terminal development program, with the Atkins/LeoADaly Joint Venture as design lead. To support the program, the airport will also construct a new terminal apron, roadways, elevated structures, new on-site parking facilities, pumping stations, extensive drainage system improvements, and airfield lighting systems. This is a massive undertaking that is among the most significant construction projects in the city since the construction of the Superdome in 1975.

But behind the headline-grabbing projects lies important work that travelers rarely notice. In addition to being a key member of the design team for the new terminal and the extensive relocation of Federal Aviation Administration (FAA) systems, Atkins airfield electrical team performed a top-to-bottom redesign of MSY’s airfield electrical system—work that has significantly decreased energy demand and improved reliability and safety.

As you can imagine, the consequences of failing to maintain and upgrade airfield electrical systems can be catastrophic. Safe and efficient movement of aircraft is a key element to ensuring air traffic demands and time schedules are met. This is particularly important at airports serving a popular tourist destination like New Orleans.

As an element of the Airfield Electrical Rehabilitation Program, we performed forensic evaluation of the existing airfield lighting systems which was exhibiting performance issues. The analysis resulted in a prioritized program for airfield electrical and lighting system improvements and an extensive list of improvement options and budgeting.

This effort ultimately gave way to a $12 million construction program for the reconstruction of electrical systems and control system upgrades. The key to the success of this program was a close partnership between Atkins, airport engineering and management staff, the airlines, and the FAA. After the comprehensive technical analysis and safety/construction phasing, the scope was clearly defined among the stakeholders and expectations surrounding implementation were set. We then developed preliminary and final design as well as construction documentation on a highly compressed, 11-week design schedule and a 12-month construction schedule.

The wholesale reconstruction of the system provided for new infrastructure and modernized system architecture designed around LED technology, which helped reduce energy demand by as much as 50 percent. A critical design stipulation for the project was that airfield operations must be maintained throughout the construction schedule, significantly complicating the construction sequencing. Extensive effort and coordination between the stake holders was developed to maintain FAA-mandated safety clearances and airfield access restrictions. We are proud to report that the project resulted in zero flight diversions due to the implementation of Airfield Electrical Rehabilitation Program.

Another unique challenge we encountered was that this system need to be built below sea level, which presents its own construction challenges—namely an extraordinary amount of ground water, rain and concerns over subsidence.

Our multidisciplinary design team consisting electrical, civil and drainage engineers had to rethink how to create a reliable system in an environment that was fundamentally hostile to electrical systems. Our solution was to rebuild the entire system from scratch—considering new technologies, updated FAA requirements, dewatering and system architecture that was forward-looking and accommodated the development of the new terminal without major reconfiguration.

The team used proven, but innovative installation techniques to accommodate the challenging conditions. Normally airports install electrical raceway systems with open-cut trenches; however, due to the saturated soils and unstable site conditions involved, it was more cost-effective and time efficient to use directional boring techniques. Since directional boring is not typically used to the extent we required, the team developed new designs, prepared a comparative analysis of alternate materials / methods and ultimately received a special approval from the FAA.. The technique worked spectacularly well, allowing us to quickly install over 800,000 feet of new cable, 2,000 light fixtures, 130 lighted guidance signs, almost 75 manhole structures, and 220,000 feet of conduit and directional bored ducts in one year’s time, minimizing the need for site restoration, and reduced FOD and pavement cleaning, while maintaining full airport operations.

Reliability and efficiency improvements to the airfield electrical system were important steps for MSY to move forward with construction of its new terminal. By close collaboration with stake holders, rethinking and innovating standards designing and looking to the future of the new system, we helped the client accommodate for future growth, dramatically improved reliability and safety, and enabled travelers to fully enjoy the airport’s new facilities without disruption.